Java tutorial
/* * Copyright (C) 2006 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.widget; import android.annotation.ColorInt; import android.annotation.DrawableRes; import android.annotation.NonNull; import android.annotation.TestApi; import android.annotation.UnsupportedAppUsage; import android.content.Context; import android.content.Intent; import android.content.res.Configuration; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Rect; import android.graphics.drawable.Drawable; import android.graphics.drawable.TransitionDrawable; import android.os.Build; import android.os.Bundle; import android.os.Debug; import android.os.Handler; import android.os.Parcel; import android.os.Parcelable; import android.os.StrictMode; import android.os.Trace; import android.text.Editable; import android.text.InputType; import android.text.TextUtils; import android.text.TextWatcher; import android.util.AttributeSet; import android.util.Log; import android.util.LongSparseArray; import android.util.SparseArray; import android.util.SparseBooleanArray; import android.util.StateSet; import android.view.ActionMode; import android.view.ContextMenu.ContextMenuInfo; import android.view.Gravity; import android.view.HapticFeedbackConstants; import android.view.InputDevice; import android.view.KeyEvent; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuItem; import android.view.MotionEvent; import android.view.PointerIcon; import android.view.VelocityTracker; import android.view.View; import android.view.ViewConfiguration; import android.view.ViewDebug; import android.view.ViewGroup; import android.view.ViewHierarchyEncoder; import android.view.ViewParent; import android.view.ViewTreeObserver; import android.view.accessibility.AccessibilityEvent; import android.view.accessibility.AccessibilityManager; import android.view.accessibility.AccessibilityNodeInfo; import android.view.accessibility.AccessibilityNodeInfo.AccessibilityAction; import android.view.accessibility.AccessibilityNodeInfo.CollectionInfo; import android.view.animation.Interpolator; import android.view.animation.LinearInterpolator; import android.view.inputmethod.BaseInputConnection; import android.view.inputmethod.CompletionInfo; import android.view.inputmethod.CorrectionInfo; import android.view.inputmethod.EditorInfo; import android.view.inputmethod.ExtractedText; import android.view.inputmethod.ExtractedTextRequest; import android.view.inputmethod.InputConnection; import android.view.inputmethod.InputContentInfo; import android.view.inputmethod.InputMethodManager; import android.widget.RemoteViews.OnClickHandler; import com.android.internal.R; import java.util.ArrayList; import java.util.List; /** * Base class that can be used to implement virtualized lists of items. A list does * not have a spatial definition here. For instance, subclasses of this class can * display the content of the list in a grid, in a carousel, as stack, etc. * * @attr ref android.R.styleable#AbsListView_listSelector * @attr ref android.R.styleable#AbsListView_drawSelectorOnTop * @attr ref android.R.styleable#AbsListView_stackFromBottom * @attr ref android.R.styleable#AbsListView_scrollingCache * @attr ref android.R.styleable#AbsListView_textFilterEnabled * @attr ref android.R.styleable#AbsListView_transcriptMode * @attr ref android.R.styleable#AbsListView_cacheColorHint * @attr ref android.R.styleable#AbsListView_fastScrollEnabled * @attr ref android.R.styleable#AbsListView_smoothScrollbar * @attr ref android.R.styleable#AbsListView_choiceMode */ public abstract class AbsListView extends AdapterView<ListAdapter> implements TextWatcher, ViewTreeObserver.OnGlobalLayoutListener, Filter.FilterListener, ViewTreeObserver.OnTouchModeChangeListener, RemoteViewsAdapter.RemoteAdapterConnectionCallback { @SuppressWarnings("UnusedDeclaration") private static final String TAG = "AbsListView"; /** * Disables the transcript mode. * * @see #setTranscriptMode(int) */ public static final int TRANSCRIPT_MODE_DISABLED = 0; /** * The list will automatically scroll to the bottom when a data set change * notification is received and only if the last item is already visible * on screen. * * @see #setTranscriptMode(int) */ public static final int TRANSCRIPT_MODE_NORMAL = 1; /** * The list will automatically scroll to the bottom, no matter what items * are currently visible. * * @see #setTranscriptMode(int) */ public static final int TRANSCRIPT_MODE_ALWAYS_SCROLL = 2; /** * Indicates that we are not in the middle of a touch gesture */ static final int TOUCH_MODE_REST = -1; /** * Indicates we just received the touch event and we are waiting to see if the it is a tap or a * scroll gesture. */ static final int TOUCH_MODE_DOWN = 0; /** * Indicates the touch has been recognized as a tap and we are now waiting to see if the touch * is a longpress */ static final int TOUCH_MODE_TAP = 1; /** * Indicates we have waited for everything we can wait for, but the user's finger is still down */ static final int TOUCH_MODE_DONE_WAITING = 2; /** * Indicates the touch gesture is a scroll */ static final int TOUCH_MODE_SCROLL = 3; /** * Indicates the view is in the process of being flung */ static final int TOUCH_MODE_FLING = 4; /** * Indicates the touch gesture is an overscroll - a scroll beyond the beginning or end. */ static final int TOUCH_MODE_OVERSCROLL = 5; /** * Indicates the view is being flung outside of normal content bounds * and will spring back. */ static final int TOUCH_MODE_OVERFLING = 6; /** * Regular layout - usually an unsolicited layout from the view system */ static final int LAYOUT_NORMAL = 0; /** * Show the first item */ static final int LAYOUT_FORCE_TOP = 1; /** * Force the selected item to be on somewhere on the screen */ static final int LAYOUT_SET_SELECTION = 2; /** * Show the last item */ static final int LAYOUT_FORCE_BOTTOM = 3; /** * Make a mSelectedItem appear in a specific location and build the rest of * the views from there. The top is specified by mSpecificTop. */ static final int LAYOUT_SPECIFIC = 4; /** * Layout to sync as a result of a data change. Restore mSyncPosition to have its top * at mSpecificTop */ static final int LAYOUT_SYNC = 5; /** * Layout as a result of using the navigation keys */ static final int LAYOUT_MOVE_SELECTION = 6; /** * Normal list that does not indicate choices */ public static final int CHOICE_MODE_NONE = 0; /** * The list allows up to one choice */ public static final int CHOICE_MODE_SINGLE = 1; /** * The list allows multiple choices */ public static final int CHOICE_MODE_MULTIPLE = 2; /** * The list allows multiple choices in a modal selection mode */ public static final int CHOICE_MODE_MULTIPLE_MODAL = 3; /** * The thread that created this view. */ private final Thread mOwnerThread; /** * Controls if/how the user may choose/check items in the list */ int mChoiceMode = CHOICE_MODE_NONE; /** * Controls CHOICE_MODE_MULTIPLE_MODAL. null when inactive. */ @UnsupportedAppUsage ActionMode mChoiceActionMode; /** * Wrapper for the multiple choice mode callback; AbsListView needs to perform * a few extra actions around what application code does. */ MultiChoiceModeWrapper mMultiChoiceModeCallback; /** * Running count of how many items are currently checked */ int mCheckedItemCount; /** * Running state of which positions are currently checked */ SparseBooleanArray mCheckStates; /** * Running state of which IDs are currently checked. * If there is a value for a given key, the checked state for that ID is true * and the value holds the last known position in the adapter for that id. */ LongSparseArray<Integer> mCheckedIdStates; /** * Controls how the next layout will happen */ @UnsupportedAppUsage int mLayoutMode = LAYOUT_NORMAL; /** * Should be used by subclasses to listen to changes in the dataset */ @UnsupportedAppUsage AdapterDataSetObserver mDataSetObserver; /** * The adapter containing the data to be displayed by this view */ @UnsupportedAppUsage ListAdapter mAdapter; /** * The remote adapter containing the data to be displayed by this view to be set */ private RemoteViewsAdapter mRemoteAdapter; /** * If mAdapter != null, whenever this is true the adapter has stable IDs. */ boolean mAdapterHasStableIds; /** * This flag indicates the a full notify is required when the RemoteViewsAdapter connects */ private boolean mDeferNotifyDataSetChanged = false; /** * Indicates whether the list selector should be drawn on top of the children or behind */ boolean mDrawSelectorOnTop = false; /** * The drawable used to draw the selector */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023) Drawable mSelector; /** * The current position of the selector in the list. */ @UnsupportedAppUsage int mSelectorPosition = INVALID_POSITION; /** * Defines the selector's location and dimension at drawing time */ @UnsupportedAppUsage Rect mSelectorRect = new Rect(); /** * The data set used to store unused views that should be reused during the next layout * to avoid creating new ones */ @UnsupportedAppUsage final RecycleBin mRecycler = new RecycleBin(); /** * The selection's left padding */ int mSelectionLeftPadding = 0; /** * The selection's top padding */ @UnsupportedAppUsage int mSelectionTopPadding = 0; /** * The selection's right padding */ int mSelectionRightPadding = 0; /** * The selection's bottom padding */ @UnsupportedAppUsage int mSelectionBottomPadding = 0; /** * This view's padding */ Rect mListPadding = new Rect(); /** * Subclasses must retain their measure spec from onMeasure() into this member */ int mWidthMeasureSpec = 0; /** * The top scroll indicator */ View mScrollUp; /** * The down scroll indicator */ View mScrollDown; /** * When the view is scrolling, this flag is set to true to indicate subclasses that * the drawing cache was enabled on the children */ boolean mCachingStarted; boolean mCachingActive; /** * The position of the view that received the down motion event */ @UnsupportedAppUsage int mMotionPosition; /** * The offset to the top of the mMotionPosition view when the down motion event was received */ int mMotionViewOriginalTop; /** * The desired offset to the top of the mMotionPosition view after a scroll */ int mMotionViewNewTop; /** * The X value associated with the the down motion event */ int mMotionX; /** * The Y value associated with the the down motion event */ @UnsupportedAppUsage int mMotionY; /** * One of TOUCH_MODE_REST, TOUCH_MODE_DOWN, TOUCH_MODE_TAP, TOUCH_MODE_SCROLL, or * TOUCH_MODE_DONE_WAITING */ @UnsupportedAppUsage int mTouchMode = TOUCH_MODE_REST; /** * Y value from on the previous motion event (if any) */ int mLastY; /** * How far the finger moved before we started scrolling */ int mMotionCorrection; /** * Determines speed during touch scrolling */ @UnsupportedAppUsage private VelocityTracker mVelocityTracker; /** * Handles one frame of a fling */ @UnsupportedAppUsage private FlingRunnable mFlingRunnable; /** * Handles scrolling between positions within the list. */ @UnsupportedAppUsage AbsPositionScroller mPositionScroller; /** * The offset in pixels form the top of the AdapterView to the top * of the currently selected view. Used to save and restore state. */ int mSelectedTop = 0; /** * Indicates whether the list is stacked from the bottom edge or * the top edge. */ boolean mStackFromBottom; /** * When set to true, the list automatically discards the children's * bitmap cache after scrolling. */ boolean mScrollingCacheEnabled; /** * Whether or not to enable the fast scroll feature on this list */ boolean mFastScrollEnabled; /** * Whether or not to always show the fast scroll feature on this list */ boolean mFastScrollAlwaysVisible; /** * Optional callback to notify client when scroll position has changed */ @UnsupportedAppUsage private OnScrollListener mOnScrollListener; /** * Keeps track of our accessory window */ @UnsupportedAppUsage PopupWindow mPopup; /** * Used with type filter window */ EditText mTextFilter; /** * Indicates whether to use pixels-based or position-based scrollbar * properties. */ private boolean mSmoothScrollbarEnabled = true; /** * Indicates that this view supports filtering */ private boolean mTextFilterEnabled; /** * Indicates that this view is currently displaying a filtered view of the data */ private boolean mFiltered; /** * Rectangle used for hit testing children */ private Rect mTouchFrame; /** * The position to resurrect the selected position to. */ int mResurrectToPosition = INVALID_POSITION; @UnsupportedAppUsage private ContextMenuInfo mContextMenuInfo = null; /** * Maximum distance to record overscroll */ int mOverscrollMax; /** * Content height divided by this is the overscroll limit. */ static final int OVERSCROLL_LIMIT_DIVISOR = 3; /** * How many positions in either direction we will search to try to * find a checked item with a stable ID that moved position across * a data set change. If the item isn't found it will be unselected. */ private static final int CHECK_POSITION_SEARCH_DISTANCE = 20; /** * Used to request a layout when we changed touch mode */ private static final int TOUCH_MODE_UNKNOWN = -1; private static final int TOUCH_MODE_ON = 0; private static final int TOUCH_MODE_OFF = 1; private int mLastTouchMode = TOUCH_MODE_UNKNOWN; private static final boolean PROFILE_SCROLLING = false; private boolean mScrollProfilingStarted = false; private static final boolean PROFILE_FLINGING = false; private boolean mFlingProfilingStarted = false; /** * The StrictMode "critical time span" objects to catch animation * stutters. Non-null when a time-sensitive animation is * in-flight. Must call finish() on them when done animating. * These are no-ops on user builds. */ private StrictMode.Span mScrollStrictSpan = null; private StrictMode.Span mFlingStrictSpan = null; /** * The last CheckForLongPress runnable we posted, if any */ @UnsupportedAppUsage private CheckForLongPress mPendingCheckForLongPress; /** * The last CheckForTap runnable we posted, if any */ @UnsupportedAppUsage private CheckForTap mPendingCheckForTap; /** * The last CheckForKeyLongPress runnable we posted, if any */ private CheckForKeyLongPress mPendingCheckForKeyLongPress; /** * Acts upon click */ private AbsListView.PerformClick mPerformClick; /** * Delayed action for touch mode. */ private Runnable mTouchModeReset; /** * Whether the most recent touch event stream resulted in a successful * long-press action. This is reset on TOUCH_DOWN. */ private boolean mHasPerformedLongPress; /** * This view is in transcript mode -- it shows the bottom of the list when the data * changes */ private int mTranscriptMode; /** * Indicates that this list is always drawn on top of a solid, single-color, opaque * background */ private int mCacheColorHint; /** * The select child's view (from the adapter's getView) is enabled. */ @UnsupportedAppUsage private boolean mIsChildViewEnabled; /** * The cached drawable state for the selector. Accounts for child enabled * state, but otherwise identical to the view's own drawable state. */ private int[] mSelectorState; /** * The last scroll state reported to clients through {@link OnScrollListener}. */ private int mLastScrollState = OnScrollListener.SCROLL_STATE_IDLE; /** * Helper object that renders and controls the fast scroll thumb. */ @UnsupportedAppUsage private FastScroller mFastScroll; /** * Temporary holder for fast scroller style until a FastScroller object * is created. */ private int mFastScrollStyle; private boolean mGlobalLayoutListenerAddedFilter; @UnsupportedAppUsage private int mTouchSlop; private float mDensityScale; private float mVerticalScrollFactor; private InputConnection mDefInputConnection; private InputConnectionWrapper mPublicInputConnection; private Runnable mClearScrollingCache; Runnable mPositionScrollAfterLayout; private int mMinimumVelocity; @UnsupportedAppUsage private int mMaximumVelocity; private float mVelocityScale = 1.0f; final boolean[] mIsScrap = new boolean[1]; private final int[] mScrollOffset = new int[2]; private final int[] mScrollConsumed = new int[2]; private final float[] mTmpPoint = new float[2]; // Used for offsetting MotionEvents that we feed to the VelocityTracker. // In the future it would be nice to be able to give this to the VelocityTracker // directly, or alternatively put a VT into absolute-positioning mode that only // reads the raw screen-coordinate x/y values. private int mNestedYOffset = 0; // True when the popup should be hidden because of a call to // dispatchDisplayHint() private boolean mPopupHidden; /** * ID of the active pointer. This is used to retain consistency during * drags/flings if multiple pointers are used. */ @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023) private int mActivePointerId = INVALID_POINTER; /** * Sentinel value for no current active pointer. * Used by {@link #mActivePointerId}. */ private static final int INVALID_POINTER = -1; /** * Maximum distance to overscroll by during edge effects */ @UnsupportedAppUsage int mOverscrollDistance; /** * Maximum distance to overfling during edge effects */ @UnsupportedAppUsage int mOverflingDistance; // These two EdgeGlows are always set and used together. // Checking one for null is as good as checking both. /** * Tracks the state of the top edge glow. */ @UnsupportedAppUsage private EdgeEffect mEdgeGlowTop; /** * Tracks the state of the bottom edge glow. */ @UnsupportedAppUsage private EdgeEffect mEdgeGlowBottom; /** * An estimate of how many pixels are between the top of the list and * the top of the first position in the adapter, based on the last time * we saw it. Used to hint where to draw edge glows. */ private int mFirstPositionDistanceGuess; /** * An estimate of how many pixels are between the bottom of the list and * the bottom of the last position in the adapter, based on the last time * we saw it. Used to hint where to draw edge glows. */ private int mLastPositionDistanceGuess; /** * Used for determining when to cancel out of overscroll. */ private int mDirection = 0; /** * Tracked on measurement in transcript mode. Makes sure that we can still pin to * the bottom correctly on resizes. */ private boolean mForceTranscriptScroll; /** * Used for interacting with list items from an accessibility service. */ private ListItemAccessibilityDelegate mAccessibilityDelegate; private int mLastAccessibilityScrollEventFromIndex; private int mLastAccessibilityScrollEventToIndex; /** * Track the item count from the last time we handled a data change. */ private int mLastHandledItemCount; /** * Used for smooth scrolling at a consistent rate */ static final Interpolator sLinearInterpolator = new LinearInterpolator(); /** * The saved state that we will be restoring from when we next sync. * Kept here so that if we happen to be asked to save our state before * the sync happens, we can return this existing data rather than losing * it. */ private SavedState mPendingSync; /** * Whether the view is in the process of detaching from its window. */ private boolean mIsDetaching; /** * Interface definition for a callback to be invoked when the list or grid * has been scrolled. */ public interface OnScrollListener { /** * The view is not scrolling. Note navigating the list using the trackball counts as * being in the idle state since these transitions are not animated. */ public static int SCROLL_STATE_IDLE = 0; /** * The user is scrolling using touch, and their finger is still on the screen */ public static int SCROLL_STATE_TOUCH_SCROLL = 1; /** * The user had previously been scrolling using touch and had performed a fling. The * animation is now coasting to a stop */ public static int SCROLL_STATE_FLING = 2; /** * Callback method to be invoked while the list view or grid view is being scrolled. If the * view is being scrolled, this method will be called before the next frame of the scroll is * rendered. In particular, it will be called before any calls to * {@link Adapter#getView(int, View, ViewGroup)}. * * @param view The view whose scroll state is being reported * * @param scrollState The current scroll state. One of * {@link #SCROLL_STATE_TOUCH_SCROLL} or {@link #SCROLL_STATE_IDLE}. */ public void onScrollStateChanged(AbsListView view, int scrollState); /** * Callback method to be invoked when the list or grid has been scrolled. This will be * called after the scroll has completed * @param view The view whose scroll state is being reported * @param firstVisibleItem the index of the first visible cell (ignore if * visibleItemCount == 0) * @param visibleItemCount the number of visible cells * @param totalItemCount the number of items in the list adapter */ public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount); } /** * The top-level view of a list item can implement this interface to allow * itself to modify the bounds of the selection shown for that item. */ public interface SelectionBoundsAdjuster { /** * Called to allow the list item to adjust the bounds shown for * its selection. * * @param bounds On call, this contains the bounds the list has * selected for the item (that is the bounds of the entire view). The * values can be modified as desired. */ public void adjustListItemSelectionBounds(Rect bounds); } public AbsListView(Context context) { super(context); initAbsListView(); mOwnerThread = Thread.currentThread(); setVerticalScrollBarEnabled(true); TypedArray a = context.obtainStyledAttributes(R.styleable.View); initializeScrollbarsInternal(a); a.recycle(); } public AbsListView(Context context, AttributeSet attrs) { this(context, attrs, com.android.internal.R.attr.absListViewStyle); } public AbsListView(Context context, AttributeSet attrs, int defStyleAttr) { this(context, attrs, defStyleAttr, 0); } public AbsListView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { super(context, attrs, defStyleAttr, defStyleRes); initAbsListView(); mOwnerThread = Thread.currentThread(); final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.AbsListView, defStyleAttr, defStyleRes); final Drawable selector = a.getDrawable(R.styleable.AbsListView_listSelector); if (selector != null) { setSelector(selector); } mDrawSelectorOnTop = a.getBoolean(R.styleable.AbsListView_drawSelectorOnTop, false); setStackFromBottom(a.getBoolean(R.styleable.AbsListView_stackFromBottom, false)); setScrollingCacheEnabled(a.getBoolean(R.styleable.AbsListView_scrollingCache, true)); setTextFilterEnabled(a.getBoolean(R.styleable.AbsListView_textFilterEnabled, false)); setTranscriptMode(a.getInt(R.styleable.AbsListView_transcriptMode, TRANSCRIPT_MODE_DISABLED)); setCacheColorHint(a.getColor(R.styleable.AbsListView_cacheColorHint, 0)); setSmoothScrollbarEnabled(a.getBoolean(R.styleable.AbsListView_smoothScrollbar, true)); setChoiceMode(a.getInt(R.styleable.AbsListView_choiceMode, CHOICE_MODE_NONE)); setFastScrollEnabled(a.getBoolean(R.styleable.AbsListView_fastScrollEnabled, false)); setFastScrollStyle(a.getResourceId(R.styleable.AbsListView_fastScrollStyle, 0)); setFastScrollAlwaysVisible(a.getBoolean(R.styleable.AbsListView_fastScrollAlwaysVisible, false)); a.recycle(); if (context.getResources().getConfiguration().uiMode == Configuration.UI_MODE_TYPE_WATCH) { setRevealOnFocusHint(false); } } private void initAbsListView() { // Setting focusable in touch mode will set the focusable property to true setClickable(true); setFocusableInTouchMode(true); setWillNotDraw(false); setAlwaysDrawnWithCacheEnabled(false); setScrollingCacheEnabled(true); final ViewConfiguration configuration = ViewConfiguration.get(mContext); mTouchSlop = configuration.getScaledTouchSlop(); mVerticalScrollFactor = configuration.getScaledVerticalScrollFactor(); mMinimumVelocity = configuration.getScaledMinimumFlingVelocity(); mMaximumVelocity = configuration.getScaledMaximumFlingVelocity(); mOverscrollDistance = configuration.getScaledOverscrollDistance(); mOverflingDistance = configuration.getScaledOverflingDistance(); mDensityScale = getContext().getResources().getDisplayMetrics().density; } @Override public void setOverScrollMode(int mode) { if (mode != OVER_SCROLL_NEVER) { if (mEdgeGlowTop == null) { Context context = getContext(); mEdgeGlowTop = new EdgeEffect(context); mEdgeGlowBottom = new EdgeEffect(context); } } else { mEdgeGlowTop = null; mEdgeGlowBottom = null; } super.setOverScrollMode(mode); } /** * {@inheritDoc} */ @Override public void setAdapter(ListAdapter adapter) { if (adapter != null) { mAdapterHasStableIds = mAdapter.hasStableIds(); if (mChoiceMode != CHOICE_MODE_NONE && mAdapterHasStableIds && mCheckedIdStates == null) { mCheckedIdStates = new LongSparseArray<Integer>(); } } clearChoices(); } /** * Returns the number of items currently selected. This will only be valid * if the choice mode is not {@link #CHOICE_MODE_NONE} (default). * * <p>To determine the specific items that are currently selected, use one of * the <code>getChecked*</code> methods. * * @return The number of items currently selected * * @see #getCheckedItemPosition() * @see #getCheckedItemPositions() * @see #getCheckedItemIds() */ public int getCheckedItemCount() { return mCheckedItemCount; } /** * Returns the checked state of the specified position. The result is only * valid if the choice mode has been set to {@link #CHOICE_MODE_SINGLE} * or {@link #CHOICE_MODE_MULTIPLE}. * * @param position The item whose checked state to return * @return The item's checked state or <code>false</code> if choice mode * is invalid * * @see #setChoiceMode(int) */ public boolean isItemChecked(int position) { if (mChoiceMode != CHOICE_MODE_NONE && mCheckStates != null) { return mCheckStates.get(position); } return false; } /** * Returns the currently checked item. The result is only valid if the choice * mode has been set to {@link #CHOICE_MODE_SINGLE}. * * @return The position of the currently checked item or * {@link #INVALID_POSITION} if nothing is selected * * @see #setChoiceMode(int) */ public int getCheckedItemPosition() { if (mChoiceMode == CHOICE_MODE_SINGLE && mCheckStates != null && mCheckStates.size() == 1) { return mCheckStates.keyAt(0); } return INVALID_POSITION; } /** * Returns the set of checked items in the list. The result is only valid if * the choice mode has not been set to {@link #CHOICE_MODE_NONE}. * * @return A SparseBooleanArray which will return true for each call to * get(int position) where position is a checked position in the * list and false otherwise, or <code>null</code> if the choice * mode is set to {@link #CHOICE_MODE_NONE}. */ public SparseBooleanArray getCheckedItemPositions() { if (mChoiceMode != CHOICE_MODE_NONE) { return mCheckStates; } return null; } /** * Returns the set of checked items ids. The result is only valid if the * choice mode has not been set to {@link #CHOICE_MODE_NONE} and the adapter * has stable IDs. ({@link ListAdapter#hasStableIds()} == {@code true}) * * @return A new array which contains the id of each checked item in the * list. */ public long[] getCheckedItemIds() { if (mChoiceMode == CHOICE_MODE_NONE || mCheckedIdStates == null || mAdapter == null) { return new long[0]; } final LongSparseArray<Integer> idStates = mCheckedIdStates; final int count = idStates.size(); final long[] ids = new long[count]; for (int i = 0; i < count; i++) { ids[i] = idStates.keyAt(i); } return ids; } /** * Clear any choices previously set */ public void clearChoices() { if (mCheckStates != null) { mCheckStates.clear(); } if (mCheckedIdStates != null) { mCheckedIdStates.clear(); } mCheckedItemCount = 0; } /** * Sets the checked state of the specified position. The is only valid if * the choice mode has been set to {@link #CHOICE_MODE_SINGLE} or * {@link #CHOICE_MODE_MULTIPLE}. * * @param position The item whose checked state is to be checked * @param value The new checked state for the item */ public void setItemChecked(int position, boolean value) { if (mChoiceMode == CHOICE_MODE_NONE) { return; } // Start selection mode if needed. We don't need to if we're unchecking something. if (value && mChoiceMode == CHOICE_MODE_MULTIPLE_MODAL && mChoiceActionMode == null) { if (mMultiChoiceModeCallback == null || !mMultiChoiceModeCallback.hasWrappedCallback()) { throw new IllegalStateException("AbsListView: attempted to start selection mode " + "for CHOICE_MODE_MULTIPLE_MODAL but no choice mode callback was " + "supplied. Call setMultiChoiceModeListener to set a callback."); } mChoiceActionMode = startActionMode(mMultiChoiceModeCallback); } final boolean itemCheckChanged; if (mChoiceMode == CHOICE_MODE_MULTIPLE || mChoiceMode == CHOICE_MODE_MULTIPLE_MODAL) { boolean oldValue = mCheckStates.get(position); mCheckStates.put(position, value); if (mCheckedIdStates != null && mAdapter.hasStableIds()) { if (value) { mCheckedIdStates.put(mAdapter.getItemId(position), position); } else { mCheckedIdStates.delete(mAdapter.getItemId(position)); } } itemCheckChanged = oldValue != value; if (itemCheckChanged) { if (value) { mCheckedItemCount++; } else { mCheckedItemCount--; } } if (mChoiceActionMode != null) { final long id = mAdapter.getItemId(position); mMultiChoiceModeCallback.onItemCheckedStateChanged(mChoiceActionMode, position, id, value); } } else { boolean updateIds = mCheckedIdStates != null && mAdapter.hasStableIds(); // Clear all values if we're checking something, or unchecking the currently // selected item itemCheckChanged = isItemChecked(position) != value; if (value || isItemChecked(position)) { mCheckStates.clear(); if (updateIds) { mCheckedIdStates.clear(); } } // this may end up selecting the value we just cleared but this way // we ensure length of mCheckStates is 1, a fact getCheckedItemPosition relies on if (value) { mCheckStates.put(position, true); if (updateIds) { mCheckedIdStates.put(mAdapter.getItemId(position), position); } mCheckedItemCount = 1; } else if (mCheckStates.size() == 0 || !mCheckStates.valueAt(0)) { mCheckedItemCount = 0; } } // Do not generate a data change while we are in the layout phase or data has not changed if (!mInLayout && !mBlockLayoutRequests && itemCheckChanged) { mDataChanged = true; rememberSyncState(); requestLayout(); } } @Override public boolean performItemClick(View view, int position, long id) { boolean handled = false; boolean dispatchItemClick = true; if (mChoiceMode != CHOICE_MODE_NONE) { handled = true; boolean checkedStateChanged = false; if (mChoiceMode == CHOICE_MODE_MULTIPLE || (mChoiceMode == CHOICE_MODE_MULTIPLE_MODAL && mChoiceActionMode != null)) { boolean checked = !mCheckStates.get(position, false); mCheckStates.put(position, checked); if (mCheckedIdStates != null && mAdapter.hasStableIds()) { if (checked) { mCheckedIdStates.put(mAdapter.getItemId(position), position); } else { mCheckedIdStates.delete(mAdapter.getItemId(position)); } } if (checked) { mCheckedItemCount++; } else { mCheckedItemCount--; } if (mChoiceActionMode != null) { mMultiChoiceModeCallback.onItemCheckedStateChanged(mChoiceActionMode, position, id, checked); dispatchItemClick = false; } checkedStateChanged = true; } else if (mChoiceMode == CHOICE_MODE_SINGLE) { boolean checked = !mCheckStates.get(position, false); if (checked) { mCheckStates.clear(); mCheckStates.put(position, true); if (mCheckedIdStates != null && mAdapter.hasStableIds()) { mCheckedIdStates.clear(); mCheckedIdStates.put(mAdapter.getItemId(position), position); } mCheckedItemCount = 1; } else if (mCheckStates.size() == 0 || !mCheckStates.valueAt(0)) { mCheckedItemCount = 0; } checkedStateChanged = true; } if (checkedStateChanged) { updateOnScreenCheckedViews(); } } if (dispatchItemClick) { handled |= super.performItemClick(view, position, id); } return handled; } /** * Perform a quick, in-place update of the checked or activated state * on all visible item views. This should only be called when a valid * choice mode is active. */ private void updateOnScreenCheckedViews() { final int firstPos = mFirstPosition; final int count = getChildCount(); final boolean useActivated = getContext() .getApplicationInfo().targetSdkVersion >= android.os.Build.VERSION_CODES.HONEYCOMB; for (int i = 0; i < count; i++) { final View child = getChildAt(i); final int position = firstPos + i; if (child instanceof Checkable) { ((Checkable) child).setChecked(mCheckStates.get(position)); } else if (useActivated) { child.setActivated(mCheckStates.get(position)); } } } /** * @see #setChoiceMode(int) * * @return The current choice mode */ public int getChoiceMode() { return mChoiceMode; } /** * Defines the choice behavior for the List. By default, Lists do not have any choice behavior * ({@link #CHOICE_MODE_NONE}). By setting the choiceMode to {@link #CHOICE_MODE_SINGLE}, the * List allows up to one item to be in a chosen state. By setting the choiceMode to * {@link #CHOICE_MODE_MULTIPLE}, the list allows any number of items to be chosen. * * @param choiceMode One of {@link #CHOICE_MODE_NONE}, {@link #CHOICE_MODE_SINGLE}, or * {@link #CHOICE_MODE_MULTIPLE} */ public void setChoiceMode(int choiceMode) { mChoiceMode = choiceMode; if (mChoiceActionMode != null) { mChoiceActionMode.finish(); mChoiceActionMode = null; } if (mChoiceMode != CHOICE_MODE_NONE) { if (mCheckStates == null) { mCheckStates = new SparseBooleanArray(0); } if (mCheckedIdStates == null && mAdapter != null && mAdapter.hasStableIds()) { mCheckedIdStates = new LongSparseArray<Integer>(0); } // Modal multi-choice mode only has choices when the mode is active. Clear them. if (mChoiceMode == CHOICE_MODE_MULTIPLE_MODAL) { clearChoices(); setLongClickable(true); } } } /** * Set a {@link MultiChoiceModeListener} that will manage the lifecycle of the * selection {@link ActionMode}. Only used when the choice mode is set to * {@link #CHOICE_MODE_MULTIPLE_MODAL}. * * @param listener Listener that will manage the selection mode * * @see #setChoiceMode(int) */ public void setMultiChoiceModeListener(MultiChoiceModeListener listener) { if (mMultiChoiceModeCallback == null) { mMultiChoiceModeCallback = new MultiChoiceModeWrapper(); } mMultiChoiceModeCallback.setWrapped(listener); } /** * @return true if all list content currently fits within the view boundaries */ private boolean contentFits() { final int childCount = getChildCount(); if (childCount == 0) return true; if (childCount != mItemCount) return false; return getChildAt(0).getTop() >= mListPadding.top && getChildAt(childCount - 1).getBottom() <= getHeight() - mListPadding.bottom; } /** * Specifies whether fast scrolling is enabled or disabled. * <p> * When fast scrolling is enabled, the user can quickly scroll through lists * by dragging the fast scroll thumb. * <p> * If the adapter backing this list implements {@link SectionIndexer}, the * fast scroller will display section header previews as the user scrolls. * Additionally, the user will be able to quickly jump between sections by * tapping along the length of the scroll bar. * * @see SectionIndexer * @see #isFastScrollEnabled() * @param enabled true to enable fast scrolling, false otherwise */ public void setFastScrollEnabled(final boolean enabled) { if (mFastScrollEnabled != enabled) { mFastScrollEnabled = enabled; if (isOwnerThread()) { setFastScrollerEnabledUiThread(enabled); } else { post(new Runnable() { @Override public void run() { setFastScrollerEnabledUiThread(enabled); } }); } } } private void setFastScrollerEnabledUiThread(boolean enabled) { if (mFastScroll != null) { mFastScroll.setEnabled(enabled); } else if (enabled) { mFastScroll = new FastScroller(this, mFastScrollStyle); mFastScroll.setEnabled(true); } resolvePadding(); if (mFastScroll != null) { mFastScroll.updateLayout(); } } /** * Specifies the style of the fast scroller decorations. * * @param styleResId style resource containing fast scroller properties * @see android.R.styleable#FastScroll */ public void setFastScrollStyle(int styleResId) { if (mFastScroll == null) { mFastScrollStyle = styleResId; } else { mFastScroll.setStyle(styleResId); } } /** * Set whether or not the fast scroller should always be shown in place of * the standard scroll bars. This will enable fast scrolling if it is not * already enabled. * <p> * Fast scrollers shown in this way will not fade out and will be a * permanent fixture within the list. This is best combined with an inset * scroll bar style to ensure the scroll bar does not overlap content. * * @param alwaysShow true if the fast scroller should always be displayed, * false otherwise * @see #setScrollBarStyle(int) * @see #setFastScrollEnabled(boolean) */ public void setFastScrollAlwaysVisible(final boolean alwaysShow) { if (mFastScrollAlwaysVisible != alwaysShow) { if (alwaysShow && !mFastScrollEnabled) { setFastScrollEnabled(true); } mFastScrollAlwaysVisible = alwaysShow; if (isOwnerThread()) { setFastScrollerAlwaysVisibleUiThread(alwaysShow); } else { post(new Runnable() { @Override public void run() { setFastScrollerAlwaysVisibleUiThread(alwaysShow); } }); } } } private void setFastScrollerAlwaysVisibleUiThread(boolean alwaysShow) { if (mFastScroll != null) { mFastScroll.setAlwaysShow(alwaysShow); } } /** * @return whether the current thread is the one that created the view */ private boolean isOwnerThread() { return mOwnerThread == Thread.currentThread(); } /** * Returns true if the fast scroller is set to always show on this view. * * @return true if the fast scroller will always show * @see #setFastScrollAlwaysVisible(boolean) */ public boolean isFastScrollAlwaysVisible() { if (mFastScroll == null) { return mFastScrollEnabled && mFastScrollAlwaysVisible; } else { return mFastScroll.isEnabled() && mFastScroll.isAlwaysShowEnabled(); } } @Override public int getVerticalScrollbarWidth() { if (mFastScroll != null && mFastScroll.isEnabled()) { return Math.max(super.getVerticalScrollbarWidth(), mFastScroll.getWidth()); } return super.getVerticalScrollbarWidth(); } /** * Returns true if the fast scroller is enabled. * * @see #setFastScrollEnabled(boolean) * @return true if fast scroll is enabled, false otherwise */ @ViewDebug.ExportedProperty public boolean isFastScrollEnabled() { if (mFastScroll == null) { return mFastScrollEnabled; } else { return mFastScroll.isEnabled(); } } @Override public void setVerticalScrollbarPosition(int position) { super.setVerticalScrollbarPosition(position); if (mFastScroll != null) { mFastScroll.setScrollbarPosition(position); } } @Override public void setScrollBarStyle(int style) { super.setScrollBarStyle(style); if (mFastScroll != null) { mFastScroll.setScrollBarStyle(style); } } /** * If fast scroll is enabled, then don't draw the vertical scrollbar. * @hide */ @Override @UnsupportedAppUsage protected boolean isVerticalScrollBarHidden() { return isFastScrollEnabled(); } /** * When smooth scrollbar is enabled, the position and size of the scrollbar thumb * is computed based on the number of visible pixels in the visible items. This * however assumes that all list items have the same height. If you use a list in * which items have different heights, the scrollbar will change appearance as the * user scrolls through the list. To avoid this issue, you need to disable this * property. * * When smooth scrollbar is disabled, the position and size of the scrollbar thumb * is based solely on the number of items in the adapter and the position of the * visible items inside the adapter. This provides a stable scrollbar as the user * navigates through a list of items with varying heights. * * @param enabled Whether or not to enable smooth scrollbar. * * @see #setSmoothScrollbarEnabled(boolean) * @attr ref android.R.styleable#AbsListView_smoothScrollbar */ public void setSmoothScrollbarEnabled(boolean enabled) { mSmoothScrollbarEnabled = enabled; } /** * Returns the current state of the fast scroll feature. * * @return True if smooth scrollbar is enabled is enabled, false otherwise. * * @see #setSmoothScrollbarEnabled(boolean) */ @ViewDebug.ExportedProperty public boolean isSmoothScrollbarEnabled() { return mSmoothScrollbarEnabled; } /** * Set the listener that will receive notifications every time the list scrolls. * * @param l the scroll listener */ public void setOnScrollListener(OnScrollListener l) { mOnScrollListener = l; invokeOnItemScrollListener(); } /** * Notify our scroll listener (if there is one) of a change in scroll state */ @UnsupportedAppUsage void invokeOnItemScrollListener() { if (mFastScroll != null) { mFastScroll.onScroll(mFirstPosition, getChildCount(), mItemCount); } if (mOnScrollListener != null) { mOnScrollListener.onScroll(this, mFirstPosition, getChildCount(), mItemCount); } onScrollChanged(0, 0, 0, 0); // dummy values, View's implementation does not use these. } /** @hide */ @Override public void sendAccessibilityEventUnchecked(AccessibilityEvent event) { // Since this class calls onScrollChanged even if the mFirstPosition and the // child count have not changed we will avoid sending duplicate accessibility // events. if (event.getEventType() == AccessibilityEvent.TYPE_VIEW_SCROLLED) { final int firstVisiblePosition = getFirstVisiblePosition(); final int lastVisiblePosition = getLastVisiblePosition(); if (mLastAccessibilityScrollEventFromIndex == firstVisiblePosition && mLastAccessibilityScrollEventToIndex == lastVisiblePosition) { return; } else { mLastAccessibilityScrollEventFromIndex = firstVisiblePosition; mLastAccessibilityScrollEventToIndex = lastVisiblePosition; } } super.sendAccessibilityEventUnchecked(event); } @Override public CharSequence getAccessibilityClassName() { return AbsListView.class.getName(); } /** @hide */ @Override public void onInitializeAccessibilityNodeInfoInternal(AccessibilityNodeInfo info) { super.onInitializeAccessibilityNodeInfoInternal(info); if (isEnabled()) { if (canScrollUp()) { info.addAction(AccessibilityAction.ACTION_SCROLL_BACKWARD); info.addAction(AccessibilityAction.ACTION_SCROLL_UP); info.setScrollable(true); } if (canScrollDown()) { info.addAction(AccessibilityAction.ACTION_SCROLL_FORWARD); info.addAction(AccessibilityAction.ACTION_SCROLL_DOWN); info.setScrollable(true); } } info.removeAction(AccessibilityAction.ACTION_CLICK); info.setClickable(false); } int getSelectionModeForAccessibility() { final int choiceMode = getChoiceMode(); switch (choiceMode) { case CHOICE_MODE_NONE: return CollectionInfo.SELECTION_MODE_NONE; case CHOICE_MODE_SINGLE: return CollectionInfo.SELECTION_MODE_SINGLE; case CHOICE_MODE_MULTIPLE: case CHOICE_MODE_MULTIPLE_MODAL: return CollectionInfo.SELECTION_MODE_MULTIPLE; default: return CollectionInfo.SELECTION_MODE_NONE; } } /** @hide */ @Override public boolean performAccessibilityActionInternal(int action, Bundle arguments) { if (super.performAccessibilityActionInternal(action, arguments)) { return true; } switch (action) { case AccessibilityNodeInfo.ACTION_SCROLL_FORWARD: case R.id.accessibilityActionScrollDown: { if (isEnabled() && canScrollDown()) { final int viewportHeight = getHeight() - mListPadding.top - mListPadding.bottom; smoothScrollBy(viewportHeight, PositionScroller.SCROLL_DURATION); return true; } } return false; case AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD: case R.id.accessibilityActionScrollUp: { if (isEnabled() && canScrollUp()) { final int viewportHeight = getHeight() - mListPadding.top - mListPadding.bottom; smoothScrollBy(-viewportHeight, PositionScroller.SCROLL_DURATION); return true; } } return false; } return false; } /** @hide */ @Override public View findViewByAccessibilityIdTraversal(int accessibilityId) { if (accessibilityId == getAccessibilityViewId()) { return this; } return super.findViewByAccessibilityIdTraversal(accessibilityId); } /** * Indicates whether the children's drawing cache is used during a scroll. * By default, the drawing cache is enabled but this will consume more memory. * * @return true if the scrolling cache is enabled, false otherwise * * @see #setScrollingCacheEnabled(boolean) * @see View#setDrawingCacheEnabled(boolean) */ @ViewDebug.ExportedProperty public boolean isScrollingCacheEnabled() { return mScrollingCacheEnabled; } /** * Enables or disables the children's drawing cache during a scroll. * By default, the drawing cache is enabled but this will use more memory. * * When the scrolling cache is enabled, the caches are kept after the * first scrolling. You can manually clear the cache by calling * {@link android.view.ViewGroup#setChildrenDrawingCacheEnabled(boolean)}. * * @param enabled true to enable the scroll cache, false otherwise * * @see #isScrollingCacheEnabled() * @see View#setDrawingCacheEnabled(boolean) */ public void setScrollingCacheEnabled(boolean enabled) { if (mScrollingCacheEnabled && !enabled) { clearScrollingCache(); } mScrollingCacheEnabled = enabled; } /** * Enables or disables the type filter window. If enabled, typing when * this view has focus will filter the children to match the users input. * Note that the {@link Adapter} used by this view must implement the * {@link Filterable} interface. * * @param textFilterEnabled true to enable type filtering, false otherwise * * @see Filterable */ public void setTextFilterEnabled(boolean textFilterEnabled) { mTextFilterEnabled = textFilterEnabled; } /** * Indicates whether type filtering is enabled for this view * * @return true if type filtering is enabled, false otherwise * * @see #setTextFilterEnabled(boolean) * @see Filterable */ @ViewDebug.ExportedProperty public boolean isTextFilterEnabled() { return mTextFilterEnabled; } @Override public void getFocusedRect(Rect r) { View view = getSelectedView(); if (view != null && view.getParent() == this) { // the focused rectangle of the selected view offset into the // coordinate space of this view. view.getFocusedRect(r); offsetDescendantRectToMyCoords(view, r); } else { // otherwise, just the norm super.getFocusedRect(r); } } private void useDefaultSelector() { setSelector(getContext().getDrawable(com.android.internal.R.drawable.list_selector_background)); } /** * Indicates whether the content of this view is pinned to, or stacked from, * the bottom edge. * * @return true if the content is stacked from the bottom edge, false otherwise */ @ViewDebug.ExportedProperty public boolean isStackFromBottom() { return mStackFromBottom; } /** * When stack from bottom is set to true, the list fills its content starting from * the bottom of the view. * * @param stackFromBottom true to pin the view's content to the bottom edge, * false to pin the view's content to the top edge */ public void setStackFromBottom(boolean stackFromBottom) { if (mStackFromBottom != stackFromBottom) { mStackFromBottom = stackFromBottom; requestLayoutIfNecessary(); } } void requestLayoutIfNecessary() { if (getChildCount() > 0) { resetList(); requestLayout(); invalidate(); } } static class SavedState extends BaseSavedState { long selectedId; @UnsupportedAppUsage long firstId; @UnsupportedAppUsage int viewTop; int position; int height; String filter; boolean inActionMode; int checkedItemCount; SparseBooleanArray checkState; LongSparseArray<Integer> checkIdState; /** * Constructor called from {@link AbsListView#onSaveInstanceState()} */ SavedState(Parcelable superState) { super(superState); } /** * Constructor called from {@link #CREATOR} */ private SavedState(Parcel in) { super(in); selectedId = in.readLong(); firstId = in.readLong(); viewTop = in.readInt(); position = in.readInt(); height = in.readInt(); filter = in.readString(); inActionMode = in.readByte() != 0; checkedItemCount = in.readInt(); checkState = in.readSparseBooleanArray(); final int N = in.readInt(); if (N > 0) { checkIdState = new LongSparseArray<Integer>(); for (int i = 0; i < N; i++) { final long key = in.readLong(); final int value = in.readInt(); checkIdState.put(key, value); } } } @Override public void writeToParcel(Parcel out, int flags) { super.writeToParcel(out, flags); out.writeLong(selectedId); out.writeLong(firstId); out.writeInt(viewTop); out.writeInt(position); out.writeInt(height); out.writeString(filter); out.writeByte((byte) (inActionMode ? 1 : 0)); out.writeInt(checkedItemCount); out.writeSparseBooleanArray(checkState); final int N = checkIdState != null ? checkIdState.size() : 0; out.writeInt(N); for (int i = 0; i < N; i++) { out.writeLong(checkIdState.keyAt(i)); out.writeInt(checkIdState.valueAt(i)); } } @Override public String toString() { return "AbsListView.SavedState{" + Integer.toHexString(System.identityHashCode(this)) + " selectedId=" + selectedId + " firstId=" + firstId + " viewTop=" + viewTop + " position=" + position + " height=" + height + " filter=" + filter + " checkState=" + checkState + "}"; } public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() { @Override public SavedState createFromParcel(Parcel in) { return new SavedState(in); } @Override public SavedState[] newArray(int size) { return new SavedState[size]; } }; } @Override public Parcelable onSaveInstanceState() { /* * This doesn't really make sense as the place to dismiss the * popups, but there don't seem to be any other useful hooks * that happen early enough to keep from getting complaints * about having leaked the window. */ dismissPopup(); Parcelable superState = super.onSaveInstanceState(); SavedState ss = new SavedState(superState); if (mPendingSync != null) { // Just keep what we last restored. ss.selectedId = mPendingSync.selectedId; ss.firstId = mPendingSync.firstId; ss.viewTop = mPendingSync.viewTop; ss.position = mPendingSync.position; ss.height = mPendingSync.height; ss.filter = mPendingSync.filter; ss.inActionMode = mPendingSync.inActionMode; ss.checkedItemCount = mPendingSync.checkedItemCount; ss.checkState = mPendingSync.checkState; ss.checkIdState = mPendingSync.checkIdState; return ss; } boolean haveChildren = getChildCount() > 0 && mItemCount > 0; long selectedId = getSelectedItemId(); ss.selectedId = selectedId; ss.height = getHeight(); if (selectedId >= 0) { // Remember the selection ss.viewTop = mSelectedTop; ss.position = getSelectedItemPosition(); ss.firstId = INVALID_POSITION; } else { if (haveChildren && mFirstPosition > 0) { // Remember the position of the first child. // We only do this if we are not currently at the top of // the list, for two reasons: // (1) The list may be in the process of becoming empty, in // which case mItemCount may not be 0, but if we try to // ask for any information about position 0 we will crash. // (2) Being "at the top" seems like a special case, anyway, // and the user wouldn't expect to end up somewhere else when // they revisit the list even if its content has changed. View v = getChildAt(0); ss.viewTop = v.getTop(); int firstPos = mFirstPosition; if (firstPos >= mItemCount) { firstPos = mItemCount - 1; } ss.position = firstPos; ss.firstId = mAdapter.getItemId(firstPos); } else { ss.viewTop = 0; ss.firstId = INVALID_POSITION; ss.position = 0; } } ss.filter = null; if (mFiltered) { final EditText textFilter = mTextFilter; if (textFilter != null) { Editable filterText = textFilter.getText(); if (filterText != null) { ss.filter = filterText.toString(); } } } ss.inActionMode = mChoiceMode == CHOICE_MODE_MULTIPLE_MODAL && mChoiceActionMode != null; if (mCheckStates != null) { ss.checkState = mCheckStates.clone(); } if (mCheckedIdStates != null) { final LongSparseArray<Integer> idState = new LongSparseArray<Integer>(); final int count = mCheckedIdStates.size(); for (int i = 0; i < count; i++) { idState.put(mCheckedIdStates.keyAt(i), mCheckedIdStates.valueAt(i)); } ss.checkIdState = idState; } ss.checkedItemCount = mCheckedItemCount; if (mRemoteAdapter != null) { mRemoteAdapter.saveRemoteViewsCache(); } return ss; } @Override public void onRestoreInstanceState(Parcelable state) { SavedState ss = (SavedState) state; super.onRestoreInstanceState(ss.getSuperState()); mDataChanged = true; mSyncHeight = ss.height; if (ss.selectedId >= 0) { mNeedSync = true; mPendingSync = ss; mSyncRowId = ss.selectedId; mSyncPosition = ss.position; mSpecificTop = ss.viewTop; mSyncMode = SYNC_SELECTED_POSITION; } else if (ss.firstId >= 0) { setSelectedPositionInt(INVALID_POSITION); // Do this before setting mNeedSync since setNextSelectedPosition looks at mNeedSync setNextSelectedPositionInt(INVALID_POSITION); mSelectorPosition = INVALID_POSITION; mNeedSync = true; mPendingSync = ss; mSyncRowId = ss.firstId; mSyncPosition = ss.position; mSpecificTop = ss.viewTop; mSyncMode = SYNC_FIRST_POSITION; } setFilterText(ss.filter); if (ss.checkState != null) { mCheckStates = ss.checkState; } if (ss.checkIdState != null) { mCheckedIdStates = ss.checkIdState; } mCheckedItemCount = ss.checkedItemCount; if (ss.inActionMode && mChoiceMode == CHOICE_MODE_MULTIPLE_MODAL && mMultiChoiceModeCallback != null) { mChoiceActionMode = startActionMode(mMultiChoiceModeCallback); } requestLayout(); } private boolean acceptFilter() { return mTextFilterEnabled && getAdapter() instanceof Filterable && ((Filterable) getAdapter()).getFilter() != null; } /** * Sets the initial value for the text filter. * @param filterText The text to use for the filter. * * @see #setTextFilterEnabled */ public void setFilterText(String filterText) { // TODO: Should we check for acceptFilter()? if (mTextFilterEnabled && !TextUtils.isEmpty(filterText)) { createTextFilter(false); // This is going to call our listener onTextChanged, but we might not // be ready to bring up a window yet mTextFilter.setText(filterText); mTextFilter.setSelection(filterText.length()); if (mAdapter instanceof Filterable) { // if mPopup is non-null, then onTextChanged will do the filtering if (mPopup == null) { Filter f = ((Filterable) mAdapter).getFilter(); f.filter(filterText); } // Set filtered to true so we will display the filter window when our main // window is ready mFiltered = true; mDataSetObserver.clearSavedState(); } } } /** * Returns the list's text filter, if available. * @return the list's text filter or null if filtering isn't enabled */ public CharSequence getTextFilter() { if (mTextFilterEnabled && mTextFilter != null) { return mTextFilter.getText(); } return null; } @Override protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) { super.onFocusChanged(gainFocus, direction, previouslyFocusedRect); if (gainFocus && mSelectedPosition < 0 && !isInTouchMode()) { if (!isAttachedToWindow() && mAdapter != null) { // Data may have changed while we were detached and it's valid // to change focus while detached. Refresh so we don't die. mDataChanged = true; mOldItemCount = mItemCount; mItemCount = mAdapter.getCount(); } resurrectSelection(); } } @Override public void requestLayout() { if (!mBlockLayoutRequests && !mInLayout) { super.requestLayout(); } } /** * The list is empty. Clear everything out. */ void resetList() { removeAllViewsInLayout(); mFirstPosition = 0; mDataChanged = false; mPositionScrollAfterLayout = null; mNeedSync = false; mPendingSync = null; mOldSelectedPosition = INVALID_POSITION; mOldSelectedRowId = INVALID_ROW_ID; setSelectedPositionInt(INVALID_POSITION); setNextSelectedPositionInt(INVALID_POSITION); mSelectedTop = 0; mSelectorPosition = INVALID_POSITION; mSelectorRect.setEmpty(); invalidate(); } @Override protected int computeVerticalScrollExtent() { final int count = getChildCount(); if (count > 0) { if (mSmoothScrollbarEnabled) { int extent = count * 100; View view = getChildAt(0); final int top = view.getTop(); int height = view.getHeight(); if (height > 0) { extent += (top * 100) / height; } view = getChildAt(count - 1); final int bottom = view.getBottom(); height = view.getHeight(); if (height > 0) { extent -= ((bottom - getHeight()) * 100) / height; } return extent; } else { return 1; } } return 0; } @Override protected int computeVerticalScrollOffset() { final int firstPosition = mFirstPosition; final int childCount = getChildCount(); if (firstPosition >= 0 && childCount > 0) { if (mSmoothScrollbarEnabled) { final View view = getChildAt(0); final int top = view.getTop(); int height = view.getHeight(); if (height > 0) { return Math.max(firstPosition * 100 - (top * 100) / height + (int) ((float) mScrollY / getHeight() * mItemCount * 100), 0); } } else { int index; final int count = mItemCount; if (firstPosition == 0) { index = 0; } else if (firstPosition + childCount == count) { index = count; } else { index = firstPosition + childCount / 2; } return (int) (firstPosition + childCount * (index / (float) count)); } } return 0; } @Override protected int computeVerticalScrollRange() { int result; if (mSmoothScrollbarEnabled) { result = Math.max(mItemCount * 100, 0); if (mScrollY != 0) { // Compensate for overscroll result += Math.abs((int) ((float) mScrollY / getHeight() * mItemCount * 100)); } } else { result = mItemCount; } return result; } @Override protected float getTopFadingEdgeStrength() { final int count = getChildCount(); final float fadeEdge = super.getTopFadingEdgeStrength(); if (count == 0) { return fadeEdge; } else { if (mFirstPosition > 0) { return 1.0f; } final int top = getChildAt(0).getTop(); final float fadeLength = getVerticalFadingEdgeLength(); return top < mPaddingTop ? -(top - mPaddingTop) / fadeLength : fadeEdge; } } @Override protected float getBottomFadingEdgeStrength() { final int count = getChildCount(); final float fadeEdge = super.getBottomFadingEdgeStrength(); if (count == 0) { return fadeEdge; } else { if (mFirstPosition + count - 1 < mItemCount - 1) { return 1.0f; } final int bottom = getChildAt(count - 1).getBottom(); final int height = getHeight(); final float fadeLength = getVerticalFadingEdgeLength(); return bottom > height - mPaddingBottom ? (bottom - height + mPaddingBottom) / fadeLength : fadeEdge; } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { if (mSelector == null) { useDefaultSelector(); } final Rect listPadding = mListPadding; listPadding.left = mSelectionLeftPadding + mPaddingLeft; listPadding.top = mSelectionTopPadding + mPaddingTop; listPadding.right = mSelectionRightPadding + mPaddingRight; listPadding.bottom = mSelectionBottomPadding + mPaddingBottom; // Check if our previous measured size was at a point where we should scroll later. if (mTranscriptMode == TRANSCRIPT_MODE_NORMAL) { final int childCount = getChildCount(); final int listBottom = getHeight() - getPaddingBottom(); final View lastChild = getChildAt(childCount - 1); final int lastBottom = lastChild != null ? lastChild.getBottom() : listBottom; mForceTranscriptScroll = mFirstPosition + childCount >= mLastHandledItemCount && lastBottom <= listBottom; } } /** * Subclasses should NOT override this method but * {@link #layoutChildren()} instead. */ @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { super.onLayout(changed, l, t, r, b); mInLayout = true; final int childCount = getChildCount(); if (changed) { for (int i = 0; i < childCount; i++) { getChildAt(i).forceLayout(); } mRecycler.markChildrenDirty(); } layoutChildren(); mOverscrollMax = (b - t) / OVERSCROLL_LIMIT_DIVISOR; // TODO: Move somewhere sane. This doesn't belong in onLayout(). if (mFastScroll != null) { mFastScroll.onItemCountChanged(getChildCount(), mItemCount); } mInLayout = false; } /** * @hide */ @Override protected boolean setFrame(int left, int top, int right, int bottom) { final boolean changed = super.setFrame(left, top, right, bottom); if (changed) { // Reposition the popup when the frame has changed. This includes // translating the widget, not just changing its dimension. The // filter popup needs to follow the widget. final boolean visible = getWindowVisibility() == View.VISIBLE; if (mFiltered && visible && mPopup != null && mPopup.isShowing()) { positionPopup(); } } return changed; } /** * Subclasses must override this method to layout their children. */ protected void layoutChildren() { } /** * @param focusedView view that holds accessibility focus * @return direct child that contains accessibility focus, or null if no * child contains accessibility focus */ View getAccessibilityFocusedChild(View focusedView) { ViewParent viewParent = focusedView.getParent(); while ((viewParent instanceof View) && (viewParent != this)) { focusedView = (View) viewParent; viewParent = viewParent.getParent(); } if (!(viewParent instanceof View)) { return null; } return focusedView; } void updateScrollIndicators() { if (mScrollUp != null) { mScrollUp.setVisibility(canScrollUp() ? View.VISIBLE : View.INVISIBLE); } if (mScrollDown != null) { mScrollDown.setVisibility(canScrollDown() ? View.VISIBLE : View.INVISIBLE); } } @UnsupportedAppUsage private boolean canScrollUp() { boolean canScrollUp; // 0th element is not visible canScrollUp = mFirstPosition > 0; // ... Or top of 0th element is not visible if (!canScrollUp) { if (getChildCount() > 0) { View child = getChildAt(0); canScrollUp = child.getTop() < mListPadding.top; } } return canScrollUp; } @UnsupportedAppUsage private boolean canScrollDown() { boolean canScrollDown; int count = getChildCount(); // Last item is not visible canScrollDown = (mFirstPosition + count) < mItemCount; // ... Or bottom of the last element is not visible if (!canScrollDown && count > 0) { View child = getChildAt(count - 1); canScrollDown = child.getBottom() > mBottom - mListPadding.bottom; } return canScrollDown; } @Override @ViewDebug.ExportedProperty public View getSelectedView() { if (mItemCount > 0 && mSelectedPosition >= 0) { return getChildAt(mSelectedPosition - mFirstPosition); } else { return null; } } /** * List padding is the maximum of the normal view's padding and the padding of the selector. * * @see android.view.View#getPaddingTop() * @see #getSelector() * * @return The top list padding. */ public int getListPaddingTop() { return mListPadding.top; } /** * List padding is the maximum of the normal view's padding and the padding of the selector. * * @see android.view.View#getPaddingBottom() * @see #getSelector() * * @return The bottom list padding. */ public int getListPaddingBottom() { return mListPadding.bottom; } /** * List padding is the maximum of the normal view's padding and the padding of the selector. * * @see android.view.View#getPaddingLeft() * @see #getSelector() * * @return The left list padding. */ public int getListPaddingLeft() { return mListPadding.left; } /** * List padding is the maximum of the normal view's padding and the padding of the selector. * * @see android.view.View#getPaddingRight() * @see #getSelector() * * @return The right list padding. */ public int getListPaddingRight() { return mListPadding.right; } /** * Gets a view and have it show the data associated with the specified * position. This is called when we have already discovered that the view * is not available for reuse in the recycle bin. The only choices left are * converting an old view or making a new one. * * @param position the position to display * @param outMetadata an array of at least 1 boolean where the first entry * will be set {@code true} if the view is currently * attached to the window, {@code false} otherwise (e.g. * newly-inflated or remained scrap for multiple layout * passes) * * @return A view displaying the data associated with the specified position */ View obtainView(int position, boolean[] outMetadata) { Trace.traceBegin(Trace.TRACE_TAG_VIEW, "obtainView"); outMetadata[0] = false; // Check whether we have a transient state view. Attempt to re-bind the // data and discard the view if we fail. final View transientView = mRecycler.getTransientStateView(position); if (transientView != null) { final LayoutParams params = (LayoutParams) transientView.getLayoutParams(); // If the view type hasn't changed, attempt to re-bind the data. if (params.viewType == mAdapter.getItemViewType(position)) { final View updatedView = mAdapter.getView(position, transientView, this); // If we failed to re-bind the data, scrap the obtained view. if (updatedView != transientView) { setItemViewLayoutParams(updatedView, position); mRecycler.addScrapView(updatedView, position); } } outMetadata[0] = true; // Finish the temporary detach started in addScrapView(). transientView.dispatchFinishTemporaryDetach(); return transientView; } final View scrapView = mRecycler.getScrapView(position); final View child = mAdapter.getView(position, scrapView, this); if (scrapView != null) { if (child != scrapView) { // Failed to re-bind the data, return scrap to the heap. mRecycler.addScrapView(scrapView, position); } else if (child.isTemporarilyDetached()) { outMetadata[0] = true; // Finish the temporary detach started in addScrapView(). child.dispatchFinishTemporaryDetach(); } } if (mCacheColorHint != 0) { child.setDrawingCacheBackgroundColor(mCacheColorHint); } if (child.getImportantForAccessibility() == IMPORTANT_FOR_ACCESSIBILITY_AUTO) { child.setImportantForAccessibility(IMPORTANT_FOR_ACCESSIBILITY_YES); } setItemViewLayoutParams(child, position); if (AccessibilityManager.getInstance(mContext).isEnabled()) { if (mAccessibilityDelegate == null) { mAccessibilityDelegate = new ListItemAccessibilityDelegate(); } if (child.getAccessibilityDelegate() == null) { child.setAccessibilityDelegate(mAccessibilityDelegate); } } Trace.traceEnd(Trace.TRACE_TAG_VIEW); return child; } private void setItemViewLayoutParams(View child, int position) { final ViewGroup.LayoutParams vlp = child.getLayoutParams(); LayoutParams lp; if (vlp == null) { lp = (LayoutParams) generateDefaultLayoutParams(); } else if (!checkLayoutParams(vlp)) { lp = (LayoutParams) generateLayoutParams(vlp); } else { lp = (LayoutParams) vlp; } if (mAdapterHasStableIds) { lp.itemId = mAdapter.getItemId(position); } lp.viewType = mAdapter.getItemViewType(position); lp.isEnabled = mAdapter.isEnabled(position); if (lp != vlp) { child.setLayoutParams(lp); } } class ListItemAccessibilityDelegate extends AccessibilityDelegate { @Override public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfo info) { super.onInitializeAccessibilityNodeInfo(host, info); final int position = getPositionForView(host); onInitializeAccessibilityNodeInfoForItem(host, position, info); } @Override public boolean performAccessibilityAction(View host, int action, Bundle arguments) { if (super.performAccessibilityAction(host, action, arguments)) { return true; } final int position = getPositionForView(host); if (position == INVALID_POSITION || mAdapter == null) { // Cannot perform actions on invalid items. return false; } if (position >= mAdapter.getCount()) { // The position is no longer valid, likely due to a data set // change. We could fail here for all data set changes, since // there is a chance that the data bound to the view may no // longer exist at the same position within the adapter, but // it's more consistent with the standard touch interaction to // click at whatever may have moved into that position. return false; } final boolean isItemEnabled; final ViewGroup.LayoutParams lp = host.getLayoutParams(); if (lp instanceof AbsListView.LayoutParams) { isItemEnabled = ((AbsListView.LayoutParams) lp).isEnabled; } else { isItemEnabled = false; } if (!isEnabled() || !isItemEnabled) { // Cannot perform actions on disabled items. return false; } switch (action) { case AccessibilityNodeInfo.ACTION_CLEAR_SELECTION: { if (getSelectedItemPosition() == position) { setSelection(INVALID_POSITION); return true; } } return false; case AccessibilityNodeInfo.ACTION_SELECT: { if (getSelectedItemPosition() != position) { setSelection(position); return true; } } return false; case AccessibilityNodeInfo.ACTION_CLICK: { if (isItemClickable(host)) { final long id = getItemIdAtPosition(position); return performItemClick(host, position, id); } } return false; case AccessibilityNodeInfo.ACTION_LONG_CLICK: { if (isLongClickable()) { final long id = getItemIdAtPosition(position); return performLongPress(host, position, id); } } return false; } return false; } } /** * Initializes an {@link AccessibilityNodeInfo} with information about a * particular item in the list. * * @param view View representing the list item. * @param position Position of the list item within the adapter. * @param info Node info to populate. */ public void onInitializeAccessibilityNodeInfoForItem(View view, int position, AccessibilityNodeInfo info) { if (position == INVALID_POSITION) { // The item doesn't exist, so there's not much we can do here. return; } final boolean isItemEnabled; final ViewGroup.LayoutParams lp = view.getLayoutParams(); if (lp instanceof AbsListView.LayoutParams) { isItemEnabled = ((AbsListView.LayoutParams) lp).isEnabled; } else { isItemEnabled = false; } if (!isEnabled() || !isItemEnabled) { info.setEnabled(false); return; } if (position == getSelectedItemPosition()) { info.setSelected(true); info.addAction(AccessibilityAction.ACTION_CLEAR_SELECTION); } else { info.addAction(AccessibilityAction.ACTION_SELECT); } if (isItemClickable(view)) { info.addAction(AccessibilityAction.ACTION_CLICK); info.setClickable(true); } if (isLongClickable()) { info.addAction(AccessibilityAction.ACTION_LONG_CLICK); info.setLongClickable(true); } } private boolean isItemClickable(View view) { return !view.hasExplicitFocusable(); } /** * Positions the selector in a way that mimics touch. */ void positionSelectorLikeTouch(int position, View sel, float x, float y) { positionSelector(position, sel, true, x, y); } /** * Positions the selector in a way that mimics keyboard focus. */ void positionSelectorLikeFocus(int position, View sel) { if (mSelector != null && mSelectorPosition != position && position != INVALID_POSITION) { final Rect bounds = mSelectorRect; final float x = bounds.exactCenterX(); final float y = bounds.exactCenterY(); positionSelector(position, sel, true, x, y); } else { positionSelector(position, sel); } } void positionSelector(int position, View sel) { positionSelector(position, sel, false, -1, -1); } @UnsupportedAppUsage private void positionSelector(int position, View sel, boolean manageHotspot, float x, float y) { final boolean positionChanged = position != mSelectorPosition; if (position != INVALID_POSITION) { mSelectorPosition = position; } final Rect selectorRect = mSelectorRect; selectorRect.set(sel.getLeft(), sel.getTop(), sel.getRight(), sel.getBottom()); if (sel instanceof SelectionBoundsAdjuster) { ((SelectionBoundsAdjuster) sel).adjustListItemSelectionBounds(selectorRect); } // Adjust for selection padding. selectorRect.left -= mSelectionLeftPadding; selectorRect.top -= mSelectionTopPadding; selectorRect.right += mSelectionRightPadding; selectorRect.bottom += mSelectionBottomPadding; // Update the child enabled state prior to updating the selector. final boolean isChildViewEnabled = sel.isEnabled(); if (mIsChildViewEnabled != isChildViewEnabled) { mIsChildViewEnabled = isChildViewEnabled; } // Update the selector drawable's state and position. final Drawable selector = mSelector; if (selector != null) { if (positionChanged) { // Wipe out the current selector state so that we can start // over in the new position with a fresh state. selector.setVisible(false, false); selector.setState(StateSet.NOTHING); } selector.setBounds(selectorRect); if (positionChanged) { if (getVisibility() == VISIBLE) { selector.setVisible(true, false); } updateSelectorState(); } if (manageHotspot) { selector.setHotspot(x, y); } } } @Override protected void dispatchDraw(Canvas canvas) { int saveCount = 0; final boolean clipToPadding = (mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK; if (clipToPadding) { saveCount = canvas.save(); final int scrollX = mScrollX; final int scrollY = mScrollY; canvas.clipRect(scrollX + mPaddingLeft, scrollY + mPaddingTop, scrollX + mRight - mLeft - mPaddingRight, scrollY + mBottom - mTop - mPaddingBottom); mGroupFlags &= ~CLIP_TO_PADDING_MASK; } final boolean drawSelectorOnTop = mDrawSelectorOnTop; if (!drawSelectorOnTop) { drawSelector(canvas); } super.dispatchDraw(canvas); if (drawSelectorOnTop) { drawSelector(canvas); } if (clipToPadding) { canvas.restoreToCount(saveCount); mGroupFlags |= CLIP_TO_PADDING_MASK; } } @Override protected boolean isPaddingOffsetRequired() { return (mGroupFlags & CLIP_TO_PADDING_MASK) != CLIP_TO_PADDING_MASK; } @Override protected int getLeftPaddingOffset() { return (mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK ? 0 : -mPaddingLeft; } @Override protected int getTopPaddingOffset() { return (mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK ? 0 : -mPaddingTop; } @Override protected int getRightPaddingOffset() { return (mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK ? 0 : mPaddingRight; } @Override protected int getBottomPaddingOffset() { return (mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK ? 0 : mPaddingBottom; } /** * @hide */ @Override protected void internalSetPadding(int left, int top, int right, int bottom) { super.internalSetPadding(left, top, right, bottom); if (isLayoutRequested()) { handleBoundsChange(); } } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { handleBoundsChange(); if (mFastScroll != null) { mFastScroll.onSizeChanged(w, h, oldw, oldh); } } /** * Called when bounds of the AbsListView are changed. AbsListView marks data set as changed * and force layouts all children that don't have exact measure specs. * <p> * This invalidation is necessary, otherwise, AbsListView may think the children are valid and * fail to relayout them properly to accommodate for new bounds. */ void handleBoundsChange() { if (mInLayout) { return; } final int childCount = getChildCount(); if (childCount > 0) { mDataChanged = true; rememberSyncState(); for (int i = 0; i < childCount; i++) { final View child = getChildAt(i); final ViewGroup.LayoutParams lp = child.getLayoutParams(); // force layout child unless it has exact specs if (lp == null || lp.width < 1 || lp.height < 1) { child.forceLayout(); } } } } /** * @return True if the current touch mode requires that we draw the selector in the pressed * state. */ boolean touchModeDrawsInPressedState() { // FIXME use isPressed for this switch (mTouchMode) { case TOUCH_MODE_TAP: case TOUCH_MODE_DONE_WAITING: return true; default: return false; } } /** * Indicates whether this view is in a state where the selector should be drawn. This will * happen if we have focus but are not in touch mode, or we are in the middle of displaying * the pressed state for an item. * * @return True if the selector should be shown */ boolean shouldShowSelector() { return (isFocused() && !isInTouchMode()) || (touchModeDrawsInPressedState() && isPressed()); } private void drawSelector(Canvas canvas) { if (shouldDrawSelector()) { final Drawable selector = mSelector; selector.setBounds(mSelectorRect); selector.draw(canvas); } } /** * @hide */ @TestApi public final boolean shouldDrawSelector() { return !mSelectorRect.isEmpty(); } /** * Controls whether the selection highlight drawable should be drawn on top of the item or * behind it. * * @param onTop If true, the selector will be drawn on the item it is highlighting. The default * is false. * * @attr ref android.R.styleable#AbsListView_drawSelectorOnTop */ public void setDrawSelectorOnTop(boolean onTop) { mDrawSelectorOnTop = onTop; } /** * Set a Drawable that should be used to highlight the currently selected item. * * @param resID A Drawable resource to use as the selection highlight. * * @attr ref android.R.styleable#AbsListView_listSelector */ public void setSelector(@DrawableRes int resID) { setSelector(getContext().getDrawable(resID)); } public void setSelector(Drawable sel) { if (mSelector != null) { mSelector.setCallback(null); unscheduleDrawable(mSelector); } mSelector = sel; Rect padding = new Rect(); sel.getPadding(padding); mSelectionLeftPadding = padding.left; mSelectionTopPadding = padding.top; mSelectionRightPadding = padding.right; mSelectionBottomPadding = padding.bottom; sel.setCallback(this); updateSelectorState(); } /** * Returns the selector {@link android.graphics.drawable.Drawable} that is used to draw the * selection in the list. * * @return the drawable used to display the selector */ public Drawable getSelector() { return mSelector; } /** * Sets the selector state to "pressed" and posts a CheckForKeyLongPress to see if * this is a long press. */ void keyPressed() { if (!isEnabled() || !isClickable()) { return; } Drawable selector = mSelector; Rect selectorRect = mSelectorRect; if (selector != null && (isFocused() || touchModeDrawsInPressedState()) && !selectorRect.isEmpty()) { final View v = getChildAt(mSelectedPosition - mFirstPosition); if (v != null) { if (v.hasExplicitFocusable()) return; v.setPressed(true); } setPressed(true); final boolean longClickable = isLongClickable(); Drawable d = selector.getCurrent(); if (d != null && d instanceof TransitionDrawable) { if (longClickable) { ((TransitionDrawable) d).startTransition(ViewConfiguration.getLongPressTimeout()); } else { ((TransitionDrawable) d).resetTransition(); } } if (longClickable && !mDataChanged) { if (mPendingCheckForKeyLongPress == null) { mPendingCheckForKeyLongPress = new CheckForKeyLongPress(); } mPendingCheckForKeyLongPress.rememberWindowAttachCount(); postDelayed(mPendingCheckForKeyLongPress, ViewConfiguration.getLongPressTimeout()); } } } public void setScrollIndicators(View up, View down) { mScrollUp = up; mScrollDown = down; } @UnsupportedAppUsage void updateSelectorState() { final Drawable selector = mSelector; if (selector != null && selector.isStateful()) { if (shouldShowSelector()) { if (selector.setState(getDrawableStateForSelector())) { invalidateDrawable(selector); } } else { selector.setState(StateSet.NOTHING); } } } @Override protected void drawableStateChanged() { super.drawableStateChanged(); updateSelectorState(); } private int[] getDrawableStateForSelector() { // If the child view is enabled then do the default behavior. if (mIsChildViewEnabled) { // Common case return super.getDrawableState(); } // The selector uses this View's drawable state. The selected child view // is disabled, so we need to remove the enabled state from the drawable // states. final int enabledState = ENABLED_STATE_SET[0]; // If we don't have any extra space, it will return one of the static // state arrays, and clearing the enabled state on those arrays is a // bad thing! If we specify we need extra space, it will create+copy // into a new array that is safely mutable. final int[] state = onCreateDrawableState(1); int enabledPos = -1; for (int i = state.length - 1; i >= 0; i--) { if (state[i] == enabledState) { enabledPos = i; break; } } // Remove the enabled state if (enabledPos >= 0) { System.arraycopy(state, enabledPos + 1, state, enabledPos, state.length - enabledPos - 1); } return state; } @Override public boolean verifyDrawable(@NonNull Drawable dr) { return mSelector == dr || super.verifyDrawable(dr); } @Override public void jumpDrawablesToCurrentState() { super.jumpDrawablesToCurrentState(); if (mSelector != null) mSelector.jumpToCurrentState(); } @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); final ViewTreeObserver treeObserver = getViewTreeObserver(); treeObserver.addOnTouchModeChangeListener(this); if (mTextFilterEnabled && mPopup != null && !mGlobalLayoutListenerAddedFilter) { treeObserver.addOnGlobalLayoutListener(this); } if (mAdapter != null && mDataSetObserver == null) { mDataSetObserver = new AdapterDataSetObserver(); mAdapter.registerDataSetObserver(mDataSetObserver); // Data may have changed while we were detached. Refresh. mDataChanged = true; mOldItemCount = mItemCount; mItemCount = mAdapter.getCount(); } } @Override protected void onDetachedFromWindow() { super.onDetachedFromWindow(); mIsDetaching = true; // Dismiss the popup in case onSaveInstanceState() was not invoked dismissPopup(); // Detach any view left in the scrap heap mRecycler.clear(); final ViewTreeObserver treeObserver = getViewTreeObserver(); treeObserver.removeOnTouchModeChangeListener(this); if (mTextFilterEnabled && mPopup != null) { treeObserver.removeOnGlobalLayoutListener(this); mGlobalLayoutListenerAddedFilter = false; } if (mAdapter != null && mDataSetObserver != null) { mAdapter.unregisterDataSetObserver(mDataSetObserver); mDataSetObserver = null; } if (mScrollStrictSpan != null) { mScrollStrictSpan.finish(); mScrollStrictSpan = null; } if (mFlingStrictSpan != null) { mFlingStrictSpan.finish(); mFlingStrictSpan = null; } if (mFlingRunnable != null) { removeCallbacks(mFlingRunnable); } if (mPositionScroller != null) { mPositionScroller.stop(); } if (mClearScrollingCache != null) { removeCallbacks(mClearScrollingCache); } if (mPerformClick != null) { removeCallbacks(mPerformClick); } if (mTouchModeReset != null) { removeCallbacks(mTouchModeReset); mTouchModeReset.run(); } mIsDetaching = false; } @Override public void onWindowFocusChanged(boolean hasWindowFocus) { super.onWindowFocusChanged(hasWindowFocus); final int touchMode = isInTouchMode() ? TOUCH_MODE_ON : TOUCH_MODE_OFF; if (!hasWindowFocus) { setChildrenDrawingCacheEnabled(false); if (mFlingRunnable != null) { removeCallbacks(mFlingRunnable); // let the fling runnable report its new state which // should be idle mFlingRunnable.mSuppressIdleStateChangeCall = false; mFlingRunnable.endFling(); if (mPositionScroller != null) { mPositionScroller.stop(); } if (mScrollY != 0) { mScrollY = 0; invalidateParentCaches(); finishGlows(); invalidate(); } } // Always hide the type filter dismissPopup(); if (touchMode == TOUCH_MODE_OFF) { // Remember the last selected element mResurrectToPosition = mSelectedPosition; } } else { if (mFiltered && !mPopupHidden) { // Show the type filter only if a filter is in effect showPopup(); } // If we changed touch mode since the last time we had focus if (touchMode != mLastTouchMode && mLastTouchMode != TOUCH_MODE_UNKNOWN) { // If we come back in trackball mode, we bring the selection back if (touchMode == TOUCH_MODE_OFF) { // This will trigger a layout resurrectSelection(); // If we come back in touch mode, then we want to hide the selector } else { hideSelector(); mLayoutMode = LAYOUT_NORMAL; layoutChildren(); } } } mLastTouchMode = touchMode; } @Override public void onRtlPropertiesChanged(int layoutDirection) { super.onRtlPropertiesChanged(layoutDirection); if (mFastScroll != null) { mFastScroll.setScrollbarPosition(getVerticalScrollbarPosition()); } } /** * Creates the ContextMenuInfo returned from {@link #getContextMenuInfo()}. This * methods knows the view, position and ID of the item that received the * long press. * * @param view The view that received the long press. * @param position The position of the item that received the long press. * @param id The ID of the item that received the long press. * @return The extra information that should be returned by * {@link #getContextMenuInfo()}. */ ContextMenuInfo createContextMenuInfo(View view, int position, long id) { return new AdapterContextMenuInfo(view, position, id); } @Override public void onCancelPendingInputEvents() { super.onCancelPendingInputEvents(); if (mPerformClick != null) { removeCallbacks(mPerformClick); } if (mPendingCheckForTap != null) { removeCallbacks(mPendingCheckForTap); } if (mPendingCheckForLongPress != null) { removeCallbacks(mPendingCheckForLongPress); } if (mPendingCheckForKeyLongPress != null) { removeCallbacks(mPendingCheckForKeyLongPress); } } /** * A base class for Runnables that will check that their view is still attached to * the original window as when the Runnable was created. * */ private class WindowRunnnable { private int mOriginalAttachCount; public void rememberWindowAttachCount() { mOriginalAttachCount = getWindowAttachCount(); } public boolean sameWindow() { return getWindowAttachCount() == mOriginalAttachCount; } } private class PerformClick extends WindowRunnnable implements Runnable { int mClickMotionPosition; @Override public void run() { // The data has changed since we posted this action in the event queue, // bail out before bad things happen if (mDataChanged) return; final ListAdapter adapter = mAdapter; final int motionPosition = mClickMotionPosition; if (adapter != null && mItemCount > 0 && motionPosition != INVALID_POSITION && motionPosition < adapter.getCount() && sameWindow() && adapter.isEnabled(motionPosition)) { final View view = getChildAt(motionPosition - mFirstPosition); // If there is no view, something bad happened (the view scrolled off the // screen, etc.) and we should cancel the click if (view != null) { performItemClick(view, motionPosition, adapter.getItemId(motionPosition)); } } } } private class CheckForLongPress extends WindowRunnnable implements Runnable { private static final int INVALID_COORD = -1; private float mX = INVALID_COORD; private float mY = INVALID_COORD; private void setCoords(float x, float y) { mX = x; mY = y; } @Override public void run() { final int motionPosition = mMotionPosition; final View child = getChildAt(motionPosition - mFirstPosition); if (child != null) { final int longPressPosition = mMotionPosition; final long longPressId = mAdapter.getItemId(mMotionPosition); boolean handled = false; if (sameWindow() && !mDataChanged) { if (mX != INVALID_COORD && mY != INVALID_COORD) { handled = performLongPress(child, longPressPosition, longPressId, mX, mY); } else { handled = performLongPress(child, longPressPosition, longPressId); } } if (handled) { mHasPerformedLongPress = true; mTouchMode = TOUCH_MODE_REST; setPressed(false); child.setPressed(false); } else { mTouchMode = TOUCH_MODE_DONE_WAITING; } } } } private class CheckForKeyLongPress extends WindowRunnnable implements Runnable { @Override public void run() { if (isPressed() && mSelectedPosition >= 0) { int index = mSelectedPosition - mFirstPosition; View v = getChildAt(index); if (!mDataChanged) { boolean handled = false; if (sameWindow()) { handled = performLongPress(v, mSelectedPosition, mSelectedRowId); } if (handled) { setPressed(false); v.setPressed(false); } } else { setPressed(false); if (v != null) v.setPressed(false); } } } } private boolean performStylusButtonPressAction(MotionEvent ev) { if (mChoiceMode == CHOICE_MODE_MULTIPLE_MODAL && mChoiceActionMode == null) { final View child = getChildAt(mMotionPosition - mFirstPosition); if (child != null) { final int longPressPosition = mMotionPosition; final long longPressId = mAdapter.getItemId(mMotionPosition); if (performLongPress(child, longPressPosition, longPressId)) { mTouchMode = TOUCH_MODE_REST; setPressed(false); child.setPressed(false); return true; } } } return false; } @UnsupportedAppUsage boolean performLongPress(final View child, final int longPressPosition, final long longPressId) { return performLongPress(child, longPressPosition, longPressId, CheckForLongPress.INVALID_COORD, CheckForLongPress.INVALID_COORD); } @UnsupportedAppUsage boolean performLongPress(final View child, final int longPressPosition, final long longPressId, float x, float y) { // CHOICE_MODE_MULTIPLE_MODAL takes over long press. if (mChoiceMode == CHOICE_MODE_MULTIPLE_MODAL) { if (mChoiceActionMode == null && (mChoiceActionMode = startActionMode(mMultiChoiceModeCallback)) != null) { setItemChecked(longPressPosition, true); performHapticFeedback(HapticFeedbackConstants.LONG_PRESS); } return true; } boolean handled = false; if (mOnItemLongClickListener != null) { handled = mOnItemLongClickListener.onItemLongClick(AbsListView.this, child, longPressPosition, longPressId); } if (!handled) { mContextMenuInfo = createContextMenuInfo(child, longPressPosition, longPressId); if (x != CheckForLongPress.INVALID_COORD && y != CheckForLongPress.INVALID_COORD) { handled = super.showContextMenuForChild(AbsListView.this, x, y); } else { handled = super.showContextMenuForChild(AbsListView.this); } } if (handled) { performHapticFeedback(HapticFeedbackConstants.LONG_PRESS); } return handled; } @Override protected ContextMenuInfo getContextMenuInfo() { return mContextMenuInfo; } @Override public boolean showContextMenu() { return showContextMenuInternal(0, 0, false); } @Override public boolean showContextMenu(float x, float y) { return showContextMenuInternal(x, y, true); } private boolean showContextMenuInternal(float x, float y, boolean useOffsets) { final int position = pointToPosition((int) x, (int) y); if (position != INVALID_POSITION) { final long id = mAdapter.getItemId(position); View child = getChildAt(position - mFirstPosition); if (child != null) { mContextMenuInfo = createContextMenuInfo(child, position, id); if (useOffsets) { return super.showContextMenuForChild(this, x, y); } else { return super.showContextMenuForChild(this); } } } if (useOffsets) { return super.showContextMenu(x, y); } else { return super.showContextMenu(); } } @Override public boolean showContextMenuForChild(View originalView) { if (isShowingContextMenuWithCoords()) { return false; } return showContextMenuForChildInternal(originalView, 0, 0, false); } @Override public boolean showContextMenuForChild(View originalView, float x, float y) { return showContextMenuForChildInternal(originalView, x, y, true); } private boolean showContextMenuForChildInternal(View originalView, float x, float y, boolean useOffsets) { final int longPressPosition = getPositionForView(originalView); if (longPressPosition < 0) { return false; } final long longPressId = mAdapter.getItemId(longPressPosition); boolean handled = false; if (mOnItemLongClickListener != null) { handled = mOnItemLongClickListener.onItemLongClick(this, originalView, longPressPosition, longPressId); } if (!handled) { final View child = getChildAt(longPressPosition - mFirstPosition); mContextMenuInfo = createContextMenuInfo(child, longPressPosition, longPressId); if (useOffsets) { handled = super.showContextMenuForChild(originalView, x, y); } else { handled = super.showContextMenuForChild(originalView); } } return handled; } @Override public boolean onKeyDown(int keyCode, KeyEvent event) { return false; } @Override public boolean onKeyUp(int keyCode, KeyEvent event) { if (KeyEvent.isConfirmKey(keyCode)) { if (!isEnabled()) { return true; } if (isClickable() && isPressed() && mSelectedPosition >= 0 && mAdapter != null && mSelectedPosition < mAdapter.getCount()) { final View view = getChildAt(mSelectedPosition - mFirstPosition); if (view != null) { performItemClick(view, mSelectedPosition, mSelectedRowId); view.setPressed(false); } setPressed(false); return true; } } return super.onKeyUp(keyCode, event); } @Override protected void dispatchSetPressed(boolean pressed) { // Don't dispatch setPressed to our children. We call setPressed on ourselves to // get the selector in the right state, but we don't want to press each child. } @Override public void dispatchDrawableHotspotChanged(float x, float y) { // Don't dispatch hotspot changes to children. We'll manually handle // calling drawableHotspotChanged on the correct child. } /** * Maps a point to a position in the list. * * @param x X in local coordinate * @param y Y in local coordinate * @return The position of the item which contains the specified point, or * {@link #INVALID_POSITION} if the point does not intersect an item. */ public int pointToPosition(int x, int y) { Rect frame = mTouchFrame; if (frame == null) { mTouchFrame = new Rect(); frame = mTouchFrame; } final int count = getChildCount(); for (int i = count - 1; i >= 0; i--) { final View child = getChildAt(i); if (child.getVisibility() == View.VISIBLE) { child.getHitRect(frame); if (frame.contains(x, y)) { return mFirstPosition + i; } } } return INVALID_POSITION; } /** * Maps a point to a the rowId of the item which intersects that point. * * @param x X in local coordinate * @param y Y in local coordinate * @return The rowId of the item which contains the specified point, or {@link #INVALID_ROW_ID} * if the point does not intersect an item. */ public long pointToRowId(int x, int y) { int position = pointToPosition(x, y); if (position >= 0) { return mAdapter.getItemId(position); } return INVALID_ROW_ID; } private final class CheckForTap implements Runnable { float x; float y; @Override public void run() { if (mTouchMode == TOUCH_MODE_DOWN) { mTouchMode = TOUCH_MODE_TAP; final View child = getChildAt(mMotionPosition - mFirstPosition); if (child != null && !child.hasExplicitFocusable()) { mLayoutMode = LAYOUT_NORMAL; if (!mDataChanged) { final float[] point = mTmpPoint; point[0] = x; point[1] = y; transformPointToViewLocal(point, child); child.drawableHotspotChanged(point[0], point[1]); child.setPressed(true); setPressed(true); layoutChildren(); positionSelector(mMotionPosition, child); refreshDrawableState(); final int longPressTimeout = ViewConfiguration.getLongPressTimeout(); final boolean longClickable = isLongClickable(); if (mSelector != null) { final Drawable d = mSelector.getCurrent(); if (d != null && d instanceof TransitionDrawable) { if (longClickable) { ((TransitionDrawable) d).startTransition(longPressTimeout); } else { ((TransitionDrawable) d).resetTransition(); } } mSelector.setHotspot(x, y); } if (longClickable) { if (mPendingCheckForLongPress == null) { mPendingCheckForLongPress = new CheckForLongPress(); } mPendingCheckForLongPress.setCoords(x, y); mPendingCheckForLongPress.rememberWindowAttachCount(); postDelayed(mPendingCheckForLongPress, longPressTimeout); } else { mTouchMode = TOUCH_MODE_DONE_WAITING; } } else { mTouchMode = TOUCH_MODE_DONE_WAITING; } } } } } private boolean startScrollIfNeeded(int x, int y, MotionEvent vtev) { // Check if we have moved far enough that it looks more like a // scroll than a tap final int deltaY = y - mMotionY; final int distance = Math.abs(deltaY); final boolean overscroll = mScrollY != 0; if ((overscroll || distance > mTouchSlop) && (getNestedScrollAxes() & SCROLL_AXIS_VERTICAL) == 0) { createScrollingCache(); if (overscroll) { mTouchMode = TOUCH_MODE_OVERSCROLL; mMotionCorrection = 0; } else { mTouchMode = TOUCH_MODE_SCROLL; mMotionCorrection = deltaY > 0 ? mTouchSlop : -mTouchSlop; } removeCallbacks(mPendingCheckForLongPress); setPressed(false); final View motionView = getChildAt(mMotionPosition - mFirstPosition); if (motionView != null) { motionView.setPressed(false); } reportScrollStateChange(OnScrollListener.SCROLL_STATE_TOUCH_SCROLL); // Time to start stealing events! Once we've stolen them, don't let anyone // steal from us final ViewParent parent = getParent(); if (parent != null) { parent.requestDisallowInterceptTouchEvent(true); } scrollIfNeeded(x, y, vtev); return true; } return false; } private void scrollIfNeeded(int x, int y, MotionEvent vtev) { int rawDeltaY = y - mMotionY; int scrollOffsetCorrection = 0; int scrollConsumedCorrection = 0; if (mLastY == Integer.MIN_VALUE) { rawDeltaY -= mMotionCorrection; } if (dispatchNestedPreScroll(0, mLastY != Integer.MIN_VALUE ? mLastY - y : -rawDeltaY, mScrollConsumed, mScrollOffset)) { rawDeltaY += mScrollConsumed[1]; scrollOffsetCorrection = -mScrollOffset[1]; scrollConsumedCorrection = mScrollConsumed[1]; if (vtev != null) { vtev.offsetLocation(0, mScrollOffset[1]); mNestedYOffset += mScrollOffset[1]; } } final int deltaY = rawDeltaY; int incrementalDeltaY = mLastY != Integer.MIN_VALUE ? y - mLastY + scrollConsumedCorrection : deltaY; int lastYCorrection = 0; if (mTouchMode == TOUCH_MODE_SCROLL) { if (PROFILE_SCROLLING) { if (!mScrollProfilingStarted) { Debug.startMethodTracing("AbsListViewScroll"); mScrollProfilingStarted = true; } } if (mScrollStrictSpan == null) { // If it's non-null, we're already in a scroll. mScrollStrictSpan = StrictMode.enterCriticalSpan("AbsListView-scroll"); } if (y != mLastY) { // We may be here after stopping a fling and continuing to scroll. // If so, we haven't disallowed intercepting touch events yet. // Make sure that we do so in case we're in a parent that can intercept. if ((mGroupFlags & FLAG_DISALLOW_INTERCEPT) == 0 && Math.abs(rawDeltaY) > mTouchSlop) { final ViewParent parent = getParent(); if (parent != null) { parent.requestDisallowInterceptTouchEvent(true); } } final int motionIndex; if (mMotionPosition >= 0) { motionIndex = mMotionPosition - mFirstPosition; } else { // If we don't have a motion position that we can reliably track, // pick something in the middle to make a best guess at things below. motionIndex = getChildCount() / 2; } int motionViewPrevTop = 0; View motionView = this.getChildAt(motionIndex); if (motionView != null) { motionViewPrevTop = motionView.getTop(); } // No need to do all this work if we're not going to move anyway boolean atEdge = false; if (incrementalDeltaY != 0) { atEdge = trackMotionScroll(deltaY, incrementalDeltaY); } // Check to see if we have bumped into the scroll limit motionView = this.getChildAt(motionIndex); if (motionView != null) { // Check if the top of the motion view is where it is // supposed to be final int motionViewRealTop = motionView.getTop(); if (atEdge) { // Apply overscroll int overscroll = -incrementalDeltaY - (motionViewRealTop - motionViewPrevTop); if (dispatchNestedScroll(0, overscroll - incrementalDeltaY, 0, overscroll, mScrollOffset)) { lastYCorrection -= mScrollOffset[1]; if (vtev != null) { vtev.offsetLocation(0, mScrollOffset[1]); mNestedYOffset += mScrollOffset[1]; } } else { final boolean atOverscrollEdge = overScrollBy(0, overscroll, 0, mScrollY, 0, 0, 0, mOverscrollDistance, true); if (atOverscrollEdge && mVelocityTracker != null) { // Don't allow overfling if we're at the edge mVelocityTracker.clear(); } final int overscrollMode = getOverScrollMode(); if (overscrollMode == OVER_SCROLL_ALWAYS || (overscrollMode == OVER_SCROLL_IF_CONTENT_SCROLLS && !contentFits())) { if (!atOverscrollEdge) { mDirection = 0; // Reset when entering overscroll. mTouchMode = TOUCH_MODE_OVERSCROLL; } if (incrementalDeltaY > 0) { mEdgeGlowTop.onPull((float) -overscroll / getHeight(), (float) x / getWidth()); if (!mEdgeGlowBottom.isFinished()) { mEdgeGlowBottom.onRelease(); } invalidateTopGlow(); } else if (incrementalDeltaY < 0) { mEdgeGlowBottom.onPull((float) overscroll / getHeight(), 1.f - (float) x / getWidth()); if (!mEdgeGlowTop.isFinished()) { mEdgeGlowTop.onRelease(); } invalidateBottomGlow(); } } } } mMotionY = y + lastYCorrection + scrollOffsetCorrection; } mLastY = y + lastYCorrection + scrollOffsetCorrection; } } else if (mTouchMode == TOUCH_MODE_OVERSCROLL) { if (y != mLastY) { final int oldScroll = mScrollY; final int newScroll = oldScroll - incrementalDeltaY; int newDirection = y > mLastY ? 1 : -1; if (mDirection == 0) { mDirection = newDirection; } int overScrollDistance = -incrementalDeltaY; if ((newScroll < 0 && oldScroll >= 0) || (newScroll > 0 && oldScroll <= 0)) { overScrollDistance = -oldScroll; incrementalDeltaY += overScrollDistance; } else { incrementalDeltaY = 0; } if (overScrollDistance != 0) { overScrollBy(0, overScrollDistance, 0, mScrollY, 0, 0, 0, mOverscrollDistance, true); final int overscrollMode = getOverScrollMode(); if (overscrollMode == OVER_SCROLL_ALWAYS || (overscrollMode == OVER_SCROLL_IF_CONTENT_SCROLLS && !contentFits())) { if (rawDeltaY > 0) { mEdgeGlowTop.onPull((float) overScrollDistance / getHeight(), (float) x / getWidth()); if (!mEdgeGlowBottom.isFinished()) { mEdgeGlowBottom.onRelease(); } invalidateTopGlow(); } else if (rawDeltaY < 0) { mEdgeGlowBottom.onPull((float) overScrollDistance / getHeight(), 1.f - (float) x / getWidth()); if (!mEdgeGlowTop.isFinished()) { mEdgeGlowTop.onRelease(); } invalidateBottomGlow(); } } } if (incrementalDeltaY != 0) { // Coming back to 'real' list scrolling if (mScrollY != 0) { mScrollY = 0; invalidateParentIfNeeded(); } trackMotionScroll(incrementalDeltaY, incrementalDeltaY); mTouchMode = TOUCH_MODE_SCROLL; // We did not scroll the full amount. Treat this essentially like the // start of a new touch scroll final int motionPosition = findClosestMotionRow(y); mMotionCorrection = 0; View motionView = getChildAt(motionPosition - mFirstPosition); mMotionViewOriginalTop = motionView != null ? motionView.getTop() : 0; mMotionY = y + scrollOffsetCorrection; mMotionPosition = motionPosition; } mLastY = y + lastYCorrection + scrollOffsetCorrection; mDirection = newDirection; } } } private void invalidateTopGlow() { if (mEdgeGlowTop == null) { return; } final boolean clipToPadding = getClipToPadding(); final int top = clipToPadding ? mPaddingTop : 0; final int left = clipToPadding ? mPaddingLeft : 0; final int right = clipToPadding ? getWidth() - mPaddingRight : getWidth(); invalidate(left, top, right, top + mEdgeGlowTop.getMaxHeight()); } private void invalidateBottomGlow() { if (mEdgeGlowBottom == null) { return; } final boolean clipToPadding = getClipToPadding(); final int bottom = clipToPadding ? getHeight() - mPaddingBottom : getHeight(); final int left = clipToPadding ? mPaddingLeft : 0; final int right = clipToPadding ? getWidth() - mPaddingRight : getWidth(); invalidate(left, bottom - mEdgeGlowBottom.getMaxHeight(), right, bottom); } @Override public void onTouchModeChanged(boolean isInTouchMode) { if (isInTouchMode) { // Get rid of the selection when we enter touch mode hideSelector(); // Layout, but only if we already have done so previously. // (Otherwise may clobber a LAYOUT_SYNC layout that was requested to restore // state.) if (getHeight() > 0 && getChildCount() > 0) { // We do not lose focus initiating a touch (since AbsListView is focusable in // touch mode). Force an initial layout to get rid of the selection. layoutChildren(); } updateSelectorState(); } else { int touchMode = mTouchMode; if (touchMode == TOUCH_MODE_OVERSCROLL || touchMode == TOUCH_MODE_OVERFLING) { if (mFlingRunnable != null) { mFlingRunnable.endFling(); } if (mPositionScroller != null) { mPositionScroller.stop(); } if (mScrollY != 0) { mScrollY = 0; invalidateParentCaches(); finishGlows(); invalidate(); } } } } /** @hide */ @Override protected boolean handleScrollBarDragging(MotionEvent event) { // Doesn't support normal scroll bar dragging. Use FastScroller. return false; } @Override public boolean onTouchEvent(MotionEvent ev) { if (!isEnabled()) { // A disabled view that is clickable still consumes the touch // events, it just doesn't respond to them. return isClickable() || isLongClickable(); } if (mPositionScroller != null) { mPositionScroller.stop(); } if (mIsDetaching || !isAttachedToWindow()) { // Something isn't right. // Since we rely on being attached to get data set change notifications, // don't risk doing anything where we might try to resync and find things // in a bogus state. return false; } startNestedScroll(SCROLL_AXIS_VERTICAL); if (mFastScroll != null && mFastScroll.onTouchEvent(ev)) { return true; } initVelocityTrackerIfNotExists(); final MotionEvent vtev = MotionEvent.obtain(ev); final int actionMasked = ev.getActionMasked(); if (actionMasked == MotionEvent.ACTION_DOWN) { mNestedYOffset = 0; } vtev.offsetLocation(0, mNestedYOffset); switch (actionMasked) { case MotionEvent.ACTION_DOWN: { onTouchDown(ev); break; } case MotionEvent.ACTION_MOVE: { onTouchMove(ev, vtev); break; } case MotionEvent.ACTION_UP: { onTouchUp(ev); break; } case MotionEvent.ACTION_CANCEL: { onTouchCancel(); break; } case MotionEvent.ACTION_POINTER_UP: { onSecondaryPointerUp(ev); final int x = mMotionX; final int y = mMotionY; final int motionPosition = pointToPosition(x, y); if (motionPosition >= 0) { // Remember where the motion event started final View child = getChildAt(motionPosition - mFirstPosition); mMotionViewOriginalTop = child.getTop(); mMotionPosition = motionPosition; } mLastY = y; break; } case MotionEvent.ACTION_POINTER_DOWN: { // New pointers take over dragging duties final int index = ev.getActionIndex(); final int id = ev.getPointerId(index); final int x = (int) ev.getX(index); final int y = (int) ev.getY(index); mMotionCorrection = 0; mActivePointerId = id; mMotionX = x; mMotionY = y; final int motionPosition = pointToPosition(x, y); if (motionPosition >= 0) { // Remember where the motion event started final View child = getChildAt(motionPosition - mFirstPosition); mMotionViewOriginalTop = child.getTop(); mMotionPosition = motionPosition; } mLastY = y; break; } } if (mVelocityTracker != null) { mVelocityTracker.addMovement(vtev); } vtev.recycle(); return true; } private void onTouchDown(MotionEvent ev) { mHasPerformedLongPress = false; mActivePointerId = ev.getPointerId(0); hideSelector(); if (mTouchMode == TOUCH_MODE_OVERFLING) { // Stopped the fling. It is a scroll. mFlingRunnable.endFling(); if (mPositionScroller != null) { mPositionScroller.stop(); } mTouchMode = TOUCH_MODE_OVERSCROLL; mMotionX = (int) ev.getX(); mMotionY = (int) ev.getY(); mLastY = mMotionY; mMotionCorrection = 0; mDirection = 0; } else { final int x = (int) ev.getX(); final int y = (int) ev.getY(); int motionPosition = pointToPosition(x, y); if (!mDataChanged) { if (mTouchMode == TOUCH_MODE_FLING) { // Stopped a fling. It is a scroll. createScrollingCache(); mTouchMode = TOUCH_MODE_SCROLL; mMotionCorrection = 0; motionPosition = findMotionRow(y); mFlingRunnable.flywheelTouch(); } else if ((motionPosition >= 0) && getAdapter().isEnabled(motionPosition)) { // User clicked on an actual view (and was not stopping a // fling). It might be a click or a scroll. Assume it is a // click until proven otherwise. mTouchMode = TOUCH_MODE_DOWN; // FIXME Debounce if (mPendingCheckForTap == null) { mPendingCheckForTap = new CheckForTap(); } mPendingCheckForTap.x = ev.getX(); mPendingCheckForTap.y = ev.getY(); postDelayed(mPendingCheckForTap, ViewConfiguration.getTapTimeout()); } } if (motionPosition >= 0) { // Remember where the motion event started final View v = getChildAt(motionPosition - mFirstPosition); mMotionViewOriginalTop = v.getTop(); } mMotionX = x; mMotionY = y; mMotionPosition = motionPosition; mLastY = Integer.MIN_VALUE; } if (mTouchMode == TOUCH_MODE_DOWN && mMotionPosition != INVALID_POSITION && performButtonActionOnTouchDown(ev)) { removeCallbacks(mPendingCheckForTap); } } private void onTouchMove(MotionEvent ev, MotionEvent vtev) { if (mHasPerformedLongPress) { // Consume all move events following a successful long press. return; } int pointerIndex = ev.findPointerIndex(mActivePointerId); if (pointerIndex == -1) { pointerIndex = 0; mActivePointerId = ev.getPointerId(pointerIndex); } if (mDataChanged) { // Re-sync everything if data has been changed // since the scroll operation can query the adapter. layoutChildren(); } final int y = (int) ev.getY(pointerIndex); switch (mTouchMode) { case TOUCH_MODE_DOWN: case TOUCH_MODE_TAP: case TOUCH_MODE_DONE_WAITING: // Check if we have moved far enough that it looks more like a // scroll than a tap. If so, we'll enter scrolling mode. if (startScrollIfNeeded((int) ev.getX(pointerIndex), y, vtev)) { break; } // Otherwise, check containment within list bounds. If we're // outside bounds, cancel any active presses. final View motionView = getChildAt(mMotionPosition - mFirstPosition); final float x = ev.getX(pointerIndex); if (!pointInView(x, y, mTouchSlop)) { setPressed(false); if (motionView != null) { motionView.setPressed(false); } removeCallbacks(mTouchMode == TOUCH_MODE_DOWN ? mPendingCheckForTap : mPendingCheckForLongPress); mTouchMode = TOUCH_MODE_DONE_WAITING; updateSelectorState(); } else if (motionView != null) { // Still within bounds, update the hotspot. final float[] point = mTmpPoint; point[0] = x; point[1] = y; transformPointToViewLocal(point, motionView); motionView.drawableHotspotChanged(point[0], point[1]); } break; case TOUCH_MODE_SCROLL: case TOUCH_MODE_OVERSCROLL: scrollIfNeeded((int) ev.getX(pointerIndex), y, vtev); break; } } private void onTouchUp(MotionEvent ev) { switch (mTouchMode) { case TOUCH_MODE_DOWN: case TOUCH_MODE_TAP: case TOUCH_MODE_DONE_WAITING: final int motionPosition = mMotionPosition; final View child = getChildAt(motionPosition - mFirstPosition); if (child != null) { if (mTouchMode != TOUCH_MODE_DOWN) { child.setPressed(false); } final float x = ev.getX(); final boolean inList = x > mListPadding.left && x < getWidth() - mListPadding.right; if (inList && !child.hasExplicitFocusable()) { if (mPerformClick == null) { mPerformClick = new PerformClick(); } final AbsListView.PerformClick performClick = mPerformClick; performClick.mClickMotionPosition = motionPosition; performClick.rememberWindowAttachCount(); mResurrectToPosition = motionPosition; if (mTouchMode == TOUCH_MODE_DOWN || mTouchMode == TOUCH_MODE_TAP) { removeCallbacks( mTouchMode == TOUCH_MODE_DOWN ? mPendingCheckForTap : mPendingCheckForLongPress); mLayoutMode = LAYOUT_NORMAL; if (!mDataChanged && mAdapter.isEnabled(motionPosition)) { mTouchMode = TOUCH_MODE_TAP; setSelectedPositionInt(mMotionPosition); layoutChildren(); child.setPressed(true); positionSelector(mMotionPosition, child); setPressed(true); if (mSelector != null) { Drawable d = mSelector.getCurrent(); if (d != null && d instanceof TransitionDrawable) { ((TransitionDrawable) d).resetTransition(); } mSelector.setHotspot(x, ev.getY()); } if (mTouchModeReset != null) { removeCallbacks(mTouchModeReset); } mTouchModeReset = new Runnable() { @Override public void run() { mTouchModeReset = null; mTouchMode = TOUCH_MODE_REST; child.setPressed(false); setPressed(false); if (!mDataChanged && !mIsDetaching && isAttachedToWindow()) { performClick.run(); } } }; postDelayed(mTouchModeReset, ViewConfiguration.getPressedStateDuration()); } else { mTouchMode = TOUCH_MODE_REST; updateSelectorState(); } return; } else if (!mDataChanged && mAdapter.isEnabled(motionPosition)) { performClick.run(); } } } mTouchMode = TOUCH_MODE_REST; updateSelectorState(); break; case TOUCH_MODE_SCROLL: final int childCount = getChildCount(); if (childCount > 0) { final int firstChildTop = getChildAt(0).getTop(); final int lastChildBottom = getChildAt(childCount - 1).getBottom(); final int contentTop = mListPadding.top; final int contentBottom = getHeight() - mListPadding.bottom; if (mFirstPosition == 0 && firstChildTop >= contentTop && mFirstPosition + childCount < mItemCount && lastChildBottom <= getHeight() - contentBottom) { mTouchMode = TOUCH_MODE_REST; reportScrollStateChange(OnScrollListener.SCROLL_STATE_IDLE); } else { final VelocityTracker velocityTracker = mVelocityTracker; velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity); final int initialVelocity = (int) (velocityTracker.getYVelocity(mActivePointerId) * mVelocityScale); // Fling if we have enough velocity and we aren't at a boundary. // Since we can potentially overfling more than we can overscroll, don't // allow the weird behavior where you can scroll to a boundary then // fling further. boolean flingVelocity = Math.abs(initialVelocity) > mMinimumVelocity; if (flingVelocity && !((mFirstPosition == 0 && firstChildTop == contentTop - mOverscrollDistance) || (mFirstPosition + childCount == mItemCount && lastChildBottom == contentBottom + mOverscrollDistance))) { if (!dispatchNestedPreFling(0, -initialVelocity)) { if (mFlingRunnable == null) { mFlingRunnable = new FlingRunnable(); } reportScrollStateChange(OnScrollListener.SCROLL_STATE_FLING); mFlingRunnable.start(-initialVelocity); dispatchNestedFling(0, -initialVelocity, true); } else { mTouchMode = TOUCH_MODE_REST; reportScrollStateChange(OnScrollListener.SCROLL_STATE_IDLE); } } else { mTouchMode = TOUCH_MODE_REST; reportScrollStateChange(OnScrollListener.SCROLL_STATE_IDLE); if (mFlingRunnable != null) { mFlingRunnable.endFling(); } if (mPositionScroller != null) { mPositionScroller.stop(); } if (flingVelocity && !dispatchNestedPreFling(0, -initialVelocity)) { dispatchNestedFling(0, -initialVelocity, false); } } } } else { mTouchMode = TOUCH_MODE_REST; reportScrollStateChange(OnScrollListener.SCROLL_STATE_IDLE); } break; case TOUCH_MODE_OVERSCROLL: if (mFlingRunnable == null) { mFlingRunnable = new FlingRunnable(); } final VelocityTracker velocityTracker = mVelocityTracker; velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity); final int initialVelocity = (int) velocityTracker.getYVelocity(mActivePointerId); reportScrollStateChange(OnScrollListener.SCROLL_STATE_FLING); if (Math.abs(initialVelocity) > mMinimumVelocity) { mFlingRunnable.startOverfling(-initialVelocity); } else { mFlingRunnable.startSpringback(); } break; } setPressed(false); if (mEdgeGlowTop != null) { mEdgeGlowTop.onRelease(); mEdgeGlowBottom.onRelease(); } // Need to redraw since we probably aren't drawing the selector anymore invalidate(); removeCallbacks(mPendingCheckForLongPress); recycleVelocityTracker(); mActivePointerId = INVALID_POINTER; if (PROFILE_SCROLLING) { if (mScrollProfilingStarted) { Debug.stopMethodTracing(); mScrollProfilingStarted = false; } } if (mScrollStrictSpan != null) { mScrollStrictSpan.finish(); mScrollStrictSpan = null; } } private void onTouchCancel() { switch (mTouchMode) { case TOUCH_MODE_OVERSCROLL: if (mFlingRunnable == null) { mFlingRunnable = new FlingRunnable(); } mFlingRunnable.startSpringback(); break; case TOUCH_MODE_OVERFLING: // Do nothing - let it play out. break; default: mTouchMode = TOUCH_MODE_REST; setPressed(false); final View motionView = this.getChildAt(mMotionPosition - mFirstPosition); if (motionView != null) { motionView.setPressed(false); } clearScrollingCache(); removeCallbacks(mPendingCheckForLongPress); recycleVelocityTracker(); } if (mEdgeGlowTop != null) { mEdgeGlowTop.onRelease(); mEdgeGlowBottom.onRelease(); } mActivePointerId = INVALID_POINTER; } @Override protected void onOverScrolled(int scrollX, int scrollY, boolean clampedX, boolean clampedY) { if (mScrollY != scrollY) { onScrollChanged(mScrollX, scrollY, mScrollX, mScrollY); mScrollY = scrollY; invalidateParentIfNeeded(); awakenScrollBars(); } } @Override public boolean onGenericMotionEvent(MotionEvent event) { switch (event.getAction()) { case MotionEvent.ACTION_SCROLL: final float axisValue; if (event.isFromSource(InputDevice.SOURCE_CLASS_POINTER)) { axisValue = event.getAxisValue(MotionEvent.AXIS_VSCROLL); } else if (event.isFromSource(InputDevice.SOURCE_ROTARY_ENCODER)) { axisValue = event.getAxisValue(MotionEvent.AXIS_SCROLL); } else { axisValue = 0; } final int delta = Math.round(axisValue * mVerticalScrollFactor); if (delta != 0) { if (!trackMotionScroll(delta, delta)) { return true; } } break; case MotionEvent.ACTION_BUTTON_PRESS: if (event.isFromSource(InputDevice.SOURCE_CLASS_POINTER)) { int actionButton = event.getActionButton(); if ((actionButton == MotionEvent.BUTTON_STYLUS_PRIMARY || actionButton == MotionEvent.BUTTON_SECONDARY) && (mTouchMode == TOUCH_MODE_DOWN || mTouchMode == TOUCH_MODE_TAP)) { if (performStylusButtonPressAction(event)) { removeCallbacks(mPendingCheckForLongPress); removeCallbacks(mPendingCheckForTap); } } } break; } return super.onGenericMotionEvent(event); } /** * Initiate a fling with the given velocity. * * <p>Applications can use this method to manually initiate a fling as if the user * initiated it via touch interaction.</p> * * @param velocityY Vertical velocity in pixels per second. Note that this is velocity of * content, not velocity of a touch that initiated the fling. */ public void fling(int velocityY) { if (mFlingRunnable == null) { mFlingRunnable = new FlingRunnable(); } reportScrollStateChange(OnScrollListener.SCROLL_STATE_FLING); mFlingRunnable.start(velocityY); } @Override public boolean onStartNestedScroll(View child, View target, int nestedScrollAxes) { return ((nestedScrollAxes & SCROLL_AXIS_VERTICAL) != 0); } @Override public void onNestedScrollAccepted(View child, View target, int axes) { super.onNestedScrollAccepted(child, target, axes); startNestedScroll(SCROLL_AXIS_VERTICAL); } @Override public void onNestedScroll(View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) { final int motionIndex = getChildCount() / 2; final View motionView = getChildAt(motionIndex); final int oldTop = motionView != null ? motionView.getTop() : 0; if (motionView == null || trackMotionScroll(-dyUnconsumed, -dyUnconsumed)) { int myUnconsumed = dyUnconsumed; int myConsumed = 0; if (motionView != null) { myConsumed = motionView.getTop() - oldTop; myUnconsumed -= myConsumed; } dispatchNestedScroll(0, myConsumed, 0, myUnconsumed, null); } } @Override public boolean onNestedFling(View target, float velocityX, float velocityY, boolean consumed) { final int childCount = getChildCount(); if (!consumed && childCount > 0 && canScrollList((int) velocityY) && Math.abs(velocityY) > mMinimumVelocity) { reportScrollStateChange(OnScrollListener.SCROLL_STATE_FLING); if (mFlingRunnable == null) { mFlingRunnable = new FlingRunnable(); } if (!dispatchNestedPreFling(0, velocityY)) { mFlingRunnable.start((int) velocityY); } return true; } return dispatchNestedFling(velocityX, velocityY, consumed); } @Override public void draw(Canvas canvas) { super.draw(canvas); if (mEdgeGlowTop != null) { final int scrollY = mScrollY; final boolean clipToPadding = getClipToPadding(); final int width; final int height; final int translateX; final int translateY; if (clipToPadding) { width = getWidth() - mPaddingLeft - mPaddingRight; height = getHeight() - mPaddingTop - mPaddingBottom; translateX = mPaddingLeft; translateY = mPaddingTop; } else { width = getWidth(); height = getHeight(); translateX = 0; translateY = 0; } mEdgeGlowTop.setSize(width, height); mEdgeGlowBottom.setSize(width, height); if (!mEdgeGlowTop.isFinished()) { final int restoreCount = canvas.save(); canvas.clipRect(translateX, translateY, translateX + width, translateY + mEdgeGlowTop.getMaxHeight()); final int edgeY = Math.min(0, scrollY + mFirstPositionDistanceGuess) + translateY; canvas.translate(translateX, edgeY); if (mEdgeGlowTop.draw(canvas)) { invalidateTopGlow(); } canvas.restoreToCount(restoreCount); } if (!mEdgeGlowBottom.isFinished()) { final int restoreCount = canvas.save(); canvas.clipRect(translateX, translateY + height - mEdgeGlowBottom.getMaxHeight(), translateX + width, translateY + height); final int edgeX = -width + translateX; final int edgeY = Math.max(getHeight(), scrollY + mLastPositionDistanceGuess) - (clipToPadding ? mPaddingBottom : 0); canvas.translate(edgeX, edgeY); canvas.rotate(180, width, 0); if (mEdgeGlowBottom.draw(canvas)) { invalidateBottomGlow(); } canvas.restoreToCount(restoreCount); } } } private void initOrResetVelocityTracker() { if (mVelocityTracker == null) { mVelocityTracker = VelocityTracker.obtain(); } else { mVelocityTracker.clear(); } } private void initVelocityTrackerIfNotExists() { if (mVelocityTracker == null) { mVelocityTracker = VelocityTracker.obtain(); } } private void recycleVelocityTracker() { if (mVelocityTracker != null) { mVelocityTracker.recycle(); mVelocityTracker = null; } } @Override public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) { if (disallowIntercept) { recycleVelocityTracker(); } super.requestDisallowInterceptTouchEvent(disallowIntercept); } @Override public boolean onInterceptHoverEvent(MotionEvent event) { if (mFastScroll != null && mFastScroll.onInterceptHoverEvent(event)) { return true; } return super.onInterceptHoverEvent(event); } @Override public PointerIcon onResolvePointerIcon(MotionEvent event, int pointerIndex) { if (mFastScroll != null) { PointerIcon pointerIcon = mFastScroll.onResolvePointerIcon(event, pointerIndex); if (pointerIcon != null) { return pointerIcon; } } return super.onResolvePointerIcon(event, pointerIndex); } @Override public boolean onInterceptTouchEvent(MotionEvent ev) { final int actionMasked = ev.getActionMasked(); View v; if (mPositionScroller != null) { mPositionScroller.stop(); } if (mIsDetaching || !isAttachedToWindow()) { // Something isn't right. // Since we rely on being attached to get data set change notifications, // don't risk doing anything where we might try to resync and find things // in a bogus state. return false; } if (mFastScroll != null && mFastScroll.onInterceptTouchEvent(ev)) { return true; } switch (actionMasked) { case MotionEvent.ACTION_DOWN: { int touchMode = mTouchMode; if (touchMode == TOUCH_MODE_OVERFLING || touchMode == TOUCH_MODE_OVERSCROLL) { mMotionCorrection = 0; return true; } final int x = (int) ev.getX(); final int y = (int) ev.getY(); mActivePointerId = ev.getPointerId(0); int motionPosition = findMotionRow(y); if (touchMode != TOUCH_MODE_FLING && motionPosition >= 0) { // User clicked on an actual view (and was not stopping a fling). // Remember where the motion event started v = getChildAt(motionPosition - mFirstPosition); mMotionViewOriginalTop = v.getTop(); mMotionX = x; mMotionY = y; mMotionPosition = motionPosition; mTouchMode = TOUCH_MODE_DOWN; clearScrollingCache(); } mLastY = Integer.MIN_VALUE; initOrResetVelocityTracker(); mVelocityTracker.addMovement(ev); mNestedYOffset = 0; startNestedScroll(SCROLL_AXIS_VERTICAL); if (touchMode == TOUCH_MODE_FLING) { return true; } break; } case MotionEvent.ACTION_MOVE: { switch (mTouchMode) { case TOUCH_MODE_DOWN: int pointerIndex = ev.findPointerIndex(mActivePointerId); if (pointerIndex == -1) { pointerIndex = 0; mActivePointerId = ev.getPointerId(pointerIndex); } final int y = (int) ev.getY(pointerIndex); initVelocityTrackerIfNotExists(); mVelocityTracker.addMovement(ev); if (startScrollIfNeeded((int) ev.getX(pointerIndex), y, null)) { return true; } break; } break; } case MotionEvent.ACTION_CANCEL: case MotionEvent.ACTION_UP: { mTouchMode = TOUCH_MODE_REST; mActivePointerId = INVALID_POINTER; recycleVelocityTracker(); reportScrollStateChange(OnScrollListener.SCROLL_STATE_IDLE); stopNestedScroll(); break; } case MotionEvent.ACTION_POINTER_UP: { onSecondaryPointerUp(ev); break; } } return false; } private void onSecondaryPointerUp(MotionEvent ev) { final int pointerIndex = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT; final int pointerId = ev.getPointerId(pointerIndex); if (pointerId == mActivePointerId) { // This was our active pointer going up. Choose a new // active pointer and adjust accordingly. // TODO: Make this decision more intelligent. final int newPointerIndex = pointerIndex == 0 ? 1 : 0; mMotionX = (int) ev.getX(newPointerIndex); mMotionY = (int) ev.getY(newPointerIndex); mMotionCorrection = 0; mActivePointerId = ev.getPointerId(newPointerIndex); } } /** * {@inheritDoc} */ @Override public void addTouchables(ArrayList<View> views) { final int count = getChildCount(); final int firstPosition = mFirstPosition; final ListAdapter adapter = mAdapter; if (adapter == null) { return; } for (int i = 0; i < count; i++) { final View child = getChildAt(i); if (adapter.isEnabled(firstPosition + i)) { views.add(child); } child.addTouchables(views); } } /** * Fires an "on scroll state changed" event to the registered * {@link android.widget.AbsListView.OnScrollListener}, if any. The state change * is fired only if the specified state is different from the previously known state. * * @param newState The new scroll state. */ @UnsupportedAppUsage void reportScrollStateChange(int newState) { if (newState != mLastScrollState) { if (mOnScrollListener != null) { mLastScrollState = newState; mOnScrollListener.onScrollStateChanged(this, newState); } } } /** * Responsible for fling behavior. Use {@link #start(int)} to * initiate a fling. Each frame of the fling is handled in {@link #run()}. * A FlingRunnable will keep re-posting itself until the fling is done. * */ private class FlingRunnable implements Runnable { /** * Tracks the decay of a fling scroll */ @UnsupportedAppUsage private final OverScroller mScroller; /** * Y value reported by mScroller on the previous fling */ private int mLastFlingY; /** * If true, {@link #endFling()} will not report scroll state change to * {@link OnScrollListener#SCROLL_STATE_IDLE}. */ private boolean mSuppressIdleStateChangeCall; private final Runnable mCheckFlywheel = new Runnable() { @Override public void run() { final int activeId = mActivePointerId; final VelocityTracker vt = mVelocityTracker; final OverScroller scroller = mScroller; if (vt == null || activeId == INVALID_POINTER) { return; } vt.computeCurrentVelocity(1000, mMaximumVelocity); final float yvel = -vt.getYVelocity(activeId); if (Math.abs(yvel) >= mMinimumVelocity && scroller.isScrollingInDirection(0, yvel)) { // Keep the fling alive a little longer postDelayed(this, FLYWHEEL_TIMEOUT); } else { endFling(); mTouchMode = TOUCH_MODE_SCROLL; reportScrollStateChange(OnScrollListener.SCROLL_STATE_TOUCH_SCROLL); } } }; private static final int FLYWHEEL_TIMEOUT = 40; // milliseconds FlingRunnable() { mScroller = new OverScroller(getContext()); } @UnsupportedAppUsage void start(int initialVelocity) { int initialY = initialVelocity < 0 ? Integer.MAX_VALUE : 0; mLastFlingY = initialY; mScroller.setInterpolator(null); mScroller.fling(0, initialY, 0, initialVelocity, 0, Integer.MAX_VALUE, 0, Integer.MAX_VALUE); mTouchMode = TOUCH_MODE_FLING; mSuppressIdleStateChangeCall = false; postOnAnimation(this); if (PROFILE_FLINGING) { if (!mFlingProfilingStarted) { Debug.startMethodTracing("AbsListViewFling"); mFlingProfilingStarted = true; } } if (mFlingStrictSpan == null) { mFlingStrictSpan = StrictMode.enterCriticalSpan("AbsListView-fling"); } } void startSpringback() { mSuppressIdleStateChangeCall = false; if (mScroller.springBack(0, mScrollY, 0, 0, 0, 0)) { mTouchMode = TOUCH_MODE_OVERFLING; invalidate(); postOnAnimation(this); } else { mTouchMode = TOUCH_MODE_REST; reportScrollStateChange(OnScrollListener.SCROLL_STATE_IDLE); } } void startOverfling(int initialVelocity) { mScroller.setInterpolator(null); mScroller.fling(0, mScrollY, 0, initialVelocity, 0, 0, Integer.MIN_VALUE, Integer.MAX_VALUE, 0, getHeight()); mTouchMode = TOUCH_MODE_OVERFLING; mSuppressIdleStateChangeCall = false; invalidate(); postOnAnimation(this); } void edgeReached(int delta) { mScroller.notifyVerticalEdgeReached(mScrollY, 0, mOverflingDistance); final int overscrollMode = getOverScrollMode(); if (overscrollMode == OVER_SCROLL_ALWAYS || (overscrollMode == OVER_SCROLL_IF_CONTENT_SCROLLS && !contentFits())) { mTouchMode = TOUCH_MODE_OVERFLING; final int vel = (int) mScroller.getCurrVelocity(); if (delta > 0) { mEdgeGlowTop.onAbsorb(vel); } else { mEdgeGlowBottom.onAbsorb(vel); } } else { mTouchMode = TOUCH_MODE_REST; if (mPositionScroller != null) { mPositionScroller.stop(); } } invalidate(); postOnAnimation(this); } void startScroll(int distance, int duration, boolean linear, boolean suppressEndFlingStateChangeCall) { int initialY = distance < 0 ? Integer.MAX_VALUE : 0; mLastFlingY = initialY; mScroller.setInterpolator(linear ? sLinearInterpolator : null); mScroller.startScroll(0, initialY, 0, distance, duration); mTouchMode = TOUCH_MODE_FLING; mSuppressIdleStateChangeCall = suppressEndFlingStateChangeCall; postOnAnimation(this); } @UnsupportedAppUsage void endFling() { mTouchMode = TOUCH_MODE_REST; removeCallbacks(this); removeCallbacks(mCheckFlywheel); if (!mSuppressIdleStateChangeCall) { reportScrollStateChange(OnScrollListener.SCROLL_STATE_IDLE); } clearScrollingCache(); mScroller.abortAnimation(); if (mFlingStrictSpan != null) { mFlingStrictSpan.finish(); mFlingStrictSpan = null; } } void flywheelTouch() { postDelayed(mCheckFlywheel, FLYWHEEL_TIMEOUT); } @Override public void run() { switch (mTouchMode) { default: endFling(); return; case TOUCH_MODE_SCROLL: if (mScroller.isFinished()) { return; } // Fall through case TOUCH_MODE_FLING: { if (mDataChanged) { layoutChildren(); } if (mItemCount == 0 || getChildCount() == 0) { endFling(); return; } final OverScroller scroller = mScroller; boolean more = scroller.computeScrollOffset(); final int y = scroller.getCurrY(); // Flip sign to convert finger direction to list items direction // (e.g. finger moving down means list is moving towards the top) int delta = mLastFlingY - y; // Pretend that each frame of a fling scroll is a touch scroll if (delta > 0) { // List is moving towards the top. Use first view as mMotionPosition mMotionPosition = mFirstPosition; final View firstView = getChildAt(0); mMotionViewOriginalTop = firstView.getTop(); // Don't fling more than 1 screen delta = Math.min(getHeight() - mPaddingBottom - mPaddingTop - 1, delta); } else { // List is moving towards the bottom. Use last view as mMotionPosition int offsetToLast = getChildCount() - 1; mMotionPosition = mFirstPosition + offsetToLast; final View lastView = getChildAt(offsetToLast); mMotionViewOriginalTop = lastView.getTop(); // Don't fling more than 1 screen delta = Math.max(-(getHeight() - mPaddingBottom - mPaddingTop - 1), delta); } // Check to see if we have bumped into the scroll limit View motionView = getChildAt(mMotionPosition - mFirstPosition); int oldTop = 0; if (motionView != null) { oldTop = motionView.getTop(); } // Don't stop just because delta is zero (it could have been rounded) final boolean atEdge = trackMotionScroll(delta, delta); final boolean atEnd = atEdge && (delta != 0); if (atEnd) { if (motionView != null) { // Tweak the scroll for how far we overshot int overshoot = -(delta - (motionView.getTop() - oldTop)); overScrollBy(0, overshoot, 0, mScrollY, 0, 0, 0, mOverflingDistance, false); } if (more) { edgeReached(delta); } break; } if (more && !atEnd) { if (atEdge) invalidate(); mLastFlingY = y; postOnAnimation(this); } else { endFling(); if (PROFILE_FLINGING) { if (mFlingProfilingStarted) { Debug.stopMethodTracing(); mFlingProfilingStarted = false; } if (mFlingStrictSpan != null) { mFlingStrictSpan.finish(); mFlingStrictSpan = null; } } } break; } case TOUCH_MODE_OVERFLING: { final OverScroller scroller = mScroller; if (scroller.computeScrollOffset()) { final int scrollY = mScrollY; final int currY = scroller.getCurrY(); final int deltaY = currY - scrollY; if (overScrollBy(0, deltaY, 0, scrollY, 0, 0, 0, mOverflingDistance, false)) { final boolean crossDown = scrollY <= 0 && currY > 0; final boolean crossUp = scrollY >= 0 && currY < 0; if (crossDown || crossUp) { int velocity = (int) scroller.getCurrVelocity(); if (crossUp) velocity = -velocity; // Don't flywheel from this; we're just continuing things. scroller.abortAnimation(); start(velocity); } else { startSpringback(); } } else { invalidate(); postOnAnimation(this); } } else { endFling(); } break; } } } } /** * The amount of friction applied to flings. The default value * is {@link ViewConfiguration#getScrollFriction}. */ public void setFriction(float friction) { if (mFlingRunnable == null) { mFlingRunnable = new FlingRunnable(); } mFlingRunnable.mScroller.setFriction(friction); } /** * Sets a scale factor for the fling velocity. The initial scale * factor is 1.0. * * @param scale The scale factor to multiply the velocity by. */ public void setVelocityScale(float scale) { mVelocityScale = scale; } /** * Override this for better control over position scrolling. */ AbsPositionScroller createPositionScroller() { return new PositionScroller(); } /** * Smoothly scroll to the specified adapter position. The view will * scroll such that the indicated position is displayed. * @param position Scroll to this adapter position. */ public void smoothScrollToPosition(int position) { if (mPositionScroller == null) { mPositionScroller = createPositionScroller(); } mPositionScroller.start(position); } /** * Smoothly scroll to the specified adapter position. The view will scroll * such that the indicated position is displayed <code>offset</code> pixels below * the top edge of the view. If this is impossible, (e.g. the offset would scroll * the first or last item beyond the boundaries of the list) it will get as close * as possible. The scroll will take <code>duration</code> milliseconds to complete. * * @param position Position to scroll to * @param offset Desired distance in pixels of <code>position</code> from the top * of the view when scrolling is finished * @param duration Number of milliseconds to use for the scroll */ public void smoothScrollToPositionFromTop(int position, int offset, int duration) { if (mPositionScroller == null) { mPositionScroller = createPositionScroller(); } mPositionScroller.startWithOffset(position, offset, duration); } /** * Smoothly scroll to the specified adapter position. The view will scroll * such that the indicated position is displayed <code>offset</code> pixels below * the top edge of the view. If this is impossible, (e.g. the offset would scroll * the first or last item beyond the boundaries of the list) it will get as close * as possible. * * @param position Position to scroll to * @param offset Desired distance in pixels of <code>position</code> from the top * of the view when scrolling is finished */ public void smoothScrollToPositionFromTop(int position, int offset) { if (mPositionScroller == null) { mPositionScroller = createPositionScroller(); } mPositionScroller.startWithOffset(position, offset); } /** * Smoothly scroll to the specified adapter position. The view will * scroll such that the indicated position is displayed, but it will * stop early if scrolling further would scroll boundPosition out of * view. * * @param position Scroll to this adapter position. * @param boundPosition Do not scroll if it would move this adapter * position out of view. */ public void smoothScrollToPosition(int position, int boundPosition) { if (mPositionScroller == null) { mPositionScroller = createPositionScroller(); } mPositionScroller.start(position, boundPosition); } /** * Smoothly scroll by distance pixels over duration milliseconds. * @param distance Distance to scroll in pixels. * @param duration Duration of the scroll animation in milliseconds. */ public void smoothScrollBy(int distance, int duration) { smoothScrollBy(distance, duration, false, false); } @UnsupportedAppUsage void smoothScrollBy(int distance, int duration, boolean linear, boolean suppressEndFlingStateChangeCall) { if (mFlingRunnable == null) { mFlingRunnable = new FlingRunnable(); } // No sense starting to scroll if we're not going anywhere final int firstPos = mFirstPosition; final int childCount = getChildCount(); final int lastPos = firstPos + childCount; final int topLimit = getPaddingTop(); final int bottomLimit = getHeight() - getPaddingBottom(); if (distance == 0 || mItemCount == 0 || childCount == 0 || (firstPos == 0 && getChildAt(0).getTop() == topLimit && distance < 0) || (lastPos == mItemCount && getChildAt(childCount - 1).getBottom() == bottomLimit && distance > 0)) { mFlingRunnable.endFling(); if (mPositionScroller != null) { mPositionScroller.stop(); } } else { reportScrollStateChange(OnScrollListener.SCROLL_STATE_FLING); mFlingRunnable.startScroll(distance, duration, linear, suppressEndFlingStateChangeCall); } } /** * Allows RemoteViews to scroll relatively to a position. */ void smoothScrollByOffset(int position) { int index = -1; if (position < 0) { index = getFirstVisiblePosition(); } else if (position > 0) { index = getLastVisiblePosition(); } if (index > -1) { View child = getChildAt(index - getFirstVisiblePosition()); if (child != null) { Rect visibleRect = new Rect(); if (child.getGlobalVisibleRect(visibleRect)) { // the child is partially visible int childRectArea = child.getWidth() * child.getHeight(); int visibleRectArea = visibleRect.width() * visibleRect.height(); float visibleArea = (visibleRectArea / (float) childRectArea); final float visibleThreshold = 0.75f; if ((position < 0) && (visibleArea < visibleThreshold)) { // the top index is not perceivably visible so offset // to account for showing that top index as well ++index; } else if ((position > 0) && (visibleArea < visibleThreshold)) { // the bottom index is not perceivably visible so offset // to account for showing that bottom index as well --index; } } smoothScrollToPosition(Math.max(0, Math.min(getCount(), index + position))); } } } private void createScrollingCache() { if (mScrollingCacheEnabled && !mCachingStarted && !isHardwareAccelerated()) { setChildrenDrawnWithCacheEnabled(true); setChildrenDrawingCacheEnabled(true); mCachingStarted = mCachingActive = true; } } private void clearScrollingCache() { if (!isHardwareAccelerated()) { if (mClearScrollingCache == null) { mClearScrollingCache = new Runnable() { @Override public void run() { if (mCachingStarted) { mCachingStarted = mCachingActive = false; setChildrenDrawnWithCacheEnabled(false); if ((mPersistentDrawingCache & PERSISTENT_SCROLLING_CACHE) == 0) { setChildrenDrawingCacheEnabled(false); } if (!isAlwaysDrawnWithCacheEnabled()) { invalidate(); } } } }; } post(mClearScrollingCache); } } /** * Scrolls the list items within the view by a specified number of pixels. * * <p>The actual amount of scroll is capped by the list content viewport height * which is the list height minus top and bottom paddings minus one pixel.</p> * * @param y the amount of pixels to scroll by vertically * @see #canScrollList(int) */ public void scrollListBy(int y) { trackMotionScroll(-y, -y); } /** * Check if the items in the list can be scrolled in a certain direction. * * @param direction Negative to check scrolling up, positive to check * scrolling down. * @return true if the list can be scrolled in the specified direction, * false otherwise. * @see #scrollListBy(int) */ public boolean canScrollList(int direction) { final int childCount = getChildCount(); if (childCount == 0) { return false; } final int firstPosition = mFirstPosition; final Rect listPadding = mListPadding; if (direction > 0) { final int lastBottom = getChildAt(childCount - 1).getBottom(); final int lastPosition = firstPosition + childCount; return lastPosition < mItemCount || lastBottom > getHeight() - listPadding.bottom; } else { final int firstTop = getChildAt(0).getTop(); return firstPosition > 0 || firstTop < listPadding.top; } } /** * Track a motion scroll * * @param deltaY Amount to offset mMotionView. This is the accumulated delta since the motion * began. Positive numbers mean the user's finger is moving down the screen. * @param incrementalDeltaY Change in deltaY from the previous event. * @return true if we're already at the beginning/end of the list and have nothing to do. */ @UnsupportedAppUsage boolean trackMotionScroll(int deltaY, int incrementalDeltaY) { final int childCount = getChildCount(); if (childCount == 0) { return true; } final int firstTop = getChildAt(0).getTop(); final int lastBottom = getChildAt(childCount - 1).getBottom(); final Rect listPadding = mListPadding; // "effective padding" In this case is the amount of padding that affects // how much space should not be filled by items. If we don't clip to padding // there is no effective padding. int effectivePaddingTop = 0; int effectivePaddingBottom = 0; if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { effectivePaddingTop = listPadding.top; effectivePaddingBottom = listPadding.bottom; } // FIXME account for grid vertical spacing too? final int spaceAbove = effectivePaddingTop - firstTop; final int end = getHeight() - effectivePaddingBottom; final int spaceBelow = lastBottom - end; final int height = getHeight() - mPaddingBottom - mPaddingTop; if (deltaY < 0) { deltaY = Math.max(-(height - 1), deltaY); } else { deltaY = Math.min(height - 1, deltaY); } if (incrementalDeltaY < 0) { incrementalDeltaY = Math.max(-(height - 1), incrementalDeltaY); } else { incrementalDeltaY = Math.min(height - 1, incrementalDeltaY); } final int firstPosition = mFirstPosition; // Update our guesses for where the first and last views are if (firstPosition == 0) { mFirstPositionDistanceGuess = firstTop - listPadding.top; } else { mFirstPositionDistanceGuess += incrementalDeltaY; } if (firstPosition + childCount == mItemCount) { mLastPositionDistanceGuess = lastBottom + listPadding.bottom; } else { mLastPositionDistanceGuess += incrementalDeltaY; } final boolean cannotScrollDown = (firstPosition == 0 && firstTop >= listPadding.top && incrementalDeltaY >= 0); final boolean cannotScrollUp = (firstPosition + childCount == mItemCount && lastBottom <= getHeight() - listPadding.bottom && incrementalDeltaY <= 0); if (cannotScrollDown || cannotScrollUp) { return incrementalDeltaY != 0; } final boolean down = incrementalDeltaY < 0; final boolean inTouchMode = isInTouchMode(); if (inTouchMode) { hideSelector(); } final int headerViewsCount = getHeaderViewsCount(); final int footerViewsStart = mItemCount - getFooterViewsCount(); int start = 0; int count = 0; if (down) { int top = -incrementalDeltaY; if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { top += listPadding.top; } for (int i = 0; i < childCount; i++) { final View child = getChildAt(i); if (child.getBottom() >= top) { break; } else { count++; int position = firstPosition + i; if (position >= headerViewsCount && position < footerViewsStart) { // The view will be rebound to new data, clear any // system-managed transient state. child.clearAccessibilityFocus(); mRecycler.addScrapView(child, position); } } } } else { int bottom = getHeight() - incrementalDeltaY; if ((mGroupFlags & CLIP_TO_PADDING_MASK) == CLIP_TO_PADDING_MASK) { bottom -= listPadding.bottom; } for (int i = childCount - 1; i >= 0; i--) { final View child = getChildAt(i); if (child.getTop() <= bottom) { break; } else { start = i; count++; int position = firstPosition + i; if (position >= headerViewsCount && position < footerViewsStart) { // The view will be rebound to new data, clear any // system-managed transient state. child.clearAccessibilityFocus(); mRecycler.addScrapView(child, position); } } } } mMotionViewNewTop = mMotionViewOriginalTop + deltaY; mBlockLayoutRequests = true; if (count > 0) { detachViewsFromParent(start, count); mRecycler.removeSkippedScrap(); } // invalidate before moving the children to avoid unnecessary invalidate // calls to bubble up from the children all the way to the top if (!awakenScrollBars()) { invalidate(); } offsetChildrenTopAndBottom(incrementalDeltaY); if (down) { mFirstPosition += count; } final int absIncrementalDeltaY = Math.abs(incrementalDeltaY); if (spaceAbove < absIncrementalDeltaY || spaceBelow < absIncrementalDeltaY) { fillGap(down); } mRecycler.fullyDetachScrapViews(); boolean selectorOnScreen = false; if (!inTouchMode && mSelectedPosition != INVALID_POSITION) { final int childIndex = mSelectedPosition - mFirstPosition; if (childIndex >= 0 && childIndex < getChildCount()) { positionSelector(mSelectedPosition, getChildAt(childIndex)); selectorOnScreen = true; } } else if (mSelectorPosition != INVALID_POSITION) { final int childIndex = mSelectorPosition - mFirstPosition; if (childIndex >= 0 && childIndex < getChildCount()) { positionSelector(mSelectorPosition, getChildAt(childIndex)); selectorOnScreen = true; } } if (!selectorOnScreen) { mSelectorRect.setEmpty(); } mBlockLayoutRequests = false; invokeOnItemScrollListener(); return false; } /** * Returns the number of header views in the list. Header views are special views * at the top of the list that should not be recycled during a layout. * * @return The number of header views, 0 in the default implementation. */ int getHeaderViewsCount() { return 0; } /** * Returns the number of footer views in the list. Footer views are special views * at the bottom of the list that should not be recycled during a layout. * * @return The number of footer views, 0 in the default implementation. */ int getFooterViewsCount() { return 0; } /** * Fills the gap left open by a touch-scroll. During a touch scroll, children that * remain on screen are shifted and the other ones are discarded. The role of this * method is to fill the gap thus created by performing a partial layout in the * empty space. * * @param down true if the scroll is going down, false if it is going up */ abstract void fillGap(boolean down); void hideSelector() { if (mSelectedPosition != INVALID_POSITION) { if (mLayoutMode != LAYOUT_SPECIFIC) { mResurrectToPosition = mSelectedPosition; } if (mNextSelectedPosition >= 0 && mNextSelectedPosition != mSelectedPosition) { mResurrectToPosition = mNextSelectedPosition; } setSelectedPositionInt(INVALID_POSITION); setNextSelectedPositionInt(INVALID_POSITION); mSelectedTop = 0; } } /** * @return A position to select. First we try mSelectedPosition. If that has been clobbered by * entering touch mode, we then try mResurrectToPosition. Values are pinned to the range * of items available in the adapter */ int reconcileSelectedPosition() { int position = mSelectedPosition; if (position < 0) { position = mResurrectToPosition; } position = Math.max(0, position); position = Math.min(position, mItemCount - 1); return position; } /** * Find the row closest to y. This row will be used as the motion row when scrolling * * @param y Where the user touched * @return The position of the first (or only) item in the row containing y */ @UnsupportedAppUsage abstract int findMotionRow(int y); /** * Find the row closest to y. This row will be used as the motion row when scrolling. * * @param y Where the user touched * @return The position of the first (or only) item in the row closest to y */ int findClosestMotionRow(int y) { final int childCount = getChildCount(); if (childCount == 0) { return INVALID_POSITION; } final int motionRow = findMotionRow(y); return motionRow != INVALID_POSITION ? motionRow : mFirstPosition + childCount - 1; } /** * Causes all the views to be rebuilt and redrawn. */ public void invalidateViews() { mDataChanged = true; rememberSyncState(); requestLayout(); invalidate(); } /** * If there is a selection returns false. * Otherwise resurrects the selection and returns true if resurrected. */ @UnsupportedAppUsage boolean resurrectSelectionIfNeeded() { if (mSelectedPosition < 0 && resurrectSelection()) { updateSelectorState(); return true; } return false; } /** * Makes the item at the supplied position selected. * * @param position the position of the new selection */ abstract void setSelectionInt(int position); /** * Attempt to bring the selection back if the user is switching from touch * to trackball mode * @return Whether selection was set to something. */ boolean resurrectSelection() { final int childCount = getChildCount(); if (childCount <= 0) { return false; } int selectedTop = 0; int selectedPos; int childrenTop = mListPadding.top; int childrenBottom = mBottom - mTop - mListPadding.bottom; final int firstPosition = mFirstPosition; final int toPosition = mResurrectToPosition; boolean down = true; if (toPosition >= firstPosition && toPosition < firstPosition + childCount) { selectedPos = toPosition; final View selected = getChildAt(selectedPos - mFirstPosition); selectedTop = selected.getTop(); int selectedBottom = selected.getBottom(); // We are scrolled, don't get in the fade if (selectedTop < childrenTop) { selectedTop = childrenTop + getVerticalFadingEdgeLength(); } else if (selectedBottom > childrenBottom) { selectedTop = childrenBottom - selected.getMeasuredHeight() - getVerticalFadingEdgeLength(); } } else { if (toPosition < firstPosition) { // Default to selecting whatever is first selectedPos = firstPosition; for (int i = 0; i < childCount; i++) { final View v = getChildAt(i); final int top = v.getTop(); if (i == 0) { // Remember the position of the first item selectedTop = top; // See if we are scrolled at all if (firstPosition > 0 || top < childrenTop) { // If we are scrolled, don't select anything that is // in the fade region childrenTop += getVerticalFadingEdgeLength(); } } if (top >= childrenTop) { // Found a view whose top is fully visisble selectedPos = firstPosition + i; selectedTop = top; break; } } } else { final int itemCount = mItemCount; down = false; selectedPos = firstPosition + childCount - 1; for (int i = childCount - 1; i >= 0; i--) { final View v = getChildAt(i); final int top = v.getTop(); final int bottom = v.getBottom(); if (i == childCount - 1) { selectedTop = top; if (firstPosition + childCount < itemCount || bottom > childrenBottom) { childrenBottom -= getVerticalFadingEdgeLength(); } } if (bottom <= childrenBottom) { selectedPos = firstPosition + i; selectedTop = top; break; } } } } mResurrectToPosition = INVALID_POSITION; removeCallbacks(mFlingRunnable); if (mPositionScroller != null) { mPositionScroller.stop(); } mTouchMode = TOUCH_MODE_REST; clearScrollingCache(); mSpecificTop = selectedTop; selectedPos = lookForSelectablePosition(selectedPos, down); if (selectedPos >= firstPosition && selectedPos <= getLastVisiblePosition()) { mLayoutMode = LAYOUT_SPECIFIC; updateSelectorState(); setSelectionInt(selectedPos); invokeOnItemScrollListener(); } else { selectedPos = INVALID_POSITION; } reportScrollStateChange(OnScrollListener.SCROLL_STATE_IDLE); return selectedPos >= 0; } void confirmCheckedPositionsById() { // Clear out the positional check states, we'll rebuild it below from IDs. mCheckStates.clear(); boolean checkedCountChanged = false; for (int checkedIndex = 0; checkedIndex < mCheckedIdStates.size(); checkedIndex++) { final long id = mCheckedIdStates.keyAt(checkedIndex); final int lastPos = mCheckedIdStates.valueAt(checkedIndex); final long lastPosId = mAdapter.getItemId(lastPos); if (id != lastPosId) { // Look around to see if the ID is nearby. If not, uncheck it. final int start = Math.max(0, lastPos - CHECK_POSITION_SEARCH_DISTANCE); final int end = Math.min(lastPos + CHECK_POSITION_SEARCH_DISTANCE, mItemCount); boolean found = false; for (int searchPos = start; searchPos < end; searchPos++) { final long searchId = mAdapter.getItemId(searchPos); if (id == searchId) { found = true; mCheckStates.put(searchPos, true); mCheckedIdStates.setValueAt(checkedIndex, searchPos); break; } } if (!found) { mCheckedIdStates.delete(id); checkedIndex--; mCheckedItemCount--; checkedCountChanged = true; if (mChoiceActionMode != null && mMultiChoiceModeCallback != null) { mMultiChoiceModeCallback.onItemCheckedStateChanged(mChoiceActionMode, lastPos, id, false); } } } else { mCheckStates.put(lastPos, true); } } if (checkedCountChanged && mChoiceActionMode != null) { mChoiceActionMode.invalidate(); } } @Override protected void handleDataChanged() { int count = mItemCount; int lastHandledItemCount = mLastHandledItemCount; mLastHandledItemCount = mItemCount; if (mChoiceMode != CHOICE_MODE_NONE && mAdapter != null && mAdapter.hasStableIds()) { confirmCheckedPositionsById(); } // TODO: In the future we can recycle these views based on stable ID instead. mRecycler.clearTransientStateViews(); if (count > 0) { int newPos; int selectablePos; // Find the row we are supposed to sync to if (mNeedSync) { // Update this first, since setNextSelectedPositionInt inspects it mNeedSync = false; mPendingSync = null; if (mTranscriptMode == TRANSCRIPT_MODE_ALWAYS_SCROLL) { mLayoutMode = LAYOUT_FORCE_BOTTOM; return; } else if (mTranscriptMode == TRANSCRIPT_MODE_NORMAL) { if (mForceTranscriptScroll) { mForceTranscriptScroll = false; mLayoutMode = LAYOUT_FORCE_BOTTOM; return; } final int childCount = getChildCount(); final int listBottom = getHeight() - getPaddingBottom(); final View lastChild = getChildAt(childCount - 1); final int lastBottom = lastChild != null ? lastChild.getBottom() : listBottom; if (mFirstPosition + childCount >= lastHandledItemCount && lastBottom <= listBottom) { mLayoutMode = LAYOUT_FORCE_BOTTOM; return; } // Something new came in and we didn't scroll; give the user a clue that // there's something new. awakenScrollBars(); } switch (mSyncMode) { case SYNC_SELECTED_POSITION: if (isInTouchMode()) { // We saved our state when not in touch mode. (We know this because // mSyncMode is SYNC_SELECTED_POSITION.) Now we are trying to // restore in touch mode. Just leave mSyncPosition as it is (possibly // adjusting if the available range changed) and return. mLayoutMode = LAYOUT_SYNC; mSyncPosition = Math.min(Math.max(0, mSyncPosition), count - 1); return; } else { // See if we can find a position in the new data with the same // id as the old selection. This will change mSyncPosition. newPos = findSyncPosition(); if (newPos >= 0) { // Found it. Now verify that new selection is still selectable selectablePos = lookForSelectablePosition(newPos, true); if (selectablePos == newPos) { // Same row id is selected mSyncPosition = newPos; if (mSyncHeight == getHeight()) { // If we are at the same height as when we saved state, try // to restore the scroll position too. mLayoutMode = LAYOUT_SYNC; } else { // We are not the same height as when the selection was saved, so // don't try to restore the exact position mLayoutMode = LAYOUT_SET_SELECTION; } // Restore selection setNextSelectedPositionInt(newPos); return; } } } break; case SYNC_FIRST_POSITION: // Leave mSyncPosition as it is -- just pin to available range mLayoutMode = LAYOUT_SYNC; mSyncPosition = Math.min(Math.max(0, mSyncPosition), count - 1); return; } } if (!isInTouchMode()) { // We couldn't find matching data -- try to use the same position newPos = getSelectedItemPosition(); // Pin position to the available range if (newPos >= count) { newPos = count - 1; } if (newPos < 0) { newPos = 0; } // Make sure we select something selectable -- first look down selectablePos = lookForSelectablePosition(newPos, true); if (selectablePos >= 0) { setNextSelectedPositionInt(selectablePos); return; } else { // Looking down didn't work -- try looking up selectablePos = lookForSelectablePosition(newPos, false); if (selectablePos >= 0) { setNextSelectedPositionInt(selectablePos); return; } } } else { // We already know where we want to resurrect the selection if (mResurrectToPosition >= 0) { return; } } } // Nothing is selected. Give up and reset everything. mLayoutMode = mStackFromBottom ? LAYOUT_FORCE_BOTTOM : LAYOUT_FORCE_TOP; mSelectedPosition = INVALID_POSITION; mSelectedRowId = INVALID_ROW_ID; mNextSelectedPosition = INVALID_POSITION; mNextSelectedRowId = INVALID_ROW_ID; mNeedSync = false; mPendingSync = null; mSelectorPosition = INVALID_POSITION; checkSelectionChanged(); } @Override protected void onDisplayHint(int hint) { super.onDisplayHint(hint); switch (hint) { case INVISIBLE: if (mPopup != null && mPopup.isShowing()) { dismissPopup(); } break; case VISIBLE: if (mFiltered && mPopup != null && !mPopup.isShowing()) { showPopup(); } break; } mPopupHidden = hint == INVISIBLE; } /** * Removes the filter window */ private void dismissPopup() { if (mPopup != null) { mPopup.dismiss(); } } /** * Shows the filter window */ private void showPopup() { // Make sure we have a window before showing the popup if (getWindowVisibility() == View.VISIBLE) { createTextFilter(true); positionPopup(); // Make sure we get focus if we are showing the popup checkFocus(); } } private void positionPopup() { int screenHeight = getResources().getDisplayMetrics().heightPixels; final int[] xy = new int[2]; getLocationOnScreen(xy); // TODO: The 20 below should come from the theme // TODO: And the gravity should be defined in the theme as well final int bottomGap = screenHeight - xy[1] - getHeight() + (int) (mDensityScale * 20); if (!mPopup.isShowing()) { mPopup.showAtLocation(this, Gravity.BOTTOM | Gravity.CENTER_HORIZONTAL, xy[0], bottomGap); } else { mPopup.update(xy[0], bottomGap, -1, -1); } } /** * What is the distance between the source and destination rectangles given the direction of * focus navigation between them? The direction basically helps figure out more quickly what is * self evident by the relationship between the rects... * * @param source the source rectangle * @param dest the destination rectangle * @param direction the direction * @return the distance between the rectangles */ static int getDistance(Rect source, Rect dest, int direction) { int sX, sY; // source x, y int dX, dY; // dest x, y switch (direction) { case View.FOCUS_RIGHT: sX = source.right; sY = source.top + source.height() / 2; dX = dest.left; dY = dest.top + dest.height() / 2; break; case View.FOCUS_DOWN: sX = source.left + source.width() / 2; sY = source.bottom; dX = dest.left + dest.width() / 2; dY = dest.top; break; case View.FOCUS_LEFT: sX = source.left; sY = source.top + source.height() / 2; dX = dest.right; dY = dest.top + dest.height() / 2; break; case View.FOCUS_UP: sX = source.left + source.width() / 2; sY = source.top; dX = dest.left + dest.width() / 2; dY = dest.bottom; break; case View.FOCUS_FORWARD: case View.FOCUS_BACKWARD: sX = source.right + source.width() / 2; sY = source.top + source.height() / 2; dX = dest.left + dest.width() / 2; dY = dest.top + dest.height() / 2; break; default: throw new IllegalArgumentException("direction must be one of " + "{FOCUS_UP, FOCUS_DOWN, FOCUS_LEFT, FOCUS_RIGHT, " + "FOCUS_FORWARD, FOCUS_BACKWARD}."); } int deltaX = dX - sX; int deltaY = dY - sY; return deltaY * deltaY + deltaX * deltaX; } @Override protected boolean isInFilterMode() { return mFiltered; } /** * Sends a key to the text filter window * * @param keyCode The keycode for the event * @param event The actual key event * * @return True if the text filter handled the event, false otherwise. */ boolean sendToTextFilter(int keyCode, int count, KeyEvent event) { if (!acceptFilter()) { return false; } boolean handled = false; boolean okToSend = true; switch (keyCode) { case KeyEvent.KEYCODE_DPAD_UP: case KeyEvent.KEYCODE_DPAD_DOWN: case KeyEvent.KEYCODE_DPAD_LEFT: case KeyEvent.KEYCODE_DPAD_RIGHT: case KeyEvent.KEYCODE_DPAD_CENTER: case KeyEvent.KEYCODE_ENTER: okToSend = false; break; case KeyEvent.KEYCODE_BACK: if (mFiltered && mPopup != null && mPopup.isShowing()) { if (event.getAction() == KeyEvent.ACTION_DOWN && event.getRepeatCount() == 0) { KeyEvent.DispatcherState state = getKeyDispatcherState(); if (state != null) { state.startTracking(event, this); } handled = true; } else if (event.getAction() == KeyEvent.ACTION_UP && event.isTracking() && !event.isCanceled()) { handled = true; mTextFilter.setText(""); } } okToSend = false; break; case KeyEvent.KEYCODE_SPACE: // Only send spaces once we are filtered okToSend = mFiltered; break; } if (okToSend) { createTextFilter(true); KeyEvent forwardEvent = event; if (forwardEvent.getRepeatCount() > 0) { forwardEvent = KeyEvent.changeTimeRepeat(event, event.getEventTime(), 0); } int action = event.getAction(); switch (action) { case KeyEvent.ACTION_DOWN: handled = mTextFilter.onKeyDown(keyCode, forwardEvent); break; case KeyEvent.ACTION_UP: handled = mTextFilter.onKeyUp(keyCode, forwardEvent); break; case KeyEvent.ACTION_MULTIPLE: handled = mTextFilter.onKeyMultiple(keyCode, count, event); break; } } return handled; } /** * Return an InputConnection for editing of the filter text. */ @Override public InputConnection onCreateInputConnection(EditorInfo outAttrs) { if (isTextFilterEnabled()) { if (mPublicInputConnection == null) { mDefInputConnection = new BaseInputConnection(this, false); mPublicInputConnection = new InputConnectionWrapper(outAttrs); } outAttrs.inputType = EditorInfo.TYPE_CLASS_TEXT | EditorInfo.TYPE_TEXT_VARIATION_FILTER; outAttrs.imeOptions = EditorInfo.IME_ACTION_DONE; return mPublicInputConnection; } return null; } private class InputConnectionWrapper implements InputConnection { private final EditorInfo mOutAttrs; private InputConnection mTarget; public InputConnectionWrapper(EditorInfo outAttrs) { mOutAttrs = outAttrs; } private InputConnection getTarget() { if (mTarget == null) { mTarget = getTextFilterInput().onCreateInputConnection(mOutAttrs); } return mTarget; } @Override public boolean reportFullscreenMode(boolean enabled) { // Use our own input connection, since it is // the "real" one the IME is talking with. return mDefInputConnection.reportFullscreenMode(enabled); } @Override public boolean performEditorAction(int editorAction) { // The editor is off in its own window; we need to be // the one that does this. if (editorAction == EditorInfo.IME_ACTION_DONE) { InputMethodManager imm = getContext().getSystemService(InputMethodManager.class); if (imm != null) { imm.hideSoftInputFromWindow(getWindowToken(), 0); } return true; } return false; } @Override public boolean sendKeyEvent(KeyEvent event) { // Use our own input connection, since the filter // text view may not be shown in a window so has // no ViewAncestor to dispatch events with. return mDefInputConnection.sendKeyEvent(event); } @Override public CharSequence getTextBeforeCursor(int n, int flags) { if (mTarget == null) return ""; return mTarget.getTextBeforeCursor(n, flags); } @Override public CharSequence getTextAfterCursor(int n, int flags) { if (mTarget == null) return ""; return mTarget.getTextAfterCursor(n, flags); } @Override public CharSequence getSelectedText(int flags) { if (mTarget == null) return ""; return mTarget.getSelectedText(flags); } @Override public int getCursorCapsMode(int reqModes) { if (mTarget == null) return InputType.TYPE_TEXT_FLAG_CAP_SENTENCES; return mTarget.getCursorCapsMode(reqModes); } @Override public ExtractedText getExtractedText(ExtractedTextRequest request, int flags) { return getTarget().getExtractedText(request, flags); } @Override public boolean deleteSurroundingText(int beforeLength, int afterLength) { return getTarget().deleteSurroundingText(beforeLength, afterLength); } @Override public boolean deleteSurroundingTextInCodePoints(int beforeLength, int afterLength) { return getTarget().deleteSurroundingTextInCodePoints(beforeLength, afterLength); } @Override public boolean setComposingText(CharSequence text, int newCursorPosition) { return getTarget().setComposingText(text, newCursorPosition); } @Override public boolean setComposingRegion(int start, int end) { return getTarget().setComposingRegion(start, end); } @Override public boolean finishComposingText() { return mTarget == null || mTarget.finishComposingText(); } @Override public boolean commitText(CharSequence text, int newCursorPosition) { return getTarget().commitText(text, newCursorPosition); } @Override public boolean commitCompletion(CompletionInfo text) { return getTarget().commitCompletion(text); } @Override public boolean commitCorrection(CorrectionInfo correctionInfo) { return getTarget().commitCorrection(correctionInfo); } @Override public boolean setSelection(int start, int end) { return getTarget().setSelection(start, end); } @Override public boolean performContextMenuAction(int id) { return getTarget().performContextMenuAction(id); } @Override public boolean beginBatchEdit() { return getTarget().beginBatchEdit(); } @Override public boolean endBatchEdit() { return getTarget().endBatchEdit(); } @Override public boolean clearMetaKeyStates(int states) { return getTarget().clearMetaKeyStates(states); } @Override public boolean performPrivateCommand(String action, Bundle data) { return getTarget().performPrivateCommand(action, data); } @Override public boolean requestCursorUpdates(int cursorUpdateMode) { return getTarget().requestCursorUpdates(cursorUpdateMode); } @Override public Handler getHandler() { return getTarget().getHandler(); } @Override public void closeConnection() { getTarget().closeConnection(); } @Override public boolean commitContent(InputContentInfo inputContentInfo, int flags, Bundle opts) { return getTarget().commitContent(inputContentInfo, flags, opts); } } /** * For filtering we proxy an input connection to an internal text editor, * and this allows the proxying to happen. */ @Override public boolean checkInputConnectionProxy(View view) { return view == mTextFilter; } /** * Creates the window for the text filter and populates it with an EditText field; * * @param animateEntrance true if the window should appear with an animation */ private void createTextFilter(boolean animateEntrance) { if (mPopup == null) { PopupWindow p = new PopupWindow(getContext()); p.setFocusable(false); p.setTouchable(false); p.setInputMethodMode(PopupWindow.INPUT_METHOD_NOT_NEEDED); p.setContentView(getTextFilterInput()); p.setWidth(LayoutParams.WRAP_CONTENT); p.setHeight(LayoutParams.WRAP_CONTENT); p.setBackgroundDrawable(null); mPopup = p; getViewTreeObserver().addOnGlobalLayoutListener(this); mGlobalLayoutListenerAddedFilter = true; } if (animateEntrance) { mPopup.setAnimationStyle(com.android.internal.R.style.Animation_TypingFilter); } else { mPopup.setAnimationStyle(com.android.internal.R.style.Animation_TypingFilterRestore); } } private EditText getTextFilterInput() { if (mTextFilter == null) { final LayoutInflater layoutInflater = LayoutInflater.from(getContext()); mTextFilter = (EditText) layoutInflater.inflate(com.android.internal.R.layout.typing_filter, null); // For some reason setting this as the "real" input type changes // the text view in some way that it doesn't work, and I don't // want to figure out why this is. mTextFilter.setRawInputType(EditorInfo.TYPE_CLASS_TEXT | EditorInfo.TYPE_TEXT_VARIATION_FILTER); mTextFilter.setImeOptions(EditorInfo.IME_FLAG_NO_EXTRACT_UI); mTextFilter.addTextChangedListener(this); } return mTextFilter; } /** * Clear the text filter. */ public void clearTextFilter() { if (mFiltered) { getTextFilterInput().setText(""); mFiltered = false; if (mPopup != null && mPopup.isShowing()) { dismissPopup(); } } } /** * Returns if the ListView currently has a text filter. */ public boolean hasTextFilter() { return mFiltered; } @Override public void onGlobalLayout() { if (isShown()) { // Show the popup if we are filtered if (mFiltered && mPopup != null && !mPopup.isShowing() && !mPopupHidden) { showPopup(); } } else { // Hide the popup when we are no longer visible if (mPopup != null && mPopup.isShowing()) { dismissPopup(); } } } /** * For our text watcher that is associated with the text filter. Does * nothing. */ @Override public void beforeTextChanged(CharSequence s, int start, int count, int after) { } /** * For our text watcher that is associated with the text filter. Performs * the actual filtering as the text changes, and takes care of hiding and * showing the popup displaying the currently entered filter text. */ @Override public void onTextChanged(CharSequence s, int start, int before, int count) { if (isTextFilterEnabled()) { createTextFilter(true); int length = s.length(); boolean showing = mPopup.isShowing(); if (!showing && length > 0) { // Show the filter popup if necessary showPopup(); mFiltered = true; } else if (showing && length == 0) { // Remove the filter popup if the user has cleared all text dismissPopup(); mFiltered = false; } if (mAdapter instanceof Filterable) { Filter f = ((Filterable) mAdapter).getFilter(); // Filter should not be null when we reach this part if (f != null) { f.filter(s, this); } else { throw new IllegalStateException( "You cannot call onTextChanged with a non " + "filterable adapter"); } } } } /** * For our text watcher that is associated with the text filter. Does * nothing. */ @Override public void afterTextChanged(Editable s) { } @Override public void onFilterComplete(int count) { if (mSelectedPosition < 0 && count > 0) { mResurrectToPosition = INVALID_POSITION; resurrectSelection(); } } @Override protected ViewGroup.LayoutParams generateDefaultLayoutParams() { return new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT, 0); } @Override protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) { return new LayoutParams(p); } @Override public LayoutParams generateLayoutParams(AttributeSet attrs) { return new AbsListView.LayoutParams(getContext(), attrs); } @Override protected boolean checkLayoutParams(ViewGroup.LayoutParams p) { return p instanceof AbsListView.LayoutParams; } /** * Puts the list or grid into transcript mode. In this mode the list or grid will always scroll * to the bottom to show new items. * * @param mode the transcript mode to set * * @see #TRANSCRIPT_MODE_DISABLED * @see #TRANSCRIPT_MODE_NORMAL * @see #TRANSCRIPT_MODE_ALWAYS_SCROLL */ public void setTranscriptMode(int mode) { mTranscriptMode = mode; } /** * Returns the current transcript mode. * * @return {@link #TRANSCRIPT_MODE_DISABLED}, {@link #TRANSCRIPT_MODE_NORMAL} or * {@link #TRANSCRIPT_MODE_ALWAYS_SCROLL} */ public int getTranscriptMode() { return mTranscriptMode; } @Override public int getSolidColor() { return mCacheColorHint; } /** * When set to a non-zero value, the cache color hint indicates that this list is always drawn * on top of a solid, single-color, opaque background. * * Zero means that what's behind this object is translucent (non solid) or is not made of a * single color. This hint will not affect any existing background drawable set on this view ( * typically set via {@link #setBackgroundDrawable(Drawable)}). * * @param color The background color */ public void setCacheColorHint(@ColorInt int color) { if (color != mCacheColorHint) { mCacheColorHint = color; int count = getChildCount(); for (int i = 0; i < count; i++) { getChildAt(i).setDrawingCacheBackgroundColor(color); } mRecycler.setCacheColorHint(color); } } /** * When set to a non-zero value, the cache color hint indicates that this list is always drawn * on top of a solid, single-color, opaque background * * @return The cache color hint */ @ViewDebug.ExportedProperty(category = "drawing") @ColorInt public int getCacheColorHint() { return mCacheColorHint; } /** * Move all views (excluding headers and footers) held by this AbsListView into the supplied * List. This includes views displayed on the screen as well as views stored in AbsListView's * internal view recycler. * * @param views A list into which to put the reclaimed views */ public void reclaimViews(List<View> views) { int childCount = getChildCount(); RecyclerListener listener = mRecycler.mRecyclerListener; // Reclaim views on screen for (int i = 0; i < childCount; i++) { View child = getChildAt(i); AbsListView.LayoutParams lp = (AbsListView.LayoutParams) child.getLayoutParams(); // Don't reclaim header or footer views, or views that should be ignored if (lp != null && mRecycler.shouldRecycleViewType(lp.viewType)) { views.add(child); child.setAccessibilityDelegate(null); if (listener != null) { // Pretend they went through the scrap heap listener.onMovedToScrapHeap(child); } } } mRecycler.reclaimScrapViews(views); removeAllViewsInLayout(); } private void finishGlows() { if (mEdgeGlowTop != null) { mEdgeGlowTop.finish(); mEdgeGlowBottom.finish(); } } /** * Sets up this AbsListView to use a remote views adapter which connects to a RemoteViewsService * through the specified intent. * @param intent the intent used to identify the RemoteViewsService for the adapter to connect to. */ public void setRemoteViewsAdapter(Intent intent) { setRemoteViewsAdapter(intent, false); } /** @hide **/ public Runnable setRemoteViewsAdapterAsync(final Intent intent) { return new RemoteViewsAdapter.AsyncRemoteAdapterAction(this, intent); } /** @hide **/ @Override public void setRemoteViewsAdapter(Intent intent, boolean isAsync) { // Ensure that we don't already have a RemoteViewsAdapter that is bound to an existing // service handling the specified intent. if (mRemoteAdapter != null) { Intent.FilterComparison fcNew = new Intent.FilterComparison(intent); Intent.FilterComparison fcOld = new Intent.FilterComparison( mRemoteAdapter.getRemoteViewsServiceIntent()); if (fcNew.equals(fcOld)) { return; } } mDeferNotifyDataSetChanged = false; // Otherwise, create a new RemoteViewsAdapter for binding mRemoteAdapter = new RemoteViewsAdapter(getContext(), intent, this, isAsync); if (mRemoteAdapter.isDataReady()) { setAdapter(mRemoteAdapter); } } /** * Sets up the onClickHandler to be used by the RemoteViewsAdapter when inflating RemoteViews * * @param handler The OnClickHandler to use when inflating RemoteViews. * * @hide */ public void setRemoteViewsOnClickHandler(OnClickHandler handler) { // Ensure that we don't already have a RemoteViewsAdapter that is bound to an existing // service handling the specified intent. if (mRemoteAdapter != null) { mRemoteAdapter.setRemoteViewsOnClickHandler(handler); } } /** * This defers a notifyDataSetChanged on the pending RemoteViewsAdapter if it has not * connected yet. */ @Override public void deferNotifyDataSetChanged() { mDeferNotifyDataSetChanged = true; } /** * Called back when the adapter connects to the RemoteViewsService. */ @Override public boolean onRemoteAdapterConnected() { if (mRemoteAdapter != mAdapter) { setAdapter(mRemoteAdapter); if (mDeferNotifyDataSetChanged) { mRemoteAdapter.notifyDataSetChanged(); mDeferNotifyDataSetChanged = false; } return false; } else if (mRemoteAdapter != null) { mRemoteAdapter.superNotifyDataSetChanged(); return true; } return false; } /** * Called back when the adapter disconnects from the RemoteViewsService. */ @Override public void onRemoteAdapterDisconnected() { // If the remote adapter disconnects, we keep it around // since the currently displayed items are still cached. // Further, we want the service to eventually reconnect // when necessary, as triggered by this view requesting // items from the Adapter. } /** * Hints the RemoteViewsAdapter, if it exists, about which views are currently * being displayed by the AbsListView. */ void setVisibleRangeHint(int start, int end) { if (mRemoteAdapter != null) { mRemoteAdapter.setVisibleRangeHint(start, end); } } /** * Sets the recycler listener to be notified whenever a View is set aside in * the recycler for later reuse. This listener can be used to free resources * associated to the View. * * @param listener The recycler listener to be notified of views set aside * in the recycler. * * @see android.widget.AbsListView.RecycleBin * @see android.widget.AbsListView.RecyclerListener */ public void setRecyclerListener(RecyclerListener listener) { mRecycler.mRecyclerListener = listener; } class AdapterDataSetObserver extends AdapterView<ListAdapter>.AdapterDataSetObserver { @Override public void onChanged() { super.onChanged(); if (mFastScroll != null) { mFastScroll.onSectionsChanged(); } } @Override public void onInvalidated() { super.onInvalidated(); if (mFastScroll != null) { mFastScroll.onSectionsChanged(); } } } /** * A MultiChoiceModeListener receives events for {@link AbsListView#CHOICE_MODE_MULTIPLE_MODAL}. * It acts as the {@link ActionMode.Callback} for the selection mode and also receives * {@link #onItemCheckedStateChanged(ActionMode, int, long, boolean)} events when the user * selects and deselects list items. */ public interface MultiChoiceModeListener extends ActionMode.Callback { /** * Called when an item is checked or unchecked during selection mode. * * @param mode The {@link ActionMode} providing the selection mode * @param position Adapter position of the item that was checked or unchecked * @param id Adapter ID of the item that was checked or unchecked * @param checked <code>true</code> if the item is now checked, <code>false</code> * if the item is now unchecked. */ public void onItemCheckedStateChanged(ActionMode mode, int position, long id, boolean checked); } class MultiChoiceModeWrapper implements MultiChoiceModeListener { private MultiChoiceModeListener mWrapped; public void setWrapped(MultiChoiceModeListener wrapped) { mWrapped = wrapped; } public boolean hasWrappedCallback() { return mWrapped != null; } @Override public boolean onCreateActionMode(ActionMode mode, Menu menu) { if (mWrapped.onCreateActionMode(mode, menu)) { // Initialize checked graphic state? setLongClickable(false); return true; } return false; } @Override public boolean onPrepareActionMode(ActionMode mode, Menu menu) { return mWrapped.onPrepareActionMode(mode, menu); } @Override public boolean onActionItemClicked(ActionMode mode, MenuItem item) { return mWrapped.onActionItemClicked(mode, item); } @Override public void onDestroyActionMode(ActionMode mode) { mWrapped.onDestroyActionMode(mode); mChoiceActionMode = null; // Ending selection mode means deselecting everything. clearChoices(); mDataChanged = true; rememberSyncState(); requestLayout(); setLongClickable(true); } @Override public void onItemCheckedStateChanged(ActionMode mode, int position, long id, boolean checked) { mWrapped.onItemCheckedStateChanged(mode, position, id, checked); // If there are no items selected we no longer need the selection mode. if (getCheckedItemCount() == 0) { mode.finish(); } } } /** * AbsListView extends LayoutParams to provide a place to hold the view type. */ public static class LayoutParams extends ViewGroup.LayoutParams { /** * View type for this view, as returned by * {@link android.widget.Adapter#getItemViewType(int) } */ @ViewDebug.ExportedProperty(category = "list", mapping = { @ViewDebug.IntToString(from = ITEM_VIEW_TYPE_IGNORE, to = "ITEM_VIEW_TYPE_IGNORE"), @ViewDebug.IntToString(from = ITEM_VIEW_TYPE_HEADER_OR_FOOTER, to = "ITEM_VIEW_TYPE_HEADER_OR_FOOTER") }) @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023) int viewType; /** * When this boolean is set, the view has been added to the AbsListView * at least once. It is used to know whether headers/footers have already * been added to the list view and whether they should be treated as * recycled views or not. */ @ViewDebug.ExportedProperty(category = "list") boolean recycledHeaderFooter; /** * When an AbsListView is measured with an AT_MOST measure spec, it needs * to obtain children views to measure itself. When doing so, the children * are not attached to the window, but put in the recycler which assumes * they've been attached before. Setting this flag will force the reused * view to be attached to the window rather than just attached to the * parent. */ @ViewDebug.ExportedProperty(category = "list") boolean forceAdd; /** * The position the view was removed from when pulled out of the * scrap heap. * @hide */ @UnsupportedAppUsage int scrappedFromPosition; /** * The ID the view represents */ long itemId = -1; /** Whether the adapter considers the item enabled. */ boolean isEnabled; public LayoutParams(Context c, AttributeSet attrs) { super(c, attrs); } public LayoutParams(int w, int h) { super(w, h); } public LayoutParams(int w, int h, int viewType) { super(w, h); this.viewType = viewType; } public LayoutParams(ViewGroup.LayoutParams source) { super(source); } /** @hide */ @Override protected void encodeProperties(@NonNull ViewHierarchyEncoder encoder) { super.encodeProperties(encoder); encoder.addProperty("list:viewType", viewType); encoder.addProperty("list:recycledHeaderFooter", recycledHeaderFooter); encoder.addProperty("list:forceAdd", forceAdd); encoder.addProperty("list:isEnabled", isEnabled); } } /** * A RecyclerListener is used to receive a notification whenever a View is placed * inside the RecycleBin's scrap heap. This listener is used to free resources * associated to Views placed in the RecycleBin. * * @see android.widget.AbsListView.RecycleBin * @see android.widget.AbsListView#setRecyclerListener(android.widget.AbsListView.RecyclerListener) */ public static interface RecyclerListener { /** * Indicates that the specified View was moved into the recycler's scrap heap. * The view is not displayed on screen any more and any expensive resource * associated with the view should be discarded. * * @param view */ void onMovedToScrapHeap(View view); } /** * The RecycleBin facilitates reuse of views across layouts. The RecycleBin has two levels of * storage: ActiveViews and ScrapViews. ActiveViews are those views which were onscreen at the * start of a layout. By construction, they are displaying current information. At the end of * layout, all views in ActiveViews are demoted to ScrapViews. ScrapViews are old views that * could potentially be used by the adapter to avoid allocating views unnecessarily. * * @see android.widget.AbsListView#setRecyclerListener(android.widget.AbsListView.RecyclerListener) * @see android.widget.AbsListView.RecyclerListener */ class RecycleBin { @UnsupportedAppUsage private RecyclerListener mRecyclerListener; /** * The position of the first view stored in mActiveViews. */ private int mFirstActivePosition; /** * Views that were on screen at the start of layout. This array is populated at the start of * layout, and at the end of layout all view in mActiveViews are moved to mScrapViews. * Views in mActiveViews represent a contiguous range of Views, with position of the first * view store in mFirstActivePosition. */ private View[] mActiveViews = new View[0]; /** * Unsorted views that can be used by the adapter as a convert view. */ private ArrayList<View>[] mScrapViews; private int mViewTypeCount; private ArrayList<View> mCurrentScrap; private ArrayList<View> mSkippedScrap; private SparseArray<View> mTransientStateViews; private LongSparseArray<View> mTransientStateViewsById; public void setViewTypeCount(int viewTypeCount) { if (viewTypeCount < 1) { throw new IllegalArgumentException("Can't have a viewTypeCount < 1"); } //noinspection unchecked ArrayList<View>[] scrapViews = new ArrayList[viewTypeCount]; for (int i = 0; i < viewTypeCount; i++) { scrapViews[i] = new ArrayList<View>(); } mViewTypeCount = viewTypeCount; mCurrentScrap = scrapViews[0]; mScrapViews = scrapViews; } public void markChildrenDirty() { if (mViewTypeCount == 1) { final ArrayList<View> scrap = mCurrentScrap; final int scrapCount = scrap.size(); for (int i = 0; i < scrapCount; i++) { scrap.get(i).forceLayout(); } } else { final int typeCount = mViewTypeCount; for (int i = 0; i < typeCount; i++) { final ArrayList<View> scrap = mScrapViews[i]; final int scrapCount = scrap.size(); for (int j = 0; j < scrapCount; j++) { scrap.get(j).forceLayout(); } } } if (mTransientStateViews != null) { final int count = mTransientStateViews.size(); for (int i = 0; i < count; i++) { mTransientStateViews.valueAt(i).forceLayout(); } } if (mTransientStateViewsById != null) { final int count = mTransientStateViewsById.size(); for (int i = 0; i < count; i++) { mTransientStateViewsById.valueAt(i).forceLayout(); } } } public boolean shouldRecycleViewType(int viewType) { return viewType >= 0; } /** * Clears the scrap heap. */ @UnsupportedAppUsage void clear() { if (mViewTypeCount == 1) { final ArrayList<View> scrap = mCurrentScrap; clearScrap(scrap); } else { final int typeCount = mViewTypeCount; for (int i = 0; i < typeCount; i++) { final ArrayList<View> scrap = mScrapViews[i]; clearScrap(scrap); } } clearTransientStateViews(); } /** * Fill ActiveViews with all of the children of the AbsListView. * * @param childCount The minimum number of views mActiveViews should hold * @param firstActivePosition The position of the first view that will be stored in * mActiveViews */ void fillActiveViews(int childCount, int firstActivePosition) { if (mActiveViews.length < childCount) { mActiveViews = new View[childCount]; } mFirstActivePosition = firstActivePosition; //noinspection MismatchedReadAndWriteOfArray final View[] activeViews = mActiveViews; for (int i = 0; i < childCount; i++) { View child = getChildAt(i); AbsListView.LayoutParams lp = (AbsListView.LayoutParams) child.getLayoutParams(); // Don't put header or footer views into the scrap heap if (lp != null && lp.viewType != ITEM_VIEW_TYPE_HEADER_OR_FOOTER) { // Note: We do place AdapterView.ITEM_VIEW_TYPE_IGNORE in active views. // However, we will NOT place them into scrap views. activeViews[i] = child; // Remember the position so that setupChild() doesn't reset state. lp.scrappedFromPosition = firstActivePosition + i; } } } /** * Get the view corresponding to the specified position. The view will be removed from * mActiveViews if it is found. * * @param position The position to look up in mActiveViews * @return The view if it is found, null otherwise */ View getActiveView(int position) { int index = position - mFirstActivePosition; final View[] activeViews = mActiveViews; if (index >= 0 && index < activeViews.length) { final View match = activeViews[index]; activeViews[index] = null; return match; } return null; } View getTransientStateView(int position) { if (mAdapter != null && mAdapterHasStableIds && mTransientStateViewsById != null) { long id = mAdapter.getItemId(position); View result = mTransientStateViewsById.get(id); mTransientStateViewsById.remove(id); return result; } if (mTransientStateViews != null) { final int index = mTransientStateViews.indexOfKey(position); if (index >= 0) { View result = mTransientStateViews.valueAt(index); mTransientStateViews.removeAt(index); return result; } } return null; } /** * Dumps and fully detaches any currently saved views with transient * state. */ void clearTransientStateViews() { final SparseArray<View> viewsByPos = mTransientStateViews; if (viewsByPos != null) { final int N = viewsByPos.size(); for (int i = 0; i < N; i++) { removeDetachedView(viewsByPos.valueAt(i), false); } viewsByPos.clear(); } final LongSparseArray<View> viewsById = mTransientStateViewsById; if (viewsById != null) { final int N = viewsById.size(); for (int i = 0; i < N; i++) { removeDetachedView(viewsById.valueAt(i), false); } viewsById.clear(); } } /** * @return A view from the ScrapViews collection. These are unordered. */ View getScrapView(int position) { final int whichScrap = mAdapter.getItemViewType(position); if (whichScrap < 0) { return null; } if (mViewTypeCount == 1) { return retrieveFromScrap(mCurrentScrap, position); } else if (whichScrap < mScrapViews.length) { return retrieveFromScrap(mScrapViews[whichScrap], position); } return null; } /** * Puts a view into the list of scrap views. * <p> * If the list data hasn't changed or the adapter has stable IDs, views * with transient state will be preserved for later retrieval. * * @param scrap The view to add * @param position The view's position within its parent */ void addScrapView(View scrap, int position) { final AbsListView.LayoutParams lp = (AbsListView.LayoutParams) scrap.getLayoutParams(); if (lp == null) { // Can't recycle, but we don't know anything about the view. // Ignore it completely. return; } lp.scrappedFromPosition = position; // Remove but don't scrap header or footer views, or views that // should otherwise not be recycled. final int viewType = lp.viewType; if (!shouldRecycleViewType(viewType)) { // Can't recycle. If it's not a header or footer, which have // special handling and should be ignored, then skip the scrap // heap and we'll fully detach the view later. if (viewType != ITEM_VIEW_TYPE_HEADER_OR_FOOTER) { getSkippedScrap().add(scrap); } return; } scrap.dispatchStartTemporaryDetach(); // The the accessibility state of the view may change while temporary // detached and we do not allow detached views to fire accessibility // events. So we are announcing that the subtree changed giving a chance // to clients holding on to a view in this subtree to refresh it. notifyViewAccessibilityStateChangedIfNeeded(AccessibilityEvent.CONTENT_CHANGE_TYPE_SUBTREE); // Don't scrap views that have transient state. final boolean scrapHasTransientState = scrap.hasTransientState(); if (scrapHasTransientState) { if (mAdapter != null && mAdapterHasStableIds) { // If the adapter has stable IDs, we can reuse the view for // the same data. if (mTransientStateViewsById == null) { mTransientStateViewsById = new LongSparseArray<>(); } mTransientStateViewsById.put(lp.itemId, scrap); } else if (!mDataChanged) { // If the data hasn't changed, we can reuse the views at // their old positions. if (mTransientStateViews == null) { mTransientStateViews = new SparseArray<>(); } mTransientStateViews.put(position, scrap); } else { // Otherwise, we'll have to remove the view and start over. clearScrapForRebind(scrap); getSkippedScrap().add(scrap); } } else { clearScrapForRebind(scrap); if (mViewTypeCount == 1) { mCurrentScrap.add(scrap); } else { mScrapViews[viewType].add(scrap); } if (mRecyclerListener != null) { mRecyclerListener.onMovedToScrapHeap(scrap); } } } private ArrayList<View> getSkippedScrap() { if (mSkippedScrap == null) { mSkippedScrap = new ArrayList<>(); } return mSkippedScrap; } /** * Finish the removal of any views that skipped the scrap heap. */ void removeSkippedScrap() { if (mSkippedScrap == null) { return; } final int count = mSkippedScrap.size(); for (int i = 0; i < count; i++) { removeDetachedView(mSkippedScrap.get(i), false); } mSkippedScrap.clear(); } /** * Move all views remaining in mActiveViews to mScrapViews. */ void scrapActiveViews() { final View[] activeViews = mActiveViews; final boolean hasListener = mRecyclerListener != null; final boolean multipleScraps = mViewTypeCount > 1; ArrayList<View> scrapViews = mCurrentScrap; final int count = activeViews.length; for (int i = count - 1; i >= 0; i--) { final View victim = activeViews[i]; if (victim != null) { final AbsListView.LayoutParams lp = (AbsListView.LayoutParams) victim.getLayoutParams(); final int whichScrap = lp.viewType; activeViews[i] = null; if (victim.hasTransientState()) { // Store views with transient state for later use. victim.dispatchStartTemporaryDetach(); if (mAdapter != null && mAdapterHasStableIds) { if (mTransientStateViewsById == null) { mTransientStateViewsById = new LongSparseArray<View>(); } long id = mAdapter.getItemId(mFirstActivePosition + i); mTransientStateViewsById.put(id, victim); } else if (!mDataChanged) { if (mTransientStateViews == null) { mTransientStateViews = new SparseArray<View>(); } mTransientStateViews.put(mFirstActivePosition + i, victim); } else if (whichScrap != ITEM_VIEW_TYPE_HEADER_OR_FOOTER) { // The data has changed, we can't keep this view. removeDetachedView(victim, false); } } else if (!shouldRecycleViewType(whichScrap)) { // Discard non-recyclable views except headers/footers. if (whichScrap != ITEM_VIEW_TYPE_HEADER_OR_FOOTER) { removeDetachedView(victim, false); } } else { // Store everything else on the appropriate scrap heap. if (multipleScraps) { scrapViews = mScrapViews[whichScrap]; } lp.scrappedFromPosition = mFirstActivePosition + i; removeDetachedView(victim, false); scrapViews.add(victim); if (hasListener) { mRecyclerListener.onMovedToScrapHeap(victim); } } } } pruneScrapViews(); } /** * At the end of a layout pass, all temp detached views should either be re-attached or * completely detached. This method ensures that any remaining view in the scrap list is * fully detached. */ void fullyDetachScrapViews() { final int viewTypeCount = mViewTypeCount; final ArrayList<View>[] scrapViews = mScrapViews; for (int i = 0; i < viewTypeCount; ++i) { final ArrayList<View> scrapPile = scrapViews[i]; for (int j = scrapPile.size() - 1; j >= 0; j--) { final View view = scrapPile.get(j); if (view.isTemporarilyDetached()) { removeDetachedView(view, false); } } } } /** * Makes sure that the size of mScrapViews does not exceed the size of * mActiveViews, which can happen if an adapter does not recycle its * views. Removes cached transient state views that no longer have * transient state. */ private void pruneScrapViews() { final int maxViews = mActiveViews.length; final int viewTypeCount = mViewTypeCount; final ArrayList<View>[] scrapViews = mScrapViews; for (int i = 0; i < viewTypeCount; ++i) { final ArrayList<View> scrapPile = scrapViews[i]; int size = scrapPile.size(); while (size > maxViews) { scrapPile.remove(--size); } } final SparseArray<View> transViewsByPos = mTransientStateViews; if (transViewsByPos != null) { for (int i = 0; i < transViewsByPos.size(); i++) { final View v = transViewsByPos.valueAt(i); if (!v.hasTransientState()) { removeDetachedView(v, false); transViewsByPos.removeAt(i); i--; } } } final LongSparseArray<View> transViewsById = mTransientStateViewsById; if (transViewsById != null) { for (int i = 0; i < transViewsById.size(); i++) { final View v = transViewsById.valueAt(i); if (!v.hasTransientState()) { removeDetachedView(v, false); transViewsById.removeAt(i); i--; } } } } /** * Puts all views in the scrap heap into the supplied list. */ void reclaimScrapViews(List<View> views) { if (mViewTypeCount == 1) { views.addAll(mCurrentScrap); } else { final int viewTypeCount = mViewTypeCount; final ArrayList<View>[] scrapViews = mScrapViews; for (int i = 0; i < viewTypeCount; ++i) { final ArrayList<View> scrapPile = scrapViews[i]; views.addAll(scrapPile); } } } /** * Updates the cache color hint of all known views. * * @param color The new cache color hint. */ void setCacheColorHint(int color) { if (mViewTypeCount == 1) { final ArrayList<View> scrap = mCurrentScrap; final int scrapCount = scrap.size(); for (int i = 0; i < scrapCount; i++) { scrap.get(i).setDrawingCacheBackgroundColor(color); } } else { final int typeCount = mViewTypeCount; for (int i = 0; i < typeCount; i++) { final ArrayList<View> scrap = mScrapViews[i]; final int scrapCount = scrap.size(); for (int j = 0; j < scrapCount; j++) { scrap.get(j).setDrawingCacheBackgroundColor(color); } } } // Just in case this is called during a layout pass final View[] activeViews = mActiveViews; final int count = activeViews.length; for (int i = 0; i < count; ++i) { final View victim = activeViews[i]; if (victim != null) { victim.setDrawingCacheBackgroundColor(color); } } } private View retrieveFromScrap(ArrayList<View> scrapViews, int position) { final int size = scrapViews.size(); if (size > 0) { // See if we still have a view for this position or ID. // Traverse backwards to find the most recently used scrap view for (int i = size - 1; i >= 0; i--) { final View view = scrapViews.get(i); final AbsListView.LayoutParams params = (AbsListView.LayoutParams) view.getLayoutParams(); if (mAdapterHasStableIds) { final long id = mAdapter.getItemId(position); if (id == params.itemId) { return scrapViews.remove(i); } } else if (params.scrappedFromPosition == position) { final View scrap = scrapViews.remove(i); clearScrapForRebind(scrap); return scrap; } } final View scrap = scrapViews.remove(size - 1); clearScrapForRebind(scrap); return scrap; } else { return null; } } private void clearScrap(final ArrayList<View> scrap) { final int scrapCount = scrap.size(); for (int j = 0; j < scrapCount; j++) { removeDetachedView(scrap.remove(scrapCount - 1 - j), false); } } private void clearScrapForRebind(View view) { view.clearAccessibilityFocus(); view.setAccessibilityDelegate(null); } private void removeDetachedView(View child, boolean animate) { child.setAccessibilityDelegate(null); AbsListView.this.removeDetachedView(child, animate); } } /** * Returns the height of the view for the specified position. * * @param position the item position * @return view height in pixels */ int getHeightForPosition(int position) { final int firstVisiblePosition = getFirstVisiblePosition(); final int childCount = getChildCount(); final int index = position - firstVisiblePosition; if (index >= 0 && index < childCount) { // Position is on-screen, use existing view. final View view = getChildAt(index); return view.getHeight(); } else { // Position is off-screen, obtain & recycle view. final View view = obtainView(position, mIsScrap); view.measure(mWidthMeasureSpec, MeasureSpec.UNSPECIFIED); final int height = view.getMeasuredHeight(); mRecycler.addScrapView(view, position); return height; } } /** * Sets the selected item and positions the selection y pixels from the top edge * of the ListView. (If in touch mode, the item will not be selected but it will * still be positioned appropriately.) * * @param position Index (starting at 0) of the data item to be selected. * @param y The distance from the top edge of the ListView (plus padding) that the * item will be positioned. */ public void setSelectionFromTop(int position, int y) { if (mAdapter == null) { return; } if (!isInTouchMode()) { position = lookForSelectablePosition(position, true); if (position >= 0) { setNextSelectedPositionInt(position); } } else { mResurrectToPosition = position; } if (position >= 0) { mLayoutMode = LAYOUT_SPECIFIC; mSpecificTop = mListPadding.top + y; if (mNeedSync) { mSyncPosition = position; mSyncRowId = mAdapter.getItemId(position); } if (mPositionScroller != null) { mPositionScroller.stop(); } requestLayout(); } } /** @hide */ @Override protected void encodeProperties(@NonNull ViewHierarchyEncoder encoder) { super.encodeProperties(encoder); encoder.addProperty("drawing:cacheColorHint", getCacheColorHint()); encoder.addProperty("list:fastScrollEnabled", isFastScrollEnabled()); encoder.addProperty("list:scrollingCacheEnabled", isScrollingCacheEnabled()); encoder.addProperty("list:smoothScrollbarEnabled", isSmoothScrollbarEnabled()); encoder.addProperty("list:stackFromBottom", isStackFromBottom()); encoder.addProperty("list:textFilterEnabled", isTextFilterEnabled()); View selectedView = getSelectedView(); if (selectedView != null) { encoder.addPropertyKey("selectedView"); selectedView.encode(encoder); } } /** * Abstract positon scroller used to handle smooth scrolling. */ static abstract class AbsPositionScroller { public abstract void start(int position); public abstract void start(int position, int boundPosition); public abstract void startWithOffset(int position, int offset); public abstract void startWithOffset(int position, int offset, int duration); public abstract void stop(); } /** * Default position scroller that simulates a fling. */ class PositionScroller extends AbsPositionScroller implements Runnable { private static final int SCROLL_DURATION = 200; private static final int MOVE_DOWN_POS = 1; private static final int MOVE_UP_POS = 2; private static final int MOVE_DOWN_BOUND = 3; private static final int MOVE_UP_BOUND = 4; private static final int MOVE_OFFSET = 5; private int mMode; private int mTargetPos; private int mBoundPos; private int mLastSeenPos; private int mScrollDuration; private final int mExtraScroll; private int mOffsetFromTop; PositionScroller() { mExtraScroll = ViewConfiguration.get(mContext).getScaledFadingEdgeLength(); } @Override public void start(final int position) { stop(); if (mDataChanged) { // Wait until we're back in a stable state to try this. mPositionScrollAfterLayout = new Runnable() { @Override public void run() { start(position); } }; return; } final int childCount = getChildCount(); if (childCount == 0) { // Can't scroll without children. return; } final int firstPos = mFirstPosition; final int lastPos = firstPos + childCount - 1; int viewTravelCount; int clampedPosition = Math.max(0, Math.min(getCount() - 1, position)); if (clampedPosition < firstPos) { viewTravelCount = firstPos - clampedPosition + 1; mMode = MOVE_UP_POS; } else if (clampedPosition > lastPos) { viewTravelCount = clampedPosition - lastPos + 1; mMode = MOVE_DOWN_POS; } else { scrollToVisible(clampedPosition, INVALID_POSITION, SCROLL_DURATION); return; } if (viewTravelCount > 0) { mScrollDuration = SCROLL_DURATION / viewTravelCount; } else { mScrollDuration = SCROLL_DURATION; } mTargetPos = clampedPosition; mBoundPos = INVALID_POSITION; mLastSeenPos = INVALID_POSITION; postOnAnimation(this); } @Override public void start(final int position, final int boundPosition) { stop(); if (boundPosition == INVALID_POSITION) { start(position); return; } if (mDataChanged) { // Wait until we're back in a stable state to try this. mPositionScrollAfterLayout = new Runnable() { @Override public void run() { start(position, boundPosition); } }; return; } final int childCount = getChildCount(); if (childCount == 0) { // Can't scroll without children. return; } final int firstPos = mFirstPosition; final int lastPos = firstPos + childCount - 1; int viewTravelCount; int clampedPosition = Math.max(0, Math.min(getCount() - 1, position)); if (clampedPosition < firstPos) { final int boundPosFromLast = lastPos - boundPosition; if (boundPosFromLast < 1) { // Moving would shift our bound position off the screen. Abort. return; } final int posTravel = firstPos - clampedPosition + 1; final int boundTravel = boundPosFromLast - 1; if (boundTravel < posTravel) { viewTravelCount = boundTravel; mMode = MOVE_UP_BOUND; } else { viewTravelCount = posTravel; mMode = MOVE_UP_POS; } } else if (clampedPosition > lastPos) { final int boundPosFromFirst = boundPosition - firstPos; if (boundPosFromFirst < 1) { // Moving would shift our bound position off the screen. Abort. return; } final int posTravel = clampedPosition - lastPos + 1; final int boundTravel = boundPosFromFirst - 1; if (boundTravel < posTravel) { viewTravelCount = boundTravel; mMode = MOVE_DOWN_BOUND; } else { viewTravelCount = posTravel; mMode = MOVE_DOWN_POS; } } else { scrollToVisible(clampedPosition, boundPosition, SCROLL_DURATION); return; } if (viewTravelCount > 0) { mScrollDuration = SCROLL_DURATION / viewTravelCount; } else { mScrollDuration = SCROLL_DURATION; } mTargetPos = clampedPosition; mBoundPos = boundPosition; mLastSeenPos = INVALID_POSITION; postOnAnimation(this); } @Override public void startWithOffset(int position, int offset) { startWithOffset(position, offset, SCROLL_DURATION); } @Override public void startWithOffset(final int position, int offset, final int duration) { stop(); if (mDataChanged) { // Wait until we're back in a stable state to try this. final int postOffset = offset; mPositionScrollAfterLayout = new Runnable() { @Override public void run() { startWithOffset(position, postOffset, duration); } }; return; } final int childCount = getChildCount(); if (childCount == 0) { // Can't scroll without children. return; } offset += getPaddingTop(); mTargetPos = Math.max(0, Math.min(getCount() - 1, position)); mOffsetFromTop = offset; mBoundPos = INVALID_POSITION; mLastSeenPos = INVALID_POSITION; mMode = MOVE_OFFSET; final int firstPos = mFirstPosition; final int lastPos = firstPos + childCount - 1; int viewTravelCount; if (mTargetPos < firstPos) { viewTravelCount = firstPos - mTargetPos; } else if (mTargetPos > lastPos) { viewTravelCount = mTargetPos - lastPos; } else { // On-screen, just scroll. final int targetTop = getChildAt(mTargetPos - firstPos).getTop(); smoothScrollBy(targetTop - offset, duration, true, false); return; } // Estimate how many screens we should travel final float screenTravelCount = (float) viewTravelCount / childCount; mScrollDuration = screenTravelCount < 1 ? duration : (int) (duration / screenTravelCount); mLastSeenPos = INVALID_POSITION; postOnAnimation(this); } /** * Scroll such that targetPos is in the visible padded region without scrolling * boundPos out of view. Assumes targetPos is onscreen. */ private void scrollToVisible(int targetPos, int boundPos, int duration) { final int firstPos = mFirstPosition; final int childCount = getChildCount(); final int lastPos = firstPos + childCount - 1; final int paddedTop = mListPadding.top; final int paddedBottom = getHeight() - mListPadding.bottom; if (targetPos < firstPos || targetPos > lastPos) { Log.w(TAG, "scrollToVisible called with targetPos " + targetPos + " not visible [" + firstPos + ", " + lastPos + "]"); } if (boundPos < firstPos || boundPos > lastPos) { // boundPos doesn't matter, it's already offscreen. boundPos = INVALID_POSITION; } final View targetChild = getChildAt(targetPos - firstPos); final int targetTop = targetChild.getTop(); final int targetBottom = targetChild.getBottom(); int scrollBy = 0; if (targetBottom > paddedBottom) { scrollBy = targetBottom - paddedBottom; } if (targetTop < paddedTop) { scrollBy = targetTop - paddedTop; } if (scrollBy == 0) { return; } if (boundPos >= 0) { final View boundChild = getChildAt(boundPos - firstPos); final int boundTop = boundChild.getTop(); final int boundBottom = boundChild.getBottom(); final int absScroll = Math.abs(scrollBy); if (scrollBy < 0 && boundBottom + absScroll > paddedBottom) { // Don't scroll the bound view off the bottom of the screen. scrollBy = Math.max(0, boundBottom - paddedBottom); } else if (scrollBy > 0 && boundTop - absScroll < paddedTop) { // Don't scroll the bound view off the top of the screen. scrollBy = Math.min(0, boundTop - paddedTop); } } smoothScrollBy(scrollBy, duration); } @Override public void stop() { removeCallbacks(this); } @Override public void run() { final int listHeight = getHeight(); final int firstPos = mFirstPosition; switch (mMode) { case MOVE_DOWN_POS: { final int lastViewIndex = getChildCount() - 1; final int lastPos = firstPos + lastViewIndex; if (lastViewIndex < 0) { return; } if (lastPos == mLastSeenPos) { // No new views, let things keep going. postOnAnimation(this); return; } final View lastView = getChildAt(lastViewIndex); final int lastViewHeight = lastView.getHeight(); final int lastViewTop = lastView.getTop(); final int lastViewPixelsShowing = listHeight - lastViewTop; final int extraScroll = lastPos < mItemCount - 1 ? Math.max(mListPadding.bottom, mExtraScroll) : mListPadding.bottom; final int scrollBy = lastViewHeight - lastViewPixelsShowing + extraScroll; smoothScrollBy(scrollBy, mScrollDuration, true, lastPos < mTargetPos); mLastSeenPos = lastPos; if (lastPos < mTargetPos) { postOnAnimation(this); } break; } case MOVE_DOWN_BOUND: { final int nextViewIndex = 1; final int childCount = getChildCount(); if (firstPos == mBoundPos || childCount <= nextViewIndex || firstPos + childCount >= mItemCount) { reportScrollStateChange(OnScrollListener.SCROLL_STATE_IDLE); return; } final int nextPos = firstPos + nextViewIndex; if (nextPos == mLastSeenPos) { // No new views, let things keep going. postOnAnimation(this); return; } final View nextView = getChildAt(nextViewIndex); final int nextViewHeight = nextView.getHeight(); final int nextViewTop = nextView.getTop(); final int extraScroll = Math.max(mListPadding.bottom, mExtraScroll); if (nextPos < mBoundPos) { smoothScrollBy(Math.max(0, nextViewHeight + nextViewTop - extraScroll), mScrollDuration, true, true); mLastSeenPos = nextPos; postOnAnimation(this); } else { if (nextViewTop > extraScroll) { smoothScrollBy(nextViewTop - extraScroll, mScrollDuration, true, false); } else { reportScrollStateChange(OnScrollListener.SCROLL_STATE_IDLE); } } break; } case MOVE_UP_POS: { if (firstPos == mLastSeenPos) { // No new views, let things keep going. postOnAnimation(this); return; } final View firstView = getChildAt(0); if (firstView == null) { return; } final int firstViewTop = firstView.getTop(); final int extraScroll = firstPos > 0 ? Math.max(mExtraScroll, mListPadding.top) : mListPadding.top; smoothScrollBy(firstViewTop - extraScroll, mScrollDuration, true, firstPos > mTargetPos); mLastSeenPos = firstPos; if (firstPos > mTargetPos) { postOnAnimation(this); } break; } case MOVE_UP_BOUND: { final int lastViewIndex = getChildCount() - 2; if (lastViewIndex < 0) { return; } final int lastPos = firstPos + lastViewIndex; if (lastPos == mLastSeenPos) { // No new views, let things keep going. postOnAnimation(this); return; } final View lastView = getChildAt(lastViewIndex); final int lastViewHeight = lastView.getHeight(); final int lastViewTop = lastView.getTop(); final int lastViewPixelsShowing = listHeight - lastViewTop; final int extraScroll = Math.max(mListPadding.top, mExtraScroll); mLastSeenPos = lastPos; if (lastPos > mBoundPos) { smoothScrollBy(-(lastViewPixelsShowing - extraScroll), mScrollDuration, true, true); postOnAnimation(this); } else { final int bottom = listHeight - extraScroll; final int lastViewBottom = lastViewTop + lastViewHeight; if (bottom > lastViewBottom) { smoothScrollBy(-(bottom - lastViewBottom), mScrollDuration, true, false); } else { reportScrollStateChange(OnScrollListener.SCROLL_STATE_IDLE); } } break; } case MOVE_OFFSET: { if (mLastSeenPos == firstPos) { // No new views, let things keep going. postOnAnimation(this); return; } mLastSeenPos = firstPos; final int childCount = getChildCount(); if (childCount <= 0) { return; } final int position = mTargetPos; final int lastPos = firstPos + childCount - 1; // Account for the visible "portion" of the first / last child when we estimate // how many screens we should travel to reach our target final View firstChild = getChildAt(0); final int firstChildHeight = firstChild.getHeight(); final View lastChild = getChildAt(childCount - 1); final int lastChildHeight = lastChild.getHeight(); final float firstPositionVisiblePart = (firstChildHeight == 0.0f) ? 1.0f : (float) (firstChildHeight + firstChild.getTop()) / firstChildHeight; final float lastPositionVisiblePart = (lastChildHeight == 0.0f) ? 1.0f : (float) (lastChildHeight + getHeight() - lastChild.getBottom()) / lastChildHeight; float viewTravelCount = 0; if (position < firstPos) { viewTravelCount = firstPos - position + (1.0f - firstPositionVisiblePart) + 1; } else if (position > lastPos) { viewTravelCount = position - lastPos + (1.0f - lastPositionVisiblePart); } // Estimate how many screens we should travel final float screenTravelCount = viewTravelCount / childCount; final float modifier = Math.min(Math.abs(screenTravelCount), 1.f); if (position < firstPos) { final int distance = (int) (-getHeight() * modifier); final int duration = (int) (mScrollDuration * modifier); smoothScrollBy(distance, duration, true, true); postOnAnimation(this); } else if (position > lastPos) { final int distance = (int) (getHeight() * modifier); final int duration = (int) (mScrollDuration * modifier); smoothScrollBy(distance, duration, true, true); postOnAnimation(this); } else { // On-screen, just scroll. final int targetTop = getChildAt(position - firstPos).getTop(); final int distance = targetTop - mOffsetFromTop; final int duration = (int) (mScrollDuration * ((float) Math.abs(distance) / getHeight())); smoothScrollBy(distance, duration, true, false); } break; } default: break; } } } }