Java tutorial
/******************************************************************************* * Copyright (C) 2012 Google Inc. * Licensed to 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 com.chen.mail.ui; import android.animation.Animator; import android.animation.AnimatorListenerAdapter; import android.animation.TimeInterpolator; import android.app.Activity; import android.content.Context; import android.content.res.Resources; import android.support.v4.widget.DrawerLayout; import android.util.AttributeSet; import android.view.Gravity; import android.view.View; import android.view.ViewGroup; import android.view.ViewParent; import android.view.animation.AnimationUtils; import android.widget.FrameLayout; import com.chen.mail.R; import com.chen.mail.ui.ViewMode.ModeChangeListener; import com.chen.mail.utils.LogUtils; import com.chen.mail.utils.Utils; import com.google.common.annotations.VisibleForTesting; /** * This is a custom layout that manages the possible views of Gmail's large screen (read: tablet) * activity, and the transitions between them. * * This is not intended to be a generic layout; it is specific to the {@code Fragment}s * available in {@link MailActivity} and assumes their existence. It merely configures them * according to the specific <i>modes</i> the {@link Activity} can be in. * * Currently, the layout differs in three dimensions: orientation, two aspects of view modes. * This results in essentially three states: One where the folders are on the left and conversation * list is on the right, and two states where the conversation list is on the left: one in which * it's collapsed and another where it is not. * * In folder or conversation list view, conversations are hidden and folders and conversation lists * are visible. This is the case in both portrait and landscape * * In Conversation List or Conversation View, folders are hidden, and conversation lists and * conversation view is visible. This is the case in both portrait and landscape. * * In the Gmail source code, this was called TriStateSplitLayout */ final class TwoPaneLayout extends FrameLayout implements ModeChangeListener { private static final String LOG_TAG = "TwoPaneLayout"; private static final long SLIDE_DURATION_MS = 300; private final double mConversationListWeight; private final double mFolderListWeight; private final TimeInterpolator mSlideInterpolator; /** * True if and only if the conversation list is collapsible in the current device configuration. * See {@link #isConversationListCollapsed()} to see whether it is currently collapsed * (based on the current view mode). */ private final boolean mListCollapsible; /** * The current mode that the tablet layout is in. This is a constant integer that holds values * that are {@link ViewMode} constants like {@link ViewMode#CONVERSATION}. */ private int mCurrentMode = ViewMode.UNKNOWN; /** * This mode represents the current positions of the three panes. This is split out from the * current mode to give context to state transitions. */ private int mPositionedMode = ViewMode.UNKNOWN; private AbstractActivityController mController; private LayoutListener mListener; private boolean mIsSearchResult; private DrawerLayout mDrawerLayout; private View mMiscellaneousView; private View mConversationView; private View mFoldersView; private View mListView; public static final int MISCELLANEOUS_VIEW_ID = R.id.miscellaneous_pane; private final Runnable mTransitionCompleteRunnable = new Runnable() { @Override public void run() { onTransitionComplete(); } }; /** * A special view used during animation of the conversation list. * <p> * The conversation list changes width when switching view modes, so to visually smooth out * the transition, we cross-fade the old and new widths. During the transition, a bitmap of the * old conversation list is kept here, and this view moves in tandem with the real list view, * but its opacity gradually fades out to give way to the new width. */ private ConversationListCopy mListCopyView; /** * During a mode transition, this value is the final width for {@link #mListCopyView}. We want * to avoid changing its width during the animation, as it should match the initial width of * {@link #mListView}. */ private Integer mListCopyWidthOnComplete; private final boolean mIsExpansiveLayout; private boolean mDrawerInitialSetupComplete; public TwoPaneLayout(Context context) { this(context, null); } public TwoPaneLayout(Context context, AttributeSet attrs) { super(context, attrs); final Resources res = getResources(); // The conversation list might be visible now, depending on the layout: in portrait we // don't show the conversation list, but in landscape we do. This information is stored // in the constants mListCollapsible = res.getBoolean(R.bool.list_collapsible); mSlideInterpolator = AnimationUtils.loadInterpolator(context, android.R.interpolator.decelerate_cubic); final int folderListWeight = res.getInteger(R.integer.folder_list_weight); final int convListWeight = res.getInteger(R.integer.conversation_list_weight); final int convViewWeight = res.getInteger(R.integer.conversation_view_weight); mFolderListWeight = (double) folderListWeight / (folderListWeight + convListWeight); mConversationListWeight = (double) convListWeight / (convListWeight + convViewWeight); mIsExpansiveLayout = res.getBoolean(R.bool.use_expansive_tablet_ui); mDrawerInitialSetupComplete = false; } @Override protected void onFinishInflate() { super.onFinishInflate(); mFoldersView = findViewById(R.id.content_pane); mListView = findViewById(R.id.conversation_list_pane); mListCopyView = (ConversationListCopy) findViewById(R.id.conversation_list_copy); mConversationView = findViewById(R.id.conversation_pane); mMiscellaneousView = findViewById(MISCELLANEOUS_VIEW_ID); // all panes start GONE in initial UNKNOWN mode to avoid drawing misplaced panes mCurrentMode = ViewMode.UNKNOWN; mFoldersView.setVisibility(GONE); mListView.setVisibility(GONE); mListCopyView.setVisibility(GONE); mConversationView.setVisibility(GONE); mMiscellaneousView.setVisibility(GONE); } @VisibleForTesting public void setController(AbstractActivityController controller, boolean isSearchResult) { mController = controller; mListener = controller; mIsSearchResult = isSearchResult; } public void setDrawerLayout(DrawerLayout drawerLayout) { mDrawerLayout = drawerLayout; } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { LogUtils.d(Utils.VIEW_DEBUGGING_TAG, "TPL(%s).onMeasure()", this); setupPaneWidths(MeasureSpec.getSize(widthMeasureSpec)); super.onMeasure(widthMeasureSpec, heightMeasureSpec); } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { LogUtils.d(Utils.VIEW_DEBUGGING_TAG, "TPL(%s).onLayout()", this); if (changed || mCurrentMode != mPositionedMode) { positionPanes(getMeasuredWidth()); } super.onLayout(changed, l, t, r, b); } /** * Sizes up the three sliding panes. This method will ensure that the LayoutParams of the panes * have the correct widths set for the current overall size and view mode. * * @param parentWidth this view's new width */ private void setupPaneWidths(int parentWidth) { final int foldersWidth = computeFolderListWidth(parentWidth); final int foldersFragmentWidth; if (isDrawerView(mFoldersView)) { foldersFragmentWidth = getResources().getDimensionPixelSize(R.dimen.drawer_width); } else { foldersFragmentWidth = foldersWidth; } final int convWidth = computeConversationWidth(parentWidth); setPaneWidth(mFoldersView, foldersFragmentWidth); // only adjust the fixed conversation view width when my width changes if (parentWidth != getMeasuredWidth()) { LogUtils.i(LOG_TAG, "setting up new TPL, w=%d fw=%d cv=%d", parentWidth, foldersWidth, convWidth); setPaneWidth(mMiscellaneousView, convWidth); setPaneWidth(mConversationView, convWidth); } final int currListWidth = getPaneWidth(mListView); int listWidth = currListWidth; switch (mCurrentMode) { case ViewMode.AD: case ViewMode.CONVERSATION: case ViewMode.SEARCH_RESULTS_CONVERSATION: if (!mListCollapsible) { listWidth = parentWidth - convWidth; } break; case ViewMode.CONVERSATION_LIST: case ViewMode.WAITING_FOR_ACCOUNT_INITIALIZATION: case ViewMode.SEARCH_RESULTS_LIST: listWidth = parentWidth - foldersWidth; break; default: break; } LogUtils.d(LOG_TAG, "conversation list width change, w=%d", listWidth); setPaneWidth(mListView, listWidth); if ((mCurrentMode != mPositionedMode && mPositionedMode != ViewMode.UNKNOWN) || mListCopyWidthOnComplete != null) { mListCopyWidthOnComplete = listWidth; } else { setPaneWidth(mListCopyView, listWidth); } } /** * Positions the three sliding panes at the correct X offset (using {@link View#setX(float)}). * When switching from list->conversation mode or vice versa, animate the change in X. * * @param width */ private void positionPanes(int width) { if (mPositionedMode == mCurrentMode) { return; } boolean hasPositions = false; int convX = 0, listX = 0, foldersX = 0; switch (mCurrentMode) { case ViewMode.AD: case ViewMode.CONVERSATION: case ViewMode.SEARCH_RESULTS_CONVERSATION: { final int foldersW = getPaneWidth(mFoldersView); final int listW; listW = getPaneWidth(mListView); if (mListCollapsible) { convX = 0; listX = -listW; foldersX = listX - foldersW; } else { convX = listW; listX = 0; foldersX = -foldersW; } hasPositions = true; LogUtils.i(LOG_TAG, "conversation mode layout, x=%d/%d/%d", foldersX, listX, convX); break; } case ViewMode.CONVERSATION_LIST: case ViewMode.WAITING_FOR_ACCOUNT_INITIALIZATION: case ViewMode.SEARCH_RESULTS_LIST: { convX = width; listX = getPaneWidth(mFoldersView); foldersX = 0; hasPositions = true; LogUtils.i(LOG_TAG, "conv-list mode layout, x=%d/%d/%d", foldersX, listX, convX); break; } default: break; } if (hasPositions) { animatePanes(foldersX, listX, convX); } mPositionedMode = mCurrentMode; } private final AnimatorListenerAdapter mPaneAnimationListener = new AnimatorListenerAdapter() { @Override public void onAnimationEnd(Animator animation) { mListCopyView.unbind(); useHardwareLayer(false); fixupListCopyWidth(); onTransitionComplete(); } @Override public void onAnimationCancel(Animator animation) { mListCopyView.unbind(); useHardwareLayer(false); } }; /** * @param foldersX * @param listX * @param convX */ private void animatePanes(int foldersX, int listX, int convX) { // If positioning has not yet happened, we don't need to animate panes into place. // This happens on first layout, rotate, and when jumping straight to a conversation from // a view intent. if (mPositionedMode == ViewMode.UNKNOWN) { mConversationView.setX(convX); mMiscellaneousView.setX(convX); mListView.setX(listX); if (!isDrawerView(mFoldersView)) { mFoldersView.setX(foldersX); } // listeners need to know that the "transition" is complete, even if one is not run. // defer notifying listeners because we're in a layout pass, and they might do layout. post(mTransitionCompleteRunnable); return; } final boolean useListCopy = getPaneWidth(mListView) != getPaneWidth(mListCopyView); if (useListCopy) { // freeze the current list view before it gets redrawn mListCopyView.bind(mListView); mListCopyView.setX(mListView.getX()); mListCopyView.setAlpha(1.0f); mListView.setAlpha(0.0f); } useHardwareLayer(true); if (ViewMode.isAdMode(mCurrentMode)) { mMiscellaneousView.animate().x(convX); } else { mConversationView.animate().x(convX); } if (!isDrawerView(mFoldersView)) { mFoldersView.animate().x(foldersX); } if (useListCopy) { mListCopyView.animate().x(listX).alpha(0.0f); } mListView.animate().x(listX).alpha(1.0f).setListener(mPaneAnimationListener); configureAnimations(mConversationView, mFoldersView, mListView, mListCopyView, mMiscellaneousView); } private void configureAnimations(View... views) { for (View v : views) { if (isDrawerView(v)) { continue; } v.animate().setInterpolator(mSlideInterpolator).setDuration(SLIDE_DURATION_MS); } } private void useHardwareLayer(boolean useHardware) { final int layerType = useHardware ? LAYER_TYPE_HARDWARE : LAYER_TYPE_NONE; if (!isDrawerView(mFoldersView)) { mFoldersView.setLayerType(layerType, null); } mListView.setLayerType(layerType, null); mListCopyView.setLayerType(layerType, null); mConversationView.setLayerType(layerType, null); mMiscellaneousView.setLayerType(layerType, null); if (useHardware) { // these buildLayer calls are safe because layout is the only way we get here // (i.e. these views must already be attached) if (!isDrawerView(mFoldersView)) { mFoldersView.buildLayer(); } mListView.buildLayer(); mListCopyView.buildLayer(); mConversationView.buildLayer(); mMiscellaneousView.buildLayer(); } } private void fixupListCopyWidth() { if (mListCopyWidthOnComplete == null || getPaneWidth(mListCopyView) == mListCopyWidthOnComplete) { mListCopyWidthOnComplete = null; return; } LogUtils.i(LOG_TAG, "onAnimationEnd of list view, setting copy width to %d", mListCopyWidthOnComplete); setPaneWidth(mListCopyView, mListCopyWidthOnComplete); mListCopyWidthOnComplete = null; } private void onTransitionComplete() { if (mController.isDestroyed()) { // quit early if the hosting activity was destroyed before the animation finished LogUtils.i(LOG_TAG, "IN TPL.onTransitionComplete, activity destroyed->quitting early"); return; } switch (mCurrentMode) { case ViewMode.CONVERSATION: case ViewMode.SEARCH_RESULTS_CONVERSATION: dispatchConversationVisibilityChanged(true); dispatchConversationListVisibilityChange(!isConversationListCollapsed()); break; case ViewMode.CONVERSATION_LIST: case ViewMode.SEARCH_RESULTS_LIST: dispatchConversationVisibilityChanged(false); dispatchConversationListVisibilityChange(true); break; case ViewMode.AD: dispatchConversationVisibilityChanged(false); dispatchConversationListVisibilityChange(!isConversationListCollapsed()); break; default: break; } } /** * Computes the width of the conversation list in stable state of the current mode. */ public int computeConversationListWidth() { return computeConversationListWidth(getMeasuredWidth()); } /** * Computes the width of the conversation list in stable state of the current mode. */ private int computeConversationListWidth(int totalWidth) { switch (mCurrentMode) { case ViewMode.CONVERSATION_LIST: case ViewMode.WAITING_FOR_ACCOUNT_INITIALIZATION: case ViewMode.SEARCH_RESULTS_LIST: return totalWidth - computeFolderListWidth(totalWidth); case ViewMode.AD: case ViewMode.CONVERSATION: case ViewMode.SEARCH_RESULTS_CONVERSATION: return (int) (totalWidth * mConversationListWeight); } return 0; } public int computeConversationWidth() { return computeConversationWidth(getMeasuredWidth()); } /** * Computes the width of the conversation pane in stable state of the * current mode. */ private int computeConversationWidth(int totalWidth) { if (mListCollapsible) { return totalWidth; } else { return totalWidth - (int) (totalWidth * mConversationListWeight); } } /** * Computes the width of the folder list in stable state of the current mode. */ private int computeFolderListWidth(int parentWidth) { if (mIsSearchResult) { return 0; } else if (isDrawerView(mFoldersView)) { return 0; } else { return (int) (parentWidth * mFolderListWeight); } } private void dispatchConversationListVisibilityChange(boolean visible) { if (mListener != null) { mListener.onConversationListVisibilityChanged(visible); } } private void dispatchConversationVisibilityChanged(boolean visible) { if (mListener != null) { mListener.onConversationVisibilityChanged(visible); } } // does not apply to drawer children. will return zero for those. private int getPaneWidth(View pane) { return isDrawerView(pane) ? 0 : pane.getLayoutParams().width; } private boolean isDrawerView(View child) { return child != null && child.getParent() == mDrawerLayout; } /** * @return Whether or not the conversation list is visible on screen. */ public boolean isConversationListCollapsed() { return !ViewMode.isListMode(mCurrentMode) && mListCollapsible; } @Override public void onViewModeChanged(int newMode) { // make all initially GONE panes visible only when the view mode is first determined if (mCurrentMode == ViewMode.UNKNOWN) { mFoldersView.setVisibility(VISIBLE); mListView.setVisibility(VISIBLE); mListCopyView.setVisibility(VISIBLE); } if (ViewMode.isAdMode(newMode)) { mMiscellaneousView.setVisibility(VISIBLE); mConversationView.setVisibility(GONE); } else { mConversationView.setVisibility(VISIBLE); mMiscellaneousView.setVisibility(GONE); } // set up the drawer as appropriate for the configuration final ViewParent foldersParent = mFoldersView.getParent(); if (mIsExpansiveLayout && foldersParent != this) { if (foldersParent != mDrawerLayout) { throw new IllegalStateException("invalid Folders fragment parent: " + foldersParent); } mDrawerLayout.removeView(mFoldersView); addView(mFoldersView, 0); mFoldersView.findViewById(R.id.folders_pane_edge).setVisibility(VISIBLE); mFoldersView.setBackgroundDrawable(null); } else if (!mIsExpansiveLayout && foldersParent == this) { removeView(mFoldersView); mDrawerLayout.addView(mFoldersView); final DrawerLayout.LayoutParams lp = (DrawerLayout.LayoutParams) mFoldersView.getLayoutParams(); lp.gravity = Gravity.START; mFoldersView.setLayoutParams(lp); mFoldersView.findViewById(R.id.folders_pane_edge).setVisibility(GONE); mFoldersView.setBackgroundResource(R.color.list_background_color); } // detach the pager immediately from its data source (to prevent processing updates) if (ViewMode.isConversationMode(mCurrentMode)) { mController.disablePagerUpdates(); } mDrawerInitialSetupComplete = true; mCurrentMode = newMode; LogUtils.i(LOG_TAG, "onViewModeChanged(%d)", newMode); // do all the real work in onMeasure/onLayout, when panes are sized and positioned for the // current width/height anyway requestLayout(); } public boolean isModeChangePending() { return mPositionedMode != mCurrentMode; } private void setPaneWidth(View pane, int w) { final ViewGroup.LayoutParams lp = pane.getLayoutParams(); if (lp.width == w) { return; } lp.width = w; pane.setLayoutParams(lp); if (LogUtils.isLoggable(LOG_TAG, LogUtils.DEBUG)) { final String s; if (pane == mFoldersView) { s = "folders"; } else if (pane == mListView) { s = "conv-list"; } else if (pane == mConversationView) { s = "conv-view"; } else if (pane == mMiscellaneousView) { s = "misc-view"; } else { s = "???:" + pane; } LogUtils.d(LOG_TAG, "TPL: setPaneWidth, w=%spx pane=%s", w, s); } } public boolean isDrawerEnabled() { return !mIsExpansiveLayout && mDrawerInitialSetupComplete; } public boolean isExpansiveLayout() { return mIsExpansiveLayout; } }