Java tutorial
/* * Copyright (C) 2013 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 be.virtualsushi.tick5.view; import android.content.Context; import android.content.Intent; import android.content.pm.PackageManager; import android.content.pm.ResolveInfo; import android.content.res.Resources; import android.content.res.TypedArray; import android.database.DataSetObserver; import android.graphics.drawable.Drawable; import android.support.v4.view.ActionProvider; import android.support.v7.appcompat.R; import android.support.v7.internal.widget.ActivityChooserModel; import android.support.v7.internal.widget.ListPopupWindow; import android.util.AttributeSet; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.view.ViewTreeObserver; import android.view.ViewTreeObserver.OnGlobalLayoutListener; import android.widget.AdapterView; import android.widget.BaseAdapter; import android.widget.FrameLayout; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.PopupWindow; import android.widget.TextView; /** * This class is a view for choosing an activity for handling a given * {@link Intent}. * <p> * The view is composed of two adjacent buttons: * <ul> * <li> * The left button is an immediate action and allows one click activity * choosing. Tapping this button immediately executes the intent without * requiring any further user input. Long press on this button shows a popup for * changing the default activity.</li> * <li> * The right button is an overflow action and provides an optimized menu of * additional activities. Tapping this button shows a popup anchored to this * view, listing the most frequently used activities. This list is initially * limited to a small number of items in frequency used order. The last item, * "Show all..." serves as an affordance to display all available activities.</li> * </ul> * </p> * * @hide */ public class ActivityChooserView extends ViewGroup implements ActivityChooserModel.ActivityChooserModelClient { /** * An adapter for displaying the activities in an * {@link android.widget.AdapterView}. */ private final ActivityChooserViewAdapter mAdapter; /** * Implementation of various interfaces to avoid publishing them in the * APIs. */ private final Callbacks mCallbacks; /** * The content of this view. */ private final LinearLayout mActivityChooserContent; /** * The expand activities action button; */ private final FrameLayout mExpandActivityOverflowButton; /** * The image for the expand activities action button; */ private final ImageView mExpandActivityOverflowButtonImage; /** * The maximal width of the list popup. */ private final int mListPopupMaxWidth; /** * The ActionProvider hosting this view, if applicable. */ ActionProvider mProvider; /** * Observer for the model data. */ private final DataSetObserver mModelDataSetOberver = new DataSetObserver() { @Override public void onChanged() { super.onChanged(); mAdapter.notifyDataSetChanged(); } @Override public void onInvalidated() { super.onInvalidated(); mAdapter.notifyDataSetInvalidated(); } }; private final OnGlobalLayoutListener mOnGlobalLayoutListener = new OnGlobalLayoutListener() { @Override public void onGlobalLayout() { if (isShowingPopup()) { if (!isShown()) { getListPopupWindow().dismiss(); } else { getListPopupWindow().show(); if (mProvider != null) { mProvider.subUiVisibilityChanged(true); } } } } }; /** * Popup window for showing the activity overflow list. */ private ListPopupWindow mListPopupWindow; /** * Listener for the dismissal of the popup/alert. */ private PopupWindow.OnDismissListener mOnDismissListener; /** * Flag whether a default activity currently being selected. */ private boolean mIsSelectingDefaultActivity; /** * The count of activities in the popup. */ private int mInitialActivityCount = ActivityChooserViewAdapter.MAX_ACTIVITY_COUNT_DEFAULT; /** * Flag whether this view is attached to a window. */ private boolean mIsAttachedToWindow; /** * Create a new instance. * * @param context * The application environment. */ public ActivityChooserView(Context context) { this(context, null); } /** * Create a new instance. * * @param context * The application environment. * @param attrs * A collection of attributes. */ public ActivityChooserView(Context context, AttributeSet attrs) { this(context, attrs, 0); } /** * Create a new instance. * * @param context * The application environment. * @param attrs * A collection of attributes. * @param defStyle * The default style to apply to this view. */ public ActivityChooserView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); TypedArray attributesArray = context.obtainStyledAttributes(attrs, R.styleable.ActivityChooserView, defStyle, 0); mInitialActivityCount = attributesArray.getInt(R.styleable.ActivityChooserView_initialActivityCount, ActivityChooserViewAdapter.MAX_ACTIVITY_COUNT_DEFAULT); Drawable expandActivityOverflowButtonDrawable = attributesArray .getDrawable(R.styleable.ActivityChooserView_expandActivityOverflowButtonDrawable); attributesArray.recycle(); LayoutInflater inflater = LayoutInflater.from(getContext()); inflater.inflate(R.layout.abc_activity_chooser_view, this, true); mCallbacks = new Callbacks(); mActivityChooserContent = (LinearLayout) findViewById(R.id.activity_chooser_view_content); mActivityChooserContent.setBackgroundDrawable(null); findViewById(R.id.default_activity_button).setVisibility(GONE); mExpandActivityOverflowButton = (FrameLayout) findViewById(R.id.expand_activities_button); mExpandActivityOverflowButton.setOnClickListener(mCallbacks); mExpandActivityOverflowButtonImage = (ImageView) mExpandActivityOverflowButton.findViewById(R.id.image); mExpandActivityOverflowButtonImage.setImageDrawable(expandActivityOverflowButtonDrawable); mAdapter = new ActivityChooserViewAdapter(); mAdapter.registerDataSetObserver(new DataSetObserver() { @Override public void onChanged() { super.onChanged(); updateAppearance(); } }); Resources resources = context.getResources(); mListPopupMaxWidth = Math.max(resources.getDisplayMetrics().widthPixels / 2, resources.getDimensionPixelSize(R.dimen.abc_config_prefDialogWidth)); } /** * {@inheritDoc} */ public void setActivityChooserModel(ActivityChooserModel dataModel) { mAdapter.setDataModel(dataModel); if (isShowingPopup()) { dismissPopup(); showPopup(); } } /** * Sets the background for the button that expands the activity overflow * list. * * <strong>Note:</strong> Clients would like to set this drawable as a clue * about the action the chosen activity will perform. For example, if a * share activity is to be chosen the drawable should give a clue that * sharing is to be performed. * * @param drawable * The drawable. */ public void setExpandActivityOverflowButtonDrawable(Drawable drawable) { mExpandActivityOverflowButtonImage.setImageDrawable(drawable); } /** * Sets the content description for the button that expands the activity * overflow list. * * description as a clue about the action performed by the button. For * example, if a share activity is to be chosen the content description * should be something like "Share with". * * @param resourceId * The content description resource id. */ public void setExpandActivityOverflowButtonContentDescription(int resourceId) { CharSequence contentDescription = getContext().getString(resourceId); mExpandActivityOverflowButtonImage.setContentDescription(contentDescription); } /** * Set the provider hosting this view, if applicable. * * @hide Internal use only */ public void setProvider(ActionProvider provider) { mProvider = provider; } /** * Shows the popup window with activities. * * @return True if the popup was shown, false if already showing. */ public boolean showPopup() { if (isShowingPopup() || !mIsAttachedToWindow) { return false; } mIsSelectingDefaultActivity = false; showPopupUnchecked(mInitialActivityCount); return true; } /** * Shows the popup no matter if it was already showing. * * @param maxActivityCount * The max number of activities to display. */ private void showPopupUnchecked(int maxActivityCount) { if (mAdapter.getDataModel() == null) { throw new IllegalStateException("No data model. Did you call #setDataModel?"); } getViewTreeObserver().addOnGlobalLayoutListener(mOnGlobalLayoutListener); final int activityCount = mAdapter.getActivityCount(); if (maxActivityCount != ActivityChooserViewAdapter.MAX_ACTIVITY_COUNT_UNLIMITED && activityCount > maxActivityCount) { mAdapter.setShowFooterView(true); mAdapter.setMaxActivityCount(maxActivityCount - 1); } else { mAdapter.setShowFooterView(false); mAdapter.setMaxActivityCount(maxActivityCount); } ListPopupWindow popupWindow = getListPopupWindow(); if (!popupWindow.isShowing()) { final int contentWidth = Math.min(mAdapter.measureContentWidth(), mListPopupMaxWidth); popupWindow.setContentWidth(contentWidth); popupWindow.show(); if (mProvider != null) { mProvider.subUiVisibilityChanged(true); } popupWindow.getListView().setContentDescription( getContext().getString(R.string.abc_activitychooserview_choose_application)); } } /** * Dismisses the popup window with activities. * * @return True if dismissed, false if already dismissed. */ public boolean dismissPopup() { if (isShowingPopup()) { getListPopupWindow().dismiss(); ViewTreeObserver viewTreeObserver = getViewTreeObserver(); if (viewTreeObserver.isAlive()) { viewTreeObserver.removeGlobalOnLayoutListener(mOnGlobalLayoutListener); } } return true; } /** * Gets whether the popup window with activities is shown. * * @return True if the popup is shown. */ public boolean isShowingPopup() { return getListPopupWindow().isShowing(); } @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); ActivityChooserModel dataModel = mAdapter.getDataModel(); if (dataModel != null) { dataModel.registerObserver(mModelDataSetOberver); } mIsAttachedToWindow = true; } @Override protected void onDetachedFromWindow() { super.onDetachedFromWindow(); ActivityChooserModel dataModel = mAdapter.getDataModel(); if (dataModel != null) { dataModel.unregisterObserver(mModelDataSetOberver); } ViewTreeObserver viewTreeObserver = getViewTreeObserver(); if (viewTreeObserver.isAlive()) { viewTreeObserver.removeGlobalOnLayoutListener(mOnGlobalLayoutListener); } if (isShowingPopup()) { dismissPopup(); } mIsAttachedToWindow = false; } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { View child = mActivityChooserContent; // If the default action is not visible we want to be as tall as the // ActionBar so if this widget is used in the latter it will look as // a normal action button. heightMeasureSpec = MeasureSpec.makeMeasureSpec(MeasureSpec.getSize(heightMeasureSpec), MeasureSpec.EXACTLY); measureChild(child, widthMeasureSpec, heightMeasureSpec); setMeasuredDimension(child.getMeasuredWidth(), child.getMeasuredHeight()); } @Override protected void onLayout(boolean changed, int left, int top, int right, int bottom) { mActivityChooserContent.layout(0, 0, right - left, bottom - top); if (!isShowingPopup()) { dismissPopup(); } } public ActivityChooserModel getDataModel() { return mAdapter.getDataModel(); } /** * Sets a listener to receive a callback when the popup is dismissed. * * @param listener * The listener to be notified. */ public void setOnDismissListener(PopupWindow.OnDismissListener listener) { mOnDismissListener = listener; } /** * Sets the initial count of items shown in the activities popup i.e. the * items before the popup is expanded. This is an upper bound since it is * not guaranteed that such number of intent handlers exist. * * @param itemCount * The initial popup item count. */ public void setInitialActivityCount(int itemCount) { mInitialActivityCount = itemCount; } /** * Sets a content description of the default action button. This resource * should be a string taking one formatting argument and will be used for * formatting the content description of the button dynamically as the * default target changes. For example, a resource pointing to the string * "share with %1$s" will result in a content description * "share with Bluetooth" for the Bluetooth activity. * * @param resourceId * The resource id. */ public void setDefaultActionButtonContentDescription(int resourceId) { } /** * Gets the list popup window which is lazily initialized. * * @return The popup. */ private ListPopupWindow getListPopupWindow() { if (mListPopupWindow == null) { mListPopupWindow = new ListPopupWindow(getContext()); mListPopupWindow.setAdapter(mAdapter); mListPopupWindow.setAnchorView(ActivityChooserView.this); mListPopupWindow.setModal(true); mListPopupWindow.setOnItemClickListener(mCallbacks); mListPopupWindow.setOnDismissListener(mCallbacks); } return mListPopupWindow; } /** * Updates the buttons state. */ private void updateAppearance() { // Expand overflow button. if (mAdapter.getCount() > 0) { mExpandActivityOverflowButton.setEnabled(true); } else { mExpandActivityOverflowButton.setEnabled(false); } } /** * Interface implementation to avoid publishing them in the APIs. */ private class Callbacks implements AdapterView.OnItemClickListener, View.OnClickListener, PopupWindow.OnDismissListener { // AdapterView#OnItemClickListener public void onItemClick(AdapterView<?> parent, View view, int position, long id) { ActivityChooserViewAdapter adapter = (ActivityChooserViewAdapter) parent.getAdapter(); final int itemViewType = adapter.getItemViewType(position); switch (itemViewType) { case ActivityChooserViewAdapter.ITEM_VIEW_TYPE_FOOTER: { showPopupUnchecked(ActivityChooserViewAdapter.MAX_ACTIVITY_COUNT_UNLIMITED); } break; case ActivityChooserViewAdapter.ITEM_VIEW_TYPE_ACTIVITY: { dismissPopup(); if (mIsSelectingDefaultActivity) { // The item at position zero is the default already. if (position > 0) { mAdapter.getDataModel().setDefaultActivity(position); } } else { // If the default target is not shown in the list, the first // item in the model is default action => adjust index Intent launchIntent = mAdapter.getDataModel().chooseActivity(position); if (launchIntent != null) { launchIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET); getContext().startActivity(launchIntent); } } } break; default: throw new IllegalArgumentException(); } } // View.OnClickListener public void onClick(View view) { if (view == mExpandActivityOverflowButton) { mIsSelectingDefaultActivity = false; showPopupUnchecked(mInitialActivityCount); } else { throw new IllegalArgumentException(); } } // PopUpWindow.OnDismissListener#onDismiss public void onDismiss() { notifyOnDismissListener(); if (mProvider != null) { mProvider.subUiVisibilityChanged(false); } } private void notifyOnDismissListener() { if (mOnDismissListener != null) { mOnDismissListener.onDismiss(); } } } /** * Adapter for backing the list of activities shown in the popup. */ private class ActivityChooserViewAdapter extends BaseAdapter { public static final int MAX_ACTIVITY_COUNT_UNLIMITED = Integer.MAX_VALUE; public static final int MAX_ACTIVITY_COUNT_DEFAULT = 4; private static final int ITEM_VIEW_TYPE_ACTIVITY = 0; private static final int ITEM_VIEW_TYPE_FOOTER = 1; private static final int ITEM_VIEW_TYPE_COUNT = 3; private ActivityChooserModel mDataModel; private int mMaxActivityCount = MAX_ACTIVITY_COUNT_DEFAULT; private boolean mHighlightDefaultActivity; private boolean mShowFooterView; public void setDataModel(ActivityChooserModel dataModel) { ActivityChooserModel oldDataModel = mAdapter.getDataModel(); if (oldDataModel != null && isShown()) { oldDataModel.unregisterObserver(mModelDataSetOberver); } mDataModel = dataModel; if (dataModel != null && isShown()) { dataModel.registerObserver(mModelDataSetOberver); } notifyDataSetChanged(); } @Override public int getItemViewType(int position) { if (mShowFooterView && position == getCount() - 1) { return ITEM_VIEW_TYPE_FOOTER; } else { return ITEM_VIEW_TYPE_ACTIVITY; } } @Override public int getViewTypeCount() { return ITEM_VIEW_TYPE_COUNT; } public int getCount() { int count = 0; int activityCount = mDataModel.getActivityCount(); count = Math.min(activityCount, mMaxActivityCount); if (mShowFooterView) { count++; } return count; } public Object getItem(int position) { final int itemViewType = getItemViewType(position); switch (itemViewType) { case ITEM_VIEW_TYPE_FOOTER: return null; case ITEM_VIEW_TYPE_ACTIVITY: return mDataModel.getActivity(position); default: throw new IllegalArgumentException(); } } public long getItemId(int position) { return position; } public View getView(int position, View convertView, ViewGroup parent) { final int itemViewType = getItemViewType(position); switch (itemViewType) { case ITEM_VIEW_TYPE_FOOTER: if (convertView == null || convertView.getId() != ITEM_VIEW_TYPE_FOOTER) { convertView = LayoutInflater.from(getContext()) .inflate(R.layout.abc_activity_chooser_view_list_item, parent, false); convertView.setId(ITEM_VIEW_TYPE_FOOTER); TextView titleView = (TextView) convertView.findViewById(R.id.title); titleView.setText(getContext().getString(R.string.abc_activity_chooser_view_see_all)); } return convertView; case ITEM_VIEW_TYPE_ACTIVITY: if (convertView == null || convertView.getId() != R.id.list_item) { convertView = LayoutInflater.from(getContext()) .inflate(R.layout.abc_activity_chooser_view_list_item, parent, false); } PackageManager packageManager = getContext().getPackageManager(); // Set the icon ImageView iconView = (ImageView) convertView.findViewById(R.id.icon); ResolveInfo activity = (ResolveInfo) getItem(position); iconView.setImageDrawable(activity.loadIcon(packageManager)); // Set the title. TextView titleView = (TextView) convertView.findViewById(R.id.title); titleView.setText(activity.loadLabel(packageManager)); return convertView; default: throw new IllegalArgumentException(); } } public int measureContentWidth() { // The user may have specified some of the target not to be shown // but we // want to measure all of them since after expansion they should // fit. final int oldMaxActivityCount = mMaxActivityCount; mMaxActivityCount = MAX_ACTIVITY_COUNT_UNLIMITED; int contentWidth = 0; View itemView = null; final int widthMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); final int heightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); final int count = getCount(); for (int i = 0; i < count; i++) { itemView = getView(i, itemView, null); itemView.measure(widthMeasureSpec, heightMeasureSpec); contentWidth = Math.max(contentWidth, itemView.getMeasuredWidth()); } mMaxActivityCount = oldMaxActivityCount; return contentWidth; } public void setMaxActivityCount(int maxActivityCount) { if (mMaxActivityCount != maxActivityCount) { mMaxActivityCount = maxActivityCount; notifyDataSetChanged(); } } public void setShowFooterView(boolean showFooterView) { if (mShowFooterView != showFooterView) { mShowFooterView = showFooterView; notifyDataSetChanged(); } } public int getActivityCount() { return mDataModel.getActivityCount(); } public ActivityChooserModel getDataModel() { return mDataModel; } } }