| /* |
| * 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.NonNull; |
| import android.annotation.Nullable; |
| import android.compat.annotation.UnsupportedAppUsage; |
| import android.content.Context; |
| import android.database.DataSetObserver; |
| import android.os.Build; |
| import android.os.Parcelable; |
| import android.os.SystemClock; |
| import android.util.AttributeSet; |
| import android.util.SparseArray; |
| import android.view.ContextMenu; |
| import android.view.ContextMenu.ContextMenuInfo; |
| import android.view.SoundEffectConstants; |
| import android.view.View; |
| import android.view.ViewDebug; |
| import android.view.ViewGroup; |
| import android.view.ViewHierarchyEncoder; |
| import android.view.ViewStructure; |
| import android.view.accessibility.AccessibilityEvent; |
| import android.view.accessibility.AccessibilityManager; |
| import android.view.accessibility.AccessibilityNodeInfo; |
| import android.view.autofill.AutofillManager; |
| |
| /** |
| * An AdapterView is a view whose children are determined by an {@link Adapter}. |
| * |
| * <p> |
| * See {@link ListView}, {@link GridView}, {@link Spinner} and |
| * {@link Gallery} for commonly used subclasses of AdapterView. |
| * |
| * <div class="special reference"> |
| * <h3>Developer Guides</h3> |
| * <p>For more information about using AdapterView, read the |
| * <a href="{@docRoot}guide/topics/ui/binding.html">Binding to Data with AdapterView</a> |
| * developer guide.</p></div> |
| */ |
| public abstract class AdapterView<T extends Adapter> extends ViewGroup { |
| |
| /** |
| * The item view type returned by {@link Adapter#getItemViewType(int)} when |
| * the adapter does not want the item's view recycled. |
| */ |
| public static final int ITEM_VIEW_TYPE_IGNORE = -1; |
| |
| /** |
| * The item view type returned by {@link Adapter#getItemViewType(int)} when |
| * the item is a header or footer. |
| */ |
| public static final int ITEM_VIEW_TYPE_HEADER_OR_FOOTER = -2; |
| |
| /** |
| * The position of the first child displayed |
| */ |
| @ViewDebug.ExportedProperty(category = "scrolling") |
| @UnsupportedAppUsage |
| int mFirstPosition = 0; |
| |
| /** |
| * The offset in pixels from the top of the AdapterView to the top |
| * of the view to select during the next layout. |
| */ |
| int mSpecificTop; |
| |
| /** |
| * Position from which to start looking for mSyncRowId |
| */ |
| @UnsupportedAppUsage |
| int mSyncPosition; |
| |
| /** |
| * Row id to look for when data has changed |
| */ |
| long mSyncRowId = INVALID_ROW_ID; |
| |
| /** |
| * Height of the view when mSyncPosition and mSyncRowId where set |
| */ |
| long mSyncHeight; |
| |
| /** |
| * True if we need to sync to mSyncRowId |
| */ |
| @UnsupportedAppUsage |
| boolean mNeedSync = false; |
| |
| /** |
| * Indicates whether to sync based on the selection or position. Possible |
| * values are {@link #SYNC_SELECTED_POSITION} or |
| * {@link #SYNC_FIRST_POSITION}. |
| */ |
| int mSyncMode; |
| |
| /** |
| * Our height after the last layout |
| */ |
| private int mLayoutHeight; |
| |
| /** |
| * Sync based on the selected child |
| */ |
| static final int SYNC_SELECTED_POSITION = 0; |
| |
| /** |
| * Sync based on the first child displayed |
| */ |
| static final int SYNC_FIRST_POSITION = 1; |
| |
| /** |
| * Maximum amount of time to spend in {@link #findSyncPosition()} |
| */ |
| static final int SYNC_MAX_DURATION_MILLIS = 100; |
| |
| /** |
| * Indicates that this view is currently being laid out. |
| */ |
| boolean mInLayout = false; |
| |
| /** |
| * The listener that receives notifications when an item is selected. |
| */ |
| @UnsupportedAppUsage |
| OnItemSelectedListener mOnItemSelectedListener; |
| |
| /** |
| * The listener that receives notifications when an item is clicked. |
| */ |
| @UnsupportedAppUsage |
| OnItemClickListener mOnItemClickListener; |
| |
| /** |
| * The listener that receives notifications when an item is long clicked. |
| */ |
| OnItemLongClickListener mOnItemLongClickListener; |
| |
| /** |
| * True if the data has changed since the last layout |
| */ |
| @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 123768524) |
| boolean mDataChanged; |
| |
| /** |
| * The position within the adapter's data set of the item to select |
| * during the next layout. |
| */ |
| @ViewDebug.ExportedProperty(category = "list") |
| @UnsupportedAppUsage |
| int mNextSelectedPosition = INVALID_POSITION; |
| |
| /** |
| * The item id of the item to select during the next layout. |
| */ |
| @UnsupportedAppUsage |
| long mNextSelectedRowId = INVALID_ROW_ID; |
| |
| /** |
| * The position within the adapter's data set of the currently selected item. |
| */ |
| @ViewDebug.ExportedProperty(category = "list") |
| @UnsupportedAppUsage |
| int mSelectedPosition = INVALID_POSITION; |
| |
| /** |
| * The item id of the currently selected item. |
| */ |
| long mSelectedRowId = INVALID_ROW_ID; |
| |
| /** |
| * View to show if there are no items to show. |
| */ |
| private View mEmptyView; |
| |
| /** |
| * The number of items in the current adapter. |
| */ |
| @ViewDebug.ExportedProperty(category = "list") |
| int mItemCount; |
| |
| /** |
| * The number of items in the adapter before a data changed event occurred. |
| */ |
| int mOldItemCount; |
| |
| /** |
| * Represents an invalid position. All valid positions are in the range 0 to 1 less than the |
| * number of items in the current adapter. |
| */ |
| public static final int INVALID_POSITION = -1; |
| |
| /** |
| * Represents an empty or invalid row id |
| */ |
| public static final long INVALID_ROW_ID = Long.MIN_VALUE; |
| |
| /** |
| * The last selected position we used when notifying |
| */ |
| @UnsupportedAppUsage |
| int mOldSelectedPosition = INVALID_POSITION; |
| |
| /** |
| * The id of the last selected position we used when notifying |
| */ |
| long mOldSelectedRowId = INVALID_ROW_ID; |
| |
| /** |
| * Indicates what focusable state is requested when calling setFocusable(). |
| * In addition to this, this view has other criteria for actually |
| * determining the focusable state (such as whether its empty or the text |
| * filter is shown). |
| * |
| * @see #setFocusable(boolean) |
| * @see #checkFocus() |
| */ |
| private int mDesiredFocusableState = FOCUSABLE_AUTO; |
| private boolean mDesiredFocusableInTouchModeState; |
| |
| /** Lazily-constructed runnable for dispatching selection events. */ |
| private SelectionNotifier mSelectionNotifier; |
| |
| /** Selection notifier that's waiting for the next layout pass. */ |
| private SelectionNotifier mPendingSelectionNotifier; |
| |
| /** |
| * When set to true, calls to requestLayout() will not propagate up the parent hierarchy. |
| * This is used to layout the children during a layout pass. |
| */ |
| boolean mBlockLayoutRequests = false; |
| |
| public AdapterView(Context context) { |
| this(context, null); |
| } |
| |
| public AdapterView(Context context, AttributeSet attrs) { |
| this(context, attrs, 0); |
| } |
| |
| public AdapterView(Context context, AttributeSet attrs, int defStyleAttr) { |
| this(context, attrs, defStyleAttr, 0); |
| } |
| |
| public AdapterView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { |
| super(context, attrs, defStyleAttr, defStyleRes); |
| |
| // If not explicitly specified this view is important for accessibility. |
| if (getImportantForAccessibility() == IMPORTANT_FOR_ACCESSIBILITY_AUTO) { |
| setImportantForAccessibility(IMPORTANT_FOR_ACCESSIBILITY_YES); |
| } |
| |
| mDesiredFocusableState = getFocusable(); |
| if (mDesiredFocusableState == FOCUSABLE_AUTO) { |
| // Starts off without an adapter, so NOT_FOCUSABLE by default. |
| super.setFocusable(NOT_FOCUSABLE); |
| } |
| } |
| |
| /** |
| * Interface definition for a callback to be invoked when an item in this |
| * AdapterView has been clicked. |
| */ |
| public interface OnItemClickListener { |
| |
| /** |
| * Callback method to be invoked when an item in this AdapterView has |
| * been clicked. |
| * <p> |
| * Implementers can call getItemAtPosition(position) if they need |
| * to access the data associated with the selected item. |
| * |
| * @param parent The AdapterView where the click happened. |
| * @param view The view within the AdapterView that was clicked (this |
| * will be a view provided by the adapter) |
| * @param position The position of the view in the adapter. |
| * @param id The row id of the item that was clicked. |
| */ |
| void onItemClick(AdapterView<?> parent, View view, int position, long id); |
| } |
| |
| /** |
| * Register a callback to be invoked when an item in this AdapterView has |
| * been clicked. |
| * |
| * @param listener The callback that will be invoked. |
| */ |
| public void setOnItemClickListener(@Nullable OnItemClickListener listener) { |
| mOnItemClickListener = listener; |
| } |
| |
| /** |
| * @return The callback to be invoked with an item in this AdapterView has |
| * been clicked, or null if no callback has been set. |
| */ |
| @Nullable |
| public final OnItemClickListener getOnItemClickListener() { |
| return mOnItemClickListener; |
| } |
| |
| /** |
| * Call the OnItemClickListener, if it is defined. Performs all normal |
| * actions associated with clicking: reporting accessibility event, playing |
| * a sound, etc. |
| * |
| * @param view The view within the AdapterView that was clicked. |
| * @param position The position of the view in the adapter. |
| * @param id The row id of the item that was clicked. |
| * @return True if there was an assigned OnItemClickListener that was |
| * called, false otherwise is returned. |
| */ |
| public boolean performItemClick(View view, int position, long id) { |
| final boolean result; |
| if (mOnItemClickListener != null) { |
| playSoundEffect(SoundEffectConstants.CLICK); |
| mOnItemClickListener.onItemClick(this, view, position, id); |
| result = true; |
| } else { |
| result = false; |
| } |
| |
| if (view != null) { |
| view.sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_CLICKED); |
| } |
| return result; |
| } |
| |
| /** |
| * Interface definition for a callback to be invoked when an item in this |
| * view has been clicked and held. |
| */ |
| public interface OnItemLongClickListener { |
| /** |
| * Callback method to be invoked when an item in this view has been |
| * clicked and held. |
| * |
| * Implementers can call getItemAtPosition(position) if they need to access |
| * the data associated with the selected item. |
| * |
| * @param parent The AbsListView where the click happened |
| * @param view The view within the AbsListView that was clicked |
| * @param position The position of the view in the list |
| * @param id The row id of the item that was clicked |
| * |
| * @return true if the callback consumed the long click, false otherwise |
| */ |
| boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id); |
| } |
| |
| |
| /** |
| * Register a callback to be invoked when an item in this AdapterView has |
| * been clicked and held |
| * |
| * @param listener The callback that will run |
| */ |
| public void setOnItemLongClickListener(OnItemLongClickListener listener) { |
| if (!isLongClickable()) { |
| setLongClickable(true); |
| } |
| mOnItemLongClickListener = listener; |
| } |
| |
| /** |
| * @return The callback to be invoked with an item in this AdapterView has |
| * been clicked and held, or null if no callback has been set. |
| */ |
| public final OnItemLongClickListener getOnItemLongClickListener() { |
| return mOnItemLongClickListener; |
| } |
| |
| /** |
| * Interface definition for a callback to be invoked when |
| * an item in this view has been selected. |
| */ |
| public interface OnItemSelectedListener { |
| /** |
| * <p>Callback method to be invoked when an item in this view has been |
| * selected. This callback is invoked only when the newly selected |
| * position is different from the previously selected position or if |
| * there was no selected item.</p> |
| * |
| * Implementers can call getItemAtPosition(position) if they need to access the |
| * data associated with the selected item. |
| * |
| * @param parent The AdapterView where the selection happened |
| * @param view The view within the AdapterView that was clicked |
| * @param position The position of the view in the adapter |
| * @param id The row id of the item that is selected |
| */ |
| void onItemSelected(AdapterView<?> parent, View view, int position, long id); |
| |
| /** |
| * Callback method to be invoked when the selection disappears from this |
| * view. The selection can disappear for instance when touch is activated |
| * or when the adapter becomes empty. |
| * |
| * @param parent The AdapterView that now contains no selected item. |
| */ |
| void onNothingSelected(AdapterView<?> parent); |
| } |
| |
| |
| /** |
| * Register a callback to be invoked when an item in this AdapterView has |
| * been selected. |
| * |
| * @param listener The callback that will run |
| */ |
| public void setOnItemSelectedListener(@Nullable OnItemSelectedListener listener) { |
| mOnItemSelectedListener = listener; |
| } |
| |
| @Nullable |
| public final OnItemSelectedListener getOnItemSelectedListener() { |
| return mOnItemSelectedListener; |
| } |
| |
| /** |
| * Extra menu information provided to the |
| * {@link android.view.View.OnCreateContextMenuListener#onCreateContextMenu(ContextMenu, View, ContextMenuInfo) } |
| * callback when a context menu is brought up for this AdapterView. |
| * |
| */ |
| public static class AdapterContextMenuInfo implements ContextMenu.ContextMenuInfo { |
| |
| public AdapterContextMenuInfo(View targetView, int position, long id) { |
| this.targetView = targetView; |
| this.position = position; |
| this.id = id; |
| } |
| |
| /** |
| * The child view for which the context menu is being displayed. This |
| * will be one of the children of this AdapterView. |
| */ |
| public View targetView; |
| |
| /** |
| * The position in the adapter for which the context menu is being |
| * displayed. |
| */ |
| public int position; |
| |
| /** |
| * The row id of the item for which the context menu is being displayed. |
| */ |
| public long id; |
| } |
| |
| /** |
| * Returns the adapter currently associated with this widget. |
| * |
| * @return The adapter used to provide this view's content. |
| */ |
| public abstract T getAdapter(); |
| |
| /** |
| * Sets the adapter that provides the data and the views to represent the data |
| * in this widget. |
| * |
| * @param adapter The adapter to use to create this view's content. |
| */ |
| public abstract void setAdapter(T adapter); |
| |
| /** |
| * This method is not supported and throws an UnsupportedOperationException when called. |
| * |
| * @param child Ignored. |
| * |
| * @throws UnsupportedOperationException Every time this method is invoked. |
| */ |
| @Override |
| public void addView(View child) { |
| throw new UnsupportedOperationException("addView(View) is not supported in AdapterView"); |
| } |
| |
| /** |
| * This method is not supported and throws an UnsupportedOperationException when called. |
| * |
| * @param child Ignored. |
| * @param index Ignored. |
| * |
| * @throws UnsupportedOperationException Every time this method is invoked. |
| */ |
| @Override |
| public void addView(View child, int index) { |
| throw new UnsupportedOperationException("addView(View, int) is not supported in AdapterView"); |
| } |
| |
| /** |
| * This method is not supported and throws an UnsupportedOperationException when called. |
| * |
| * @param child Ignored. |
| * @param params Ignored. |
| * |
| * @throws UnsupportedOperationException Every time this method is invoked. |
| */ |
| @Override |
| public void addView(View child, LayoutParams params) { |
| throw new UnsupportedOperationException("addView(View, LayoutParams) " |
| + "is not supported in AdapterView"); |
| } |
| |
| /** |
| * This method is not supported and throws an UnsupportedOperationException when called. |
| * |
| * @param child Ignored. |
| * @param index Ignored. |
| * @param params Ignored. |
| * |
| * @throws UnsupportedOperationException Every time this method is invoked. |
| */ |
| @Override |
| public void addView(View child, int index, LayoutParams params) { |
| throw new UnsupportedOperationException("addView(View, int, LayoutParams) " |
| + "is not supported in AdapterView"); |
| } |
| |
| /** |
| * This method is not supported and throws an UnsupportedOperationException when called. |
| * |
| * @param child Ignored. |
| * |
| * @throws UnsupportedOperationException Every time this method is invoked. |
| */ |
| @Override |
| public void removeView(View child) { |
| throw new UnsupportedOperationException("removeView(View) is not supported in AdapterView"); |
| } |
| |
| /** |
| * This method is not supported and throws an UnsupportedOperationException when called. |
| * |
| * @param index Ignored. |
| * |
| * @throws UnsupportedOperationException Every time this method is invoked. |
| */ |
| @Override |
| public void removeViewAt(int index) { |
| throw new UnsupportedOperationException("removeViewAt(int) is not supported in AdapterView"); |
| } |
| |
| /** |
| * This method is not supported and throws an UnsupportedOperationException when called. |
| * |
| * @throws UnsupportedOperationException Every time this method is invoked. |
| */ |
| @Override |
| public void removeAllViews() { |
| throw new UnsupportedOperationException("removeAllViews() is not supported in AdapterView"); |
| } |
| |
| @Override |
| protected void onLayout(boolean changed, int left, int top, int right, int bottom) { |
| mLayoutHeight = getHeight(); |
| } |
| |
| /** |
| * Return the position of the currently selected item within the adapter's data set |
| * |
| * @return int Position (starting at 0), or {@link #INVALID_POSITION} if there is nothing selected. |
| */ |
| @ViewDebug.CapturedViewProperty |
| public int getSelectedItemPosition() { |
| return mNextSelectedPosition; |
| } |
| |
| /** |
| * @return The id corresponding to the currently selected item, or {@link #INVALID_ROW_ID} |
| * if nothing is selected. |
| */ |
| @ViewDebug.CapturedViewProperty |
| public long getSelectedItemId() { |
| return mNextSelectedRowId; |
| } |
| |
| /** |
| * @return The view corresponding to the currently selected item, or null |
| * if nothing is selected |
| */ |
| public abstract View getSelectedView(); |
| |
| /** |
| * @return The data corresponding to the currently selected item, or |
| * null if there is nothing selected. |
| */ |
| public Object getSelectedItem() { |
| T adapter = getAdapter(); |
| int selection = getSelectedItemPosition(); |
| if (adapter != null && adapter.getCount() > 0 && selection >= 0) { |
| return adapter.getItem(selection); |
| } else { |
| return null; |
| } |
| } |
| |
| /** |
| * @return The number of items owned by the Adapter associated with this |
| * AdapterView. (This is the number of data items, which may be |
| * larger than the number of visible views.) |
| */ |
| @ViewDebug.CapturedViewProperty |
| public int getCount() { |
| return mItemCount; |
| } |
| |
| /** |
| * Returns the position within the adapter's data set for the view, where |
| * view is a an adapter item or a descendant of an adapter item. |
| * <p> |
| * <strong>Note:</strong> The result of this method only reflects the |
| * position of the data bound to <var>view</var> during the most recent |
| * layout pass. If the adapter's data set has changed without a subsequent |
| * layout pass, the position returned by this method may not match the |
| * current position of the data within the adapter. |
| * |
| * @param view an adapter item, or a descendant of an adapter item. This |
| * must be visible in this AdapterView at the time of the call. |
| * @return the position within the adapter's data set of the view, or |
| * {@link #INVALID_POSITION} if the view does not correspond to a |
| * list item (or it is not currently visible) |
| */ |
| public int getPositionForView(View view) { |
| View listItem = view; |
| try { |
| View v; |
| while ((v = (View) listItem.getParent()) != null && !v.equals(this)) { |
| listItem = v; |
| } |
| } catch (ClassCastException e) { |
| // We made it up to the window without find this list view |
| return INVALID_POSITION; |
| } |
| |
| if (listItem != null) { |
| // Search the children for the list item |
| final int childCount = getChildCount(); |
| for (int i = 0; i < childCount; i++) { |
| if (getChildAt(i).equals(listItem)) { |
| return mFirstPosition + i; |
| } |
| } |
| } |
| |
| // Child not found! |
| return INVALID_POSITION; |
| } |
| |
| /** |
| * Returns the position within the adapter's data set for the first item |
| * displayed on screen. |
| * |
| * @return The position within the adapter's data set |
| */ |
| public int getFirstVisiblePosition() { |
| return mFirstPosition; |
| } |
| |
| /** |
| * Returns the position within the adapter's data set for the last item |
| * displayed on screen. |
| * |
| * @return The position within the adapter's data set |
| */ |
| public int getLastVisiblePosition() { |
| return mFirstPosition + getChildCount() - 1; |
| } |
| |
| /** |
| * Sets the currently selected item. To support accessibility subclasses that |
| * override this method must invoke the overridden super method first. |
| * |
| * @param position Index (starting at 0) of the data item to be selected. |
| */ |
| public abstract void setSelection(int position); |
| |
| /** |
| * Sets the view to show if the adapter is empty |
| */ |
| @android.view.RemotableViewMethod |
| public void setEmptyView(View emptyView) { |
| mEmptyView = emptyView; |
| |
| // If not explicitly specified this view is important for accessibility. |
| if (emptyView != null |
| && emptyView.getImportantForAccessibility() == IMPORTANT_FOR_ACCESSIBILITY_AUTO) { |
| emptyView.setImportantForAccessibility(IMPORTANT_FOR_ACCESSIBILITY_YES); |
| } |
| |
| final T adapter = getAdapter(); |
| final boolean empty = ((adapter == null) || adapter.isEmpty()); |
| updateEmptyStatus(empty); |
| } |
| |
| /** |
| * When the current adapter is empty, the AdapterView can display a special view |
| * called the empty view. The empty view is used to provide feedback to the user |
| * that no data is available in this AdapterView. |
| * |
| * @return The view to show if the adapter is empty. |
| */ |
| public View getEmptyView() { |
| return mEmptyView; |
| } |
| |
| /** |
| * Indicates whether this view is in filter mode. Filter mode can for instance |
| * be enabled by a user when typing on the keyboard. |
| * |
| * @return True if the view is in filter mode, false otherwise. |
| */ |
| boolean isInFilterMode() { |
| return false; |
| } |
| |
| @Override |
| public void setFocusable(@Focusable int focusable) { |
| final T adapter = getAdapter(); |
| final boolean empty = adapter == null || adapter.getCount() == 0; |
| |
| mDesiredFocusableState = focusable; |
| if ((focusable & (FOCUSABLE_AUTO | FOCUSABLE)) == 0) { |
| mDesiredFocusableInTouchModeState = false; |
| } |
| |
| super.setFocusable((!empty || isInFilterMode()) ? focusable : NOT_FOCUSABLE); |
| } |
| |
| @Override |
| public void setFocusableInTouchMode(boolean focusable) { |
| final T adapter = getAdapter(); |
| final boolean empty = adapter == null || adapter.getCount() == 0; |
| |
| mDesiredFocusableInTouchModeState = focusable; |
| if (focusable) { |
| mDesiredFocusableState = FOCUSABLE; |
| } |
| |
| super.setFocusableInTouchMode(focusable && (!empty || isInFilterMode())); |
| } |
| |
| void checkFocus() { |
| final T adapter = getAdapter(); |
| final boolean empty = adapter == null || adapter.getCount() == 0; |
| final boolean focusable = !empty || isInFilterMode(); |
| // The order in which we set focusable in touch mode/focusable may matter |
| // for the client, see View.setFocusableInTouchMode() comments for more |
| // details |
| super.setFocusableInTouchMode(focusable && mDesiredFocusableInTouchModeState); |
| super.setFocusable(focusable ? mDesiredFocusableState : NOT_FOCUSABLE); |
| if (mEmptyView != null) { |
| updateEmptyStatus((adapter == null) || adapter.isEmpty()); |
| } |
| } |
| |
| /** |
| * Update the status of the list based on the empty parameter. If empty is true and |
| * we have an empty view, display it. In all the other cases, make sure that the listview |
| * is VISIBLE and that the empty view is GONE (if it's not null). |
| */ |
| private void updateEmptyStatus(boolean empty) { |
| if (isInFilterMode()) { |
| empty = false; |
| } |
| |
| if (empty) { |
| if (mEmptyView != null) { |
| mEmptyView.setVisibility(View.VISIBLE); |
| setVisibility(View.GONE); |
| } else { |
| // If the caller just removed our empty view, make sure the list view is visible |
| setVisibility(View.VISIBLE); |
| } |
| |
| // We are now GONE, so pending layouts will not be dispatched. |
| // Force one here to make sure that the state of the list matches |
| // the state of the adapter. |
| if (mDataChanged) { |
| this.onLayout(false, mLeft, mTop, mRight, mBottom); |
| } |
| } else { |
| if (mEmptyView != null) mEmptyView.setVisibility(View.GONE); |
| setVisibility(View.VISIBLE); |
| } |
| } |
| |
| /** |
| * Gets the data associated with the specified position in the list. |
| * |
| * @param position Which data to get |
| * @return The data associated with the specified position in the list |
| */ |
| public Object getItemAtPosition(int position) { |
| T adapter = getAdapter(); |
| return (adapter == null || position < 0) ? null : adapter.getItem(position); |
| } |
| |
| public long getItemIdAtPosition(int position) { |
| T adapter = getAdapter(); |
| return (adapter == null || position < 0) ? INVALID_ROW_ID : adapter.getItemId(position); |
| } |
| |
| @Override |
| public void setOnClickListener(OnClickListener l) { |
| throw new RuntimeException("Don't call setOnClickListener for an AdapterView. " |
| + "You probably want setOnItemClickListener instead"); |
| } |
| |
| /** |
| * Override to prevent freezing of any views created by the adapter. |
| */ |
| @Override |
| protected void dispatchSaveInstanceState(SparseArray<Parcelable> container) { |
| dispatchFreezeSelfOnly(container); |
| } |
| |
| /** |
| * Override to prevent thawing of any views created by the adapter. |
| */ |
| @Override |
| protected void dispatchRestoreInstanceState(SparseArray<Parcelable> container) { |
| dispatchThawSelfOnly(container); |
| } |
| |
| class AdapterDataSetObserver extends DataSetObserver { |
| |
| private Parcelable mInstanceState = null; |
| |
| @Override |
| public void onChanged() { |
| mDataChanged = true; |
| mOldItemCount = mItemCount; |
| mItemCount = getAdapter().getCount(); |
| |
| // Detect the case where a cursor that was previously invalidated has |
| // been repopulated with new data. |
| if (AdapterView.this.getAdapter().hasStableIds() && mInstanceState != null |
| && mOldItemCount == 0 && mItemCount > 0) { |
| AdapterView.this.onRestoreInstanceState(mInstanceState); |
| mInstanceState = null; |
| } else { |
| rememberSyncState(); |
| } |
| checkFocus(); |
| requestLayout(); |
| } |
| |
| @Override |
| public void onInvalidated() { |
| mDataChanged = true; |
| |
| if (AdapterView.this.getAdapter().hasStableIds()) { |
| // Remember the current state for the case where our hosting activity is being |
| // stopped and later restarted |
| mInstanceState = AdapterView.this.onSaveInstanceState(); |
| } |
| |
| // Data is invalid so we should reset our state |
| mOldItemCount = mItemCount; |
| mItemCount = 0; |
| mSelectedPosition = INVALID_POSITION; |
| mSelectedRowId = INVALID_ROW_ID; |
| mNextSelectedPosition = INVALID_POSITION; |
| mNextSelectedRowId = INVALID_ROW_ID; |
| mNeedSync = false; |
| |
| checkFocus(); |
| requestLayout(); |
| } |
| |
| public void clearSavedState() { |
| mInstanceState = null; |
| } |
| } |
| |
| @Override |
| protected void onDetachedFromWindow() { |
| super.onDetachedFromWindow(); |
| removeCallbacks(mSelectionNotifier); |
| } |
| |
| private class SelectionNotifier implements Runnable { |
| public void run() { |
| mPendingSelectionNotifier = null; |
| |
| if (mDataChanged && getViewRootImpl() != null |
| && getViewRootImpl().isLayoutRequested()) { |
| // Data has changed between when this SelectionNotifier was |
| // posted and now. Postpone the notification until the next |
| // layout is complete and we run checkSelectionChanged(). |
| if (getAdapter() != null) { |
| mPendingSelectionNotifier = this; |
| } |
| } else { |
| dispatchOnItemSelected(); |
| } |
| } |
| } |
| |
| @UnsupportedAppUsage |
| void selectionChanged() { |
| // We're about to post or run the selection notifier, so we don't need |
| // a pending notifier. |
| mPendingSelectionNotifier = null; |
| |
| if (mOnItemSelectedListener != null |
| || AccessibilityManager.getInstance(mContext).isEnabled()) { |
| if (mInLayout || mBlockLayoutRequests) { |
| // If we are in a layout traversal, defer notification |
| // by posting. This ensures that the view tree is |
| // in a consistent state and is able to accommodate |
| // new layout or invalidate requests. |
| if (mSelectionNotifier == null) { |
| mSelectionNotifier = new SelectionNotifier(); |
| } else { |
| removeCallbacks(mSelectionNotifier); |
| } |
| post(mSelectionNotifier); |
| } else { |
| dispatchOnItemSelected(); |
| } |
| } |
| // Always notify AutoFillManager - it will return right away if autofill is disabled. |
| final AutofillManager afm = mContext.getSystemService(AutofillManager.class); |
| if (afm != null) { |
| afm.notifyValueChanged(this); |
| } |
| } |
| |
| private void dispatchOnItemSelected() { |
| fireOnSelected(); |
| performAccessibilityActionsOnSelected(); |
| } |
| |
| private void fireOnSelected() { |
| if (mOnItemSelectedListener == null) { |
| return; |
| } |
| final int selection = getSelectedItemPosition(); |
| if (selection >= 0) { |
| View v = getSelectedView(); |
| mOnItemSelectedListener.onItemSelected(this, v, selection, |
| getAdapter().getItemId(selection)); |
| } else { |
| mOnItemSelectedListener.onNothingSelected(this); |
| } |
| } |
| |
| private void performAccessibilityActionsOnSelected() { |
| if (!AccessibilityManager.getInstance(mContext).isEnabled()) { |
| return; |
| } |
| final int position = getSelectedItemPosition(); |
| if (position >= 0) { |
| // we fire selection events here not in View |
| // posting the event should delay it long enough for UI changes to take effect. |
| post(() -> sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_SELECTED)); |
| } |
| } |
| |
| /** @hide */ |
| @Override |
| public boolean dispatchPopulateAccessibilityEventInternal(AccessibilityEvent event) { |
| View selectedView = getSelectedView(); |
| if (selectedView != null && selectedView.getVisibility() == VISIBLE |
| && selectedView.dispatchPopulateAccessibilityEvent(event)) { |
| return true; |
| } |
| return false; |
| } |
| |
| /** @hide */ |
| @Override |
| public boolean onRequestSendAccessibilityEventInternal(View child, AccessibilityEvent event) { |
| if (super.onRequestSendAccessibilityEventInternal(child, event)) { |
| // Add a record for ourselves as well. |
| AccessibilityEvent record = AccessibilityEvent.obtain(); |
| onInitializeAccessibilityEvent(record); |
| // Populate with the text of the requesting child. |
| child.dispatchPopulateAccessibilityEvent(record); |
| event.appendRecord(record); |
| return true; |
| } |
| return false; |
| } |
| |
| @Override |
| public CharSequence getAccessibilityClassName() { |
| return AdapterView.class.getName(); |
| } |
| |
| /** @hide */ |
| @Override |
| public void onInitializeAccessibilityNodeInfoInternal(AccessibilityNodeInfo info) { |
| super.onInitializeAccessibilityNodeInfoInternal(info); |
| info.setScrollable(isScrollableForAccessibility()); |
| View selectedView = getSelectedView(); |
| if (selectedView != null) { |
| info.setEnabled(selectedView.isEnabled()); |
| } |
| } |
| |
| /** @hide */ |
| @Override |
| public void onInitializeAccessibilityEventInternal(AccessibilityEvent event) { |
| super.onInitializeAccessibilityEventInternal(event); |
| event.setScrollable(isScrollableForAccessibility()); |
| View selectedView = getSelectedView(); |
| if (selectedView != null) { |
| event.setEnabled(selectedView.isEnabled()); |
| } |
| event.setCurrentItemIndex(getSelectedItemPosition()); |
| event.setFromIndex(getFirstVisiblePosition()); |
| event.setToIndex(getLastVisiblePosition()); |
| event.setItemCount(getCount()); |
| } |
| |
| private boolean isScrollableForAccessibility() { |
| T adapter = getAdapter(); |
| if (adapter != null) { |
| final int itemCount = adapter.getCount(); |
| return itemCount > 0 |
| && (getFirstVisiblePosition() > 0 || getLastVisiblePosition() < itemCount - 1); |
| } |
| return false; |
| } |
| |
| @Override |
| protected boolean canAnimate() { |
| return super.canAnimate() && mItemCount > 0; |
| } |
| |
| void handleDataChanged() { |
| final int count = mItemCount; |
| boolean found = false; |
| |
| if (count > 0) { |
| |
| int newPos; |
| |
| // Find the row we are supposed to sync to |
| if (mNeedSync) { |
| // Update this first, since setNextSelectedPositionInt inspects |
| // it |
| mNeedSync = false; |
| |
| // See if we can find a position in the new data with the same |
| // id as the old selection |
| newPos = findSyncPosition(); |
| if (newPos >= 0) { |
| // Verify that new selection is selectable |
| int selectablePos = lookForSelectablePosition(newPos, true); |
| if (selectablePos == newPos) { |
| // Same row id is selected |
| setNextSelectedPositionInt(newPos); |
| found = true; |
| } |
| } |
| } |
| if (!found) { |
| // Try to use the same position if we can't find matching data |
| 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 |
| int selectablePos = lookForSelectablePosition(newPos, true); |
| if (selectablePos < 0) { |
| // Looking down didn't work -- try looking up |
| selectablePos = lookForSelectablePosition(newPos, false); |
| } |
| if (selectablePos >= 0) { |
| setNextSelectedPositionInt(selectablePos); |
| checkSelectionChanged(); |
| found = true; |
| } |
| } |
| } |
| if (!found) { |
| // Nothing is selected |
| mSelectedPosition = INVALID_POSITION; |
| mSelectedRowId = INVALID_ROW_ID; |
| mNextSelectedPosition = INVALID_POSITION; |
| mNextSelectedRowId = INVALID_ROW_ID; |
| mNeedSync = false; |
| checkSelectionChanged(); |
| } |
| |
| notifySubtreeAccessibilityStateChangedIfNeeded(); |
| } |
| |
| /** |
| * Called after layout to determine whether the selection position needs to |
| * be updated. Also used to fire any pending selection events. |
| */ |
| void checkSelectionChanged() { |
| if ((mSelectedPosition != mOldSelectedPosition) || (mSelectedRowId != mOldSelectedRowId)) { |
| selectionChanged(); |
| mOldSelectedPosition = mSelectedPosition; |
| mOldSelectedRowId = mSelectedRowId; |
| } |
| |
| // If we have a pending selection notification -- and we won't if we |
| // just fired one in selectionChanged() -- run it now. |
| if (mPendingSelectionNotifier != null) { |
| mPendingSelectionNotifier.run(); |
| } |
| } |
| |
| /** |
| * Searches the adapter for a position matching mSyncRowId. The search starts at mSyncPosition |
| * and then alternates between moving up and moving down until 1) we find the right position, or |
| * 2) we run out of time, or 3) we have looked at every position |
| * |
| * @return Position of the row that matches mSyncRowId, or {@link #INVALID_POSITION} if it can't |
| * be found |
| */ |
| int findSyncPosition() { |
| int count = mItemCount; |
| |
| if (count == 0) { |
| return INVALID_POSITION; |
| } |
| |
| long idToMatch = mSyncRowId; |
| int seed = mSyncPosition; |
| |
| // If there isn't a selection don't hunt for it |
| if (idToMatch == INVALID_ROW_ID) { |
| return INVALID_POSITION; |
| } |
| |
| // Pin seed to reasonable values |
| seed = Math.max(0, seed); |
| seed = Math.min(count - 1, seed); |
| |
| long endTime = SystemClock.uptimeMillis() + SYNC_MAX_DURATION_MILLIS; |
| |
| long rowId; |
| |
| // first position scanned so far |
| int first = seed; |
| |
| // last position scanned so far |
| int last = seed; |
| |
| // True if we should move down on the next iteration |
| boolean next = false; |
| |
| // True when we have looked at the first item in the data |
| boolean hitFirst; |
| |
| // True when we have looked at the last item in the data |
| boolean hitLast; |
| |
| // Get the item ID locally (instead of getItemIdAtPosition), so |
| // we need the adapter |
| T adapter = getAdapter(); |
| if (adapter == null) { |
| return INVALID_POSITION; |
| } |
| |
| while (SystemClock.uptimeMillis() <= endTime) { |
| rowId = adapter.getItemId(seed); |
| if (rowId == idToMatch) { |
| // Found it! |
| return seed; |
| } |
| |
| hitLast = last == count - 1; |
| hitFirst = first == 0; |
| |
| if (hitLast && hitFirst) { |
| // Looked at everything |
| break; |
| } |
| |
| if (hitFirst || (next && !hitLast)) { |
| // Either we hit the top, or we are trying to move down |
| last++; |
| seed = last; |
| // Try going up next time |
| next = false; |
| } else if (hitLast || (!next && !hitFirst)) { |
| // Either we hit the bottom, or we are trying to move up |
| first--; |
| seed = first; |
| // Try going down next time |
| next = true; |
| } |
| |
| } |
| |
| return INVALID_POSITION; |
| } |
| |
| /** |
| * Find a position that can be selected (i.e., is not a separator). |
| * |
| * @param position The starting position to look at. |
| * @param lookDown Whether to look down for other positions. |
| * @return The next selectable position starting at position and then searching either up or |
| * down. Returns {@link #INVALID_POSITION} if nothing can be found. |
| */ |
| int lookForSelectablePosition(int position, boolean lookDown) { |
| return position; |
| } |
| |
| /** |
| * Utility to keep mSelectedPosition and mSelectedRowId in sync |
| * @param position Our current position |
| */ |
| @UnsupportedAppUsage |
| void setSelectedPositionInt(int position) { |
| mSelectedPosition = position; |
| mSelectedRowId = getItemIdAtPosition(position); |
| } |
| |
| /** |
| * Utility to keep mNextSelectedPosition and mNextSelectedRowId in sync |
| * @param position Intended value for mSelectedPosition the next time we go |
| * through layout |
| */ |
| @UnsupportedAppUsage |
| void setNextSelectedPositionInt(int position) { |
| mNextSelectedPosition = position; |
| mNextSelectedRowId = getItemIdAtPosition(position); |
| // If we are trying to sync to the selection, update that too |
| if (mNeedSync && mSyncMode == SYNC_SELECTED_POSITION && position >= 0) { |
| mSyncPosition = position; |
| mSyncRowId = mNextSelectedRowId; |
| } |
| } |
| |
| /** |
| * Remember enough information to restore the screen state when the data has |
| * changed. |
| * |
| */ |
| void rememberSyncState() { |
| if (getChildCount() > 0) { |
| mNeedSync = true; |
| mSyncHeight = mLayoutHeight; |
| if (mSelectedPosition >= 0) { |
| // Sync the selection state |
| View v = getChildAt(mSelectedPosition - mFirstPosition); |
| mSyncRowId = mNextSelectedRowId; |
| mSyncPosition = mNextSelectedPosition; |
| if (v != null) { |
| mSpecificTop = v.getTop(); |
| } |
| mSyncMode = SYNC_SELECTED_POSITION; |
| } else { |
| // Sync the based on the offset of the first view |
| View v = getChildAt(0); |
| T adapter = getAdapter(); |
| if (mFirstPosition >= 0 && mFirstPosition < adapter.getCount()) { |
| mSyncRowId = adapter.getItemId(mFirstPosition); |
| } else { |
| mSyncRowId = NO_ID; |
| } |
| mSyncPosition = mFirstPosition; |
| if (v != null) { |
| mSpecificTop = v.getTop(); |
| } |
| mSyncMode = SYNC_FIRST_POSITION; |
| } |
| } |
| } |
| |
| /** @hide */ |
| @Override |
| protected void encodeProperties(@NonNull ViewHierarchyEncoder encoder) { |
| super.encodeProperties(encoder); |
| |
| encoder.addProperty("scrolling:firstPosition", mFirstPosition); |
| encoder.addProperty("list:nextSelectedPosition", mNextSelectedPosition); |
| encoder.addProperty("list:nextSelectedRowId", mNextSelectedRowId); |
| encoder.addProperty("list:selectedPosition", mSelectedPosition); |
| encoder.addProperty("list:itemCount", mItemCount); |
| } |
| |
| /** |
| * {@inheritDoc} |
| * |
| * <p>It also sets the autofill options in the structure; when overridden, it should set it as |
| * well, either explicitly by calling {@link ViewStructure#setAutofillOptions(CharSequence[])} |
| * or implicitly by calling {@code super.onProvideAutofillStructure(structure, flags)}. |
| */ |
| @Override |
| public void onProvideAutofillStructure(ViewStructure structure, int flags) { |
| super.onProvideAutofillStructure(structure, flags); |
| } |
| |
| /** @hide */ |
| @Override |
| protected void onProvideStructure(@NonNull ViewStructure structure, |
| @ViewStructureType int viewFor, int flags) { |
| super.onProvideStructure(structure, viewFor, flags); |
| |
| if (viewFor == VIEW_STRUCTURE_FOR_AUTOFILL |
| || viewFor == VIEW_STRUCTURE_FOR_CONTENT_CAPTURE) { |
| final Adapter adapter = getAdapter(); |
| if (adapter == null) return; |
| |
| final CharSequence[] options = adapter.getAutofillOptions(); |
| if (options != null) { |
| structure.setAutofillOptions(options); |
| } |
| } |
| } |
| } |
