1 /* 2 * Copyright (C) 2014 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.support.v7.widget; 18 19 import android.os.Bundle; 20 import android.support.v4.view.AccessibilityDelegateCompat; 21 import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat; 22 import android.view.View; 23 import android.view.accessibility.AccessibilityEvent; 24 25 /** 26 * The AccessibilityDelegate used by RecyclerView. 27 * <p> 28 * This class handles basic accessibility actions and delegates them to LayoutManager. 29 */ 30 public class RecyclerViewAccessibilityDelegate extends AccessibilityDelegateCompat { 31 final RecyclerView mRecyclerView; 32 final AccessibilityDelegateCompat mItemDelegate; 33 34 RecyclerViewAccessibilityDelegate(RecyclerView recyclerView)35 public RecyclerViewAccessibilityDelegate(RecyclerView recyclerView) { 36 mRecyclerView = recyclerView; 37 mItemDelegate = new ItemDelegate(this); 38 } 39 shouldIgnore()40 boolean shouldIgnore() { 41 return mRecyclerView.hasPendingAdapterUpdates(); 42 } 43 44 @Override performAccessibilityAction(View host, int action, Bundle args)45 public boolean performAccessibilityAction(View host, int action, Bundle args) { 46 if (super.performAccessibilityAction(host, action, args)) { 47 return true; 48 } 49 if (!shouldIgnore() && mRecyclerView.getLayoutManager() != null) { 50 return mRecyclerView.getLayoutManager().performAccessibilityAction(action, args); 51 } 52 53 return false; 54 } 55 56 @Override onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info)57 public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) { 58 super.onInitializeAccessibilityNodeInfo(host, info); 59 info.setClassName(RecyclerView.class.getName()); 60 if (!shouldIgnore() && mRecyclerView.getLayoutManager() != null) { 61 mRecyclerView.getLayoutManager().onInitializeAccessibilityNodeInfo(info); 62 } 63 } 64 65 @Override onInitializeAccessibilityEvent(View host, AccessibilityEvent event)66 public void onInitializeAccessibilityEvent(View host, AccessibilityEvent event) { 67 super.onInitializeAccessibilityEvent(host, event); 68 event.setClassName(RecyclerView.class.getName()); 69 if (host instanceof RecyclerView && !shouldIgnore()) { 70 RecyclerView rv = (RecyclerView) host; 71 if (rv.getLayoutManager() != null) { 72 rv.getLayoutManager().onInitializeAccessibilityEvent(event); 73 } 74 } 75 } 76 77 /** 78 * Gets the AccessibilityDelegate for an individual item in the RecyclerView. 79 * A basic item delegate is provided by default, but you can override this 80 * method to provide a custom per-item delegate. 81 */ getItemDelegate()82 public AccessibilityDelegateCompat getItemDelegate() { 83 return mItemDelegate; 84 } 85 86 /** 87 * The default implementation of accessibility delegate for the individual items of the 88 * RecyclerView. 89 * <p> 90 * If you are overriding {@code RecyclerViewAccessibilityDelegate#getItemDelegate()} but still 91 * want to keep some default behavior, you can create an instance of this class and delegate to 92 * the parent as necessary. 93 */ 94 public static class ItemDelegate extends AccessibilityDelegateCompat { 95 final RecyclerViewAccessibilityDelegate mRecyclerViewDelegate; 96 97 /** 98 * Creates an item delegate for the given {@code RecyclerViewAccessibilityDelegate}. 99 * 100 * @param recyclerViewDelegate The parent RecyclerView's accessibility delegate. 101 */ ItemDelegate(RecyclerViewAccessibilityDelegate recyclerViewDelegate)102 public ItemDelegate(RecyclerViewAccessibilityDelegate recyclerViewDelegate) { 103 mRecyclerViewDelegate = recyclerViewDelegate; 104 } 105 106 @Override onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info)107 public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) { 108 super.onInitializeAccessibilityNodeInfo(host, info); 109 if (!mRecyclerViewDelegate.shouldIgnore() 110 && mRecyclerViewDelegate.mRecyclerView.getLayoutManager() != null) { 111 mRecyclerViewDelegate.mRecyclerView.getLayoutManager() 112 .onInitializeAccessibilityNodeInfoForItem(host, info); 113 } 114 } 115 116 @Override performAccessibilityAction(View host, int action, Bundle args)117 public boolean performAccessibilityAction(View host, int action, Bundle args) { 118 if (super.performAccessibilityAction(host, action, args)) { 119 return true; 120 } 121 if (!mRecyclerViewDelegate.shouldIgnore() 122 && mRecyclerViewDelegate.mRecyclerView.getLayoutManager() != null) { 123 return mRecyclerViewDelegate.mRecyclerView.getLayoutManager() 124 .performAccessibilityActionForItem(host, action, args); 125 } 126 return false; 127 } 128 } 129 } 130 131