1 /* 2 * Copyright 2018 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 androidx.recyclerview.widget; 18 19 import android.os.Bundle; 20 import android.view.View; 21 import android.view.accessibility.AccessibilityEvent; 22 23 import androidx.annotation.NonNull; 24 import androidx.core.view.AccessibilityDelegateCompat; 25 import androidx.core.view.accessibility.AccessibilityNodeInfoCompat; 26 27 /** 28 * The AccessibilityDelegate used by RecyclerView. 29 * <p> 30 * This class handles basic accessibility actions and delegates them to LayoutManager. 31 */ 32 public class RecyclerViewAccessibilityDelegate extends AccessibilityDelegateCompat { 33 final RecyclerView mRecyclerView; 34 final AccessibilityDelegateCompat mItemDelegate; 35 36 RecyclerViewAccessibilityDelegate(@onNull RecyclerView recyclerView)37 public RecyclerViewAccessibilityDelegate(@NonNull RecyclerView recyclerView) { 38 mRecyclerView = recyclerView; 39 mItemDelegate = new ItemDelegate(this); 40 } 41 shouldIgnore()42 boolean shouldIgnore() { 43 return mRecyclerView.hasPendingAdapterUpdates(); 44 } 45 46 @Override performAccessibilityAction(View host, int action, Bundle args)47 public boolean performAccessibilityAction(View host, int action, Bundle args) { 48 if (super.performAccessibilityAction(host, action, args)) { 49 return true; 50 } 51 if (!shouldIgnore() && mRecyclerView.getLayoutManager() != null) { 52 return mRecyclerView.getLayoutManager().performAccessibilityAction(action, args); 53 } 54 55 return false; 56 } 57 58 @Override onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info)59 public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) { 60 super.onInitializeAccessibilityNodeInfo(host, info); 61 info.setClassName(RecyclerView.class.getName()); 62 if (!shouldIgnore() && mRecyclerView.getLayoutManager() != null) { 63 mRecyclerView.getLayoutManager().onInitializeAccessibilityNodeInfo(info); 64 } 65 } 66 67 @Override onInitializeAccessibilityEvent(View host, AccessibilityEvent event)68 public void onInitializeAccessibilityEvent(View host, AccessibilityEvent event) { 69 super.onInitializeAccessibilityEvent(host, event); 70 event.setClassName(RecyclerView.class.getName()); 71 if (host instanceof RecyclerView && !shouldIgnore()) { 72 RecyclerView rv = (RecyclerView) host; 73 if (rv.getLayoutManager() != null) { 74 rv.getLayoutManager().onInitializeAccessibilityEvent(event); 75 } 76 } 77 } 78 79 /** 80 * Gets the AccessibilityDelegate for an individual item in the RecyclerView. 81 * A basic item delegate is provided by default, but you can override this 82 * method to provide a custom per-item delegate. 83 */ 84 @NonNull getItemDelegate()85 public AccessibilityDelegateCompat getItemDelegate() { 86 return mItemDelegate; 87 } 88 89 /** 90 * The default implementation of accessibility delegate for the individual items of the 91 * RecyclerView. 92 * <p> 93 * If you are overriding {@code RecyclerViewAccessibilityDelegate#getItemDelegate()} but still 94 * want to keep some default behavior, you can create an instance of this class and delegate to 95 * the parent as necessary. 96 */ 97 public static class ItemDelegate extends AccessibilityDelegateCompat { 98 final RecyclerViewAccessibilityDelegate mRecyclerViewDelegate; 99 100 /** 101 * Creates an item delegate for the given {@code RecyclerViewAccessibilityDelegate}. 102 * 103 * @param recyclerViewDelegate The parent RecyclerView's accessibility delegate. 104 */ ItemDelegate(@onNull RecyclerViewAccessibilityDelegate recyclerViewDelegate)105 public ItemDelegate(@NonNull RecyclerViewAccessibilityDelegate recyclerViewDelegate) { 106 mRecyclerViewDelegate = recyclerViewDelegate; 107 } 108 109 @Override onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info)110 public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) { 111 super.onInitializeAccessibilityNodeInfo(host, info); 112 if (!mRecyclerViewDelegate.shouldIgnore() 113 && mRecyclerViewDelegate.mRecyclerView.getLayoutManager() != null) { 114 mRecyclerViewDelegate.mRecyclerView.getLayoutManager() 115 .onInitializeAccessibilityNodeInfoForItem(host, info); 116 } 117 } 118 119 @Override performAccessibilityAction(View host, int action, Bundle args)120 public boolean performAccessibilityAction(View host, int action, Bundle args) { 121 if (super.performAccessibilityAction(host, action, args)) { 122 return true; 123 } 124 if (!mRecyclerViewDelegate.shouldIgnore() 125 && mRecyclerViewDelegate.mRecyclerView.getLayoutManager() != null) { 126 return mRecyclerViewDelegate.mRecyclerView.getLayoutManager() 127 .performAccessibilityActionForItem(host, action, args); 128 } 129 return false; 130 } 131 } 132 } 133 134