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      1 /*
      2  * Copyright (C) 2017 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 com.android.internal.widget;
     18 
     19 import android.os.Bundle;
     20 import android.view.View;
     21 import android.view.View.AccessibilityDelegate;
     22 import android.view.accessibility.AccessibilityEvent;
     23 import android.view.accessibility.AccessibilityNodeInfo;
     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 AccessibilityDelegate {
     31     final RecyclerView mRecyclerView;
     32 
     33 
     34     public RecyclerViewAccessibilityDelegate(RecyclerView recyclerView) {
     35         mRecyclerView = recyclerView;
     36     }
     37 
     38     boolean shouldIgnore() {
     39         return mRecyclerView.hasPendingAdapterUpdates();
     40     }
     41 
     42     @Override
     43     public boolean performAccessibilityAction(View host, int action, Bundle args) {
     44         if (super.performAccessibilityAction(host, action, args)) {
     45             return true;
     46         }
     47         if (!shouldIgnore() && mRecyclerView.getLayoutManager() != null) {
     48             return mRecyclerView.getLayoutManager().performAccessibilityAction(action, args);
     49         }
     50 
     51         return false;
     52     }
     53 
     54     @Override
     55     public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfo info) {
     56         super.onInitializeAccessibilityNodeInfo(host, info);
     57         info.setClassName(RecyclerView.class.getName());
     58         if (!shouldIgnore() && mRecyclerView.getLayoutManager() != null) {
     59             mRecyclerView.getLayoutManager().onInitializeAccessibilityNodeInfo(info);
     60         }
     61     }
     62 
     63     @Override
     64     public void onInitializeAccessibilityEvent(View host, AccessibilityEvent event) {
     65         super.onInitializeAccessibilityEvent(host, event);
     66         event.setClassName(RecyclerView.class.getName());
     67         if (host instanceof RecyclerView && !shouldIgnore()) {
     68             RecyclerView rv = (RecyclerView) host;
     69             if (rv.getLayoutManager() != null) {
     70                 rv.getLayoutManager().onInitializeAccessibilityEvent(event);
     71             }
     72         }
     73     }
     74 
     75     /**
     76      * Gets the AccessibilityDelegate for an individual item in the RecyclerView.
     77      * A basic item delegate is provided by default, but you can override this
     78      * method to provide a custom per-item delegate.
     79      */
     80     public AccessibilityDelegate getItemDelegate() {
     81         return mItemDelegate;
     82     }
     83 
     84     final AccessibilityDelegate mItemDelegate = new AccessibilityDelegate() {
     85         @Override
     86         public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfo info) {
     87             super.onInitializeAccessibilityNodeInfo(host, info);
     88             if (!shouldIgnore() && mRecyclerView.getLayoutManager() != null) {
     89                 mRecyclerView.getLayoutManager()
     90                         .onInitializeAccessibilityNodeInfoForItem(host, info);
     91             }
     92         }
     93 
     94         @Override
     95         public boolean performAccessibilityAction(View host, int action, Bundle args) {
     96             if (super.performAccessibilityAction(host, action, args)) {
     97                 return true;
     98             }
     99             if (!shouldIgnore() && mRecyclerView.getLayoutManager() != null) {
    100                 return mRecyclerView.getLayoutManager()
    101                         .performAccessibilityActionForItem(host, action, args);
    102             }
    103             return false;
    104         }
    105     };
    106 }
    107 
    108