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 
RecyclerViewAccessibilityDelegate(RecyclerView recyclerView)34     public RecyclerViewAccessibilityDelegate(RecyclerView recyclerView) {
35         mRecyclerView = recyclerView;
36     }
37 
shouldIgnore()38     boolean shouldIgnore() {
39         return mRecyclerView.hasPendingAdapterUpdates();
40     }
41 
42     @Override
performAccessibilityAction(View host, int action, Bundle args)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
onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfo info)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
onInitializeAccessibilityEvent(View host, AccessibilityEvent event)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      */
getItemDelegate()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