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      1 /*
      2  * Copyright (C) 2012 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.launcher2;
     18 
     19 import android.view.View;
     20 import android.view.ViewGroup;
     21 import android.view.ViewGroup.OnHierarchyChangeListener;
     22 
     23 import java.util.HashMap;
     24 
     25 public class HideFromAccessibilityHelper implements OnHierarchyChangeListener {
     26     private HashMap<View, Integer> mPreviousValues;
     27     boolean mHide;
     28     boolean mOnlyAllApps;
     29 
     30     public HideFromAccessibilityHelper() {
     31         mPreviousValues = new HashMap<View, Integer>();
     32         mHide = false;
     33     }
     34 
     35     public void setImportantForAccessibilityToNo(View v, boolean onlyAllApps) {
     36         mOnlyAllApps = onlyAllApps;
     37         setImportantForAccessibilityToNoHelper(v);
     38         mHide = true;
     39     }
     40 
     41     private void setImportantForAccessibilityToNoHelper(View v) {
     42         mPreviousValues.put(v, v.getImportantForAccessibility());
     43         v.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_NO);
     44 
     45         // Call method on children recursively
     46         if (v instanceof ViewGroup) {
     47             ViewGroup vg = (ViewGroup) v;
     48             vg.setOnHierarchyChangeListener(this);
     49             for (int i = 0; i < vg.getChildCount(); i++) {
     50                 View child = vg.getChildAt(i);
     51 
     52                 if (includeView(child)) {
     53                     setImportantForAccessibilityToNoHelper(child);
     54                 }
     55             }
     56         }
     57     }
     58 
     59     public void restoreImportantForAccessibility(View v) {
     60         if (mHide) {
     61             restoreImportantForAccessibilityHelper(v);
     62         }
     63         mHide = false;
     64     }
     65 
     66     private void restoreImportantForAccessibilityHelper(View v) {
     67         v.setImportantForAccessibility(mPreviousValues.get(v));
     68         mPreviousValues.remove(v);
     69 
     70         // Call method on children recursively
     71         if (v instanceof ViewGroup) {
     72             ViewGroup vg = (ViewGroup) v;
     73 
     74             // We assume if a class implements OnHierarchyChangeListener, it listens
     75             // to changes to any of its children (happens to be the case in Launcher)
     76             if (vg instanceof OnHierarchyChangeListener) {
     77                 vg.setOnHierarchyChangeListener((OnHierarchyChangeListener) vg);
     78             } else {
     79                 vg.setOnHierarchyChangeListener(null);
     80             }
     81             for (int i = 0; i < vg.getChildCount(); i++) {
     82                 View child = vg.getChildAt(i);
     83                 if (includeView(child)) {
     84                     restoreImportantForAccessibilityHelper(child);
     85                 }
     86             }
     87         }
     88     }
     89 
     90     public void onChildViewAdded(View parent, View child) {
     91         if (mHide && includeView(child)) {
     92             setImportantForAccessibilityToNoHelper(child);
     93         }
     94     }
     95 
     96     public void onChildViewRemoved(View parent, View child) {
     97         if (mHide && includeView(child)) {
     98             restoreImportantForAccessibilityHelper(child);
     99         }
    100     }
    101 
    102     private boolean includeView(View v) {
    103         return !hasAncestorOfType(v, Cling.class) &&
    104                 (!mOnlyAllApps || hasAncestorOfType(v, AppsCustomizeTabHost.class));
    105     }
    106 
    107     private boolean hasAncestorOfType(View v, Class c) {
    108         return v != null &&
    109                 (v.getClass().equals(c) ||
    110                  (v.getParent() instanceof ViewGroup &&
    111                   hasAncestorOfType((ViewGroup) v.getParent(), c)));
    112     }
    113 }