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      1 /*
      2  * Copyright (C) 2013 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.keyguard;
     18 
     19 import android.content.ContentResolver;
     20 import android.content.Context;
     21 import android.media.AudioManager;
     22 import android.provider.Settings;
     23 import android.view.View;
     24 import android.view.View.AccessibilityDelegate;
     25 import android.view.accessibility.AccessibilityEvent;
     26 import android.view.accessibility.AccessibilityNodeInfo;
     27 
     28 import com.android.internal.R;
     29 
     30 /**
     31  * Accessibility delegate that obscures speech for a view when the user has
     32  * not turned on the "speak passwords" preference and is not listening
     33  * through headphones.
     34  */
     35 class ObscureSpeechDelegate extends AccessibilityDelegate {
     36     /** Whether any client has announced the "headset" notification. */
     37     static boolean sAnnouncedHeadset = false;
     38 
     39     private final ContentResolver mContentResolver;
     40     private final AudioManager mAudioManager;
     41 
     42     public ObscureSpeechDelegate(Context context) {
     43         mContentResolver = context.getContentResolver();
     44         mAudioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
     45     }
     46 
     47     @Override
     48     public void sendAccessibilityEvent(View host, int eventType) {
     49         super.sendAccessibilityEvent(host, eventType);
     50 
     51         // Play the "headset required" announcement the first time the user
     52         // places accessibility focus on a key.
     53         if ((eventType == AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED)
     54                 && !sAnnouncedHeadset && shouldObscureSpeech()) {
     55             sAnnouncedHeadset = true;
     56             host.announceForAccessibility(host.getContext().getString(
     57                     R.string.keyboard_headset_required_to_hear_password));
     58         }
     59     }
     60 
     61     @Override
     62     public void onPopulateAccessibilityEvent(View host, AccessibilityEvent event) {
     63         super.onPopulateAccessibilityEvent(host, event);
     64 
     65         if ((event.getEventType() != AccessibilityEvent.TYPE_ANNOUNCEMENT)
     66                 && shouldObscureSpeech()) {
     67             event.getText().clear();
     68             event.setContentDescription(host.getContext().getString(
     69                     R.string.keyboard_password_character_no_headset));
     70         }
     71     }
     72 
     73     @Override
     74     public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfo info) {
     75         super.onInitializeAccessibilityNodeInfo(host, info);
     76 
     77         if (shouldObscureSpeech()) {
     78             final Context ctx = host.getContext();
     79             info.setText(null);
     80             info.setContentDescription(
     81                     ctx.getString(R.string.keyboard_password_character_no_headset));
     82         }
     83     }
     84 
     85     @SuppressWarnings("deprecation")
     86     private boolean shouldObscureSpeech() {
     87         // The user can optionally force speaking passwords.
     88         if (Settings.Secure.getInt(mContentResolver,
     89                 Settings.Secure.ACCESSIBILITY_SPEAK_PASSWORD, 0) != 0) {
     90             return false;
     91         }
     92 
     93         // Always speak if the user is listening through headphones.
     94         if (mAudioManager.isWiredHeadsetOn() || mAudioManager.isBluetoothA2dpOn()) {
     95             return false;
     96         }
     97 
     98         // Don't speak since this key is used to type a password.
     99         return true;
    100     }
    101 }