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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.os.UserHandle;
     23 import android.provider.Settings;
     24 import android.view.View;
     25 import android.view.View.AccessibilityDelegate;
     26 import android.view.accessibility.AccessibilityEvent;
     27 import android.view.accessibility.AccessibilityNodeInfo;
     28 
     29 import com.android.internal.R;
     30 
     31 /**
     32  * Accessibility delegate that obscures speech for a view when the user has
     33  * not turned on the "speak passwords" preference and is not listening
     34  * through headphones.
     35  */
     36 class ObscureSpeechDelegate extends AccessibilityDelegate {
     37     /** Whether any client has announced the "headset" notification. */
     38     static boolean sAnnouncedHeadset = false;
     39 
     40     private final ContentResolver mContentResolver;
     41     private final AudioManager mAudioManager;
     42 
     43     public ObscureSpeechDelegate(Context context) {
     44         mContentResolver = context.getContentResolver();
     45         mAudioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
     46     }
     47 
     48     @Override
     49     public void sendAccessibilityEvent(View host, int eventType) {
     50         super.sendAccessibilityEvent(host, eventType);
     51 
     52         // Play the "headset required" announcement the first time the user
     53         // places accessibility focus on a key.
     54         if ((eventType == AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED)
     55                 && !sAnnouncedHeadset && shouldObscureSpeech()) {
     56             sAnnouncedHeadset = true;
     57             host.announceForAccessibility(host.getContext().getString(
     58                     R.string.keyboard_headset_required_to_hear_password));
     59         }
     60     }
     61 
     62     @Override
     63     public void onPopulateAccessibilityEvent(View host, AccessibilityEvent event) {
     64         super.onPopulateAccessibilityEvent(host, event);
     65 
     66         if ((event.getEventType() != AccessibilityEvent.TYPE_ANNOUNCEMENT)
     67                 && shouldObscureSpeech()) {
     68             event.getText().clear();
     69             event.setContentDescription(host.getContext().getString(
     70                     R.string.keyboard_password_character_no_headset));
     71         }
     72     }
     73 
     74     @Override
     75     public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfo info) {
     76         super.onInitializeAccessibilityNodeInfo(host, info);
     77 
     78         if (shouldObscureSpeech()) {
     79             final Context ctx = host.getContext();
     80             info.setText(null);
     81             info.setContentDescription(
     82                     ctx.getString(R.string.keyboard_password_character_no_headset));
     83         }
     84     }
     85 
     86     @SuppressWarnings("deprecation")
     87     private boolean shouldObscureSpeech() {
     88         // The user can optionally force speaking passwords.
     89         if (Settings.Secure.getIntForUser(mContentResolver,
     90                 Settings.Secure.ACCESSIBILITY_SPEAK_PASSWORD, 0, UserHandle.USER_CURRENT) != 0) {
     91             return false;
     92         }
     93 
     94         // Always speak if the user is listening through headphones.
     95         if (mAudioManager.isWiredHeadsetOn() || mAudioManager.isBluetoothA2dpOn()) {
     96             return false;
     97         }
     98 
     99         // Don't speak since this key is used to type a password.
    100         return true;
    101     }
    102 }