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
17package com.android.keyguard;
18
19import android.content.ContentResolver;
20import android.content.Context;
21import android.media.AudioManager;
22import android.provider.Settings;
23import android.view.View;
24import android.view.View.AccessibilityDelegate;
25import android.view.accessibility.AccessibilityEvent;
26import android.view.accessibility.AccessibilityNodeInfo;
27
28import 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 */
35class 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}