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.os.UserHandle;
23import android.provider.Settings;
24import android.view.View;
25import android.view.View.AccessibilityDelegate;
26import android.view.accessibility.AccessibilityEvent;
27import android.view.accessibility.AccessibilityNodeInfo;
28
29import 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 */
36class 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}