1/*
2 * Copyright (C) 2012 Google Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
5 * use this file except in compliance with the License. You may obtain a copy of
6 * 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, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations under
14 * the License.
15 */
16
17package com.android.internal.policy.impl;
18
19import android.accessibilityservice.AccessibilityServiceInfo;
20import android.app.ActivityManager;
21import android.content.ComponentName;
22import android.content.ContentResolver;
23import android.content.Context;
24import android.content.pm.ServiceInfo;
25import android.media.AudioManager;
26import android.media.Ringtone;
27import android.media.RingtoneManager;
28import android.os.Handler;
29import android.os.Message;
30import android.os.RemoteException;
31import android.os.ServiceManager;
32import android.os.UserManager;
33import android.provider.Settings;
34import android.speech.tts.TextToSpeech;
35import android.util.MathUtils;
36import android.view.IWindowManager;
37import android.view.MotionEvent;
38import android.view.accessibility.AccessibilityManager;
39import android.view.accessibility.IAccessibilityManager;
40
41import com.android.internal.R;
42
43import java.util.ArrayList;
44import java.util.Iterator;
45import java.util.List;
46
47public class EnableAccessibilityController {
48
49    private static final int SPEAK_WARNING_DELAY_MILLIS = 2000;
50    private static final int ENABLE_ACCESSIBILITY_DELAY_MILLIS = 6000;
51
52    public static final int MESSAGE_SPEAK_WARNING = 1;
53    public static final int MESSAGE_SPEAK_ENABLE_CANCELED = 2;
54    public static final int MESSAGE_ENABLE_ACCESSIBILITY = 3;
55
56    private final Handler mHandler = new Handler() {
57        @Override
58        public void handleMessage(Message message) {
59            switch (message.what) {
60                case MESSAGE_SPEAK_WARNING: {
61                    String text = mContext.getString(R.string.continue_to_enable_accessibility);
62                    mTts.speak(text, TextToSpeech.QUEUE_FLUSH, null);
63                } break;
64                case MESSAGE_SPEAK_ENABLE_CANCELED: {
65                    String text = mContext.getString(R.string.enable_accessibility_canceled);
66                    mTts.speak(text, TextToSpeech.QUEUE_FLUSH, null);
67                } break;
68                case MESSAGE_ENABLE_ACCESSIBILITY: {
69                    enableAccessibility();
70                    mTone.play();
71                    mTts.speak(mContext.getString(R.string.accessibility_enabled),
72                            TextToSpeech.QUEUE_FLUSH, null);
73                } break;
74            }
75        }
76    };
77
78    private final IWindowManager mWindowManager = IWindowManager.Stub.asInterface(
79            ServiceManager.getService("window"));
80
81    private final IAccessibilityManager mAccessibilityManager = IAccessibilityManager
82            .Stub.asInterface(ServiceManager.getService("accessibility"));
83
84
85    private final Context mContext;
86    private final UserManager mUserManager;
87    private final TextToSpeech mTts;
88    private final Ringtone mTone;
89
90    private final float mTouchSlop;
91
92    private boolean mDestroyed;
93    private boolean mCanceled;
94
95    private float mFirstPointerDownX;
96    private float mFirstPointerDownY;
97    private float mSecondPointerDownX;
98    private float mSecondPointerDownY;
99
100    public EnableAccessibilityController(Context context) {
101        mContext = context;
102        mUserManager = (UserManager) mContext.getSystemService(Context.USER_SERVICE);
103        mTts = new TextToSpeech(context, new TextToSpeech.OnInitListener() {
104            @Override
105            public void onInit(int status) {
106                if (mDestroyed) {
107                    mTts.shutdown();
108                }
109            }
110        });
111        mTone = RingtoneManager.getRingtone(context, Settings.System.DEFAULT_NOTIFICATION_URI);
112        mTone.setStreamType(AudioManager.STREAM_MUSIC);
113        mTouchSlop = context.getResources().getDimensionPixelSize(
114                R.dimen.accessibility_touch_slop);
115    }
116
117    public static boolean canEnableAccessibilityViaGesture(Context context) {
118        AccessibilityManager accessibilityManager = AccessibilityManager.getInstance(context);
119        // Accessibility is enabled and there is an enabled speaking
120        // accessibility service, then we have nothing to do.
121        if (accessibilityManager.isEnabled()
122                && !accessibilityManager.getEnabledAccessibilityServiceList(
123                        AccessibilityServiceInfo.FEEDBACK_SPOKEN).isEmpty()) {
124            return false;
125        }
126        // If the global gesture is enabled and there is a speaking service
127        // installed we are good to go, otherwise there is nothing to do.
128        return Settings.Global.getInt(context.getContentResolver(),
129                Settings.Global.ENABLE_ACCESSIBILITY_GLOBAL_GESTURE_ENABLED, 0) == 1
130                && !getInstalledSpeakingAccessibilityServices(context).isEmpty();
131    }
132
133    private static List<AccessibilityServiceInfo> getInstalledSpeakingAccessibilityServices(
134            Context context) {
135        List<AccessibilityServiceInfo> services = new ArrayList<AccessibilityServiceInfo>();
136        services.addAll(AccessibilityManager.getInstance(context)
137                .getInstalledAccessibilityServiceList());
138        Iterator<AccessibilityServiceInfo> iterator = services.iterator();
139        while (iterator.hasNext()) {
140            AccessibilityServiceInfo service = iterator.next();
141            if ((service.feedbackType & AccessibilityServiceInfo.FEEDBACK_SPOKEN) == 0) {
142                iterator.remove();
143            }
144        }
145        return services;
146    }
147
148    public void onDestroy() {
149        mDestroyed = true;
150    }
151
152    public boolean onInterceptTouchEvent(MotionEvent event) {
153        if (event.getActionMasked() == MotionEvent.ACTION_POINTER_DOWN
154                && event.getPointerCount() == 2) {
155            mFirstPointerDownX = event.getX(0);
156            mFirstPointerDownY = event.getY(0);
157            mSecondPointerDownX = event.getX(1);
158            mSecondPointerDownY = event.getY(1);
159            mHandler.sendEmptyMessageDelayed(MESSAGE_SPEAK_WARNING,
160                    SPEAK_WARNING_DELAY_MILLIS);
161            mHandler.sendEmptyMessageDelayed(MESSAGE_ENABLE_ACCESSIBILITY,
162                   ENABLE_ACCESSIBILITY_DELAY_MILLIS);
163            return true;
164        }
165        return false;
166    }
167
168    public boolean onTouchEvent(MotionEvent event) {
169        final int pointerCount = event.getPointerCount();
170        final int action = event.getActionMasked();
171        if (mCanceled) {
172            if (action == MotionEvent.ACTION_UP) {
173                mCanceled = false;
174            }
175            return true;
176        }
177        switch (action) {
178            case MotionEvent.ACTION_POINTER_DOWN: {
179                if (pointerCount > 2) {
180                    cancel();
181                }
182            } break;
183            case MotionEvent.ACTION_MOVE: {
184                final float firstPointerMove = MathUtils.dist(event.getX(0),
185                        event.getY(0), mFirstPointerDownX, mFirstPointerDownY);
186                if (Math.abs(firstPointerMove) > mTouchSlop) {
187                    cancel();
188                }
189                final float secondPointerMove = MathUtils.dist(event.getX(1),
190                        event.getY(1), mSecondPointerDownX, mSecondPointerDownY);
191                if (Math.abs(secondPointerMove) > mTouchSlop) {
192                    cancel();
193                }
194            } break;
195            case MotionEvent.ACTION_POINTER_UP:
196            case MotionEvent.ACTION_CANCEL: {
197                cancel();
198            } break;
199        }
200        return true;
201    }
202
203    private void cancel() {
204        mCanceled = true;
205        if (mHandler.hasMessages(MESSAGE_SPEAK_WARNING)) {
206            mHandler.removeMessages(MESSAGE_SPEAK_WARNING);
207        } else if (mHandler.hasMessages(MESSAGE_ENABLE_ACCESSIBILITY)) {
208            mHandler.sendEmptyMessage(MESSAGE_SPEAK_ENABLE_CANCELED);
209        }
210        mHandler.removeMessages(MESSAGE_ENABLE_ACCESSIBILITY);
211    }
212
213    private void enableAccessibility() {
214        List<AccessibilityServiceInfo> services = getInstalledSpeakingAccessibilityServices(
215                mContext);
216        if (services.isEmpty()) {
217            return;
218        }
219        boolean keyguardLocked = false;
220        try {
221            keyguardLocked = mWindowManager.isKeyguardLocked();
222        } catch (RemoteException re) {
223            /* ignore */
224        }
225
226        final boolean hasMoreThanOneUser = mUserManager.getUsers().size() > 1;
227
228        AccessibilityServiceInfo service = services.get(0);
229        boolean enableTouchExploration = (service.flags
230                & AccessibilityServiceInfo.FLAG_REQUEST_TOUCH_EXPLORATION_MODE) != 0;
231        // Try to find a service supporting explore by touch.
232        if (!enableTouchExploration) {
233            final int serviceCount = services.size();
234            for (int i = 1; i < serviceCount; i++) {
235                AccessibilityServiceInfo candidate = services.get(i);
236                if ((candidate.flags & AccessibilityServiceInfo
237                        .FLAG_REQUEST_TOUCH_EXPLORATION_MODE) != 0) {
238                    enableTouchExploration = true;
239                    service = candidate;
240                    break;
241                }
242            }
243        }
244
245        ServiceInfo serviceInfo = service.getResolveInfo().serviceInfo;
246        ComponentName componentName = new ComponentName(serviceInfo.packageName, serviceInfo.name);
247        if (!keyguardLocked || !hasMoreThanOneUser) {
248            final int userId = ActivityManager.getCurrentUser();
249            String enabledServiceString = componentName.flattenToString();
250            ContentResolver resolver = mContext.getContentResolver();
251            // Enable one speaking accessibility service.
252            Settings.Secure.putStringForUser(resolver,
253                    Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES,
254                    enabledServiceString, userId);
255            // Allow the services we just enabled to toggle touch exploration.
256            Settings.Secure.putStringForUser(resolver,
257                    Settings.Secure.TOUCH_EXPLORATION_GRANTED_ACCESSIBILITY_SERVICES,
258                    enabledServiceString, userId);
259            // Enable touch exploration.
260            if (enableTouchExploration) {
261                Settings.Secure.putIntForUser(resolver, Settings.Secure.TOUCH_EXPLORATION_ENABLED,
262                        1, userId);
263            }
264            // Enable accessibility script injection (AndroidVox) for web content.
265            Settings.Secure.putIntForUser(resolver, Settings.Secure.ACCESSIBILITY_SCRIPT_INJECTION,
266                    1, userId);
267            // Turn on accessibility mode last.
268            Settings.Secure.putIntForUser(resolver, Settings.Secure.ACCESSIBILITY_ENABLED,
269                    1, userId);
270        } else if (keyguardLocked) {
271            try {
272                mAccessibilityManager.temporaryEnableAccessibilityStateUntilKeyguardRemoved(
273                        componentName, enableTouchExploration);
274            } catch (RemoteException re) {
275                /* ignore */
276            }
277        }
278    }
279}
280