Sandman.java revision 11159e9a785a143c9f3765bdf5a5ccfd77842d7a 
1/*
2 * Copyright (C) 2012 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 android.service.dreams;
18
19import android.content.ComponentName;
20import android.content.Context;
21import android.content.Intent;
22import android.os.PowerManager;
23import android.os.RemoteException;
24import android.os.ServiceManager;
25import android.os.SystemClock;
26import android.os.UserHandle;
27import android.provider.Settings;
28import android.util.Slog;
29
30/**
31 * Internal helper for launching dreams to ensure consistency between the
32 * <code>UiModeManagerService</code> system service and the <code>Somnambulator</code> activity.
33 *
34 * @hide
35 */
36public final class Sandman {
37    private static final String TAG = "Sandman";
38
39    private static final int DEFAULT_SCREENSAVER_ENABLED = 1;
40    private static final int DEFAULT_SCREENSAVER_ACTIVATED_ON_DOCK = 1;
41
42    // The component name of a special dock app that merely launches a dream.
43    // We don't want to launch this app when docked because it causes an unnecessary
44    // activity transition.  We just want to start the dream.
45    private static final ComponentName SOMNAMBULATOR_COMPONENT =
46            new ComponentName("com.android.systemui", "com.android.systemui.Somnambulator");
47
48
49    // The sandman is eternal.  No one instantiates him.
50    private Sandman() {
51    }
52
53    /**
54     * Returns true if the specified dock app intent should be started.
55     * False if we should dream instead, if appropriate.
56     */
57    public static boolean shouldStartDockApp(Context context, Intent intent) {
58        ComponentName name = intent.resolveActivity(context.getPackageManager());
59        return name != null && !name.equals(SOMNAMBULATOR_COMPONENT);
60    }
61
62    /**
63     * Starts a dream manually.
64     */
65    public static void startDreamByUserRequest(Context context) {
66        startDream(context, false);
67    }
68
69    /**
70     * Starts a dream when docked if the system has been configured to do so,
71     * otherwise does nothing.
72     */
73    public static void startDreamWhenDockedIfAppropriate(Context context) {
74        if (!isScreenSaverEnabled(context)
75                || !isScreenSaverActivatedOnDock(context)) {
76            Slog.i(TAG, "Dreams currently disabled for docks.");
77            return;
78        }
79
80        startDream(context, true);
81    }
82
83    private static void startDream(Context context, boolean docked) {
84        try {
85            IDreamManager dreamManagerService = IDreamManager.Stub.asInterface(
86                    ServiceManager.getService(DreamService.DREAM_SERVICE));
87            if (dreamManagerService != null && !dreamManagerService.isDreaming()) {
88                if (docked) {
89                    Slog.i(TAG, "Activating dream while docked.");
90
91                    // Wake up.
92                    // The power manager will wake up the system automatically when it starts
93                    // receiving power from a dock but there is a race between that happening
94                    // and the UI mode manager starting a dream.  We want the system to already
95                    // be awake by the time this happens.  Otherwise the dream may not start.
96                    PowerManager powerManager =
97                            (PowerManager)context.getSystemService(Context.POWER_SERVICE);
98                    powerManager.wakeUp(SystemClock.uptimeMillis());
99                } else {
100                    Slog.i(TAG, "Activating dream by user request.");
101                }
102
103                // Dream.
104                dreamManagerService.dream();
105            }
106        } catch (RemoteException ex) {
107            Slog.e(TAG, "Could not start dream when docked.", ex);
108        }
109    }
110
111    private static boolean isScreenSaverEnabled(Context context) {
112        return Settings.Secure.getIntForUser(context.getContentResolver(),
113                Settings.Secure.SCREENSAVER_ENABLED, DEFAULT_SCREENSAVER_ENABLED,
114                UserHandle.USER_CURRENT) != 0;
115    }
116
117    private static boolean isScreenSaverActivatedOnDock(Context context) {
118        return Settings.Secure.getIntForUser(context.getContentResolver(),
119                Settings.Secure.SCREENSAVER_ACTIVATE_ON_DOCK,
120                DEFAULT_SCREENSAVER_ACTIVATED_ON_DOCK, UserHandle.USER_CURRENT) != 0;
121    }
122}
123