RotationPolicy.java revision 79578b29bf4ba1d210586b9d7bb832eddf0960b7 
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 com.android.internal.view;
18
19import android.content.Context;
20import android.content.pm.PackageManager;
21import android.database.ContentObserver;
22import android.net.Uri;
23import android.os.AsyncTask;
24import android.os.Build;
25import android.os.Handler;
26import android.os.RemoteException;
27import android.os.UserHandle;
28import android.provider.Settings;
29import android.util.Log;
30import android.view.IWindowManager;
31import android.view.Surface;
32import android.view.WindowManagerGlobal;
33
34/**
35 * Provides helper functions for configuring the display rotation policy.
36 */
37public final class RotationPolicy {
38    private static final String TAG = "RotationPolicy";
39
40    private RotationPolicy() {
41    }
42
43    /**
44     * Gets whether the device supports rotation. In general such a
45     * device has an accelerometer and has the portrait and landscape
46     * features.
47     *
48     * @param context Context for accessing system resources.
49     * @return Whether the device supports rotation.
50     */
51    public static boolean isRotationSupported(Context context) {
52        PackageManager pm = context.getPackageManager();
53        return pm.hasSystemFeature(PackageManager.FEATURE_SENSOR_ACCELEROMETER)
54                && pm.hasSystemFeature(PackageManager.FEATURE_SCREEN_PORTRAIT)
55                && pm.hasSystemFeature(PackageManager.FEATURE_SCREEN_LANDSCAPE);
56    }
57
58    /**
59     * Returns true if the device supports the rotation-lock toggle feature
60     * in the system UI or system bar.
61     *
62     * When the rotation-lock toggle is supported, the "auto-rotate screen" option in
63     * Display settings should be hidden, but it should remain available in Accessibility
64     * settings.
65     */
66    public static boolean isRotationLockToggleSupported(Context context) {
67        return isRotationSupported(context)
68                && context.getResources().getConfiguration().smallestScreenWidthDp >= 600;
69    }
70
71    /**
72     * Returns true if the rotation-lock toggle should be shown in the UI.
73     */
74    public static boolean isRotationLockToggleVisible(Context context) {
75        return isRotationLockToggleSupported(context) &&
76                Settings.System.getIntForUser(context.getContentResolver(),
77                        Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, 0,
78                        UserHandle.USER_CURRENT) == 0;
79    }
80
81    /**
82     * Returns true if rotation lock is enabled.
83     */
84    public static boolean isRotationLocked(Context context) {
85        return Settings.System.getIntForUser(context.getContentResolver(),
86                Settings.System.ACCELEROMETER_ROTATION, 0, UserHandle.USER_CURRENT) == 0;
87    }
88
89    /**
90     * Enables or disables rotation lock.
91     *
92     * Should be used by the rotation lock toggle.
93     */
94    public static void setRotationLock(Context context, final boolean enabled) {
95        Settings.System.putIntForUser(context.getContentResolver(),
96                Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, 0,
97                UserHandle.USER_CURRENT);
98
99        AsyncTask.execute(new Runnable() {
100            @Override
101            public void run() {
102                try {
103                    IWindowManager wm = WindowManagerGlobal.getWindowManagerService();
104                    if (enabled) {
105                        wm.freezeRotation(-1);
106                    } else {
107                        wm.thawRotation();
108                    }
109                } catch (RemoteException exc) {
110                    Log.w(TAG, "Unable to save auto-rotate setting");
111                }
112            }
113        });
114    }
115
116    /**
117     * Enables or disables rotation lock and adjusts whether the rotation lock toggle
118     * should be hidden for accessibility purposes.
119     *
120     * Should be used by Display settings and Accessibility settings.
121     */
122    public static void setRotationLockForAccessibility(Context context, final boolean enabled) {
123        Settings.System.putIntForUser(context.getContentResolver(),
124                Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, enabled ? 1 : 0,
125                        UserHandle.USER_CURRENT);
126
127        AsyncTask.execute(new Runnable() {
128            @Override
129            public void run() {
130                try {
131                    IWindowManager wm = WindowManagerGlobal.getWindowManagerService();
132                    if (enabled) {
133                        wm.freezeRotation(Surface.ROTATION_0);
134                    } else {
135                        wm.thawRotation();
136                    }
137                } catch (RemoteException exc) {
138                    Log.w(TAG, "Unable to save auto-rotate setting");
139                }
140            }
141        });
142    }
143
144    /**
145     * Registers a listener for rotation policy changes affecting the caller's user
146     */
147    public static void registerRotationPolicyListener(Context context,
148            RotationPolicyListener listener) {
149        registerRotationPolicyListener(context, listener, UserHandle.getCallingUserId());
150    }
151
152    /**
153     * Registers a listener for rotation policy changes affecting a specific user,
154     * or USER_ALL for all users.
155     */
156    public static void registerRotationPolicyListener(Context context,
157            RotationPolicyListener listener, int userHandle) {
158        context.getContentResolver().registerContentObserver(Settings.System.getUriFor(
159                Settings.System.ACCELEROMETER_ROTATION),
160                false, listener.mObserver, userHandle);
161        context.getContentResolver().registerContentObserver(Settings.System.getUriFor(
162                Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY),
163                false, listener.mObserver, userHandle);
164    }
165
166    /**
167     * Unregisters a listener for rotation policy changes.
168     */
169    public static void unregisterRotationPolicyListener(Context context,
170            RotationPolicyListener listener) {
171        context.getContentResolver().unregisterContentObserver(listener.mObserver);
172    }
173
174    /**
175     * Listener that is invoked whenever a change occurs that might affect the rotation policy.
176     */
177    public static abstract class RotationPolicyListener {
178        final ContentObserver mObserver = new ContentObserver(new Handler()) {
179            public void onChange(boolean selfChange, Uri uri) {
180                RotationPolicyListener.this.onChange();
181            }
182        };
183
184        public abstract void onChange();
185    }
186}