RotationPolicy.java revision 98365d7663cbd82979a5700faf0050220b01084d 
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.database.ContentObserver;
21import android.net.Uri;
22import android.os.AsyncTask;
23import android.os.Handler;
24import android.os.RemoteException;
25import android.os.ServiceManager;
26import android.provider.Settings;
27import android.util.Log;
28import android.view.IWindowManager;
29import android.view.Surface;
30import android.view.WindowManagerGlobal;
31
32/**
33 * Provides helper functions for configuring the display rotation policy.
34 */
35public final class RotationPolicy {
36    private static final String TAG = "RotationPolicy";
37
38    private RotationPolicy() {
39    }
40
41    /**
42     * Returns true if the device supports the rotation-lock toggle feature
43     * in the system UI or system bar.
44     *
45     * When the rotation-lock toggle is supported, the "auto-rotate screen" option in
46     * Display settings should be hidden, but it should remain available in Accessibility
47     * settings.
48     */
49    public static boolean isRotationLockToggleSupported(Context context) {
50        return context.getResources().getConfiguration().smallestScreenWidthDp >= 600;
51    }
52
53    /**
54     * Returns true if the rotation-lock toggle should be shown in the UI.
55     */
56    public static boolean isRotationLockToggleVisible(Context context) {
57        return isRotationLockToggleSupported(context) &&
58                Settings.System.getInt(context.getContentResolver(),
59                        Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, 0) == 0;
60    }
61
62    /**
63     * Returns true if rotation lock is enabled.
64     */
65    public static boolean isRotationLocked(Context context) {
66        return Settings.System.getInt(context.getContentResolver(),
67                Settings.System.ACCELEROMETER_ROTATION, 0) == 0;
68    }
69
70    /**
71     * Enables or disables rotation lock.
72     *
73     * Should be used by the rotation lock toggle.
74     */
75    public static void setRotationLock(Context context, final boolean enabled) {
76        Settings.System.putInt(context.getContentResolver(),
77                Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, 0);
78
79        AsyncTask.execute(new Runnable() {
80            @Override
81            public void run() {
82                try {
83                    IWindowManager wm = WindowManagerGlobal.getWindowManagerService();
84                    if (enabled) {
85                        wm.freezeRotation(-1);
86                    } else {
87                        wm.thawRotation();
88                    }
89                } catch (RemoteException exc) {
90                    Log.w(TAG, "Unable to save auto-rotate setting");
91                }
92            }
93        });
94    }
95
96    /**
97     * Enables or disables rotation lock and adjusts whether the rotation lock toggle
98     * should be hidden for accessibility purposes.
99     *
100     * Should be used by Display settings and Accessibility settings.
101     */
102    public static void setRotationLockForAccessibility(Context context, final boolean enabled) {
103        Settings.System.putInt(context.getContentResolver(),
104                Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, enabled ? 1 : 0);
105
106        AsyncTask.execute(new Runnable() {
107            @Override
108            public void run() {
109                try {
110                    IWindowManager wm = WindowManagerGlobal.getWindowManagerService();
111                    if (enabled) {
112                        wm.freezeRotation(Surface.ROTATION_0);
113                    } else {
114                        wm.thawRotation();
115                    }
116                } catch (RemoteException exc) {
117                    Log.w(TAG, "Unable to save auto-rotate setting");
118                }
119            }
120        });
121    }
122
123    /**
124     * Registers a listener for rotation policy changes.
125     */
126    public static void registerRotationPolicyListener(Context context,
127            RotationPolicyListener listener) {
128        context.getContentResolver().registerContentObserver(Settings.System.getUriFor(
129                Settings.System.ACCELEROMETER_ROTATION),
130                false, listener.mObserver);
131        context.getContentResolver().registerContentObserver(Settings.System.getUriFor(
132                Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY),
133                false, listener.mObserver);
134    }
135
136    /**
137     * Unregisters a listener for rotation policy changes.
138     */
139    public static void unregisterRotationPolicyListener(Context context,
140            RotationPolicyListener listener) {
141        context.getContentResolver().unregisterContentObserver(listener.mObserver);
142    }
143
144    /**
145     * Listener that is invoked whenever a change occurs that might affect the rotation policy.
146     */
147    public static abstract class RotationPolicyListener {
148        final ContentObserver mObserver = new ContentObserver(new Handler()) {
149            public void onChange(boolean selfChange, Uri uri) {
150                RotationPolicyListener.this.onChange();
151            }
152        };
153
154        public abstract void onChange();
155    }
156}