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.content.res.Configuration;
22import android.database.ContentObserver;
23import android.graphics.Point;
24import android.net.Uri;
25import android.os.AsyncTask;
26import android.os.Handler;
27import android.os.RemoteException;
28import android.os.UserHandle;
29import android.provider.Settings;
30import android.util.Log;
31import android.view.Display;
32import android.view.IWindowManager;
33import android.view.Surface;
34import android.view.WindowManagerGlobal;
35
36import com.android.internal.R;
37
38/**
39 * Provides helper functions for configuring the display rotation policy.
40 */
41public final class RotationPolicy {
42    private static final String TAG = "RotationPolicy";
43    private static final int CURRENT_ROTATION = -1;
44    private static final int NATURAL_ROTATION = Surface.ROTATION_0;
45
46    private RotationPolicy() {
47    }
48
49    /**
50     * Gets whether the device supports rotation. In general such a
51     * device has an accelerometer and has the portrait and landscape
52     * features.
53     *
54     * @param context Context for accessing system resources.
55     * @return Whether the device supports rotation.
56     */
57    public static boolean isRotationSupported(Context context) {
58        PackageManager pm = context.getPackageManager();
59        return pm.hasSystemFeature(PackageManager.FEATURE_SENSOR_ACCELEROMETER)
60                && pm.hasSystemFeature(PackageManager.FEATURE_SCREEN_PORTRAIT)
61                && pm.hasSystemFeature(PackageManager.FEATURE_SCREEN_LANDSCAPE)
62                && context.getResources().getBoolean(
63                        com.android.internal.R.bool.config_supportAutoRotation);
64    }
65
66    /**
67     * Returns the orientation that will be used when locking the orientation from system UI
68     * with {@link #setRotationLock}.
69     *
70     * If the device only supports locking to its natural orientation, this will be either
71     * Configuration.ORIENTATION_PORTRAIT or Configuration.ORIENTATION_LANDSCAPE,
72     * otherwise Configuration.ORIENTATION_UNDEFINED if any orientation is lockable.
73     */
74    public static int getRotationLockOrientation(Context context) {
75        if (!areAllRotationsAllowed(context)) {
76            final Point size = new Point();
77            final IWindowManager wm = WindowManagerGlobal.getWindowManagerService();
78            try {
79                wm.getInitialDisplaySize(Display.DEFAULT_DISPLAY, size);
80                return size.x < size.y ?
81                        Configuration.ORIENTATION_PORTRAIT : Configuration.ORIENTATION_LANDSCAPE;
82            } catch (RemoteException e) {
83                Log.w(TAG, "Unable to get the display size");
84            }
85        }
86        return Configuration.ORIENTATION_UNDEFINED;
87    }
88
89    /**
90     * Returns true if the rotation-lock toggle should be shown in system UI.
91     */
92    public static boolean isRotationLockToggleVisible(Context context) {
93        return isRotationSupported(context) &&
94                Settings.System.getIntForUser(context.getContentResolver(),
95                        Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, 0,
96                        UserHandle.USER_CURRENT) == 0;
97    }
98
99    /**
100     * Returns true if rotation lock is enabled.
101     */
102    public static boolean isRotationLocked(Context context) {
103        return Settings.System.getIntForUser(context.getContentResolver(),
104                Settings.System.ACCELEROMETER_ROTATION, 0, UserHandle.USER_CURRENT) == 0;
105    }
106
107    /**
108     * Enables or disables rotation lock from the system UI toggle.
109     */
110    public static void setRotationLock(Context context, final boolean enabled) {
111        Settings.System.putIntForUser(context.getContentResolver(),
112                Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, 0,
113                UserHandle.USER_CURRENT);
114
115        final int rotation = areAllRotationsAllowed(context) ? CURRENT_ROTATION : NATURAL_ROTATION;
116        setRotationLock(enabled, rotation);
117    }
118
119    /**
120     * Enables or disables natural rotation lock from Accessibility settings.
121     *
122     * If rotation is locked for accessibility, the system UI toggle is hidden to avoid confusion.
123     */
124    public static void setRotationLockForAccessibility(Context context, final boolean enabled) {
125        Settings.System.putIntForUser(context.getContentResolver(),
126                Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, enabled ? 1 : 0,
127                        UserHandle.USER_CURRENT);
128
129        setRotationLock(enabled, NATURAL_ROTATION);
130    }
131
132    private static boolean areAllRotationsAllowed(Context context) {
133        return context.getResources().getBoolean(R.bool.config_allowAllRotations);
134    }
135
136    private static void setRotationLock(final boolean enabled, final int rotation) {
137        AsyncTask.execute(new Runnable() {
138            @Override
139            public void run() {
140                try {
141                    IWindowManager wm = WindowManagerGlobal.getWindowManagerService();
142                    if (enabled) {
143                        wm.freezeRotation(rotation);
144                    } else {
145                        wm.thawRotation();
146                    }
147                } catch (RemoteException exc) {
148                    Log.w(TAG, "Unable to save auto-rotate setting");
149                }
150            }
151        });
152    }
153
154    /**
155     * Registers a listener for rotation policy changes affecting the caller's user
156     */
157    public static void registerRotationPolicyListener(Context context,
158            RotationPolicyListener listener) {
159        registerRotationPolicyListener(context, listener, UserHandle.getCallingUserId());
160    }
161
162    /**
163     * Registers a listener for rotation policy changes affecting a specific user,
164     * or USER_ALL for all users.
165     */
166    public static void registerRotationPolicyListener(Context context,
167            RotationPolicyListener listener, int userHandle) {
168        context.getContentResolver().registerContentObserver(Settings.System.getUriFor(
169                Settings.System.ACCELEROMETER_ROTATION),
170                false, listener.mObserver, userHandle);
171        context.getContentResolver().registerContentObserver(Settings.System.getUriFor(
172                Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY),
173                false, listener.mObserver, userHandle);
174    }
175
176    /**
177     * Unregisters a listener for rotation policy changes.
178     */
179    public static void unregisterRotationPolicyListener(Context context,
180            RotationPolicyListener listener) {
181        context.getContentResolver().unregisterContentObserver(listener.mObserver);
182    }
183
184    /**
185     * Listener that is invoked whenever a change occurs that might affect the rotation policy.
186     */
187    public static abstract class RotationPolicyListener {
188        final ContentObserver mObserver = new ContentObserver(new Handler()) {
189            @Override
190            public void onChange(boolean selfChange, Uri uri) {
191                RotationPolicyListener.this.onChange();
192            }
193        };
194
195        public abstract void onChange();
196    }
197}