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      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 
     17 package com.android.internal.view;
     18 
     19 import android.content.Context;
     20 import android.content.pm.PackageManager;
     21 import android.content.res.Configuration;
     22 import android.database.ContentObserver;
     23 import android.graphics.Point;
     24 import android.net.Uri;
     25 import android.os.AsyncTask;
     26 import android.os.Handler;
     27 import android.os.RemoteException;
     28 import android.os.UserHandle;
     29 import android.provider.Settings;
     30 import android.util.Log;
     31 import android.view.Display;
     32 import android.view.IWindowManager;
     33 import android.view.Surface;
     34 import android.view.WindowManagerGlobal;
     35 
     36 import com.android.internal.R;
     37 
     38 /**
     39  * Provides helper functions for configuring the display rotation policy.
     40  */
     41 public 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 }