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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.database.ContentObserver;
     21 import android.net.Uri;
     22 import android.os.AsyncTask;
     23 import android.os.Handler;
     24 import android.os.RemoteException;
     25 import android.os.ServiceManager;
     26 import android.provider.Settings;
     27 import android.util.Log;
     28 import android.view.IWindowManager;
     29 import android.view.Surface;
     30 
     31 /**
     32  * Provides helper functions for configuring the display rotation policy.
     33  */
     34 public final class RotationPolicy {
     35     private static final String TAG = "RotationPolicy";
     36 
     37     private RotationPolicy() {
     38     }
     39 
     40     /**
     41      * Returns true if the device supports the rotation-lock toggle feature
     42      * in the system UI or system bar.
     43      *
     44      * When the rotation-lock toggle is supported, the "auto-rotate screen" option in
     45      * Display settings should be hidden, but it should remain available in Accessibility
     46      * settings.
     47      */
     48     public static boolean isRotationLockToggleSupported(Context context) {
     49         return context.getResources().getConfiguration().smallestScreenWidthDp >= 600;
     50     }
     51 
     52     /**
     53      * Returns true if the rotation-lock toggle should be shown in the UI.
     54      */
     55     public static boolean isRotationLockToggleVisible(Context context) {
     56         return isRotationLockToggleSupported(context) &&
     57                 Settings.System.getInt(context.getContentResolver(),
     58                         Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, 0) == 0;
     59     }
     60 
     61     /**
     62      * Returns true if rotation lock is enabled.
     63      */
     64     public static boolean isRotationLocked(Context context) {
     65         return Settings.System.getInt(context.getContentResolver(),
     66                 Settings.System.ACCELEROMETER_ROTATION, 0) == 0;
     67     }
     68 
     69     /**
     70      * Enables or disables rotation lock.
     71      *
     72      * Should be used by the rotation lock toggle.
     73      */
     74     public static void setRotationLock(Context context, final boolean enabled) {
     75         Settings.System.putInt(context.getContentResolver(),
     76                 Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, 0);
     77 
     78         AsyncTask.execute(new Runnable() {
     79             @Override
     80             public void run() {
     81                 try {
     82                     IWindowManager wm = IWindowManager.Stub.asInterface(
     83                             ServiceManager.getService(Context.WINDOW_SERVICE));
     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 = IWindowManager.Stub.asInterface(
    111                             ServiceManager.getService(Context.WINDOW_SERVICE));
    112                     if (enabled) {
    113                         wm.freezeRotation(Surface.ROTATION_0);
    114                     } else {
    115                         wm.thawRotation();
    116                     }
    117                 } catch (RemoteException exc) {
    118                     Log.w(TAG, "Unable to save auto-rotate setting");
    119                 }
    120             }
    121         });
    122     }
    123 
    124     /**
    125      * Registers a listener for rotation policy changes.
    126      */
    127     public static void registerRotationPolicyListener(Context context,
    128             RotationPolicyListener listener) {
    129         context.getContentResolver().registerContentObserver(Settings.System.getUriFor(
    130                 Settings.System.ACCELEROMETER_ROTATION),
    131                 false, listener.mObserver);
    132         context.getContentResolver().registerContentObserver(Settings.System.getUriFor(
    133                 Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY),
    134                 false, listener.mObserver);
    135     }
    136 
    137     /**
    138      * Unregisters a listener for rotation policy changes.
    139      */
    140     public static void unregisterRotationPolicyListener(Context context,
    141             RotationPolicyListener listener) {
    142         context.getContentResolver().unregisterContentObserver(listener.mObserver);
    143     }
    144 
    145     /**
    146      * Listener that is invoked whenever a change occurs that might affect the rotation policy.
    147      */
    148     public static abstract class RotationPolicyListener {
    149         final ContentObserver mObserver = new ContentObserver(new Handler()) {
    150             public void onChange(boolean selfChange, Uri uri) {
    151                 RotationPolicyListener.this.onChange();
    152             }
    153         };
    154 
    155         public abstract void onChange();
    156     }
    157 }