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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.database.ContentObserver;
     22 import android.net.Uri;
     23 import android.os.AsyncTask;
     24 import android.os.Build;
     25 import android.os.Handler;
     26 import android.os.RemoteException;
     27 import android.os.UserHandle;
     28 import android.provider.Settings;
     29 import android.util.Log;
     30 import android.view.IWindowManager;
     31 import android.view.Surface;
     32 import android.view.WindowManagerGlobal;
     33 
     34 /**
     35  * Provides helper functions for configuring the display rotation policy.
     36  */
     37 public 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 }