content: /*
   * Copyright (C) 2012 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.android.internal.view;
  
  import android.content.Context;
  import android.content.pm.PackageManager;
  import android.content.res.Configuration;
  import android.database.ContentObserver;
  import android.graphics.Point;
  import android.net.Uri;
  import android.os.AsyncTask;
  import android.os.Handler;
  import android.os.RemoteException;
  import android.os.UserHandle;
  import android.provider.Settings;
  import android.util.Log;
  import android.view.Display;
  import android.view.IWindowManager;
  import android.view.Surface;
  import android.view.WindowManagerGlobal;
  
  import com.android.internal.R;
  
  /**
   * Provides helper functions for configuring the display rotation policy.
   */
  public final class RotationPolicy {
      private static final String TAG = "RotationPolicy";
      private static final int CURRENT_ROTATION = -1;
  
      public static final int NATURAL_ROTATION = Surface.ROTATION_0;
  
      private RotationPolicy() {
      }
  
      /**
       * Gets whether the device supports rotation. In general such a
       * device has an accelerometer and has the portrait and landscape
       * features.
       *
       * @param context Context for accessing system resources.
       * @return Whether the device supports rotation.
       */
      public static boolean isRotationSupported(Context context) {
          PackageManager pm = context.getPackageManager();
          return pm.hasSystemFeature(PackageManager.FEATURE_SENSOR_ACCELEROMETER)
                  && pm.hasSystemFeature(PackageManager.FEATURE_SCREEN_PORTRAIT)
                  && pm.hasSystemFeature(PackageManager.FEATURE_SCREEN_LANDSCAPE)
                  && context.getResources().getBoolean(
                          com.android.internal.R.bool.config_supportAutoRotation);
      }
  
      /**
       * Returns the orientation that will be used when locking the orientation from system UI
       * with {@link #setRotationLock}.
       *
       * If the device only supports locking to its natural orientation, this will be either
       * Configuration.ORIENTATION_PORTRAIT or Configuration.ORIENTATION_LANDSCAPE,
       * otherwise Configuration.ORIENTATION_UNDEFINED if any orientation is lockable.
       */
      public static int getRotationLockOrientation(Context context) {
          if (!areAllRotationsAllowed(context)) {
              final Point size = new Point();
              final IWindowManager wm = WindowManagerGlobal.getWindowManagerService();
              try {
                  final Display display = context.getDisplay();
                  final int displayId = display != null
                          ? display.getDisplayId()
                          : Display.DEFAULT_DISPLAY;
                  wm.getInitialDisplaySize(displayId, size);
                  return size.x < size.y ?
                          Configuration.ORIENTATION_PORTRAIT : Configuration.ORIENTATION_LANDSCAPE;
              } catch (RemoteException e) {
                  Log.w(TAG, "Unable to get the display size");
              }
          }
          return Configuration.ORIENTATION_UNDEFINED;
      }
  
      /**
       * Returns true if the rotation-lock toggle should be shown in system UI.
       */
      public static boolean isRotationLockToggleVisible(Context context) {
          return isRotationSupported(context) &&
                  Settings.System.getIntForUser(context.getContentResolver(),
                          Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, 0,
                          UserHandle.USER_CURRENT) == 0;
      }
  
      /**
       * Returns true if rotation lock is enabled.
       */
      public static boolean isRotationLocked(Context context) {
          return Settings.System.getIntForUser(context.getContentResolver(),
                  Settings.System.ACCELEROMETER_ROTATION, 0, UserHandle.USER_CURRENT) == 0;
      }
  
      /**
       * Enables or disables rotation lock from the system UI toggle.
       */
      public static void setRotationLock(Context context, final boolean enabled) {
          final int rotation = areAllRotationsAllowed(context) ? CURRENT_ROTATION : NATURAL_ROTATION;
          setRotationLockAtAngle(context, enabled, rotation);
      }
  
      /**
       * Enables or disables rotation lock at a specific rotation from system UI.
       */
      public static void setRotationLockAtAngle(Context context, final boolean enabled,
              final int rotation) {
          Settings.System.putIntForUser(context.getContentResolver(),
                  Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, 0,
                  UserHandle.USER_CURRENT);
  
          setRotationLock(enabled, rotation);
      }
  
      /**
       * Enables or disables natural rotation lock from Accessibility settings.
       *
       * If rotation is locked for accessibility, the system UI toggle is hidden to avoid confusion.
       */
      public static void setRotationLockForAccessibility(Context context, final boolean enabled) {
          Settings.System.putIntForUser(context.getContentResolver(),
                  Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY, enabled ? 1 : 0,
                          UserHandle.USER_CURRENT);
  
          setRotationLock(enabled, NATURAL_ROTATION);
      }
  
      private static boolean areAllRotationsAllowed(Context context) {
          return context.getResources().getBoolean(R.bool.config_allowAllRotations);
      }
  
      private static void setRotationLock(final boolean enabled, final int rotation) {
          AsyncTask.execute(new Runnable() {
              @Override
              public void run() {
                  try {
                      IWindowManager wm = WindowManagerGlobal.getWindowManagerService();
                      if (enabled) {
                          wm.freezeRotation(rotation);
                      } else {
                          wm.thawRotation();
                      }
                  } catch (RemoteException exc) {
                      Log.w(TAG, "Unable to save auto-rotate setting");
                  }
              }
          });
      }
  
      /**
       * Registers a listener for rotation policy changes affecting the caller's user
       */
      public static void registerRotationPolicyListener(Context context,
              RotationPolicyListener listener) {
          registerRotationPolicyListener(context, listener, UserHandle.getCallingUserId());
      }
  
      /**
       * Registers a listener for rotation policy changes affecting a specific user,
       * or USER_ALL for all users.
       */
      public static void registerRotationPolicyListener(Context context,
              RotationPolicyListener listener, int userHandle) {
          context.getContentResolver().registerContentObserver(Settings.System.getUriFor(
                  Settings.System.ACCELEROMETER_ROTATION),
                  false, listener.mObserver, userHandle);
          context.getContentResolver().registerContentObserver(Settings.System.getUriFor(
                  Settings.System.HIDE_ROTATION_LOCK_TOGGLE_FOR_ACCESSIBILITY),
                  false, listener.mObserver, userHandle);
      }
  
      /**
       * Unregisters a listener for rotation policy changes.
       */
      public static void unregisterRotationPolicyListener(Context context,
              RotationPolicyListener listener) {
          context.getContentResolver().unregisterContentObserver(listener.mObserver);
      }
  
      /**
       * Listener that is invoked whenever a change occurs that might affect the rotation policy.
       */
      public static abstract class RotationPolicyListener {
          final ContentObserver mObserver = new ContentObserver(new Handler()) {
              @Override
              public void onChange(boolean selfChange, Uri uri) {
                  RotationPolicyListener.this.onChange();
              }
          };
  
          public abstract void onChange();
      }
  }