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.gallery3d.app;
18 
19 import android.app.Activity;
20 import android.content.ContentResolver;
21 import android.content.Context;
22 import android.content.pm.ActivityInfo;
23 import android.content.res.Configuration;
24 import android.provider.Settings;
25 import android.view.OrientationEventListener;
26 import android.view.Surface;
27 
28 import com.android.gallery3d.common.ApiHelper;
29 import com.android.gallery3d.ui.OrientationSource;
30 
31 public class OrientationManager implements OrientationSource {
32     private static final String TAG = "OrientationManager";
33 
34     // Orientation hysteresis amount used in rounding, in degrees
35     private static final int ORIENTATION_HYSTERESIS = 5;
36 
37     private Activity mActivity;
38     private MyOrientationEventListener mOrientationListener;
39     // If the framework orientation is locked.
40     private boolean mOrientationLocked = false;
41 
42     // This is true if "Settings -> Display -> Rotation Lock" is checked. We
43     // don't allow the orientation to be unlocked if the value is true.
44     private boolean mRotationLockedSetting = false;
45 
OrientationManager(Activity activity)46     public OrientationManager(Activity activity) {
47         mActivity = activity;
48         mOrientationListener = new MyOrientationEventListener(activity);
49     }
50 
resume()51     public void resume() {
52         ContentResolver resolver = mActivity.getContentResolver();
53         mRotationLockedSetting = Settings.System.getInt(
54                 resolver, Settings.System.ACCELEROMETER_ROTATION, 0) != 1;
55         mOrientationListener.enable();
56     }
57 
pause()58     public void pause() {
59         mOrientationListener.disable();
60     }
61 
62     ////////////////////////////////////////////////////////////////////////////
63     //  Orientation handling
64     //
65     //  We can choose to lock the framework orientation or not. If we lock the
66     //  framework orientation, we calculate a a compensation value according to
67     //  current device orientation and send it to listeners. If we don't lock
68     //  the framework orientation, we always set the compensation value to 0.
69     ////////////////////////////////////////////////////////////////////////////
70 
71     // Lock the framework orientation to the current device orientation
lockOrientation()72     public void lockOrientation() {
73         if (mOrientationLocked) return;
74         mOrientationLocked = true;
75         if (ApiHelper.HAS_ORIENTATION_LOCK) {
76             mActivity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LOCKED);
77         } else {
78             mActivity.setRequestedOrientation(calculateCurrentScreenOrientation());
79         }
80     }
81 
82     // Unlock the framework orientation, so it can change when the device
83     // rotates.
unlockOrientation()84     public void unlockOrientation() {
85         if (!mOrientationLocked) return;
86         mOrientationLocked = false;
87         Log.d(TAG, "unlock orientation");
88         mActivity.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_FULL_SENSOR);
89     }
90 
calculateCurrentScreenOrientation()91     private int calculateCurrentScreenOrientation() {
92         int displayRotation = getDisplayRotation();
93         // Display rotation >= 180 means we need to use the REVERSE landscape/portrait
94         boolean standard = displayRotation < 180;
95         if (mActivity.getResources().getConfiguration().orientation
96                 == Configuration.ORIENTATION_LANDSCAPE) {
97             return standard
98                     ? ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE
99                     : ActivityInfo.SCREEN_ORIENTATION_REVERSE_LANDSCAPE;
100         } else {
101             if (displayRotation == 90 || displayRotation == 270) {
102                 // If displayRotation = 90 or 270 then we are on a landscape
103                 // device. On landscape devices, portrait is a 90 degree
104                 // clockwise rotation from landscape, so we need
105                 // to flip which portrait we pick as display rotation is counter clockwise
106                 standard = !standard;
107             }
108             return standard
109                     ? ActivityInfo.SCREEN_ORIENTATION_PORTRAIT
110                     : ActivityInfo.SCREEN_ORIENTATION_REVERSE_PORTRAIT;
111         }
112     }
113 
114     // This listens to the device orientation, so we can update the compensation.
115     private class MyOrientationEventListener extends OrientationEventListener {
116         public MyOrientationEventListener(Context context) {
117             super(context);
118         }
119 
120         @Override
121         public void onOrientationChanged(int orientation) {
122             // We keep the last known orientation. So if the user first orient
123             // the camera then point the camera to floor or sky, we still have
124             // the correct orientation.
125             if (orientation == ORIENTATION_UNKNOWN) return;
126             orientation = roundOrientation(orientation, 0);
127         }
128     }
129 
130     @Override
131     public int getDisplayRotation() {
132         return getDisplayRotation(mActivity);
133     }
134 
135     @Override
136     public int getCompensation() {
137         return 0;
138     }
139 
140     private static int roundOrientation(int orientation, int orientationHistory) {
141         boolean changeOrientation = false;
142         if (orientationHistory == OrientationEventListener.ORIENTATION_UNKNOWN) {
143             changeOrientation = true;
144         } else {
145             int dist = Math.abs(orientation - orientationHistory);
146             dist = Math.min(dist, 360 - dist);
147             changeOrientation = (dist >= 45 + ORIENTATION_HYSTERESIS);
148         }
149         if (changeOrientation) {
150             return ((orientation + 45) / 90 * 90) % 360;
151         }
152         return orientationHistory;
153     }
154 
getDisplayRotation(Activity activity)155     private static int getDisplayRotation(Activity activity) {
156         int rotation = activity.getWindowManager().getDefaultDisplay()
157                 .getRotation();
158         switch (rotation) {
159             case Surface.ROTATION_0: return 0;
160             case Surface.ROTATION_90: return 90;
161             case Surface.ROTATION_180: return 180;
162             case Surface.ROTATION_270: return 270;
163         }
164         return 0;
165     }
166 }
167