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
17package com.android.gallery3d.app;
18
19import android.app.Activity;
20import android.content.ContentResolver;
21import android.content.Context;
22import android.content.pm.ActivityInfo;
23import android.content.res.Configuration;
24import android.provider.Settings;
25import android.view.OrientationEventListener;
26import android.view.Surface;
27
28import com.android.gallery3d.common.ApiHelper;
29import com.android.gallery3d.ui.OrientationSource;
30
31public 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
46    public OrientationManager(Activity activity) {
47        mActivity = activity;
48        mOrientationListener = new MyOrientationEventListener(activity);
49    }
50
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
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
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.
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
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
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