OrientationMonitor.java

/*
 * Copyright (C) 2012 Google Inc.
 *
 * 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.talkback;

import android.content.Context;
import android.content.res.Configuration;
import android.os.PowerManager;
import com.google.android.marvin.talkback.TalkBackService;

import java.util.ArrayList;
import java.util.List;

/**
 * Watches changes in device orientation.
 */
public class OrientationMonitor {

    public interface OnOrientationChangedListener {
        public void onOrientationChanged(int newOrientation);
    }

    private final Context mContext;
    private final SpeechController mSpeechController;
    private final PowerManager mPowerManager;

    /** The orientation of the most recently received configuration. */
    private int mLastOrientation;
    private List<OnOrientationChangedListener> mListeners;

    public OrientationMonitor(SpeechController speechController, TalkBackService context) {
        if (speechController == null) throw new IllegalStateException();
        mContext = context;
        mSpeechController = speechController;
        mPowerManager = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
        mListeners = new ArrayList<>();
    }

    public void addOnOrientationChangedListener(OnOrientationChangedListener listener) {
        mListeners.add(listener);
    }

    public void removeOnOrientationChangedListener(OnOrientationChangedListener listener) {
        mListeners.remove(listener);
    }

    public void notifyOnOrientationChanged(int newOrientation) {
        for (OnOrientationChangedListener listener : mListeners) {
            listener.onOrientationChanged(newOrientation);
        }
    }

    /**
     * Called by {@link TalkBackService} when the configuration changes.
     *
     * @param newConfig The new configuration.
     */
    public void onConfigurationChanged(Configuration newConfig) {
        final int orientation = newConfig.orientation;
        if (orientation == mLastOrientation) {
            return;
        }

        mLastOrientation = orientation;
        notifyOnOrientationChanged(mLastOrientation);

        //noinspection deprecation
        if (!mPowerManager.isScreenOn()) {
            // Don't announce rotation when the screen is off.
            return;
        }

        if (orientation == Configuration.ORIENTATION_PORTRAIT) {
            mSpeechController.speak(mContext.getString(R.string.orientation_portrait),
                    SpeechController.QUEUE_MODE_UNINTERRUPTIBLE, FeedbackItem.FLAG_NO_HISTORY,
                    null);
        } else if (orientation == Configuration.ORIENTATION_LANDSCAPE) {
            mSpeechController.speak(mContext.getString(R.string.orientation_landscape),
                    SpeechController.QUEUE_MODE_UNINTERRUPTIBLE, FeedbackItem.FLAG_NO_HISTORY,
                    null);
        }
    }
}