MediaPlayPauseButton.java

package com.android.systemui.statusbar.powerwidget;

import com.android.systemui.R;

import android.content.Context;
import android.media.AudioManager;
import android.view.KeyEvent;

public class MediaPlayPauseButton extends MediaKeyEventButton {
    public MediaPlayPauseButton() { mType = BUTTON_MEDIA_PLAY_PAUSE; }

    private static final int MEDIA_STATE_UNKNOWN  = -1;
    private static final int MEDIA_STATE_INACTIVE =  0;
    private static final int MEDIA_STATE_ACTIVE   =  1;

    private int mCurrentState = MEDIA_STATE_UNKNOWN;

    @Override
    protected void updateState() {
        mState = STATE_DISABLED;
        if(isMusicActive()) {
            mIcon = R.drawable.stat_media_pause;
        } else {
            mIcon = R.drawable.stat_media_play;
        }
    }

    @Override
    protected void toggleState() {
        sendMediaKeyEvent(KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE);

        mCurrentState = (isMusicActive() ? MEDIA_STATE_INACTIVE : MEDIA_STATE_ACTIVE);

        update();
    }

    @Override
    protected boolean handleLongClick() {
        return false;
    }

    private boolean isMusicActive() {
        if(mCurrentState == MEDIA_STATE_UNKNOWN) {
            mCurrentState = MEDIA_STATE_INACTIVE;
            AudioManager am = getAudioManager(mView.getContext());
            if(am != null) {
                mCurrentState = (am.isMusicActive() ? MEDIA_STATE_ACTIVE : MEDIA_STATE_INACTIVE);
            }

            return (mCurrentState == MEDIA_STATE_ACTIVE);
        } else {
            boolean active = (mCurrentState == MEDIA_STATE_ACTIVE);
            mCurrentState = MEDIA_STATE_UNKNOWN;
            return active;
        }
    }
}