Correct usage of Android's SeekBar?

Question

I tried plugging a SeekBar into my video app, but it doesn't seem to ever reach the end of the bar. Here's the code:

videoSeekBar = (SeekBar) activity.findViewById(R.id.videoPlayerSeek);
videoDuration = player.getDuration();
videoSeekBar.setMax(videoDuration);
videoSeekBar.setProgress(0);

// Start lengthy operation in a background thread
new Thread(new Runnable() {
    public void run() {
        while (videoPlayProgress < videoDuration) {
            videoPlayProgress = player.getCurrentPosition();

            // Update the progress bar
            handler.post(new Runnable() {
                public void run() {
                    videoSeekBar.setProgress(videoPlayProgress);
                }
            });
        }
    }
}).start();

Then, I have an OnCompleteListener attached to the MediaPlayer. When it is called,

player.getCurrentPosition() returns 6209

player.getDuration() returns 6592

Which can't be right. At this point, the slider status indicator isn't quite at the end of the slider bar, but there's a slight gap. The shorter the video's length, the bigger the gap.

Answer 1

First, consider <= instead of <.

More importantly, you do not need or want a busy-loop background thread for this. Go with something like:

Runnable r=new Runnable() {
    public void run() {
        videoSeekBar.setProgress(player.getCurrentPosition());

        if (player.getCurrentPosition()<player.getDuration()) {
            videoSeekBar.postDelayed(r, 33);
        }
    }
};

and somewhere call run() on r, when your video starts up. This will update the SeekBar about 30 times per second.

Your current implementation is a foreground busy loop, posting thousands of messages onto the main application thread's queue, which will make your video playback performance worse and waste battery for no particular advantage.

This still might not get all the way to the end -- it's possible that the video will reach the end between the setProgress() call and the if test. The true test of it being at the end is the OnCompletionListener, so just position the SeekBar at the end at that point.