Update progressbar from AsyncTaskLoader?

Question

When using a AsyncTaskLoader how would you update a progressbar showing the status as it is being updated? Normally you wait for the callback to remove when done, but how to do

Answer 1

I just had this problem. I used a static AtomicInteger in my activity to store the progress. The loader updates it via a callback and the activity polls it and displays the progress.

In the loader callback onLoadFinished I hide my progress panel, which causes the polling loop to exit.

Usually I'd avoid static state, but I think overall this is simpler than the alternatives. In my case, I have a different layout in landscape, so I'm happier leaving the orientation changes behaving as normal.

private Handler progressHandler; // init with new Handler(getMainLooper())
private static AtomicInteger progress = new AtomicInteger(0);

...

private void beginProgressUiUpdates() {
    progress.set(0);
    displayProgress();
    progressHandler.postDelayed(pollProgress, PROGRESS_POLL_PERIOD_MILLIS);
}

private Runnable pollProgress = new Runnable() {
    public void run() {
        if (findViewById(R.id.progressPanel).getVisibility() == View.VISIBLE) {
            displayProgress();
            progressHandler.postDelayed(pollProgress, PROGRESS_POLL_PERIOD_MILLIS);
        }
    }
};

private void displayProgress() {
    ((ProgressBar)findViewById(R.id.progressBar)).setProgress(progress.get());
}