CODEWITHSUNDEEP
androidandroid-asynctaskprogress-barandroid-progressbar
Jeff Axelrod
Jeff Axelrod

Reputation: 28188

How can I show a ProgressBar only after a minimum delay?

I have an AsyncTask with an indeterminate ProgressBar that typically executes very quickly, but occasionally slowly. It's undesirable and distracting to for the the progress bar to flash quickly when there is no discernible wait.

Is there a way to delay display of the progress bar without creating another nested AsyncTask?

Upvotes: 5

Views: 3230

Answers (3)

Jeff Axelrod
Jeff Axelrod

Reputation: 28188

Thanks to Code Droid, I was able to write an abstract AsyncTask class that shows an indeterminate progress bar after a specified delay. Just extend this class instead of AsyncTask and be sure to call super() when appropriate:

public abstract class AsyncTaskWithDelayedIndeterminateProgress
      <Params, Progress, Result> extends AsyncTask<Params, Progress, Result> {
   private static final int MIN_DELAY = 250;
   private final ProgressDialog progressDialog;
   private final CountDownTimer countDownTimer;

   protected AsyncTaskWithDelayedIndeterminateProgress(Activity activity) {
      progressDialog = createProgressDialog(activity);
      countDownTimer = createCountDownTimer();
   }

   @Override protected void onPreExecute() {
      countDownTimer.start();
   }

   @Override protected void onPostExecute(Result children) {
      countDownTimer.cancel();
      if(progressDialog.isShowing())
         progressDialog.dismiss();
   }

   private ProgressDialog createProgressDialog(Activity activity) {
      final ProgressDialog progressDialog = new ProgressDialog(activity);
      progressDialog.setIndeterminate(true);
      return progressDialog;
   }

   private CountDownTimer createCountDownTimer() {
      return new CountDownTimer(MIN_DELAY, MIN_DELAY + 1) {
         @Override public void onTick(long millisUntilFinished) { }

         @Override public void onFinish() {
            progressDialog.show();
         }
      };
   }

Upvotes: 3

Code Droid
Code Droid

Reputation: 10472

Yes, there is and it's called a CountDownTimer and its highly underused. You can take action at each tick of the timer or when the timer runs out.

Upvotes: 4

Swifty McSwifterton
Swifty McSwifterton

Reputation: 2667

I am assuming you are calling onProgressUpdate at least a few times before your AsyncTask is finished. If that is the case, what you could do is this. Each time before you call onProgressUpdate, call Thread.sleep(250). This way your background Thread will pause before communicating with the UI Thread and give the appearance of a longer running task. Failing that, I'd probably need to see your code or get some more info.

Upvotes: 0

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