Question

I have an AsyncTask to handle a reasonably long running update process, and I want a progress dialog that shows, in order:

1. “Starting update” (for a brief second)
2. “Downloading update” (no progress bar — I don’t know how big the update will be before I download it)
3. “Saving update data” (with a 0-100% progress bar)
4. “Saving update images” (with a 0-100% progress bar)
5. “Update finished” (for a brief second before the dialog disappears)

I’m having problems toggling the progress dialog between determinate (progress bar shows up) and indeterminate (no progress bar).

The code in my AsyncTask follows:

private final ProgressDialog progressDialog;

public SynchronizeTask(Activity activity)
{
    progressDialog = new ProgressDialog(activity);
    progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
}

protected void onPreExecute() {
    progressDialog.setMessage("Starting update...");
    progressDialog.setCancelable(false);
    progressDialog.show();
}

...lots of code here...

// all of these are set from doInBackground()
private String progressMsg;
private int progressTotal;
private int progressProgress;

protected void onProgressUpdate(Void... values) {
    progressDialog.setMessage(progressMsg);
    if (progressTotal > 0) {
        progressDialog.setIndeterminate(false);
        progressDialog.setMax(progressTotal);
        progressDialog.setProgress(progressProgress);
    } else {
        progressDialog.setIndeterminate(true);
        progressDialog.setMax(0);
        progressDialog.setProgress(0);
    }
}

I tried toggling determinate with setIndeterminate() — the problem here is that the progress dialog shows “NaN” and “0%” at the bottom of the dialog even though there’s no “bar” left in indeterminate mode.

Then I tried using setProgressNumberFormat() and setProgressPercentFormat() just to hide the numbers — but neither of these are supported in Android below 3.0.

Then I tried using setProgressStyle() to toggle between STYLE_SPINNER and STYLE_HORIZONTAL — calling setProgressStyle() in my onProgressUpdate() seems to cause my app to crash.

Is there any easy way to toggle a progress dialog between determinate and indeterminate mode?

Answer 1

Might be a good idea to close one progress dialog and open another, with different style.