Question

My app has a not that frequent operation that is executed on the UI threads and takes long time (up to 3 secs). I want to display an animated ‘wait’ indications during that time. For example, a rotating spinner. No need to display the actual progress, just a fix speed animation.

I created a custom dialog that pops up during the long operation and it has this layout

<?xml version="1.0" encoding="utf-8"?>
<ProgressBar xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/spinner"
    style="?android:attr/progressBarStyleLarge"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

Problem is that it does not spin. How do I make it spin, even if the UI thread is busy?

I tried to create a chain on events to increment it but I get only two events, probably because the UI thread is busy.

// In the custom dialog class. mProgressBar is the ProgressBar in the layout.
// Called externally once when the dialog is shown
public void tick() {
    mProgressBar.incrementProgressBy(10);
    mProgressBar.postDelayed(new Runnable() {
        @Override
        public void run() {
            // Not a recursion since it's done in a future event.
            tick();
        }
    }, 100);
}

What is a simple way to achieve this animation? Will a frame by frame animation be easier to do?

Answer 1

Use AsyncTask http://developer.android.com/guide/topics/fundamentals/processes-and-threads.html It is not spin because it is executing in UI thread