Time for action – animating the second hand

The second hand is drawn with a redraw on the Canvas, but this will need to be run periodically. If it is redrawn once per second, it can emulate a clock ticking.

Eclipse has a jobs plug-in, which would be just right for this task, but this will be covered in Chapter 4, Interacting with the User. So to begin with, a simple Thread will be used to issue the redraw.

1. Open the ClockView class.

2. Add the following at the bottom of the createPartControl method:

   Runnable redraw = () -> {
     while (!clock.isDisposed()) {
       clock.redraw();
       try {
         Thread.sleep(1000);
       } catch (InterruptedException e) {
         return;
       }
     }
   };
   new Thread(redraw, "TickTock").start();

3. Relaunch the test Eclipse instance, and open the Clock View.

4. Open the host Eclipse instance and look in the Console View for the errors.

What just happened?

When the ClockView is shown, a Thread is created and started, which redraws the clock once per second. When it is shown, an exception...