Time for action – creating a reusable widget

Although the ClockView shows a single animated clock, creating an independent widget will allow the clock to be reused in other places.

1. Create a new class in the com.packtpub.e4.clock.ui package, called ClockWidget, that extends Canvas.

2. Create a constructor that takes a Composite parent and an int style bits parameter, and pass them to the superclass:

   public ClockWidget(Composite parent, int style) {
     super(parent, style);
   }

3. Move the implementation of the drawClock method from the ClockView to the ClockWidget. Remove the PaintListener references from the ClockView class.

4. In the ClockWidget constructor, register a PaintListener that delegates the call to the drawClock method:

   addPaintListener(this::drawClock);

5. Move the TickTock thread from the ClockView to the ClockWidget constructor; this will allow the ClockWidget to operate independently. Change any references for clock to this:

   Runnable redraw = () -> {
     while (!this.isDisposed()) {
       this.getDisplay...