Swing Hacks

Indefinite Progress Indicator #47

Chapter 6, Transparent and Animated Windows

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249

HACK

Picture as Indicator

The first solution relies on cycling the brightness of a picture in a panel.

Instead of moving a rectangle back and forth, you can increase and decrease

the brightness of a picture. The result is much more appealing and lets you

choose an adequate picture regarding the current running task. Figure 6-14

shows the

AnimatedPanel

in action.

When you click the Start button, the contents of the Animated tab are

replaced by a panel containing a picture and a message. With the picture’s

brightness cycles, as shown in Figure 6-15, you can see the most bright state

on the left and the less bright state on the right.

Figure 6-14. The first tab demonstrates the use of a picture as an indefinite progress

indicator

Figure 6-15. AnimatedPanel displays a picture and cycles its brightness

250

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Chapter 6, Transparent and Animated Windows

#47 Indefinite Progress Indicator

HACK

To change the brightness of the picture dynamically, AnimatedPanel starts an

animation thread responsible for computing the brightness over the time:

public void start( ) {

this.animator = new Thread(new HighlightCycler( ), "Highlighter");

this.animator.start( );

}

class HighlightCycler implements Runnable {

private int way = 1;

private final ...