Swing Hacks

Make Your Frame Dissolve #42

Chapter 6, Transparent and Animated Windows

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221

HACK

// start animation

new Thread(this).start( );

} catch (Exception ex) {

System.out.println(ex);

ex.printStackTrace( );

}

}

dissolveExit( ) saves a reference to the frame and creates a new java.awt.

Robot

to handle the screen captures. Then it captures just the area of the

screen containing the frame by calling

robot.createScreenCatpure( ), using

the rectangle returned by

frame.getBounds( )

. After making this screen cap-

ture, it hides the frame and then captures the entire screen into the second

buffer. Finally, it creates a new

Window

that covers the entire screen, adds the

Dissolver as the window’s only child, and starts the animation on a new

thread.

There are two tricky things to look out for here. First, the code uses a

Window

instead of a JFrame so that the window won’t show up in a task list or the

dock. This also means it won’t have any window decorations that would

ruin the illusion of transparency. Second, the

Window constructor requires

you to pass in another window or frame. This is because every window is

attached to a parent window and will only be visible when the parent is (on

certain platforms). Using the existing application frame won’t work because

it’s just been hidden, but if you create a new, empty

JFrame, the window will

show up fine.

Run the Animation

dissolveExit( ) creates a new thread around the run( ...