Swing Hacks

Animating a Sheet Dialog #45

Chapter 6, Transparent and Animated Windows

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233

HACK

When you click either of the options, the event listener hides the glass pane,

which makes the sheet disappear.

This is a pretty simple case of using the glass pane—in fact, the test is a few

lines longer than the implementation of the sheet. The only thing that’s

missing is the charming animation of the sheet sliding in

[Hack #45]

….

H A C K

#45

Animating a Sheet Dialog Hack #45

By animating the sheet’s appearance and disappearance, you give the user a

better clue that his attention is required. Plus, it looks cool.

Another really great thing about the sheet functionality in Mac OS X is that

it doesn’t just suddenly appear—it slides out from the titlebar, as if unroll-

ing from under the bar. This animation further reinforces the relationship

between the sheet and the window because the short animation catches your

eye and alerts you to the fact that something about the window has changed

dramatically—namely, that it is now blocked by the sheet dialog.

Animate the Sheet

You already know how to get components into the glass pane [Hack #44], so

you should expect that the key to sheet animation is to perform the anima-

tion in the glass pane, on top of the other components. Of course, you might

have also guessed that the tricky part of this is going to be showing succes-

sively larger parts of the dialog as the animation progresses. ...