Swing Hacks

Create Menus with Drop Shadows #11

Chapter 1, Basic JComponents

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49

HACK

One nice thing about assembling the drop-down from standard compo-

nents is that it will still look good when used with a different Look and Feel.

Everything the user sees on the screen is some subclass of the standard

JButton, but it is just presented in a non-traditional manner. If you switch to

another theme where standard buttons are shaped differently, the custom

component adapts automatically.

H A C K

#11

Create Menus with Drop Shadows Hack #11

This hack explores a simple way to create drop shadows on menus

throughout an entire application with minimal code changes.

Many modern operating systems provide menus with interesting effects to

make them jump off the screen. One of the most common is the drop

shadow. Some programs even provide shadows themselves when the host

operating system does not. For years, a lack of low-level graphics support

has denied Swing programs access to these kinds of cool effects. But not any

more! Most of the effects can be duplicated with Swing’s robust theming

ability.

Most custom effects require either subclassing a component or messing with

graphics overlays. I tried a variety of techniques to create this hack, but I

kept coming across the same problem over and over. If I wanted to draw a

shadow, I had to change the sizing of each menu item, plus its background,

plus the pop-up frame itself. That ...