Swing Hacks

Minimize to a Mini-Frame #40

Chapter 5, Windows, Dialogs, and Frames

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HACK

on right-clicks. If you are using Java 5.0, you can add another line to make

the frame always be on top. This can be annoying to some users, however,

so a real program would have a preference to control that feature:

// hide the extra components

bottom.hide( );

// add the pop up

panel.addMouseListener(this);

// stay on top

frame.setAlwaysOnTop(true);

// show the frame again

frame.pack( );

frame.setLocation(location);

frame.setVisible(true);

With the frame prepared, the code packs it, gives it the location of the origi-

nal frame, and makes it visible again.

Restore the Frame

When the user triggers the pop-up menu and selects Normal, the

switchToNormal( ) method will be called. This method reverses what the

switchToMini( ) method did:

public void switchToNormal( ) {

// nuke the old frame and build a new one

Point location = frame.getLocation( );

frame.setVisible(false);

frame = new JFrame( );

frame.setUndecorated(false);

frame.getContentPane( ).add(panel);

// show the extra components

bottom.show( );

frame.setJMenuBar(menubar);

// hide the pop up

panel.removeMouseListener(this);

// turn off stay on top

frame.setAlwaysOnTop(false);

// show the frame again

frame.pack( );

frame.setSize(normal_size);

frame.setLocation(location);

frame.setVisible(true);

}

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Chapter 5, Windows, Dialogs, and Frames

#40 Minimize to a Mini-Frame

HACK

switchToNormal( ) will first save the location of the frame, hide the frame,

and replace it with a new, fully decorated one. It then turns the menu bar

and bottom component back on, removes the pop-up listener, turns off

Always on Top (only for Java 5.0), and restores the frame.

To launch the application, you need to add only a

main( )

method to create a

mini and show it on screen:

public static void main(String[] args) {

MiniMizeHack mini = new MiniMizeHack( );

mini.frame.pack( );

mini.frame.setSize(300,300);

mini.frame.setVisible(true);

}

Swing doesn’t do everything by default, but it makes a lot of things possi-

ble. This hack showed how to create the sort of dynamic frame actions that

users expect today. One enhancement you would probably want to add is

the draggable background

[Hack #34] because a window without a titlebar may

be difficult to move by itself. You might also want to use small buttons

instead of a pop-up menu to control the toggling since most users will be

familiar with the min, max, and close buttons.