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The moose likes Swing / AWT / SWT and the fly likes The purpose of using getContentPane() Big Moose Saloon
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The purpose of using getContentPane()

Griff Haldeman

Joined: Jul 01, 2011
Posts: 5
What's the point of calling frame.getContentPane().add(button) when frame.add(button) works all the same? To my understanding, adding directly to the frame without first getting the content pane is disparaged, but if someone could elaborate on this, it'd be great.
Greg Charles

Joined: Oct 01, 2001
Posts: 2968

It's been awhile since I used Swing, but if I remember right, JFrame has an addImpl() method that adds components to the content pane by default. That's why frame.getContentPane.add(...) does the same thing as frame.add(...). As to why or if that's a bad practice, I'm not sure. Probably because you're not being explicit about what you're doing. There's a glass pane, where you can draw things that appear superimposed over what's in the content pane. Also a root pane and layered pane, but I forget what those do.
Griff Haldeman

Joined: Jul 01, 2011
Posts: 5
Thanks, just what I wanted to know.
Rob Spoor

Joined: Oct 27, 2005
Posts: 20276

In Java 1.4 and before, adding components to a JFrame directly, or setting its layout directly, would result in an error (of java.lang.Error or some sub class, can't remember which one it was). You really needed to use the content pane. In Java 5.0 they decided it made more sense to just redirect those calls to the content pane.

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