How to set transparent background of JDialog

Question

Hy,..

how can i set the background transparent and "remove" the closeoperation (marked red) ? I only want to show the card :-)

Thanks..!

Answer 1

yourDialog.setUndecorated(true)should do the trick for the title bar.

For having the Frame transparent. You'll have to work on the root panel with yourDialog.getRootPane().setOpaque(false)on it.

Answer 2

Although there is no problem with UNDECORATED JFrame transparency (myJFrame.setBackground (new Color (0,0,0,0)); is pretty enough), the same with JDialog is not working.

I discovered, however, the following sequence works perfect for JDialog:

myJDialog.getRootPane ().setOpaque (false);
myJDialog.getContentPane ().setBackground (new Color (0, 0, 0, 0));
myJDialog.setBackground (new Color (0, 0, 0, 0));

A also remain, but it is my PRIVATE, humble suggestion, that all setBackground call for Window extenders (e.g. JFrame, JDialog) should be tried against UnsupportedOperationException and IllegalComponentStateException.

Answer 3

I followed the instructions from the article and it worked finnaly AND it wasn't difficult at all. :) I now have my translucent SplashImage ans About screen which displays a PNG image and respect its (complex) transparency. Just awesome. Note that the method to proceed will change a little bit in JDK 7.

Just notice the difference between keywords. http://download.oracle.com/javase/tutorial/uiswing/misc/trans_shaped_windows.html#6u10

It would have been nice if the

yourDialog.setUndecorated(true);
yourDialog.getRootPane().setOpaque(false);

trick worked but it didn't to me. Maybe I did something wrong.

I also note it is important to use setContentPane(Component); instead of getContentPane.add(Component);

I'm happy it works now ! :)