Hi,

I am currently learning Java, and I wondered how I can draw to a JFrame using a backbuffer?

At first I thought that I could just create a new instance from "Image", but that's an abstract class. Searching the web only gave me some code samples which were using some "createImage"-function to create an image for the backbuffer, but I can't seem to find that function anywhere

A code sample would be very nice! I already know C# quite well, so the Java syntax itself isn't a problem.

You don't need a backbuffer with a JFRame. If you say "setDoubleBuffered(true)" ist will be doublebuffered.
If you want to paint onto the JFrame, take another component like JComponent extend it and override the "public void paintComponent(Graphcis g)" method.
If you want to add components to a JFrame, use the ContentPane of the JFrame to add. like "getContentPane().add()"
The JComponents are mostly buffered.



I hope you are using eclipse. Try to goole about "Java Swing".

Thanks for the reply

Somehow my form (derived from JFrame) does not contain a method called 'setDoublebuffered', I don't really know why - it does contain a 'isDoublebuffered'-method, but I see no way to change it

I'm using NetBeans, not Eclipse, and it seems I'm using Java version 1.6.0_16

Edit:
What is 'rootPane'? I randomly noticed that a 'this.rootPane.setDoublebuffered'-method does exist. It doesn't solve the problem though

Ok,

The JFrame:

-Is always doublebuffered (as far as i know)
-consist of several container 1. the Frame, 2. the rootPane, 3. the glas Pane, 4. the contentPane
- There are other window container types like JDialog or JWindow with special functions
-Always add other components to the contentPane. If you don't want to write frame.getContentPane().add(...) everytime do this:
"Container c = frame.getContentPane(); c.add ..."
-Don't use a visual swing gui editor, most of them are crap
-Don't forget the layouts. A JFrame's contentPane always has the BorderLayout aplied as standard. If you add a component do this c.add(myPanel, BorderLayout.CENTER) (or NORTH, SOUTH, WEST, EAST)
-Google for Layouts and JFrame or Swing. There are tons of tutorials about Java outside
-Java is the best language to do quick prototypes or toolsets. It comes with all structures like Lists or Hashmaps, all important Math functions and since 1.6 with a very improved rendering system (improved awt)
- btw. since 1.6 the awt (Component manager) supports transparent windows or perpixel masks

Thanks a lot for the info & tips

I checked my JFrame (this.isDoubleBuffered() in the class which inherits JFrame), and it returned false, so I might not be the case it seems

But, you don't need a dubblebufferred Frame, because, if you want to draw own Graphics you should use a class that extends JComponent or simply extend the JPanel. This components can be set to doubblebuffered.
Because of the multiplatform thing of the awt, the JFrame must follow some rules and there is simply no need to doublebuffer the Frame.
(If I remember correctly the basic Frame of the awt was also not doublebuffered. If you wanted to paint buffered Graphics on it you had to write an own Graphics buffer and flip it by yourselfs onto the screen.)

Hmm okay, I'm just used to do the rendering (either GDI+ or MDX) from the paint event of the form in C#, but I'll try making a new class extending JComponent or JPanel as you suggest

Well, I'm gonna try it tomorrow, it's getting too late for today

I finally got it working! Thanks a lot!

Here's the code I used for testing (IRenderable is just an interface I made)