How do I create a custom floating Swing component without a JFrame?

Question

I'd like to create a custom swing component such as a desktop widget which does not require a JFrame (or to extend it) to be printed on the screen.

I don't want to extend the JFrame because my component is really simple and JFrame implements a lot of functionality I dont need.

Who do I start? Which class should I extend?

Many Thanks

EDIT ---------------------------------------

Thanks guys!

I'll check the references you sent. Also, is it possible to java to draw on the screen without swing API?

What functionality don't you need? You can invoke [`setUndecorated(true)`](http://download.oracle.com/javase/6/docs/api/java/awt/Frame.html#setUndecorated%28boolean%29) on your `JFrame`, but regardless, you'll need a container object to render your components with! — mre, Jun 27 '11 at 16:02
@Mikhas, Then it sounds like invoking the method on your `JFrame` will do the job, although I don't understand the "child components" part...Anyway, if you wanted to add more customization to your frame, consider reading [How to Create Translucent and Shaped Windows](http://java.sun.com/developer/technicalArticles/GUI/translucent_shaped_windows) — mre, Jun 27 '11 at 16:10
Here's an [example](http://stackoverflow.com/questions/2163544/re-paint-problem-on-translucent-frame-panel-component/2166500#2166500). — trashgod, Jun 27 '11 at 16:11
+1 on trashgod comment :) for referencing my answer. I love this screenshot: http://img36.imageshack.us/img36/9195/capturadepantalla201002.png — OscarRyz, Jun 27 '11 at 16:34

jzd · Answer 1 · 2011-06-28T12:25:41.440

5

If you don't want the functions a JFrame provides and just want floating graphics then use a JWindow. It does not have window decorations.

Example with plain label in a JWindow:

public static void main(String args[]) {
    JWindow w = new JWindow();
    w.add(new JLabel("Testing a Window!!!!!"));
    w.setLocation(300, 300);
    w.pack();
    w.setVisible(true);
}

edited Jun 28 '11 at 12:25

answered Jun 27 '11 at 16:15

jzd

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Um, I think you need a [top-level container](http://download.oracle.com/javase/tutorial/uiswing/components/toplevel.html). – trashgod Jun 27 '11 at 16:19
@Trashgod, I assume you could have an invisible Frame as the owner for the Window. I haven't tried it myself though. – jzd Jun 27 '11 at 17:54
1

@trashgod, you got me curious so I just tried and added an example. The Window does need an owner, but that owner does not need to be visible. – jzd Jun 27 '11 at 17:59
@jzd why AWT Containers, is there something specific – mKorbel Jun 27 '11 at 18:23
@mKorbel, the question was how to avoid a JFrame. And want to extend/use instead that has less functionality. It is a strange question, but a Window fits the requirements. – jzd Jun 27 '11 at 18:46
@jzd for this question is only JDialog answer, how can I foud out I can't see difference between Awt Frame and Swing JFrame, looks like as this topic is nonsence... :-) +1 – mKorbel Jun 27 '11 at 19:33
The topic is a little bit nonsence. However, in my example I create a Frame, but just use it as an owner. The Window is the only thing that is set to visible. – jzd Jun 27 '11 at 19:35
@mKorbel, looking back at this with a fresh view, I have no idea why I just didn't use a JWindow instead. I have updated my example. Thanks – jzd Jun 28 '11 at 12:26
@mKorbel, yea, I just wanted you to know that thinking about it with a clear head made me reconsider your comment about AWT vs Swing. – jzd Jun 28 '11 at 13:55

score 1 · Answer 2 · answered Jun 27 '11 at 16:27

All in all, you'll need to familiarize yourself with Java2D, as demonstrated by @trashgod's comment. In particular, Composting Graphics. And understand that using a top-level container to render Swing components is always required.

NOTE

If @trashgod provides an answer, I'll gladly remove mine and up-vote his accordingly.

score 1 · Answer 3 · answered Jun 27 '11 at 16:37

1

Depend on what you need. Probably an undecorated JFrame is all you need. I don't really understand your argument about "all the functionality I don't need", because, at different levels you'll get it anyway, either by another component or by the underlaying OS. You can't get rid of that.

Now addressing your question you can always use a JDialog

answered Jun 27 '11 at 16:37

OscarRyz

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JFrame leave a button in the taskbar (uncool); (J)Window is usually the one of choice (imo) – bestsss Jun 27 '11 at 17:09
1

Yeap, much better than a (J)Window is a `JDialog` wich doesn't leave the button in the taskbar either and still toplevel containter – OscarRyz Jun 27 '11 at 18:20
JDialog w/o parent Frame uses a shared swing frame (which can be obtained via `new JDialog().getParent()` ) – bestsss Jun 27 '11 at 18:37
It is still not clear what does the OP means with *a lot of functionality I dont need* – OscarRyz Jun 27 '11 at 19:51

How do I create a custom floating Swing component without a JFrame?

3 Answers3