java screensaver?

zap

what would I have to turn a java program into a screensaver?

Hobbes

Might not be possible.

As far as I recall, SCR files are basically EXE files that have two parameters (which I forget). One parameter is for settings, one is for running the screen saver. Other then that its a normal exe.

lynchie

You need to write a c/c++ program that uses JNI to call your java app. Read up on Sun's JNI tutorial for more info

Hobbes

lynchie wrote:

You need to write a c/c++ program that uses JNI to call your java app. Read up on Sun's JNI tutorial for more info

Intresting.. wouldn't the Java application need to be running all the time?

lynchie

Not really.. AFAIK the scr file which is a plain windows exe is called by the OS with two parameters /c and /s. If /c is passed you show the standard config window, is /s is shown you show the screensaver. Only one instance can run at any given time. It would be tricky though as your app would have to exit once a mouse move or key press is made. So unless you java app is a a swing gui with a listener on mouse/key events it would be pointless trying to use a java app as a screensaver in the first place.

zap

ye it is swing gui with mouse/key action listeners, it has its own config so how would i go about it

rsynnott

Possibly (and I'm not up on my Windows programming, so don't take this as gospel) write a simple C program that just does a system call for "java -jar yourprogram.jar". Other than that, you're stuck with JNI, see Sun's website.

zap

what if i was making it for *unix?

rsynnott

For unix I'm fairly sure you can do it with a script. XScreensaver will pass it some stuff; see its docs for more details.