[gl4java-usergroup] Re : JMenuItem over GLAnimCanvas

[Alban C. <aco...@wa...>]

I=92m not an expert about Java GUI components, but this question is =
often
asked on the mailing list (and we should add it to the FAQ).=20

=20

Here is what I understood :

=20

GLAnimCanvas is an awt and heavyweight component.

JMenus are swing and lightweight components.

Lightweight and heavyweight components don=92t mix properly, as
heavyweight components are always draw on top of lightweight components.
Thus, your menu opens behind your canvas.

So if you want to be able to display a menu over your OpenGL stuff, you
need to use a GLJPanel wich is lightweight. (It works, see the demo in
swingDemos/GLSwingDemoApplet for an exemple). The drawback is the
GLJPanel is not hardware accelerated, so you will lose performance over
GLAnimCanvas.

=20

You may have 2 other alternatives :

-         Use an awt menu wich should be heavyweight and should display
properly (I am not sure about this, you have to make a test. If you do
it, please let me know how it works).

-         Draw the menu yourself in OpenGL at the right place : see
MiscDemos\tessdemo.html for an exemple.

=20

Good day

=20

Alban Cousini=E9

=20

=20

=20

=20

=20