Since Version 2.0.0, GLCanvas is one AWT toolkit implementation for the OpenGL bindings and it is defined as a package member of the java package gl4java.awt. GLCanvas is derived from AWT's Canvas. While creation GLCanvas trys to create a GLContext instance to connect the OpenGL machine to the AWT window, which is represented by the platform specific window.
Also the refresh signal is routed to OpenGL, so OpenGL can re-render.
These are the basic source files, look at 5.12, page .