Slick Forums

Sorry for all the questions on the forum lately, but I have a slight problem with TWL and would like to hear your opinion on this.
When doing 'simple' modifications of the UI like setVisible(true), openPopup or removeChild I get my fun No OpenGL context errors because they are triggered via my networking thread (Netty). But shouldn't stuff like this be some sort for flag that gets set and when the update()/render() call (passed from BasicGame (slick)) is made, it needs OpenGL stuff and thus always have the OpenGL context, preventing the error.

TWL is NOT thread safe except a few methods where it is explicitly stated: GUI.invokeLater, GUI.invokeAsync, Widget.getGUI.
All other methods must only be called from the same thread as it is rendered from.
Invoking any other methods from multiple/different threads will result in random crashes or exceptions.

The point is that all this deferred handling would require internal queues in all Widgets - also the query functions would get compilcated.
What should getNumChildren() return after a removeChild() ?

If you have several threads and need to modify the UI from other threads then use GUI.invokeLater() to do it on the UI thread.
There is absolutely no reason to distribute all this stuff through the UI lib.