I've noticed that there isn't a thread on swing so i'll post this here.

Plain and simple. I'm building a 2D map editor program using swing which loads a tile set. I'm using a JPanel which controls the map editor. It's set up in a grid reference (rows/cols determined by the user) and wherever the user clicks in the grid, the selected image, gets placed in that position. Once done, it saves the 2D array into a text file. Which is the map file used for my game programs.

My question is, why is it that my JPanel overlaps the JMenuBar whenever I select a menu? I'm going to assume it's because my JPanel uses double buffering in a thread which causes the overlapping. Or that JMenuBar is heavyweight, although i thought that all swing components are lightweight apart from japplet/jframe. I'm avoiding this problem atm by readjusting the JPanels position away from the Menus. But i'm curious to know what's going on.

Well now, this post is pointless. I found a fix to both the Canvas and JPanel problem. Good old heavyweight components

JPopupMenu.setDefaultLightWeightPopupEnabled(false);