Search:

And even more crossposts:
java - Drawing a selection box using Swing - Stack Overflow
Drawing a selection box using swing (Swing / AWT / SWT / JFace forum at JavaRanch)

Ugh, but I guess I'm just wasting my time, since you've already received and ignored this advice elsewhere.

http://www.java-forums.org/awt-swing/43694-drawing-selection-box-using-swing.html

The reason you're seeing flickering is because you're doing your painting incorrectly. If you're calling getGraphics() on a Component, you're going to have issues.

You have the general idea right-...