Seems like you want some buffer that holds the contents
of the graph without your red node on it. Then prior to
drawing the new location of the red node, you can simply
copy in the contents from the buffer in the area affected by
the last rendering of the red node. This will effectively
erase
Depending on the complexity of your drawing, simply rerendering the
scene with the objects in the new position (with double buffering) may
work well for 10 frames/second performance. Switch to using Swing with
a JPanel (you'll have to override paintComponent instead of paint) and
call repaint()
