JHotDraw is a framework for building Swing drawing applications. It's descended from a toolkit written in SmallTalk by one of the "gang of four" patterns gurus so it's heavily pattern-intensive.

http://www.jhotdraw.org/

What happens when the delete key is pressed?

     at reva.manager.view.editor.Antenna$1.figureRequestRemove(Antenna.java:100)
     at org.jhotdraw.standard.StandardDrawing.orphan(Unknown Source)
     at org.jhotdraw.standard.DeleteFromDrawingVisitor.visitFigure(Unknown Source)
     at org.jhotdraw.standard.AbstractFigure.visit(Unknown Source)
     at org.jhotdraw.standard.FigureTransferCommand.deleteFigures(Unknown Source)
     at org.jhotdraw.standard.DeleteCommand.execute(Unknown Source)
     at org.jhotdraw.util.UndoableCommand.execute(Unknown Source)
     at org.jhotdraw.standard.StandardDrawingView$DrawingViewKeyListener.keyPressed(Unknown Source)
     at java.awt.Component.processKeyEvent(Component.java:5058)