JHotDrawNotes - Tech - The Caboteria

<nop>JHotDraw is a framework for building Swing drawing applications.  It's descended from a toolkit written in <nop>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?

<pre>
     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)
</pre>

=StandardDrawingView.DrawingViewKeyListener= creates a =DeleteCommand= in the constructor.  When the delete key is pressed the listener calls =DeleteCommand.isExecutable()= and if it returns true calls =execute()=.  =DeleteCommand.isExecutable()= checks some stuff and then delegates to =DeleteCommand.isExecutableWithView()= which checks if any figures are selected and if so returns true.

Keyboard/mouse events start in the <nop>DrawingView (it's a JPanel) and then get propagated to the tool that the <nop>DrawingEditor returns from a call to =tool()=.

What happens when the mouse is dragged?

<pre>
     [java]     at reva.manager.view.editor.AntennaFigure.basicMoveBy(AntennaFigure.java:274)
     [java]     at org.jhotdraw.standard.AbstractFigure.moveBy(AbstractFigure.java:70)
     [java]     at org.jhotdraw.standard.DragTracker.mouseDrag(DragTracker.java:64)
     [java]     at org.jhotdraw.util.UndoableTool.mouseDrag(UndoableTool.java:72)
     [java]     at org.jhotdraw.standard.SelectionTool.mouseDrag(SelectionTool.java:95)
     [java]     at org.jhotdraw.contrib.CustomSelectionTool.mouseDrag(CustomSelectionTool.java:74)
     [java]     at org.jhotdraw.standard.StandardDrawingView$DrawingViewMouseMotionListener.mouseDragged(StandardDrawingView.java:1001)
     [java]     at org.jhotdraw.contrib.zoom.ZoomDrawingView$2.mouseDragged(ZoomDrawingView.java:367)
     [java]     at java.awt.Component.processMouseMotionEvent(Component.java:5148)
     [java]     at javax.swing.JComponent.processMouseMotionEvent(JComponent.java:2779)
     [java]     at java.awt.Component.processEvent(Component.java:4901)
</pre>