Mikado "tree" for "space" exercise 2

Separate Solar and Bounce

v Separate Solar system and bouncing ball logic
  v Delete IS_BOUNCING_BALL flagg
    v Move main method of Space to subclasses
      v Create subclasses of "Space"
      v Remove IS_BOUNCING_BALLS if-test in main
        v Extract main method logic to non-static method
        v Make IS_BOUNCING_BALLS into an argument
    v Convert if statements into polymorphism
      v Convert IS_BOUNCING_BALLS into non-static field in Space
        v Move IS_BOUNCING_BALLS to Space
          v Convert IS_BOUNCING_BALLS to parameter in PhysicalObject
      v Remove dead code
        v Replace IS_BOUNCING_BALLS with constants
          v push down mouseWheelMoved
          v extract and subclass call to paintPhysicalObject
          v extract and push down call doStep
          v push down collide (duplicate and delete)
          v push down mouseDragged
  v Remove isSolarSystem parameter from run()
    v replace boolean parameter with polymorphism
      v Extract and push down createPhysicalObjects
  v Move weightToColor to Solar
    v Remove isSolarSystem parameter from paintPhysicalObject
      v Align branches in if-test
        v Make Color into a parameter
        v Make scale a parameter
        v Make diameter a parameter
  v Remove spurious fields in PhysicalObject
  

Separate Swing logic

v Separate Domain Logic from Swing
  v ADD setDefaultCloseOperation(EXIT_ON_CLOSE); !!!!!
  v Cleanup
    v BUG: Resize event
    v Make scale, centerX and centerY non-static
      v Move scale, centerX, centerY to Space
    v Move EARTH_MASS to Solar
    x Move dragging logic to space (?)
    v Combine step and collide and step++
    v move second to Space
  v Remove Swing imports from PhysicalObject
    v Remove JFrame from PhysicalObject
    v Remove paint method from PhysicalObject
  v Remove Swing imports from Space
    v Remove JFrame superclass from Space
      v Remove step() from Space
        v use doStep instead of step in test
      v Remove use of getSize and getWidth from Space and subclasses and Implement Space.setSize
    v Move paint to SpaceFrame
    v Remove animation from Space
      v Remove main methods from Space subclasses
    v Move buffered painting into SwingDisplay
    v Move business logic for painting into Space
    v Push down Listeners
      v Extract add*Listener calls in run to subclasses
    v Remove Swing imports from Bounce
      v Move Swing logic in Space to SpaceFrame
          v Create SpaceFrame
        v Copy Space.run into SpaceFrame
        v Move Bounce KeyListener to SpaceFrame
        v Remove Graphics2D in doPaintObject
          v Hide implementation of doPaintObject in Solar
          v Hide implementation of doPaintObject
            v extract Display.fillCircle
    v Remove Swing imports from Solar
      v Move eventhandlers to new class SolarFrame
        v Fix backgroundcolor on drag