JXLayer 3.0 demonstration by Piet Blok

During class initialization, the method SwingUtilities3.setDelegateRepaintManager(JComponent, RepaintManager) is obtained via reflection. If this is successful, a flag is set that the mechanism is available and can be used. If not, the existing mechanism RepaintManager.setCurrentManager(RepaintManager) will be used.

As a result, the hack experiments concerning RepaintManagers don't make much sense anymore when running Java 6u10 or higher. (But I didn't remove them)

• A complete refactoring has taken place in an attempt to have the TransformUI better fit in the concept of JXLayer.
  1. The special class TransformPort has been removed. The new TransformUI works with the normal view of the JXLayer.
  2. The TransformUI sets a different LayoutManager on the JXLayer (a sub class of the DefaultLayerLayout ). This LayoutManager checks the type of LayerUI set on JXLayer. If not a TransformUI , it delegates all methods to its super class. However, if the LayerUI is of type TransformUI , it recalculates minimum size and preferred size according to a preferred AffineTransform obtained from TransformUI . The view's size is set to its preferred size and it is placed in the center of JXLayer.
  3. TransformUI inherits from MouseEventUI (that in turn directly inherits from AbstractLayerUI ). MouseEventUI 's only responsibility is re-dispatching of MouseEvents to intended components, based on the AffineTransform obtained from getTransform().
  4. TransformUI is responsible for all painting. It does not manage transformations itself. It now overrides the paint method to prepare a Graphics object from a BufferedImage and passes that object to the paintLayer method. Normally, that paintLayer method will delegate the call to its super implementation. However, there is one situation where it does something different: when the view's height or width are larger than the layer's height or width (down sizing is needed). The super implementation would have the obscured parts not painted. So, the view will be painted directly. To prevent visual artifacts outside the layer, double buffering must be disabled (this is recursively done on each child component).
  5. Transformations are now the responsibility of a TransformModel defined as an interface. A DefaultTransformModel is available that can apply a variety of transformations. A TransformUI will always have a TransformModel , either the DefaultTransformModel that is set by default, or a custom TransformModel .
  6. A RepaintManager is still needed. For testing purposes I created a hack (default disabled) to copy some properties (via reflection) from the original RepaintManager in the new RepaintManager. This hack should prevent that the "grey rectangle fix" (see RepaintManager's side effect ) is disabled. If you want to see how the hack works, click here for the source code (you will find it somewhere around line 120).

• Since the TransformUI demonstration is the most important one (at least, that is what I think), I changed the order of the demo's. The playground exercises have been moved to the end.
• I added a copy of the Transformation demo with the RepaintManager hack enabled.