This is a followup to bug 4110854.

The solution proposed by Jeff is to have isOptimizedDrawingEnabled return false. This forces each component intersecting the paint region to be drawn, however it *still* completely ignores the value returned by isOpaque().

Thsi causes a problem because if any component that intersects the invalid region requires substantial rendering time, the rendering of all the intersecting components suffer.

I would argue that the top most component should maintain the "One True" invalid rect. When told to repaint it should compile a vector of the components that intersect the dirty region. Once this list is created, it should find the bottom-most component that completely covers the invalid region and, starting with it, work it's way upwards telling each component to repaint.