split off from Issue 157 (JXTitledPanel not completely bidi-compliant)
The part that's still open is the background gradient (if set). As the title
area is a JXPanel and the JXPanel is supposed to do background gradient (or any
other, could be an image as well) painting by way of a Painter, the issue boils
down to supporting CO-aware painters. The panel itself can't (IMO) as it doesn't
know anything about the type of the painter (wouldn't want to mirror an image,
f.i., while doing so for a horizontal gradient is the thing to do).
AbstractLayoutPainter has enums for defining Alignments which aren't strong
enough: they are fixed left/right, top/bottom. Need to enhance with
leading/trailing (or startOfLine, endOfLine),
what's-the-equivalent-for-vertical? See BorderLayout.
I think this is a defect (not an enhancement) as CO compliance is considered
important in SwingX