The attached image shows a problem with dragimage
leaving artifacts under Aqua. As an item is dragged,
the drag image gets stamped around the widget. These
artifacts remain until the widget loses focus or gets
redrawn due to e.g. resizing.
I figured out the reason for this. Apparently, Quartz
doesn't support XOR, which the non-windows version of the
drag image code uses.
"In your QuickDraw application, you might have used region
updating in conjunction with XOR to minimize the amount of
drawing that needed to be done for animation or editing.
Quartz does not support XOR, but it does support transparent
windows."
Setting ::tk::mac::useCGDrawing to 0, which makes Tk use
QuickDraw instead, seems to work as a workaround. Longer
term, you'll probably want to use some other method for the
dragimage.
Note that this confirms that this bug is totally unrelated
to 975677.
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Note: 975677 was marked as a duplicate of this bug, but was
observed under Windows. This bug has only been observed
under Aqua.
Logged In: YES
user_id=498198
I figured out the reason for this. Apparently, Quartz
doesn't support XOR, which the non-windows version of the
drag image code uses.
"In your QuickDraw application, you might have used region
updating in conjunction with XOR to minimize the amount of
drawing that needed to be done for animation or editing.
Quartz does not support XOR, but it does support transparent
windows."
http://developer.apple.com/documentation/Carbon/Conceptual/QuickDrawToQuartz2D/tq_regions/chapter_8_section_1.html
Setting ::tk::mac::useCGDrawing to 0, which makes Tk use
QuickDraw instead, seems to work as a workaround. Longer
term, you'll probably want to use some other method for the
dragimage.
Note that this confirms that this bug is totally unrelated
to 975677.