9efb56e2d4 added code to rearrange
pictures on drag'n'drop. To keep the correct repainting order (i.e.
later thumbnails are painted on top of previous thumbnails), the
z-value was set accordingly. In principle a sound idea, but it did
not work out, because on hoverEnter and hoverExit events, the z-values
were modified, thus restoring the wrong drawing order.
Instead, use the QGraphicsItem::packBefore() function. Experimentation
showed that this only works if stacking is done from the back
of the list.
Silence an erroneous compiler warning by initializing a variable to 0.0.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
4931b5a8e6