Basically reverts the pieces of
21ec9beae2 to make XSpriteCanvas a
XBitmapCanvas again
Otherwise PresenterHelper::loadBitmap is not an XBitmapCanvas
and so VclFactory::createBitmap cannot succeed
Change-Id: I197adf98e915102f383ee050a8ea16d1e41cecf2
Remove the implication that XCanvas IS-A XBitmapCanvas, i.e. one can
access underlying pixels. That's a preparation for display-list based
canvas implementations, and was a rather silly assumption in the first
place.
Also fixes up all client sites.
Change-Id: I7a3d6f68ef46fe94b23cce7759cc0b8b6ca4dae9
see https://gerrit.libreoffice.org/#/c/3367/
and Change-Id: I00c96fa77d04b33a6f8c8cd3490dfcd9bdc9e84a for details
Change-Id: I199a75bc4042af20817265d5ef85b1134a96ff5a
