roman.kennke@xxxxxxxx wrote: > Hi Gary, > > > The setComposite method of anything that extends java.awt. > > Graphics2D is supposed to do a permisson check if "...this > > Graphics2D context is drawing to a Component on the display > > screen and the Composite is a custom object rather than an > > instance of the AlphaComposite class." The latter is easy > > to check, but how do I tell whether the context is drawing > > to a Component on the display screen? > > Only one subclass of CairoGraphics2D draws on the screen, I > think this is ComponentGraphics. Ok. Do you know about its subclass, VolatileImageGraphics? > However, I am not sure if we need to check this really (at least as > things are now). The point of this check is that custom Composite > objects don't get access to the pixel data on the screen, if they > aren't allowed to. This is possible by doing operations with the > CompositeContext of the Composite object. As it is implemented now, > we only support AlphaComposite anyway (no need to check for this I > think), and don't do anything with the CompositeContext, but instead > let Cairo handle this (more efficiently I hope). Yeah, I saw all the FIXMEs :) But I'd like to put the checks in anyway, even if all that happens after the check is that an UnsupportedOperationException is thrown. That way I can write Mauve tests and stuff. Cheers, Gary
