[webkit-reviews] review requested: [Bug 21883] [CAIRO] globalAlpha has to be stored and restored : [Attachment 24717] save/restore globalAlpha

[bugzilla-daemon at webkit.org]

Dirk Schulze <vbs85 at gmx.de> has asked  for review:
Bug 21883: [CAIRO] globalAlpha has to be stored and restored
https://bugs.webkit.org/show_bug.cgi?id=21883

Attachment 24717: save/restore globalAlpha
https://bugs.webkit.org/attachment.cgi?id=24717&action=edit

------- Additional Comments from Dirk Schulze <vbs85 at gmx.de>
(In reply to comment #3)
> GraphicsContext already keeps a stack with internal state (see
> GraphicsContext.cpp GraphicsContext::save() and GraphicsContextPrivate.h). I
> was thinking it might be better to add an 'alpha' field to that and let
> GraphicsContext do the work for us so we don't need to maintain our own stack

> of alpha values for GraphicsContextCairo. Could you take a look into that?

I spoke to esedeidel via IRC as I implemented the current version of
globalAlpha. And he didn't like the idea to change GraphicsContextPrivate.h. A
globalAlpha variable is only needed on cairo and would waste space for other
platforms.
Or we use #if PLATFORM(CAIRO).

This second patch uses the alternative. Only One patch should be reviewed.