Last time I blogged about the Gtk 3 windows theme we had just landed the initial support. It kinda worked but didn’t look quite right. Since then the css machinery has gotten a bit more capable, and I recently found some time to work on this again.
Testing had revealed that the theme was totally broken on Windows XP. This had two main causes; first of all there was some bugs in the Win32 theme APIs on XP when rendering to surfaces with alpha, and secondly the css file used some windows theme parts that only existed in Vista and later. I added workarounds for the alpha bug and introduced a new css file that is used on XP (although most of the css is shared). So, now XP support is working.
I also went through all the widgets, fixing a lot of details in how they render and adding theming for some less common widgets.
Here is how gtk3-widget-factory looks now:
Not bad for 998 lines of css.
This is all in the new Gtk+ 3.4.0 release. We hope to have window binaries out for it soon.