Looking to possibly get into GTK theming.

Question

I'm interested in getting into theming with GTK3 (as I'm on a bit of a mission to completely personalize my desktop), but don't have a clue where to start. So far after a fair amount of Googling, all I've come up with is this:
http://live.gnome.org/GnomeArt/Tutorials/GtkThemes
http://developer.gnome.org/ ... as for this link, I'm not sure how much if any is relevant - is the documentation here just for application developers? Does theming come into it at all?
... and a few others which seem reeeally out of date.
So I'm mainly interested in GTK3 specifically. I'd rather start out right up to date. But I can't find a tutorial anywhere... and information in general is just really hard to find. The first link above is for GTK2. I haven't gone through it yet. Would I be wasting my time? Or will I need to know what's in this tutorial to get going with GTK3 anyway? I'm also not sure about the capabilities. Particularly alpha transparency and where it can be used. What are the limits? Again, I googled this and all I seemed to find were people just as confused as myself! I've come up with this simple mockup (ignore the contradictory buttons/title) so you can see what I'm getting at:
http://zemulii.deviantart.com/#/d4hx57n
Is any of the transparency there not possible? The window borders are also transparent (in case it's hard to see). Below the title is the toolbar (as in Nautilus) which is semi-transparent. Then there are the buttons - would it be possible to give them transparency? So you could see right through the application to the desktop (or whatever's underneath)?
What's the deal with GTK/Metacity/Mutter? From my understanding, GTK handles the widgets and window content etc. Metacity/Mutter handles the window borders, and Mutter is otherwise known as Metacity 3?
As I'm sure you can tell, I'm totally confused and have probably got my facts all skewed and twisted. Please try and help me get things straight ! Hopefully I'm not asking too much, as my whole post is full of questions... but if anyone can answer what they're able to I'd be very grateful.
Last edited by kelseynz (2011-12-03 06:51:06)

Answer 1

About "whether or not I should bother with the GTK2 theming tutorial", I think it can be useful to familiarize yourself with gtk terms and notions. Many things will be found again in gtk3.
But just after reading it, concentrate on the "Part V. Migrating from Previous Versions of GTK+" of the gtk3 reference manual.
And look at the source code of some gtk3 themes.
Regarding transparency, study the alpha parameter of color definition:
The GdkRGBA structure is used to represent a (possibly translucent) color, in a way that is compatible with cairos notion of color.
gdouble red;
    The intensity of the red channel from 0.0 to 1.0 inclusive
gdouble green;
    The intensity of the green channel from 0.0 to 1.0 inclusive
gdouble blue;
    The intensity of the blue channel from 0.0 to 1.0 inclusive
gdouble alpha;
    The opacity of the color from 0.0 for completely translucent to 1.0 for opaque
I encourage you to go ahead with your project to program gtk3 new themes. It will be very useful to everyone using GUI applications in gtk3 environment.