GTK+ 3 Reference Manual
Part III. Theming in GTK+
Table of Contents
GtkStyleContext
— Rendering UI elements
GtkCssProvider
— CSS-like styling for widgets
GtkStyleProvider
— Interface to provide style information to GtkStyleContext
GtkStyleProperties
— Store for style property information
GtkThemingEngine
— Theming renderers
GtkWidgetPath
— Widget path abstraction
GtkIconTheme
— Looking up icons by name
Themeable Stock Images
— Manipulating stock icons
GtkNumerableIcon
— A GIcon that allows numbered emblems