GtkGradient is a boxed type that represents a gradient.
It is the result of parsing a gradient expression. To obtain the gradient represented by a GtkGradient, it has to be resolved
with resolve, which replaces all symbolic color references by the colors they refer
to (in a given context) and constructs a RasterSourcePattern value.
It is not normally necessary to deal directly with Gradients, since they are mostly used behind the scenes by
StyleContext and CssProvider.
Gradient is deprecated. It was used internally by GTK’s CSS engine to represent gradients. As its handling
is not conforming to modern web standards, it is not used anymore. If you want to use gradients in your own code, please use Cairo
directly.