It doesn't seem to provide anything similar to override the background
image other than building a CSS stylesheet and using a GtkCssProvider to
load it.
Using this approach requires that the image resides somewhere in the filesystem
. If you have an image already in memory you can't use it without first
saving it out.
Another approach would be to write a custom GtkStyleProvider (similar to
the GtkModifierStyle) which provides an override background image function.
This approach seems impossible as a portion of the style provider implementation
is private (the GtkStyleProviderPrivate interface).
Are there any other options for setting the background image on a widget
using an in-memory image?
