For a beamer theme, I'd like to provide two different kinds of frame titles. A normal one, plus one with an image background.
As far as I can see the best method to do this is to overload the
frametitle template, such that when certain data is available, then we choose the image version.
Since this data has to be global, we also need methods for resetting them either at the end of each frame or at the beginning.
If we look in
beamerbaseframe.sty, this is exactly what
beamer does with, say,
\insertframetitle, it is reset to empty in the end part of the definition of the
So my question is, how can we add our own variable resetting to this? (which would not be nullifying macros, but resetting them to default values.