Copy the same model as QgsMapCanvas uses, with separate
classes for individual interaction tools instead of keeping
all the logic in the QGraphicsView subclass (as is done
with composer)
A standard widget for configuring text format properties for use
with QgsTextRenderer/QgsTextFormat.
It's modelled heavily off QgsColorButton, and supports lots of nice
things like dragging formats between buttons, copying and pasting
format settings, dropping colors from color buttons, dragging colors
from font buttons to color buttons, directly setting font size
and opacity/color without having to open a dialog.
