This fixes an -Woverloaded-virtual ambiguity introduced in b5e613d45
void render (cairo_t*, cairo_rectagle*)
void render (Cairo::RefPtr<Cairo::Context> const&, cairo_rectangle_t*)
ArdourCanvas prefers cairomm and CairoWidget itself uses Cairo::Context,
this improves overall API consistency.
This functor/closure is responsible for stealing focus from any existing text entry (or whatever else may have focus)
when clicking on a CairoWidget or derived class.
The old implementation just gave focus back to the editor canvas. The new version walks up the widget packing
heirarchy to find a focusable parent (from the CairoWidget for which it is invoked). If no focusable parent
is found, it cancels keyboard focus in the toplevel window containing the CairoWidget
If a CairoWidget does not a GtkRC-defined style, then changing its name does not trigger on_style_changed(). Since we want to use CairoWidget::set_name()
to trigger changes in the rendering of a widget, this is ... bad. Adding on_name_changed() provides a workaround for that.
