Qt4 backend improvements


> There
> may be a reason it was done in the less straightforward way that aren't
> obvious to you or I (perhaps to ease embedding... just guessing).

I don't think we can use the QMainWindow's addToolBar for this. It creates


single toolbar for the entire window, but what if we want to add two
canveses, each with its own toolbar, in a single window? I am writing an
application that does this.

Well, technically this is not a problem, since you can add several toolbars
with addToolBar. But well, you are right, this would look awkward, two
times the same toolbar... But anyhow, I am calling addToolBar in the class
FigureManagerQT, which is not able to handle more than one plot in a
window it seems to me (am I missing something?). If, on the other
hand, you create your own QMainWindow, there is no problem putting the
toolbar like it was done classically. I added an example for that to the
patch request ID 1828848 (Qt4 backend improvement). I don't know your
code, but it is possible, maybe even probable, that it works even
with my modifications, as I did not change the class structure.
Only possible incompatibilities I could see is if you are inheriting
FigureManagerQT and doing something in there.

So in the end I think my patch is still a good idea. It might be needed
to change it to keep compatibility with old code, though.