[matplotlib-devel] Resizing bug in qt4 backend.

[Tony Yu <ts...@gm...>]

When resizing a figure using `fig.set_size_inches`, the Qt backend doesn't
take into account the height of the status bar or the toolbar.

For example, the following script plots two figures---both *should* be
1-inch square, but this is only true of the second figure.

#~~~~~
import matplotlib as mpl
mpl.use('qt4agg')
import matplotlib.pyplot as plt

fig = plt.figure()
fig.set_size_inches(1, 1, forward=True)

plt.figure(figsize=(1, 1))

plt.show()
#~~~~~

Note that this bug doesn't appear with `savefig` since that doesn't need to
account of toolbar/status bar heights.

I've submitted a PR for a
fix<https://github.com/matplotlib/matplotlib/pull/748>,
but I don't know how general this is. For example, I couldn't get the
figure to redraw after changing the figure size with `fig.set_figwidth` or
`fig.set_figheight`, so I couldn't test for that.

Also, I noticed that 'tkagg' has problems with this example code, but I
didn't have time to look into that.

-Tony