In thinking about Michel Sanner's problem of removing subplots, I
decided to make some changes in the way axes and subplot management
was done by the backends and the pylab interface. The problem was
that there was a chain of calls from the FigureManager for adding
subplots and axes to the Figure, and this was done so the
FigureManager could manage the current axes. The other reason it was
designed this way is the figure manager need to be notified whenever
the number of axes changed, so it could update the classic toolbar
menu.
The problem with this design is that every time I wanted to add a new
kwarg or some other feature to add_axes or add_subplot in the Figure,
these changes had to be mirrored in the FigureManager, sometimes
across backends which had concrete implementations, which proved to be
a pain. And when I wanted to think about deleting axes, I had to
worry about the FigureManager's information and the figure's
information, which was a bad design.
In its place, I added the management of the current axes to the Figure
class itself, and used an observer pattern so the backend
FigureManager could get notification when the number of axes changed.
So FigureManager add_subplot and add_axes methods no longer exist.
Note the Figure doesn't *do* anything with the current axes
information, it merely manages it.
As my Christmas present to the backend maintainers, I ported these
changes to WX, GTK, Tk and FLTK. I don't have FLTK on my system so
Gregory please test. I have run the other backends through
backend_driver.py and have done some interactive testing as well and
everything looks good. But please update from CVS after giving the
mirrors a few hours and test for yourself.
Ted, please make sure your QT implementer is advised of these changes.
There is also a new method Figure.delaxes and a pylab interface
function delaxes to remove an axes from the Figure. This is different
from merely clearing an axes with cla, and the Figure updates the
current axes after a call to delaxes using an axes stack so the
previously current axes becomes current after a deletion. Eg,
from pylab import *
ax1 = subplot(211)
plot([9,10,11])
ylabel('y1')
ax2 = subplot(212)
scatter(rand(10), rand(10))
ylabel('y2')
subplot(211) # make 211 current
title('this is a title', color='r')
grid()
delaxes(ax1) # now 212 is current again
grid()
Thanks,
JDH
