[wxPython-users] Re: Subclassing PyPlot, need some help

[Christopher Barker]

Andriy wrote:
> or can I still
> call _Draw() with the optional dc argument, then manipulate the size
> of the resulting DC so that I can draw the properly proportioned
> subplot into its place on the canvas? 

The easiest option would be to create a wx.MemoryDC for each subplot, 
then draw each resulting bitmap to the main DC where you want them.

However, while this would work great on screen, it wouldn't work so well 
for printing, as you'd be printing bitmaps, rather than vector graphics. 
It may end up looking OK, if you get the resolutions right, but it feels 
kludgy.

Better options:

Maybe the best way (and the most work) would be to move to 
wx.GraphicsContext, rather than DC -- then you could take advantage of 
transforms to put your plots where and at what size you want them.

Easier: You can probably use a combination of:

wx.DC.SetDeviceOrigin
wx.DC.SetUserScale

setting those parameters differently, you may be able draw each subplot 
where you want, all with the same DC. UserScale has issues, as DCs are 
all integer based, but you may even be able to do without that. Really, 
setting the Origin should be all you need to draw your subplots where 
you want, as long as the Drawing code doesn't use the size of the DC to 
scale and position things.

Hope that helps,

-Chris


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