[Pythoncard-users] greedy events / double buffering?

[Sean D. <se...@tr...>]

I've been using PythonCard for simple interfaces for about a year now.
Recently I decided to try something much more complex - implementing a
custom interface inside a BitmapCanvas. There are two problems I'm
facing at the moment:

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* I can't seem to fire a mouseDown event without blocking mouseMove
events until I get a mouseUp event. This basically means I can't click
and drag something interactively inside the BitmapCanvas.

* I can't figure out how to double-buffer the BitmapCanvas. I'd like to
do a clear() and then redraw my interface without causing the canvas to
blink. Is there a way to do some kind of buffer toggling from inside
PythonCard?

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I'd much appreciate if anyone has some sage advice.

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By the way, what I'm really trying to do is create a simple interface
for creating node graphs: the kind you see in 2D graphics compositing
programs/visual programming languages where you can arrange node
operators and interconnect them to form a data flow. If anyone knows of
a free Python (or even C++) API for doing this, let me know!

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Thanks,

Sean

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