orjanp wrote:
> I have a strange issue with Floatcanvas.
I'm cc-ing a copy of this to the floatcanvas list. It's the kind of
thing I want in the archives there.
> I have the following code, this is not a complete example, since the
> codebase is to big to be posted here:
In the Demos section of floatcanvas SVN, there is a MicroDemo.py Perhaps
you could add to it to make a demo of this problem. It's hard for me to
test/debug without a running sample.
> This will give the following printout. The HitDict print should have
> two objects, but it only have the last one. Why?
>
> If I remove the canv.ClearAll() and add canv._DrawList = [],
> canv.HitDict = None, it works just fine. The I get the second output,
> which is correct.
very odd. I have one idea, though. If you look at
FloatCanvas.ClearAll(), you see:
def ClearAll(self, ResetBB=True):
"""
ClearAll(ResetBB=True)
Removes all DrawObjects from the Canvas
If ResetBB is set to False, the original bounding box will remain
"""
self._DrawList = []
self._ForeDrawList = []
self._BackgroundDirty = True
self.HitColorGenerator = None
self.UseHitTest = False
if ResetBB:
self._ResetBoundingBox()
self.MakeNewBuffers()
self.HitDict = None
which tries to re-set everything back to its original state. ONe of
those calls is:
self.HitColorGenerator = None
which re-sets the HitColoGenerator. That is used to assign a unique
color to each object on teh off-screen hit-test image, and it's also a
key in HitDict.
However, in the DrawObject Bind method, there is:
if not self.HitColor:
if not self._Canvas.HitColorGenerator:
self._Canvas.HitColorGenerator = _colorGenerator()
self._Canvas.HitColorGenerator.next() # first call to
prevent the background color from being used.
self.HitColor = self._Canvas.HitColorGenerator.next()
So it's checkign to see if the object already has a HitColor, and only
giving it a new one if it doesn't.
In this case, it looks like you are re-using objects, so they may have
already been assigned a HitColor, but the HitColorGenerator is being
reset, so it could be assigning the same color to one your objects that
is already assigned to the other one -- so it gets overridden in the
HitDict.
You can test this by adding another print or two:
# Add all shapes to the canvas.
for item in obj.objects:
print '--', item.object
print item.object.HitColor
then maybe that same print after the Bind() call.
If I'm right, I'm not sure of the fix -- you can kludge around it by
clearing the HitColor yourself, but the Canvas doesn't know about all
objects, only those that are on it at the time, so I'm having trouble
figuring out where to fix this. I'll take suggestions!
-Chris
PS: thanks for teh bug report -- it's only through testing all these
use-cases I didn't think of that things get fixed!
--
Christopher Barker, Ph.D.
Oceanographer
Emergency Response Division
NOAA/NOS/OR&R (206) 526-6959 voice
7600 Sand Point Way NE (206) 526-6329 fax
Seattle, WA 98115 (206) 526-6317 main reception
[email protected]
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