Am 10.10.2010 13:01, schrieb Virgil Dupras:
It probably has something to do with the bazillions of parent() call
that are made to your model. I asked a similar question on stack
overflow a while ago. I profiled the example, so the bottleneck is
evident.
http://stackoverflow.com/questions/841096/slow-selection-in-qtreeview-why
So the answer is: In some respects, Qt sucks balls.
Regards,
--
Virgil Dupras
Hardcoded Software
http://www.hardcoded.net
Thanks for your reply. I've used your profiling instructions (never done
that before, so another thing learned;-)) and now I'm puzzled...
In my example with just 500 Items(!!) Qt calls some of the model methods
125000 times for one "expandAll()" call!!!!
What!?!?
Does anyone know something about that?
Here's the profiling data:
Sun Oct 10 13:23:55 2010 profdata
896930 function calls in 8.202 CPU seconds
Ordered by: internal time
ncalls tottime percall cumtime percall filename:lineno(function)
1 5.885 5.885 8.202 8.202 {built-in method exec_}
125853 1.238 0.000 1.943 0.000
C:\Users\Jan\Desktop\Integrations-System\Source\ipdm\QTreeView_Performance.py:220(parent)
1 0.336 0.336 2.301 2.301 {built-in method expandAll}
128294 0.239 0.000 0.300 0.000
C:\Users\Jan\Desktop\Integrations-System\Source\ipdm\QTreeView_Performance.py:235(view_item_from_index)
127372 0.212 0.000 0.217 0.000
C:\Users\Jan\Desktop\Integrations-System\Source\ipdm\QTreeView_Performance.py:53(children)
125734 0.179 0.000 0.179 0.000 {built-in method createIndex}
128294 0.040 0.000 0.040 0.000 {built-in method isValid}
125045 0.028 0.000 0.028 0.000 {method 'index' of 'list'
objects}
128168 0.020 0.000 0.020 0.000 {built-in method
internalPointer}
1638 0.008 0.000 0.023 0.000
C:\Users\Jan\Desktop\Integrations-System\Source\ipdm\QTreeView_Performance.py:180(rowCount)
689 0.004 0.000 0.008 0.000
C:\Users\Jan\Desktop\Integrations-System\Source\ipdm\QTreeView_Performance.py:215(index)
801 0.003 0.000 0.004 0.000
C:\Users\Jan\Desktop\Integrations-System\Source\ipdm\QTreeView_Performance.py:195(data)
500 0.002 0.000 0.005 0.000
C:\Users\Jan\Desktop\Integrations-System\Source\ipdm\QTreeView_Performance.py:80(get_view_item_children)
499 0.002 0.000 0.002 0.000
C:\Users\Jan\Desktop\Integrations-System\Source\ipdm\QTreeView_Performance.py:46(__init__)
1018 0.002 0.000 0.002 0.000
C:\Users\Jan\Desktop\Integrations-System\Source\ipdm\QTreeView_Performance.py:192(columnCount)
114 0.001 0.000 0.001 0.000
C:\Users\Jan\Desktop\Integrations-System\Source\ipdm\QTreeView_Performance.py:208(headerData)
2678 0.000 0.000 0.000 0.000 {len}
1 0.000 0.000 2.301 2.301
C:\Users\Jan\Desktop\Integrations-System\Source\ipdm\QTreeView_Performance.py:141(expand_all)
114 0.000 0.000 0.000 0.000 {built-in method column}
114 0.000 0.000 0.000 0.000 {getattr}
1 0.000 0.000 8.202 8.202 <string>:1(<module>)
1 0.000 0.000 0.000 0.000 {method 'disable' of
'_lsprof.Profiler' objects}
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