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Andreas Pakulat wrote:
<blockquote cite="mid20061011205435.GC4281@morpheus.apaku.dnsalias.org"
type="cite">
<pre wrap="">On 11.10.06 13:10:34, Matt Chambers wrote:
</pre>
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<pre wrap="">Andreas Pakulat wrote:
</pre>
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<pre wrap="">On 10.10.06 21:19:59, M.Chambers wrote:
</pre>
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<pre wrap="">How can I disable some that I'm not using? Seems like a waste to call
data() that many times. I'm using the model view stuff and its very
slow compared to Qt3.
</pre>
</blockquote>
<pre wrap="">You can't or at least you can't with the built-in Q*Views. You'd have to
write your own view class that only asks for the roles you need.
Also for speeding things up, try to check the role parameter as one of
the first things and return an empty QVariant() if it is uninteresting.
If that's still to slow get a profiling tool and check where the time is
really spend.
Andreas
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<pre wrap="">I ended up making a single QVariant and return that over and over again, helped
to speed it up:
</pre>
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<pre wrap=""><!---->
I'm curious as to what you had before? That's what you posted is exactly
what I would've done in the first place...
Andreas
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<br>
Many examples show data() actually doing stuff like<br>
<br>
if role != QtCore.Qt.DisplayRole:<br>
return QtCore.QVariant()<br>
<br>
I was able to eek out quite a bit more speed by creating a global
instance of QVariant and returning the same one over and over again,
instead of<br>
creating a new object every time data is called, which can be hundreds
of times in just a few seconds.<br>
<br>
so I do:<br>
if role != QtCore.Qt.DisplayRole:<br>
return EMPTY_QVARIANT<br>
<br>
<br>
My cpu fan still comes on if I use the scroll bar but its not as bad.<br>
<br>
<div class="moz-signature">-- <br>
<div
style="text-decoration: none; font-family: Arial,Tahoma,Verdana; font-size: 12px;"><b>Matt
Chambers <a class="moz-txt-link-rfc2396E" href="mailto:chambers@imageworks.com"><chambers@imageworks.com></a></b><br>
<b><span style="color: rgb(0, 0, 0);">Sony Pictures</span> <span
style="color: rgb(153, 0, 0);">Imageworks</span></b><br>
<br>
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