[Qt-interest] Performance of Model and View

[Scott Aron Bloom]

Or, don't use the generic model... Use a custom model with your own
::data method...

Handle the alignment role, and the data role, and have a custom
insertion routine...  

Pretty straight forward, much cleaner code as well..

Scott

> -----Original Message-----
> From: qt-interest-bounces at trolltech.com [mailto:qt-interest-
> bounces at trolltech.com] On Behalf Of Malyushytsky, Alex
> Sent: Tuesday, January 13, 2009 1:12 PM
> To: qt-interest at trolltech.com
> Subject: Re: [Qt-interest] Performance of Model and View
> 
> You can disable update of the widget before changing model using
> setUpdatesEnabled() and enable it after you done.
> This should help with performance.
> 
> http://doc.trolltech.com/4.4/qwidget.html#updatesEnabled-prop
> 
> Alex
> 
> 
> 
> -----Original Message-----
> From: qt-interest-bounces at trolltech.com [mailto:qt-interest-
> bounces at trolltech.com] On Behalf Of RZ
> Sent: Tuesday, January 13, 2009 1:00 PM
> To: qt-interest at trolltech.com
> Subject: [Qt-interest] Performance of Model and View
> 
> Hi,
> 
> I'm reading data from a file into the model - the (pseudo) code looks
> like this:
> 
> model->insertRow(0);
> model->setData(model->index(0, 0), QString::number(_uint16));
> model->setData(model->index(0, 1), QString::number(_uint8));
> model->setData(model->index(0, 2), QString::number(_uint16));
> model->setData(model->index(0, 3), QString::number(_uint16));
> model->setData(model->index(0, 4), QString::number(_uint16));
> model->setData(model->index(0, 5), QString::number(_uint8));
> model->setData(model->index(0, 6), QString::number(_uint8));
> model->setData(model->index(0, 7), QString::number(_uint32));
> model->setData(model->index(0, 8), QString::number(_uint16));
> for (int i = 0; i < 9; ++i)
> {
>      model->setData(model->index(0, i), Qt::AlignCenter,
> Qt::TextAlignmentRole);
> }
> 
> model->setData(model->index(0, numColumns - 1),
> QString::fromStdString(decoded));
> model->item(0, 0)->setFlags(Qt::ItemIsSelectable);
> model->setData(model->index(0, 0), Qt::green, Qt::ForegroundRole);
> model->setData(model->index(0, 0), ttInfo, Qt::ToolTipRole);
> model->setData(model->index(0, 0), type, MsgTypeRole);
> 
> 
> With this code I have several problems. First of all it is slow (as it
> seems that the view gets updated after every "setData"), second it
> doesn't look "cool" (e.g. the for-loop to set the alignement), ...
> 
> Is there a way I overlooked to improve this?
> 
> Thanks,
> 
> RZ
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> 
> 
>
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