ListView is (very) slow to move to current item

[andre]

[quote author="Alexander Kuchumov" date="1292868441"]Andre, where is it in QListView? QListView also evaluates height for all elements.[/quote]
It is right "here":http://doc.qt.nokia.com/4.6/qlistview.html#uniformItemSizes-prop. You can tell QListView that the items are all the same size, and then it only evaluates the hight of the first item.

[alexander]

Andre, I've missed this function:)

[andre]

Don't :-) It can make a huge difference in QListViews performance.

[MartinJ]

positionViewAtIndex() does not calculate the height of intermediary items. That is the point of that function.

[alexander]

MartinJ is right, positionViewAtIndex uses averageSize .

[andre]

How is averageSize calculated? It is not a property of the ListView element, so where does it come from?

[alexander]

Andre, averageSize is calculated for last visible elements.

[andre]

OK, that makes sense I guess.

[A Former User]

Hi, I have a problem similar to yours. I have a ListView with possibly thousands of elements. I keep a property in my PySide backend which is the currentIndex for my ListView. Whenever I change the index, the ListView should scroll to the current item.

It works, but the scrolling is very slow. I think it is the same problem you are describing. Do you have any idea how should I solve my case?

[A Former User]

Anybody has a suggestion? I have the same problem on my arm 300 mhz device... I also want to drop the scroll animation and just jump immediately to the next item.