QTreeView Fixed column & QTableView

[jpujolf]

Some time ago ormonde asked how to fix first column in a QTreeView. And jpn & wysota answered him that could be achieved placing two separate views one next to the other.

http://www.qtcentre.org/forum/f-qt-p...iew-13529.html

I want to apply this solution, it seems easy and effective, but I want to improve it a little bit, It's possible ?

I'm working usually with a very large amount of rows ( 50.000 or more ) and a lot of columns too ( 20-50 ). So, I've to manage a lot of data ( 1M to 2.5M different values ). QTreeView is VERY, VERY slow ( in opposition to QTableView , I used before ).

By now, when I press Page Down, it takes 3-5 seconds to move to the end with 6-7K rows. It's a little bit time expensive.

I've made some tests and reducing the number of columns in a treeview, reduces too the time to move from end to end, so I've thought that i can place a Qtreeview on the left & a QTableview on the right, making it scrollable for data. The problem is : how can I sincronize indexes & selection moves between views ?

[caduel]

Set the selectionModel of the second view to that of the first (see QAbstractItemView::setSelectionModel()).

The slowness of the treeview might be improved by setting QTreeView::setUniformRowHeights() to true.

HTH

[jpujolf]

You did it !! Setting uniformRowheights improves speed a lot !! I've presumed that that option was the default. I was wrong...

Or at least it MUST be the default

Thanks a lot !!

[jpn]

Setting uniformRowheights improves speed a lot !! I've presumed that that option was the default. I was wrong...

Or at least it MUST be the default

It cannot be the default value because it would break lists which don't happen to have uniform row heights. Having uniform row heights is a common, but still special case. Special cases can be used as optimizations but not as defaults. I guess somebody skipped the "Improving Performance" section in QTreeView while starting to use the class.

[jpujolf]

I guess somebody skipped the "Improving Performance" section in QTreeView while starting to use the class.

Oh dear !! I think I've to stop making diagonal-reads of documentation...