[Qt-interest] Slow QTreeWidget

[Malyushytsky, Alex]

You might want profile your code. The problem might be not in the tree.

I made a simple test application. Filled tree using your function (50 rows, 15 columns) and it is filled within 1 sec as it was.

Tested on Windows XP 64 bit, QT 4.4.3.

Regards,
         Alex


#include "treewidgettest.h"

treeWidgetTest::treeWidgetTest(QWidget *parent, Qt::WFlags flags)
        : QDialog(parent, flags)
{
        ui.setupUi(this);

    ui.treeWidget->setColumnCount(0);
    QStringList colTitles;
        int cols = 15;
        for (int col = 0; col<cols; col++)
        {
                colTitles << QString::number(col+1);
        }

        ui.treeWidget->setHeaderLabels(colTitles);

        connect ( ui.pushButtonFill, SIGNAL( clicked()), this, SLOT ( fillTreeWidget() ) );
}

treeWidgetTest::~treeWidgetTest()
{

}


void addResultRow(QTreeWidget *moduleRsltList, int rnr, int ct )
   {
   QList<QTreeWidgetItem *> lvitems=moduleRsltList->findItems
        (QString::number(rnr), Qt::MatchExactly,0);
   QTreeWidgetItem *lvitem=0;
   if (lvitems.count()>0)
     lvitem= lvitems[0];
   if (!lvitem)
     {
         double elaps_mins = 10.;
     lvitem= new QTreeWidgetItem(moduleRsltList);
     lvitem->setData(0,Qt::DisplayRole,QString::number(rnr));
     lvitem->setData(1,Qt::DisplayRole, QString::number(elaps_mins,'f',2));
     }
   if (ct && (lvitem!=0))
     {
     int i;
     for (i=1;i<=ct;i++)
       lvitem->setText(i+1,QString::number((i+1),'f',6));
     }
   }

void treeWidgetTest::fillTreeWidget()
{
        int rows = 50;
        int cols = 15;


        for (int row = 0; row < rows; row++ )
        addResultRow(ui.treeWidget,  row, cols );

}





-----Original Message-----
From: qt-interest-bounces at trolltech.com [mailto:qt-interest-bounces at trolltech.com] On Behalf Of Kenneth Beck
Sent: Wednesday, March 25, 2009 9:07 AM
To: R. Reucher; qt-interest at trolltech.com
Subject: Re: [Qt-interest] Slow QTreeWidget

R. Reucher wrote:
> On Wed March 25 2009 14:14:15 Kenneth Beck wrote:
>> setUpdatesEnabled(false) did not do much, except to delay the visual
>> update until the end. I have a progress bar that steps with each row
>> add, and the time between steps gets progressively slower as rows get
>> added, again as if it is looping back to somehow update all the previous
>> data with each call to setText.
> Are you sorting the entries while you insert them?
>
> I have QTreeWidget's with ~8000 entries (6 columns each) and they are filled
> within less than a second (using Qt 4.5 that is, with 4.4 this was
> perceptibly slower).
TreeView is MUCH MUCH faster! It would still be nice to know what I was
doing wrong on the TreeWidget -- there are other spots in my code that
have the same problem.
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