problem with QListWidget::currentRowChanged signal

[mattc]

Hello,
I am experiencing a problem with the QListWidget::currentRowChanged signal when I remove the first element from a QListWidget. Please see my TestWidget class:



// TestWidget.h
//
#include <QWidget>
#include <QMessageBox>
#include <QListWidget>
#include <QVBoxLayout>
#include <QPushButton>

class TestWidget: public QWidget
{
Q_OBJECT
public:
TestWidget::TestWidget(QWidget* parent = 0):
QWidget(parent)
{
lst = new QListWidget();
lst->addItem("first");
lst->addItem("second");
connect(lst, SIGNAL(currentRowChanged(int)),
this, SLOT(onRowChanged(int)));

QPushButton* btn = new QPushButton("Remove first row");
connect(btn, SIGNAL(clicked(bool)),
this, SLOT(onBtnClicked(bool)));

QVBoxLayout* l = new QVBoxLayout();
l->addWidget(lst);
l->addWidget(btn);

setLayout(l);
}

private slots:
void onRowChanged(int);
void onBtnClicked(bool);

private:
QListWidget* lst;
};

inline void TestWidget::onBtnClicked(bool)
{
delete lst->takeItem(0); // triggers rowChanged

// current row number == 0 ... Correct
QMessageBox::information(this, "Debug",
QString("onBtnClicked: current row number: %1")
.arg(lst->currentRow()));
}

inline void TestWidget::onRowChanged(int i)
{
// new row number == 1 ... Why?
QMessageBox::information(this, "Debug",
QString("onRowChanged: new row number: %1").arg(i));
}

The program starts and current row is 0. Then I click the button to remove the first row and rowChanged is triggered with a value of 1. Why? Back from the rowChanged event and the current row is 0 (correct)

Any clues?

Qt 4.6.3
Visual Studio 2008 SP1

[nernst]

Hi,

i would suggest, that by deleting of row 0, row 1 changes to row 0.
And because of this renumbering you get the trigger, that row 1 has changed.

Just a suggestion :)