How to detect if a data in a QTableWidget cell is about to change

[karim24]

what i mean is if someone double clicks it or pressing F2 in order to start typing i tried the signals:
@void cellDoubleClicked(int row, int column)@
@void cellEntered(int row, int column)@
@void itemDoubleClicked(QTableWidgetItem * item)@
@void itemEntered(QTableWidgetItem * item)@

but the slots doesn't get excuted

please note that i don't mean that the data is already changed ,but i mean before the data gets changed

[Jeroentjehome]

Hi, The cellEntered is a mouse operation detection, not a clicked signal, so you have to turn on the mousetracking option (see docs).
The cellDoubleClicked should work or the
@void QTableWidget::cellPressed(int row, int column) [signal]
or
void QTableWidget::cellActivated(int row, int column) [signal]
@
should both do the trick. My guess is that your connect isn't valid, so Qt doesn't make a connection for your event, so your slot doesn't get called. Check your application output for errors on connect function.

[pkjag]

Why don't you try reimplementing
@
QItemSelectionModel
@

[thEClaw]

If you want to detect changes, catch the proper signal.
"QTableWidget::cellChanged()":http://qt-project.org/doc/qt-5.1/qtwidgets/qtablewidget.html#cellChanged
"QTableWidget::itemChanged":http://qt-project.org/doc/qt-5.1/qtwidgets/qtablewidget.html#itemChanged
These should be emitted right before the new data is made visible, at least that's the case in other views I have experience with.

If that doesn't work, create the signal you need. Subclass "QStyledItemDelegate":http://qt-project.org/doc/qt-5.1/qtwidgets/qstyleditemdelegate.html and reimplement (in the most basic manner) "QAbstractItemDelegate::setModelData":http://qt-project.org/doc/qt-5.1/qtwidgets/qabstractitemdelegate.html#setModelData . Somewhat like this:
@void YourStyledItemDelegate::setModelData(QWidget * editor, QAbstractItemModel * model, const QModelIndex & index) const
{
emit YourCustomSignal(index);//if you need to transmit any data, index should contain enough information
QStyledItemDelegate::setModelData(editor, model, index);
}@

And in the end you need to use your custom ItemDelegate with this function, which should be public for your QTableWidget:
@QAbstractItemView::setItemDelegate(QAbstractItemDelegate *delegate)@