How to connect events from QAbstractItemDelegate widget?

[pinchoonet]

Hi,

I have a widget containing a QTreeView with a QStyledItemDelegate in column 0 creating a QSpinBox editor.
I would like to display in a QLabel and in real time the value of the QSpinBox each time it changes (so when QSpinBox::valueChanged(int) signal is emitted, for example when the mouse wheel is used inside the QSpinBox or up/down buttons are clicked).

Does someone know how to do such a connection between QStyledItemDelegate and the QLabel?

Thanks in advance for your response.
Best regards.
Pascal

[franku]

I guess, you could reimplement QStyledItemDelegate, add a slot to your derived class and connect this slot to the label after constructing it.

[andre]

Easiest is to take control of the actual creation of the QSpinBox. For instance, by subclassing QStyledItemDelegate, and reimplementing the createEditor method like this:
@
QWidget* MyDelegate::createEditor( QWidget * parent, const QStyleOptionViewItem & option, const QModelIndex & index ) const
{
//let the base class do the hard work
QWidget editor = QStyledItemDelegate::createEditor(parent, option, index);

QSpinBox* spinbox = qobject_cast<QSpinBox*>(editor);
if (spinbox) {
connect(spinbox, SIGNAL(valueChanged(int)), this, SLOT(onSpinboxValueChanged(int)));
}

return editor;
}
@

[pinchoonet]

Dear franku & Andre, thanks for your response.

To Andre: "spinbox" is NULL using qobject_cast.
But I finally wrote this code which works:
@
QWidget * AngleDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &, const QModelIndex &) const
{
QSpinBox *editor = new QSpinBox(parent);
editor->setMinimum(0);
editor->setMaximum(359);
connect(editor, SIGNAL(valueChanged(int)), this, SIGNAL(valueChanged(int)));

return editor;

}
@

I resend the "QSpinBox::valueChanged()" signal outside my delegate and can then connect any QObject (like a QLabel) to the "AngleDelegate::valueChanged()" signal.

Problem solved.
Thanks again.
Bye
Pascal

[mairesse]

Hello there, pin..

I have a similar problem and I can't figure out how to solve the connect thing, maybe you can give me a hand on it.

I have a QTableView inherited and also a QStyledItemDelegate inherited so I can change them as needed.

One of the columns has a widget (QSlider) that I paint using drawComplexControl from QStyle and I create the real QSlider to edit when the editor opens. In the other column I store the value of this slider.

The problem is that I can't figure out how to keep the value updated in real-time, because now I can only update it when setModelData is called.

I can't figure how to connect the signal valueChanged to a slot of mine that would then update the desired item in the table view (that would be in the same row but another column).

I don't think any code is relevant because I have the same structure as you with createEditor but here it goes:

Here I create the slider, the commented line is what would be my connect (but where should I use the slot or signal I'd call/emit?)
[code]QWidget *HsSubunitConfigurationDelegate::createEditor(QWidget *parent, const StyleOptionViewItem &option, const QModelIndex &index) const{
QSlider slider = new QSlider(Qt::Horizontal, parent);
/ connect(slider, SIGNAL(valueChanged(int)), this, SLOT(sliderValueChanged(int))); */
slider->setAutoFillBackground(true);
return slider;
}[/code]

Here I set the data for both the item that hold the widget (I can't get from the value column I want to update because I decode the value in a string later on and I don't feel like decoding it back to a value) and then I set the value to the column I want to be updated in real-time:
[code]void HsSubunitConfigurationDelegate::setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const{
QSlider slider = qobject_cast<QSlider>(editor);
model->setData(index, slider->value(), Qt::UserRole+12);
model->setData(model->index(index.row(), 3), slider->value(), Qt::DisplayRole);
}
[/code]

Sorry if I forgot to post any code or if I wasn't clear.. if you don't understand my problem I can try to ask it again in other words. Also sorry for any misspelling.

Thanks in advance.