Checkbox QTableWidgetItem

[Wasabi]

I've been banging my head against a wall of QTableWidget problems, but I'm thankfully very hardheaded and the wall is starting to give. I've figured out most of my issues, but now I have a small issue:

How can I make a QTableWidgetItem have no text? All I want is a checkbox. The first thing I tried was to not use Items, but a QCheckBox inserted with QTableWidget::setCellWidget(). That worked quite well, but I came upon a few issues with it. The main being that I couldn't find a way of retrieving the box's state through the QTableWidget, since the QTableWidget::cellWidget() function returns a QWidget*and I can't figure out how to get a QCheckBox's state having only access to QWidget functions.

The other issue was the same as I now have with QTableWidgetItem. I can't make it stay centralized in its parent cell, because it has an obligatory empty text-box next to it (in QTableWidgetItem's case. With QCheckbox, there simply isn't a relevant function to do so). As well, QTableWidgetItem::setTextAlignment() is, as the name implies, only in regards to the text, not the checkbox itself.

So, is there a way of setting a ItemHasNoText flag or something? And is it possible to centralize the checkbox? This isn't a huge issue, really more aesthetic than anything, but still, a solution would be more than appreciated.

[srazi]

I've been banging my head against a wall of QTableWidget problems, but I'm thankfully very hardheaded and the wall is starting to give. I've figured out most of my issues, but now I have a small issue:

How can I make a QTableWidgetItem have no text? All I want is a checkbox. The first thing I tried was to not use Items, but a QCheckBox inserted with QTableWidget::setCellWidget(). That worked quite well, but I came upon a few issues with it. The main being that I couldn't find a way of retrieving the box's state through the QTableWidget, since the QTableWidget::cellWidget() function returns a QWidget*and I can't figure out how to get a QCheckBox's state having only access to QWidget functions.

you can get checked state of QCheckBox object with something like this:


// table is your QTableWidget* object
QCheckBox *cellCheckBox = qobject_cast<QCheckBox *>(table->cellWidget());
if (cellCheckBox)
{
Qt::CheckState state = cellCheckBox->checkState();
}

[Wasabi]

Ah. Touché. Yes, that would work. However, I've changed it to a checkable QTableWidgetItem with no text, which achieves the same function while keeping things simpler. But knowing I can simply cast a parent class into a child class is mighty handy. So thanks.

The only problem that remains is that with both an inserted QCheckBox and a purely checkable QTableWidgetItem, I can't centralize them in the cell. Any hints for that?

[srazi]

I think this works (I don't try it):
You need to subclassing "QStyledItemDelegate" (or "QItemDelegate") and reimplementing its "paint" function, example:


//MyItemDelegate is subclass of QStyledItemDelegate
void MyItemDelegate::paint( QPainter * painter, const QStyleOptionViewItem & option, const QModelIndex & index ) const
{
QStyleOptionViewItem opt = option;
opt.decorationAlignment = Qt::AlignCenter;
QStyledItemDelegate::paint(painter, opt, index );
}

//your app body
table->setItemDelegate(new MyItemDelegate);