Qt - Centering a checkbox in a QTable - c++

Question

In QtCreater I added a table to my project. in my code I am generating some data to output into the table. I want to add a QCheckbox into each row to allow the row to be selected. All the content of the table is aligned left, how do I make only these checkboxes in the first column of every row align to the center?
I'm adding the QCheckbox using:
ui->data_table->setCellWidget(rowCount,0, new QCheckBox);

Answer 1

Two thumbs up for Barry Mavin! You don't even have to subclass.
one line...
pCheckBox->setStyleSheet("margin-left:50%; margin-right:50%;");
done!!

Answer 2

I usually use a layout and a container widget for this. It is an ugly solution, but it works:
QWidget * w = new QWidget();
QHBoxLayout *l = new QHBoxLayout();
l->setAlignment( Qt::AlignCenter );
l->addWidget( <add your checkbox here> );
w->setLayout( l );
ui->data_table->setCellWidget(rowCount,0, w);
So basically you will have:
Table Cell -> Widget -> Layout -> Checkbox
you'll have to consider it if you will need to access the checkbox through the table.

Answer 3

This is an old post but in fact there is a much easier and lighter way of achieving this, just subclass QCheckBox and set the stylesheet to
margin-left:50%;
margin-right:50%;

Answer 4

It works for me, but my checkbox is not completely displayed.
To have a complete view of the widget, remove margins in layout :
l->setContentsMargins(0,0,0,0);

Answer 5

As stated in similar question around Stack Overflow, it's currently an open BUG:
https://bugreports.qt-project.org/browse/QTBUG-5368

Answer 6

can be center like this too using layout if want to add more customization
// Create a widget that will contain a checkbox
QWidget *checkBoxWidget = new QWidget();
QCheckBox *checkBox = new QCheckBox(); // We declare and initialize the checkbox
QHBoxLayout *layoutCheckBox = new QHBoxLayout(checkBoxWidget); // create a layer with reference to the widget
layoutCheckBox->addWidget(checkBox); // Set the checkbox in the layer
layoutCheckBox->setAlignment(Qt::AlignCenter); // Center the checkbox
layoutCheckBox->setContentsMargins(0,0,0,0); // Set the zero padding
ui->my_table_view->setCellWidget(row_number,column_number, checkBoxWidget); // set cell widget
OR simply add left right margins
checkBox->setStyleSheet("margin-left:50%; margin-right:50%;");

Answer 7

#if QT_VERSION < 0x046000
#include <QCommonStyle>
class MyStyle : public QCommonStyle {
public:
QRect subElementRect(SubElement subElement, const QStyleOption *option, const QWidget *widget = 0) const {
switch(subElement) {
case QStyle::SE_CheckBoxIndicator: {
QRect r = QCommonStyle::subElementRect(subElement, option, widget);
r.setRect( (widget->width() - r.width())/2, r.top(), r.width(), r.height());
return QRect(r);
}
default: return QCommonStyle::subElementRect(subElement, option, widget);
}
}
};
#else
#include <QProxyStyle>
#include <QStyleFactory>
class MyStyle: public QProxyStyle {
public:
MyStyle():QProxyStyle(QStyleFactory::create("Fusion")) {}
QRect subElementRect(SubElement subElement, const QStyleOption *option, const QWidget *widget = 0) const {
switch(subElement) {
case QStyle::SE_CheckBoxIndicator: {
QRect r = QProxyStyle::subElementRect(subElement, option, widget);
r.setRect( (widget->width() - r.width())/2, r.top(), r.width(), r.height());
return QRect(r);
}
default: return QProxyStyle::subElementRect(subElement, option, widget);
}
}
};
#endif
QCheckBox *box = new QCheckBox();
box->setStyle(new MyStyle());