[Qt-interest] QHeaderView: built-in RMB menu to show/hide columns?

[Robert Hairgrove]

On Fri, 2011-02-11 at 20:49 +0100, Daniel Franke wrote:
> On Friday 11 February 2011 17:50:09 Robert Hairgrove wrote:
> > Alternatively, you could reimplement the protected mousePressEvent() in
> > your header view subclass. That might actually be the easiest way to go.
> 
> Robert, thanks for the pointer.
> 
> As I couldn't find a simple example (and didn't want to dig through the KDE 
> sources), find my working implementation below. Not sure if the actions are 
> deleted by the menu or if they are leaked, though.
> 
> Something like this could be an addition for future releases, maybe?
> 
> Cheers
> 
> 	Daniel
> 
> --
> class MyHeaderView : public QHeaderView {
>   Q_OBJECT
> 
> public:
>   MyHeaderView(QWidget *parent = 0);
> 
> protected slots:
>   void toggleSectionVisibility(int section);
> 
> protected:
>   void mousePressEvent(QMouseEvent *e);
> };
> 
> 
> 
> MyHeaderView::MyHeaderView(QWidget *parent)
>  : QHeaderView(Qt::Horizontal, parent) {
> }
> 
> void MyHeaderView::mousePressEvent(QMouseEvent *e) {
>   if (e->button() == Qt::RightButton) {
>     QMenu menu;
>     QSignalMapper mapper;
> 
>     QAbstractItemModel *m = model();
>     for (int col = 0; col < model()->columnCount(); ++col) {
>       QAction *action = new QAction(&menu);
>       action->setText(model()->headerData(col, Qt::Horizontal).toString());
>       action->setCheckable(true);
>       action->setChecked(!isSectionHidden(col));
> 
>       connect(action, SIGNAL(triggered()), &mapper, SLOT(map()));
>       mapper.setMapping(action, col);
> 
>       menu.addAction(action);
>     }
> 
>     connect(&mapper, SIGNAL(mapped(int)),
>             this, SLOT(toggleSectionVisibility(int)));
> 
>     menu.exec(e->globalPos());
>   }
> 
>   QHeaderView::mousePressEvent(e);
> }
> 
> void MyHeaderView::toggleSectionVisibility(int section) {
>   setSectionHidden(section, !isSectionHidden(section));
> }

Looks good!

Taking a quick look at the Menus Example in QtAssistant, I noticed that
they override this instead of mousePressEvent:

QWidget::contextMenuEvent(QContextMenuEvent *event)

But either way is probably OK.