如何在qt中添加条目工具栏上下文菜单？

Question

By default the context menu of a toolbar is filled with the names of the toolbars. I would like to extend this context menu by an additional entry.

I found an example extending the context menu of a QTextEdit element.

http://www.qtcentre.org/threads/35166-extend-the-standard-context-menu-of-qtextedit

However, it uses the createStandardContextMenu of the QTextEdit class. But QToolBar appears not to have that property:

http://doc.qt.io/qt-4.8/qtoolbar.html

Edit

Apparently, the default context menu is the one from the QMainWindow.

http://doc.qt.io/qt-4.8/qmainwindow.html#createPopupMenu

Unfortunately, I have no clue yet how to add an entry to it.

Edit

I am working with this source:

http://doc.qt.io/qt-5/qtwidgets-mainwindows-application-example.html

Answer 1

No need to derive QToolBar if you want to provide the same context menu for all the QToolBar s in your main window, you just need to override createPopupMenu() in your main window to add your Custom Action to the returned menu like this:

QMenu* MainWindow::createPopupMenu(){
    //call the overridden method to get the default menu  containing checkable entries
    //for the toolbars and dock widgets present in the main window
    QMenu* menu= QMainWindow::createPopupMenu();
    //you can add whatever you want to the menu before returning it
    menu->addSeparator();
    menu->addAction(tr("Custom Action"), this, SLOT(CustomActionSlot()));
    return menu;
}

Answer 2

You need to derive your own class from QToolBar and override its virtual function contextMenuEvent :

qmytoolbar.h

#ifndef QMYTOOLBAR_H
#define QMYTOOLBAR_H

#include <QToolBar>

class QMyToolBar : public QToolBar
{
    Q_OBJECT
public:
    explicit QMyToolBar(QWidget *parent = 0)
        : QToolBar(parent){}

protected:
    void contextMenuEvent(QContextMenuEvent *event);
};

#endif // QMYTOOLBAR_H

qmytoolbar.cpp

#include "qmytoolbar.h"

#include <QMenu>
#include <QContextMenuEvent>

void QMyToolBar::contextMenuEvent(QContextMenuEvent *event)
{
    // QToolBar::contextMenuEvent(event);

    QMenu *menu = new QMenu(this);
    menu->addAction(tr("My Menu Item"));
    menu->exec(event->globalPos());
    delete menu;
}

If you want to retain standard menu created my main window and add your items to it keep a pointer to your QMainWindow' in your QMyToolBar and modify 'QMyToolBar::contextMenuEvent :

void QMyToolBar::contextMenuEvent(QContextMenuEvent *event)
{
    // QToolBar::contextMenuEvent(event);

    QMenu *menu =
            //new QMenu(this);
            m_pMainWindow->createPopupMenu();


    menu->addAction(tr("My Menu Item"));
    menu->exec(event->globalPos());
    delete menu;
}