Create QAction with shortcut, without inserting in menu

Question

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>
#include <cassert>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    QAction* back = new QAction(this);
    back->setVisible(true);
    back->setShortcut(QKeySequence("Ctrl+M"));
    bool cres = connect(back, SIGNAL(triggered(bool)), this, SLOT(mySlot()));
    assert(cres);
}

In this code I tried to catch Ctrl+M key event. I don't want to put the action in menu. connect returns true but mySlot is never called. When action is inserted in menu, shortcut works well. What I have done wrong?

If you want to use "headless" (without GUI) shortcuts, I would recommend using `QShortcut` class directly. — vahancho, Jan 31 '14 at 17:02
@vahancho: `QShortcut` doesn't do anything without the gui. Quoth documentation: "A shortcut is "listened for" by Qt's event loop when the shortcut's parent widget is receiving events." — Kuba hasn't forgotten Monica, Jan 31 '14 at 20:01
@KubaOber, yes, but what I meant was that QShortcut doesn't have a visual representation, as QAction may have. — vahancho, Jan 31 '14 at 20:09

score 7 · Accepted Answer · edited May 23 '17 at 10:28

QAction is dormant until you insert it somewhere. As vahancho has suggested, use QShortcut. You need to instantiate the shortcut for each top-level widget (window) where you want it to be active. Thus if you have 5 top-level windows, you'll need 5 shortcuts, each having one of windows as its parent.

There is no way to use QShortcut as a global shortcut without the gui. QShortcut is only active when its associated widget has focus. The widget could be a top-level window.

System-global shortcuts are the subject of this question.

Create QAction with shortcut, without inserting in menu

1 Answers1