Qt: how to apply a 2-step key shortcut to action - qt

Question

I know how to apply a keyboard shortcut to an action. And in some software such as Visual Studio there are shortcuts that do the job in more than one step (such as Ctrl+K,Ctrl+C to comment the code).
Another example of that in Sublime Text:
I wonder whether or not it is possible to implement in Qt.

Answer 1

You can create it by using the multiple arguments constructor for QKeySequence.
like this:
auto ac = new QAction(this);
ac->setShortcut(QKeySequence(Qt::CTRL + Qt::Key_K, Qt::CTRL + Qt::Key_C));

Answer 2

Try this:
action->setShortcut("Ctrl+K,Ctrl+C");
QKeySequence may be implicitly created from QString.
Due to documentation:
Up to four key codes may be entered by separating them with commas, e.g. "Alt+X,Ctrl+S,Q".
MOC generates almost same code when you create shortcut for a QAction via Qt Designer. But it makes it slightly different:
action->setShortcut(QApplication::translate("MainWindow", "Ctrl+K, Ctrl+C", 0));
but it's actually same thing.

Answer 3

You can use eventFilter to get mouse & keyboard events.
I use boolean to get first and second key, Ctrl + K then C.
I made you a sample code it's working.
.cpp file:
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
firstKey = false;
secondKey = false;
this->installEventFilter(this);
}
MainWindow::~MainWindow()
{
delete ui;
}
bool MainWindow::eventFilter(QObject *object, QEvent *event)
{
if (object == this &&event->type() == QEvent::KeyPress)
{
QKeyEvent *keyEvent = static_cast<QKeyEvent *>(event);
if ((keyEvent->key() == Qt::Key_Control))
{
firstKey = true;
return true;
}
else if ((keyEvent->key() == Qt::Key_K))
{
secondKey = true;
return true;
}
else if ((keyEvent->key() == Qt::Key_C))
{
if(firstKey && secondKey)
{
firstKey = false;
secondKey = false;
QMessageBox::information(this, "", "Ctrl + k + c");
}
return true;
}
else
return false;
}
else
return false;
}
void MainWindow::keyReleaseEvent(QKeyEvent *e)
{
if (e->type() == QEvent::KeyRelease)
{
QKeyEvent *keyEvent = static_cast<QKeyEvent *>(e);
if ((keyEvent->key() == Qt::Key_Control))
{
firstKey = false;
}
}
}
.h file:
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QDebug>
#include <QMessageBox>
#include <QKeyEvent>
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
bool firstKey;
bool secondKey;
bool eventFilter(QObject *object, QEvent *event);
void keyReleaseEvent(QKeyEvent *e);
private:
Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H