How to stop spacebar from triggering a focused QPushButton?

Question

Suppose I have a focused QPushButton :

my_button = new QPushButton("Press me!", this);
my_button->setFocus();

When this button is displayed, pressing Space will trigger (ie click) the button. I don't want this behavior. Instead, I would like Ctrl + Enter to trigger the button.

How can I achieve this in Qt?

(Working examples would really help as this is part of my first Qt app)

Answer 1

you can connect the slot of the button clicked to a shortcut

connect(new QShortcut(QKeySequence(Qt::CTRL + Qt::Key_Enter), this), &QShortcut::activated, [this]() {on_pushButton_clicked();});

on the other hand, you can do set the focus policy to avoid the space bar event trigger:

my_button->setFocusPolicy(Qt::NoFocus)

Answer 2

I think the best way is to do as @thuga said. The idea is to subclass the QPushButton and reimplement keyPressEvent() .

This may look as follows:

.h

#include <QPushButton>

class MyQPushButton final : public QPushButton
{
    Q_OBJECT

    public:
        MyQPushButton(const QIcon icon, const QString & text, QWidget * parent = nullptr);
        MyQPushButton(const QString & text, QWidget * parent = nullptr);
        MyQPushButton(QWidget * parent = nullptr);

    protected:
        void keyPressEvent(QKeyEvent * e) override;
};

.cpp

#include <QKeyEvent>

MyQPushButton::MyQPushButton(const QIcon icon, const QString & text, QWidget * parent) : QPushButton(icon, text, parent)
{}
MyQPushButton::MyQPushButton(const QString & text, QWidget * parent) : QPushButton(text, parent)
{}
MyQPushButton::MyQPushButton(QWidget * parent) : QPushButton(parent)
{}

void MyQPushButton::keyPressEvent(QKeyEvent * e)
{
    if(e->key() == Qt::Key_Return && (e->modifiers() & Qt::ControlModifier))
        click();
    else
        e->ignore();
}

This way, the Space event is not handled anymore and the Ctrl + Enter will run the click() function.
I have tested it and it worked successfully.

I've written this example as simple as possible. Of course, feel free to adapt it to best fit your needs.

---

If you want it to work with the numpad Enter key too, you can catch Qt::Key_Enter too. The if condition would be something like:

if((e->key() == Qt::Key_Return || e->key() == Qt::Key_Enter) && (e->modifiers() & Qt::ControlModifier))