C++ Qt QShortcut with numpad key

Question

QShortcut makes it easy to connect a QShortcutEvent (Key press, combination or sequence) to a slot method, e.g.:

QShortcut *shortcut = new QShortcut( QKeySequence(Qt::Key_7), this, 0, 0, Qt::ApplicationShortcut);

(Hint: for number keys, a QSignalMapper can be used to map the QShortcut's activated() signal to a Slot with int parameter).

However, in this example, with NumLock (numpad enabled), both '7' keys will trigger the Shortcut's activated() signal.

Is there a way to detect the different keys other than filtering or reimplementing a widget's keyPressEvent and check QKeyEvent::modifiers() for Qt::KeypadModifier?

Digging further, I found

QTBUG-20191 Qt::KeypadModifier does not work with setShortcut linking to a patch that has been merged into 4.8 in Sept. 2012 and which comes with a test case using

button2->setShortcut(Qt::Key_5 + Qt::KeypadModifier);

which does not work for my QShortcut on Qt 4.8.1, i.e. neither of the '7' keys are recognized using (adding) the modifier flag.

So I guess the quickest way would be installing a filter to detect the modifier and let all other keyEvents be handled by the default implementation to be useable with QShortcut?

Answer 1

You can use Qt.KeypadModifier, For example [Python]:

def keyPressEvent(self, event):
    numpad_mod = int(event.modifiers()) & QtCore.Qt.KeypadModifier
    if event.key() == QtCore.Qt.Key5 and numpad_mod:
        #Numpad 5 clicked

Answer 2

For this you can use keyReleaseEvent(QKeyEvent *event) For example

void Form::keyReleaseEvent(QKeyEvent *event)    {
    int key = event->nativeScanCode();

    if( key == 79 ) //value for numpad 7
    {
       //your statement   
    }


}