Qt Quick KeyListener [eventFilter, event filter]

main.cpp

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QDebug>
#include <QKeyEvent>

class KeyListener : public QObject
{
    Q_OBJECT

public:
    KeyListener() {}

    bool eventFilter(QObject *watched, QEvent *event) {
        if (event->type() == QEvent::KeyPress) {
            QKeyEvent *keyEvent = static_cast<QKeyEvent*>(event);
            qDebug() << "text" << keyEvent->text() << "key" << keyEvent->key() << "modifiers" << keyEvent->modifiers();
        }
        QObject::eventFilter(watched, event);
        return false;
    }
};

int main(int argc, char *argv[])
{
#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
#endif
    QGuiApplication app(argc, argv);

    QQmlApplicationEngine engine;
    const QUrl url(QStringLiteral("qrc:/main.qml"));
    QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
                     &app, [url](QObject *obj, const QUrl &objUrl) {
        if (!obj && url == objUrl)
            QCoreApplication::exit(-1);
    }, Qt::QueuedConnection);
    engine.load(url);

    if (engine.rootObjects().isEmpty()) {
        qWarning() << "No root objects!";
        return 1;
    }

    KeyListener keyListener;
    engine.rootObjects().first()->installEventFilter(&keyListener);

    return app.exec();
}

#include "main.moc"

main.qml

import QtQuick 2.15
import QtQuick.Controls 2.15

ApplicationWindow {
    objectName: "window"
    width: 800
    height: 800
    visible: true
}