class MyEventFilter : public QObject { Q_OBJECT public: bool eventFilter(QObject* watched, QEvent* event) override { if (event->type() == QEvent::KeyPress) { qDebug() << "Key press event filtered!"; return true; } return false; } }; // In some function or constructor: MyEventFilter* filter = new MyEventFilter; QObject* target = someQObjectInstance; target->installEventFilter(filter);
class MyEventFilter : public QObject { Q_OBJECT public: bool eventFilter(QObject* watched, QEvent* event) override { if (event->type() == QEvent::MouseMove) { QMouseEvent* mouseEvent = static_castIn this example, we define another custom event filter class `MyEventFilter` that overrides the `eventFilter` method. This method checks if the event is a mouse move event and outputs the mouse's current position to the console. We then create an instance of this class and install it as an event filter on someQObjectInstance. Package/library: The `QObject` class is part of the QtCore module in the Qt library.(event); qDebug() << "Mouse move at (" << mouseEvent->pos().x() << "," << mouseEvent->pos().y() << ")"; } return false; } }; // In some function or constructor: MyEventFilter* filter = new MyEventFilter; QObject* target = someQObjectInstance; target->installEventFilter(filter);