Qt: Event Filter for Long Mouse Press (hold mouse for >= 1sec)

longpress.h

// LongPress: event filter Object for detecting Mouse pressed down for 1 second or more
// when triggered, it executes callback function supplied in the constructor

// usage:
/* 
	someButton->installEventFilter(new LongPress(this, [this] {
		// do some stuff
	}));
*/


class LongPress : public QObject{

	Q_OBJECT

public:
	LongPress(QObject* parent, std::function<void()> f) : QObject(parent), f(f) 
	{
		t.setInterval(1000);
		connect(&t, &QTimer::timeout, this, f);
	};

protected:
	bool eventFilter(QObject* obj, QEvent* event) override 
	{
		if(event->type() == QEvent::MouseButtonPress) {
			t.start();
		} else if(event->type() == QEvent::MouseButtonRelease) {
			t.stop();
		}
		
		return QObject::eventFilter(obj, event);
	}

private:
	std::function<void()> f;
	QTimer t;
};