gistfile1.cpp

#include <QtWidgets/QApplication>
#include <QtWidgets/QWidget>
#include <QTimer>
#include <QDebug>


class MyQWidget: public QWidget, public QTimer
{
	friend class MyTimer;
	public:
		void timerEvent(QTimerEvent*)
		{
			qDebug()<<"timerEvent";
			stop();
		}

		void paintEvent(QPaintEvent* e)
		{
			qDebug()<<"paintEvent";
			QWidget::paintEvent(e);
		}

		void keyPressEvent(QKeyEvent*)
		{
			qDebug()<<"keyPressEvent";
			qDebug()<<"timerstart";
			start(0);
			qDebug()<<"update";
			update(geometry());
		}
};

class MyTimer : public QTimer
{
	MyQWidget* mWidget;
public:
		MyTimer(MyQWidget* w)
			: mWidget(w)
		{

		}

		void timerEvent(QTimerEvent*)
		{
			stop();
			qDebug()<<"MyTimer::timerEvent";
			qDebug()<<"timerstart";
			mWidget->start(0);
			qDebug()<<"update";
			mWidget->update(mWidget->geometry());

		}
};


int main(int argv, char **args)
{
	QApplication app(argv, args);

	MyQWidget textEdit;
	MyTimer timer(&textEdit);
	timer.start(5000);
	
	textEdit.show();

	return app.exec();
}


// output:
/*
MyTimer::timerEvent 
timerstart 
update 
paintEvent 
timerEvent 
*/