Rotating a rectangle about its origin

[babu198649]

Finally i am able to rotate the rectangle about its origin.Below is the working code.

#include <QtGui>
 
class Widget : public QWidget
{
	Q_OBJECT
public:
	void paintEvent(QPaintEvent * event)
	{
		QRect rect(0,0,150,100);
		QPainter painter(this);
		painter.translate(150,150);
		painter.drawRect(rect);
		static qreal degree=0;
		painter.rotate(++degree);
		painter.translate(-rect.width()/2,-rect.height()/2);
		painter.drawRect(rect);
		painter.drawPoint(rect.center());
 
		QTimer::singleShot(0,this, SLOT(update()));
	}
};
 
int main(int argc, char *argv[])
{
	QApplication a(argc, argv);
	a.setStyleSheet("QWidget{background: white}");
	Widget w;
	w.show();
	return a.exec();
}
 
#include "main.moc"

#include <QtGui>

class Widget : public QWidget
{
	Q_OBJECT
public:
	void paintEvent(QPaintEvent * event)
	{
		QRect rect(0,0,150,100);
		QPainter painter(this);
		painter.translate(150,150);
		painter.drawRect(rect);
		static qreal degree=0;
		painter.rotate(++degree);
		painter.translate(-rect.width()/2,-rect.height()/2);
		painter.drawRect(rect);
		painter.drawPoint(rect.center());
		
		QTimer::singleShot(0,this, SLOT(update()));
	}
};

int main(int argc, char *argv[])
{
	QApplication a(argc, argv);
	a.setStyleSheet("QWidget{background: white}");
	Widget w;
	w.show();
	return a.exec();
}

#include "main.moc"

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It's strictly about doing anything concerning application logic in a paint event

Please tell the mistake in my program and how to avoid it.How would u have killed it.