#include <QApplication>
#include <QFont>
#include <QPushButton>
#include <QElapsedTimer>
#include <QFile>
#include <QTextStream>


class MyPushButton : public QPushButton
{
public:
	MyPushButton( const QString & p_text, QTextStream & timingsLog )
		: QPushButton( p_text ), timingsLog( timingsLog )
	{
	}
protected:
	virtual void paintEvent( QPaintEvent * p_event ) {
		QElapsedTimer timer; timer.start();
		QPushButton::paintEvent( p_event );
		timingsLog << "paint event time: " << timer.elapsed() << endl;
	}
private:
    QTextStream & timingsLog;
};

int main(int argc, char *argv[])
{
    QFile timingsLogFile( "timings.txt" );
    timingsLogFile.open( QFile::WriteOnly );
    QTextStream timingsLog( &timingsLogFile );

	QElapsedTimer timer; timer.start();
	timingsLog << "Clock type: " << timer.clockType() << endl;
    QApplication a(argc,argv);
	timingsLog << "app constructor time: " << timer.elapsed() << endl;

	timer.restart();
    MyPushButton quit("Hello world!", timingsLog);
    quit.resize(175,30);
    QObject::connect(&quit,SIGNAL(clicked()),&a,SLOT(quit()));
    quit.show();

    MyPushButton quit2("Hello world 2!", timingsLog);
    quit2.resize(175,30);
    quit2.setFont(QFont("Courier",18,QFont::Bold));
    QObject::connect(&quit2,SIGNAL(clicked()),&a,SLOT(quit()));
    quit2.show();

    MyPushButton quit3("Hello world 3!", timingsLog);
    quit3.resize(175,30);
    quit3.setFont(QFont("Arial",18,QFont::Bold));
    QObject::connect(&quit3,SIGNAL(clicked()),&a,SLOT(quit()));
    quit3.show();
	timingsLog << "button creation time: " << timer.elapsed() << endl;

    return a.exec();
}