Answering one question about QPainter in the mailing-list, I gave a short example like below. This is a single-file, Qt-based application, so perhaps you can compile directly and save time by avoiding qmake. The purpose of this small program is very simple, paint a picture, taken from file pic.jpg, to its main window. Of course, to try it you need to supply the JPEG file (could be anything).

#include <qmainwindow.h>
#include <qapplication.h>
#include <qpainter.h>
#include <qpixmap.h>

class PainterExample : public QMainWindow
{
public:
 PainterExample();
 virtual void paintEvent( QPaintEvent* );
};

PainterExample::PainterExample(): QMainWindow( 0, "painterexample" )
{
}

void PainterExample::paintEvent( QPaintEvent* )
{
 QPainter p( this );
 p.drawPixmap( 0,0, QPixmap("pic.jpg"),0,0,100,100 );
}

int main( int argc, char ** argv )
{
 QApplication a( argc, argv );
 QMainWindow* v = new PainterExample( );
 v->show();
 a.connect( &a, SIGNAL(lastWindowClosed()), &a, SLOT(quit()) );
 return a.exec();
}

- posted by Ariya Hidayat @ 5:03 PM 0 comments

You want to process something while your application is in idle state? Look no more, and even no need to understand multithreading programming. This cheap trick is a fabulous replacement for thread (this is also mentioned in QTimer documentation):

 idleTimer = new QTimer( this );
 QObject::connect( idleTimer, SIGNAL(timeout()), SLOT(idle()) );
 idleTimer->start( 0, FALSE ); 

Of course this is rather quick-and-dirty. But still on most cases it works rather well. Or, use the real QThread if you don't like.

- posted by Ariya Hidayat @ 3:54 PM 0 comments