Hey guys,

I have been trying to get the QGraphicsView::setTransform( const QTransform & ) to work. I have (simplified):

Qt Code: 
  1. class QPlot : public QGraphicsView
  2. {
  3. ...
  4. protected:
  5. resizeEvent( QResizeEvent *event );
  6. private:
  8. }
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with implementation:
Qt Code: 
  1. QPlot::QPlot( QWidget *parent )
  2. :   QGraphicsView( parent ),
  3.     scene( new QGraphicsScene() )
  4. {
  5.     // prepare
  6.     //setRenderHints( QPainter::Antialiasing );
  7.     setHorizontalScrollBarPolicy( Qt::ScrollBarAlwaysOff );
  8.     setVerticalScrollBarPolicy( Qt::ScrollBarAlwaysOff );
  9.     scene->setSceneRect( 0.0, 0.0, 100.0, 100.0 );
  10.  
  11.     // initial transformation
  12.     QTransform transform;
  13.     QRectF worldRect( QPointF(0.,0.), QPointF(100.,100.) );
  14.     QRectF sceneRect( QPointF(0.,0.), QPointF(100., 100.) );
  15.     QTransform::quadToQuad(QPolygon(worldRect), QPolygon(sceneRect), transform);
  16.  
  17.     setSceneRect( sceneRect );
  18.     setTransform( transform );
  19.  
  20.     // x-grid
  21.     scene->addLine( 100.0, 0.0, 0.0, 0.0 );
  22.     scene->addLine( 100.0, 20.0, 0.0, 20.0 );
  23.     scene->addLine( 100.0, 40.0, 0.0, 40.0 );
  24.     scene->addLine( 100.0, 60.0, 0.0, 60.0 );
  25.     scene->addLine( 100.0, 80.0, 0.0, 80.0 );
  26.     scene->addLine( 100.0, 100.0, 0.0, 100.0 );
  27.     // y-grid
  28.     scene->addLine( 0.0, 0.0, 0.0, 100.0 );
  29.     scene->addLine( 20.0, 0.0, 20.0, 100.0 );
  30.     scene->addLine( 40.0, 0.0, 40.0, 100.0 );
  31.     scene->addLine( 60.0, 0.0, 60.0, 100.0 );
  32.     scene->addLine( 80.0, 0.0, 80.0, 100.0 );
  33.     scene->addLine( 100.0, 0.0, 100.0, 100.0 );
  34.     // QPLotScale transform check
  35.     setScene( scene );
  36. }
  37. void QPlot::resizeEvent( QResizeEvent *event )
  38. {
  39.     fitInView( scene->sceneRect(), Qt::IgnoreAspectRatio );
  40.  
  41.  
  42.     qDebug() << transform().m11() << transform().m12() << transform().m13() << endl
  43.             << transform().m21() << transform().m22() << transform().m23() << endl
  44.             << transform().m31() << transform().m32() << transform().m33() << endl;
  45. }
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All I get is a FULL grid that stretches to fit the window size. This is okay, but...
I would like to have the grid (ten lines) to be transformed by the QTransform. I have searched the web for an example, but they always implement the transformation directly on the QPainter, not via the QGraphicsView
What I want is to have eg only a part of the grid to be shown (only the center squares, only the topleft corner, stuff like that). I have tried to ask on these forums before, but always without answer

Any help is appreciated!