void QgsDecorationNorthArrowDialog::rotatePixmap( int theRotationInt )
{
  QPixmap myQPixmap;
  QString myFileNameQString = ":/images/north_arrows/default.png";
// QgsDebugMsg(QString("Trying to load %1").arg(myFileNameQString));
  if ( myQPixmap.load( myFileNameQString ) )
  {
    QPixmap  myPainterPixmap( myQPixmap.height(), myQPixmap.width() );
    myPainterPixmap.fill();
    QPainter myQPainter;
    myQPainter.begin( &myPainterPixmap );

    myQPainter.setRenderHint( QPainter::SmoothPixmapTransform );

    double centerXDouble = myQPixmap.width() / 2.0;
    double centerYDouble = myQPixmap.height() / 2.0;
    //save the current canvas rotation
    myQPainter.save();
    //myQPainter.translate( (int)centerXDouble, (int)centerYDouble );

    //rotate the canvas
    myQPainter.rotate( theRotationInt );
    //work out how to shift the image so that it appears in the center of the canvas
    //(x cos a + y sin a - x, -x sin a + y cos a - y)
    const double PI = 3.14159265358979323846;
    double myRadiansDouble = ( PI / 180 ) * theRotationInt;
    int xShift = static_cast<int>((
                                    ( centerXDouble * cos( myRadiansDouble ) ) +
                                    ( centerYDouble * sin( myRadiansDouble ) )
                                  ) - centerXDouble );
    int yShift = static_cast<int>((
                                    ( -centerXDouble * sin( myRadiansDouble ) ) +
                                    ( centerYDouble * cos( myRadiansDouble ) )
                                  ) - centerYDouble );

    //draw the pixmap in the proper position
    myQPainter.drawPixmap( xShift, yShift, myQPixmap );

    //unrotate the canvas again
    myQPainter.restore();
    myQPainter.end();

    pixmapLabel->setPixmap( myPainterPixmap );
  }
  else
  {
    QPixmap  myPainterPixmap( 200, 200 );
    myPainterPixmap.fill();
    QPainter myQPainter;
    myQPainter.begin( &myPainterPixmap );
    QFont myQFont( "time", 12, QFont::Bold );
    myQPainter.setFont( myQFont );
    myQPainter.setPen( Qt::red );
    myQPainter.drawText( 10, 20, tr( "Pixmap not found" ) );
    myQPainter.end();
    pixmapLabel->setPixmap( myPainterPixmap );
  }
}
void QgsDecorationNorthArrowDialog::drawNorthArrow()
{
  int rotation = spinAngle->value();
  double maxLength = 64;
  QSvgRenderer svg;

  const QByteArray &svgContent = QgsApplication::svgCache()->svgContent( mDeco.svgPath(), maxLength, pbnChangeColor->color(), pbnChangeOutlineColor->color(), 1.0, 1.0 );
  svg.load( svgContent );

  if ( svg.isValid() )
  {
    QSize size( maxLength, maxLength );
    QRectF viewBox = svg.viewBoxF();
    if ( viewBox.height() > viewBox.width() )
    {
      size.setWidth( maxLength * viewBox.width() / viewBox.height() );
    }
    else
    {
      size.setHeight( maxLength * viewBox.height() / viewBox.width() );
    }

    QPixmap  myPainterPixmap( maxLength, maxLength );
    myPainterPixmap.fill();

    QPainter myQPainter;
    myQPainter.begin( &myPainterPixmap );

    myQPainter.setRenderHint( QPainter::SmoothPixmapTransform );

    double centerXDouble = size.width() / 2.0;
    double centerYDouble = size.height() / 2.0;
    //save the current canvas rotation
    myQPainter.save();
    myQPainter.translate( ( maxLength - size.width() ) / 2, ( maxLength - size.height() ) / 2 );

    //rotate the canvas
    myQPainter.rotate( rotation );
    //work out how to shift the image so that it appears in the center of the canvas
    //(x cos a + y sin a - x, -x sin a + y cos a - y)
    double myRadiansDouble = ( M_PI / 180 ) * rotation;
    int xShift = static_cast<int>( (
                                     ( centerXDouble * std::cos( myRadiansDouble ) ) +
                                     ( centerYDouble * std::sin( myRadiansDouble ) )
                                   ) - centerXDouble );
    int yShift = static_cast<int>( (
                                     ( -centerXDouble * std::sin( myRadiansDouble ) ) +
                                     ( centerYDouble * std::cos( myRadiansDouble ) )
                                   ) - centerYDouble );

    //draw the pixmap in the proper position
    myQPainter.translate( xShift, yShift );
    svg.render( &myQPainter, QRectF( 0, 0, size.width(), size.height() ) );

    //unrotate the canvas again
    myQPainter.restore();
    myQPainter.end();

    pixmapLabel->setPixmap( myPainterPixmap );
  }
  else
  {
    QPixmap  myPainterPixmap( 200, 200 );
    myPainterPixmap.fill();
    QPainter myQPainter;
    myQPainter.begin( &myPainterPixmap );
    QFont myQFont( QStringLiteral( "time" ), 12, QFont::Bold );
    myQPainter.setFont( myQFont );
    myQPainter.setPen( Qt::red );
    myQPainter.drawText( 10, 20, tr( "Pixmap not found" ) );
    myQPainter.end();
    pixmapLabel->setPixmap( myPainterPixmap );
  }
}