C++ QSvgRenderer::viewBoxF方法代码示例

// QtPluginIconPalletTool Interface
void
dmz::QtPluginIconPalletTool::_add_type (const ObjectType &Type) {

   const String IconResource = config_to_string (
      get_plugin_name () + ".resource",
      Type.get_config());

   const String IconName = _rc.find_file (IconResource);

   if (IconName) {

      const String Name = Type.get_name ();

      if (Name) {

         QImage back (
            (int)_iconExtent,
            (int)_iconExtent,
            QImage::Format_ARGB32_Premultiplied);
         QPainter painter (&back);
         painter.setCompositionMode (QPainter::CompositionMode_Source);
         painter.fillRect (back.rect (), Qt::transparent);
         painter.setCompositionMode (QPainter::CompositionMode_SourceOver);
         QSvgRenderer qsr (QString (IconName.get_buffer ()));
         QRectF size = qsr.viewBoxF ();
         qreal width = size.width ();
         qreal height = size.height ();
         qreal scale = (width > height) ? width : height;
         if (scale <= 0.0f) { scale = 1.0f; }
         scale = _iconExtent / scale;
         width *= scale;
         height *= scale;
         size.setWidth (width);
         size.setHeight (height);
         if (height < _iconExtent) { size.moveTop ((_iconExtent - height) * 0.5f); }
         if (width < _iconExtent) { size.moveLeft ((_iconExtent - width) * 0.5f); }
         qsr.render (&painter, size);
         painter.end ();
         QIcon icon;
         icon.addPixmap (QPixmap::fromImage (back));
         QStandardItem *item = new QStandardItem (icon, Name.get_buffer ());
         item->setEditable (false);
         _model.appendRow (item);
      }
   }
   else if (IconResource) {

      _log.error << "Unable to find icon resource: " << IconResource
          << " for object type: " << Type.get_name () << endl;
   }

   RuntimeIterator it;
   ObjectType next;

   while (Type.get_next_child (it, next)) { _add_type (next); }
}

void QgsDecorationNorthArrow::render( const QgsMapSettings &mapSettings, QgsRenderContext &context )
{
  if ( !enabled() )
    return;

  double maxLength = mSize * mapSettings.outputDpi() / 25.4;
  QSvgRenderer svg;

  const QByteArray &svgContent = QgsApplication::svgCache()->svgContent( svgPath(), maxLength, mColor, mOutlineColor, 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() );
    }

    double centerXDouble = size.width() / 2.0;
    double centerYDouble = size.height() / 2.0;

    //save the current canvas rotation
    context.painter()->save();
    //
    //work out how to shift the image so that it rotates
    //           properly about its center
    //(x cos a + y sin a - x, -x sin a + y cos a - y)
    //
    // could move this call to somewhere else so that it is only
    // called when the projection or map extent changes
    if ( mAutomatic )
    {
      try
      {
        mRotationInt = QgsBearingUtils:: bearingTrueNorth( mapSettings.destinationCrs(), mapSettings.transformContext(), context.extent().center() );
      }
      catch ( QgsException & )
      {
        mRotationInt = 0.0;
      }
      mRotationInt += mapSettings.rotation();
    }

    double radiansDouble = mRotationInt * M_PI / 180.0;
    int xShift = static_cast<int>( (
                                     ( centerXDouble * std::cos( radiansDouble ) ) +
                                     ( centerYDouble * std::sin( radiansDouble ) )
                                   ) - centerXDouble );
    int yShift = static_cast<int>( (
                                     ( -centerXDouble * std::sin( radiansDouble ) ) +
                                     ( centerYDouble * std::cos( radiansDouble ) )
                                   ) - centerYDouble );
    // need width/height of paint device
    int deviceHeight = context.painter()->device()->height();
    int deviceWidth = context.painter()->device()->width();

    // Set  margin according to selected units
    int xOffset = 0;
    int yOffset = 0;
    switch ( mMarginUnit )
    {
      case QgsUnitTypes::RenderMillimeters:
      {
        int pixelsInchX = context.painter()->device()->logicalDpiX();
        int pixelsInchY = context.painter()->device()->logicalDpiY();
        xOffset = pixelsInchX * INCHES_TO_MM * mMarginHorizontal;
        yOffset = pixelsInchY * INCHES_TO_MM * mMarginVertical;
        break;
      }

      case QgsUnitTypes::RenderPixels:
        xOffset = mMarginHorizontal - 5; // Minus 5 to shift tight into corner
        yOffset = mMarginVertical - 5;
        break;

      case QgsUnitTypes::RenderPercentage:
        xOffset = ( ( deviceWidth - size.width() ) / 100. ) * mMarginHorizontal;
        yOffset = ( ( deviceHeight - size.width() ) / 100. ) * mMarginVertical;
        break;
      case QgsUnitTypes::RenderMapUnits:
      case QgsUnitTypes::RenderPoints:
      case QgsUnitTypes::RenderInches:
      case QgsUnitTypes::RenderUnknownUnit:
      case QgsUnitTypes::RenderMetersInMapUnits:
        break;
    }
    //Determine placement of label from form combo box
    switch ( mPlacement )
    {
      case BottomLeft:
        context.painter()->translate( xOffset, deviceHeight - yOffset - maxLength + ( maxLength - size.height() ) / 2 );
        break;
      case TopLeft:
        context.painter()->translate( xOffset, yOffset );
//.........这里部分代码省略.........

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 );
  }
}