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C++ QgsSymbolV2List::first方法代码示例

本文整理汇总了C++中QgsSymbolV2List::first方法的典型用法代码示例。如果您正苦于以下问题:C++ QgsSymbolV2List::first方法的具体用法?C++ QgsSymbolV2List::first怎么用?C++ QgsSymbolV2List::first使用的例子?那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在QgsSymbolV2List的用法示例。


在下文中一共展示了QgsSymbolV2List::first方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C++代码示例。

示例1: writeEntities

void QgsDxfExport::writeEntities()
{
  startSection();
  writeGroup( 2, "ENTITIES" );

  //label engine
  QgsDxfPalLabeling labelEngine( this, mExtent.isEmpty() ? dxfExtent() : mExtent, mSymbologyScaleDenominator, mMapUnits );
  QgsRenderContext& ctx = labelEngine.renderContext();

  //iterate through the maplayers
  QList< QgsMapLayer* >::iterator layerIt = mLayers.begin();
  for ( ; layerIt != mLayers.end(); ++layerIt )
  {
    QgsVectorLayer* vl = qobject_cast<QgsVectorLayer*>( *layerIt );
    if ( !vl || !layerIsScaleBasedVisible( vl ) )
    {
      continue;
    }

    QgsSymbolV2RenderContext sctx( ctx, QgsSymbolV2::MM , 1.0, false, 0, 0 );
    QgsFeatureRendererV2* renderer = vl->rendererV2();
    renderer->startRender( ctx, vl->pendingFields() );

    QStringList attributes = renderer->usedAttributes();

    bool labelLayer = ( labelEngine.prepareLayer( vl, attributes, ctx ) != 0 );

    if ( mSymbologyExport == QgsDxfExport::SymbolLayerSymbology && ( renderer->capabilities() & QgsFeatureRendererV2::SymbolLevels ) &&
         renderer->usingSymbolLevels() )
    {
      writeEntitiesSymbolLevels( vl );
      renderer->stopRender( ctx );
      continue;
    }

    QgsFeatureRequest freq = QgsFeatureRequest().setSubsetOfAttributes(
                               attributes, vl->pendingFields() );
    if ( !mExtent.isEmpty() )
    {
      freq.setFilterRect( mExtent );
    }
    QgsFeatureIterator featureIt = vl->getFeatures( freq );
    QgsFeature fet;
    while ( featureIt.nextFeature( fet ) )
    {
      sctx.setFeature( &fet );
      if ( mSymbologyExport == NoSymbology )
      {
        addFeature( sctx, dxfLayerName( vl->name() ), 0, 0 ); //no symbology at all
      }
      else
      {
        if ( !renderer )
        {
          continue;
        }
        QgsSymbolV2List symbolList = renderer->symbolsForFeature( fet );
        if ( symbolList.size() < 1 )
        {
          continue;
        }

        if ( mSymbologyExport == QgsDxfExport::SymbolLayerSymbology ) //symbol layer symbology, but layer does not use symbol levels
        {
          QgsSymbolV2List::iterator symbolIt = symbolList.begin();
          for ( ; symbolIt != symbolList.end(); ++symbolIt )
          {
            int nSymbolLayers = ( *symbolIt )->symbolLayerCount();
            for ( int i = 0; i < nSymbolLayers; ++i )
            {
              addFeature( sctx, dxfLayerName( vl->name() ), ( *symbolIt )->symbolLayer( i ), *symbolIt );
            }
          }
        }
        else
        {
          //take first symbollayer from first symbol
          QgsSymbolV2* s = symbolList.first();
          if ( !s || s->symbolLayerCount() < 1 )
          {
            continue;
          }
          addFeature( sctx, dxfLayerName( vl->name() ), s->symbolLayer( 0 ), s );
        }

        if ( labelLayer )
        {
          labelEngine.registerFeature( vl->id(), fet, ctx );
        }
      }
    }
    renderer->stopRender( ctx );
  }

  labelEngine.drawLabeling( ctx );
  endSection();
}
开发者ID:Aladar64,项目名称:QGIS,代码行数:97,代码来源:qgsdxfexport.cpp


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