C++ QgsSymbolV2List::at方法代码示例

QgsSingleSymbolRendererV2* QgsSingleSymbolRendererV2::convertFromRenderer( const QgsFeatureRendererV2 *renderer )
{
  if ( renderer->type() == "singleSymbol" )
  {
    return dynamic_cast<QgsSingleSymbolRendererV2*>( renderer->clone() );
  }
  if ( renderer->type() == "pointDisplacement" )
  {
    const QgsPointDisplacementRenderer* pointDisplacementRenderer = dynamic_cast<const QgsPointDisplacementRenderer*>( renderer );
    if ( pointDisplacementRenderer )
      return convertFromRenderer( pointDisplacementRenderer->embeddedRenderer() );
  }
  if ( renderer->type() == "invertedPolygonRenderer" )
  {
    const QgsInvertedPolygonRenderer* invertedPolygonRenderer = dynamic_cast<const QgsInvertedPolygonRenderer*>( renderer );
    if ( invertedPolygonRenderer )
      return convertFromRenderer( invertedPolygonRenderer->embeddedRenderer() );
  }

  QgsSymbolV2List symbols = const_cast<QgsFeatureRendererV2 *>( renderer )->symbols();
  if ( symbols.size() > 0 )
  {
    return new QgsSingleSymbolRendererV2( symbols.at( 0 )->clone() );
  }
  return 0;
}

QgsSymbolV2* QgsPointDisplacementRenderer::firstSymbolForFeature( QgsFeatureRendererV2* r, QgsFeature& f )
{
  if ( !r )
  {
    return 0;
  }

  QgsSymbolV2List symbolList = r->symbolsForFeature( f );
  if ( symbolList.size() < 1 )
  {
    return 0;
  }

  return symbolList.at( 0 );
}

void QgsVectorLayerRenderer::drawRendererV2Levels( QgsFeatureIterator& fit )
{
  QHash< QgsSymbolV2*, QList<QgsFeature> > features; // key = symbol, value = array of features

  QgsSingleSymbolRendererV2* selRenderer = nullptr;
  if ( !mSelectedFeatureIds.isEmpty() )
  {
    selRenderer = new QgsSingleSymbolRendererV2( QgsSymbolV2::defaultSymbol( mGeometryType ) );
    selRenderer->symbol()->setColor( mContext.selectionColor() );
    selRenderer->setVertexMarkerAppearance( mVertexMarkerStyle, mVertexMarkerSize );
    selRenderer->startRender( mContext, mFields );
  }

  QgsExpressionContextScope* symbolScope = QgsExpressionContextUtils::updateSymbolScope( nullptr );
  mContext.expressionContext().appendScope( symbolScope );

  // 1. fetch features
  QgsFeature fet;
  while ( fit.nextFeature( fet ) )
  {
    if ( !fet.constGeometry() )
      continue; // skip features without geometry

    if ( mContext.renderingStopped() )
    {
      qDebug( "rendering stop!" );
      stopRendererV2( selRenderer );
      mContext.expressionContext().popScope();
      return;
    }

    mContext.expressionContext().setFeature( fet );
    QgsSymbolV2* sym = mRendererV2->symbolForFeature( fet, mContext );
    if ( !sym )
    {
      continue;
    }

    if ( !features.contains( sym ) )
    {
      features.insert( sym, QList<QgsFeature>() );
    }
    features[sym].append( fet );

    if ( mCache )
    {
      // Cache this for the use of (e.g.) modifying the feature's uncommitted geometry.
      mCache->cacheGeometry( fet.id(), *fet.constGeometry() );
    }

    if ( mContext.labelingEngine() )
    {
      mContext.expressionContext().setFeature( fet );
      if ( mLabeling )
      {
        mContext.labelingEngine()->registerFeature( mLayerID, fet, mContext );
      }
      if ( mDiagrams )
      {
        mContext.labelingEngine()->registerDiagramFeature( mLayerID, fet, mContext );
      }
    }
    // new labeling engine
    if ( mContext.labelingEngineV2() )
    {
      QScopedPointer<QgsGeometry> obstacleGeometry;
      QgsSymbolV2List symbols = mRendererV2->originalSymbolsForFeature( fet, mContext );

      if ( !symbols.isEmpty() && fet.constGeometry()->type() == QGis::Point )
      {
        obstacleGeometry.reset( QgsVectorLayerLabelProvider::getPointObstacleGeometry( fet, mContext, symbols ) );
      }

      if ( !symbols.isEmpty() )
      {
        QgsExpressionContextUtils::updateSymbolScope( symbols.at( 0 ), symbolScope );
      }

      if ( mLabelProvider )
      {
        mLabelProvider->registerFeature( fet, mContext, obstacleGeometry.data() );
      }
      if ( mDiagramProvider )
      {
        mDiagramProvider->registerFeature( fet, mContext, obstacleGeometry.data() );
      }
    }
  }

  mContext.expressionContext().popScope();

  // find out the order
  QgsSymbolV2LevelOrder levels;
  QgsSymbolV2List symbols = mRendererV2->symbols( mContext );
  for ( int i = 0; i < symbols.count(); i++ )
  {
    QgsSymbolV2* sym = symbols[i];
    for ( int j = 0; j < sym->symbolLayerCount(); j++ )
    {
      int level = sym->symbolLayer( j )->renderingPass();
//.........这里部分代码省略.........

void QgsVectorLayerRenderer::drawRendererV2( QgsFeatureIterator& fit )
{
  QgsExpressionContextScope* symbolScope = QgsExpressionContextUtils::updateSymbolScope( nullptr );
  mContext.expressionContext().appendScope( symbolScope );

  QgsFeature fet;
  while ( fit.nextFeature( fet ) )
  {
    try
    {
      if ( !fet.constGeometry() )
        continue; // skip features without geometry

      if ( mContext.renderingStopped() )
      {
        QgsDebugMsg( QString( "Drawing of vector layer %1 cancelled." ).arg( layerID() ) );
        break;
      }

      mContext.expressionContext().setFeature( fet );

      bool sel = mContext.showSelection() && mSelectedFeatureIds.contains( fet.id() );
      bool drawMarker = ( mDrawVertexMarkers && mContext.drawEditingInformation() && ( !mVertexMarkerOnlyForSelection || sel ) );

      if ( mCache )
      {
        // Cache this for the use of (e.g.) modifying the feature's uncommitted geometry.
        mCache->cacheGeometry( fet.id(), *fet.constGeometry() );
      }

      // render feature
      bool rendered = mRendererV2->renderFeature( fet, mContext, -1, sel, drawMarker );

      // labeling - register feature
      if ( rendered )
      {
        if ( mContext.labelingEngine() )
        {
          if ( mLabeling )
          {
            mContext.labelingEngine()->registerFeature( mLayerID, fet, mContext );
          }
          if ( mDiagrams )
          {
            mContext.labelingEngine()->registerDiagramFeature( mLayerID, fet, mContext );
          }
        }
        // new labeling engine
        if ( mContext.labelingEngineV2() )
        {
          QScopedPointer<QgsGeometry> obstacleGeometry;
          QgsSymbolV2List symbols = mRendererV2->originalSymbolsForFeature( fet, mContext );

          if ( !symbols.isEmpty() && fet.constGeometry()->type() == QGis::Point )
          {
            obstacleGeometry.reset( QgsVectorLayerLabelProvider::getPointObstacleGeometry( fet, mContext, symbols ) );
          }

          if ( !symbols.isEmpty() )
          {
            QgsExpressionContextUtils::updateSymbolScope( symbols.at( 0 ), symbolScope );
          }

          if ( mLabelProvider )
          {
            mLabelProvider->registerFeature( fet, mContext, obstacleGeometry.data() );
          }
          if ( mDiagramProvider )
          {
            mDiagramProvider->registerFeature( fet, mContext, obstacleGeometry.data() );
          }
        }
      }
    }
    catch ( const QgsCsException &cse )
    {
      Q_UNUSED( cse );
      QgsDebugMsg( QString( "Failed to transform a point while drawing a feature with ID '%1'. Ignoring this feature. %2" )
                   .arg( fet.id() ).arg( cse.what() ) );
    }
  }

  mContext.expressionContext().popScope();

  stopRendererV2( nullptr );
}