C++ (Cpp) QgsSymbolLayerV2AbstractMetadata::createSymbolLayer示例

示例#1

文件： qgssymbolv2propertiesdialog.cpp 项目： mmubangizi/qgis

void QgsSymbolV2PropertiesDialog::layerTypeChanged()
{
  QgsSymbolLayerV2* layer = currentLayer();
  if ( layer == NULL ) return;

  QString newLayerType = cboLayerType->itemData( cboLayerType->currentIndex() ).toString();
  if ( layer->layerType() == newLayerType )
    return;

  // get creation function for new layer from registry
  QgsSymbolLayerV2Registry* pReg = QgsSymbolLayerV2Registry::instance();
  QgsSymbolLayerV2AbstractMetadata* am = pReg->symbolLayerMetadata( newLayerType );
  if ( am == NULL ) // check whether the metadata is assigned
    return;

  // change layer to a new (with different type)
  QgsSymbolLayerV2* newLayer = am->createSymbolLayer( QgsStringMap() );
  if ( newLayer == NULL )
    return;
  mSymbol->changeSymbolLayer( currentLayerIndex(), newLayer );

  updateSymbolLayerWidget( newLayer );

  // update symbol layer item
  SymbolLayerItem* item = currentLayerItem();
  item->setLayer( newLayer );
  item->updatePreview();

  updatePreview();
}

示例#2

文件： qgslayerpropertieswidget.cpp 项目： AnAvidDeveloper/QGIS

void QgsLayerPropertiesWidget::layerTypeChanged()
{
  QgsSymbolLayerV2* layer = mLayer;
  if ( !layer )
    return;
  QString newLayerType = cboLayerType->itemData( cboLayerType->currentIndex() ).toString();
  if ( layer->layerType() == newLayerType )
    return;

  // get creation function for new layer from registry
  QgsSymbolLayerV2Registry* pReg = QgsSymbolLayerV2Registry::instance();
  QgsSymbolLayerV2AbstractMetadata* am = pReg->symbolLayerMetadata( newLayerType );
  if ( am == NULL ) // check whether the metadata is assigned
    return;

  // change layer to a new (with different type)
  QgsSymbolLayerV2* newLayer = am->createSymbolLayer( QgsStringMap() );
  if ( newLayer == NULL )
    return;

  updateSymbolLayerWidget( newLayer );
  emit changeLayer( newLayer );
}