C++ QgsSymbolV2类代码示例

void QgsCategorizedSymbolRendererV2::startRender( QgsRenderContext& context, const QgsFields& fields )
{
  mCounting = context.rendererScale() == 0.0;

  // make sure that the hash table is up to date
  rebuildHash();

  // find out classification attribute index from name
  mAttrNum = fields.fieldNameIndex( mAttrName );
  if ( mAttrNum == -1 )
  {
    mExpression.reset( new QgsExpression( mAttrName ) );
    mExpression->prepare( fields );
  }

  QgsCategoryList::iterator it = mCategories.begin();
  for ( ; it != mCategories.end(); ++it )
  {
    it->symbol()->startRender( context, &fields );

    if ( mRotation.data() || mSizeScale.data() )
    {
      QgsSymbolV2* tempSymbol = it->symbol()->clone();
      tempSymbol->setRenderHints(( mRotation.data() ? QgsSymbolV2::DataDefinedRotation : 0 ) |
                                 ( mSizeScale.data() ? QgsSymbolV2::DataDefinedSizeScale : 0 ) );
      tempSymbol->startRender( context, &fields );
      mTempSymbols[ it->symbol()] = tempSymbol;
    }
  }
  return;
}

QList<QString> QgsCategorizedSymbolRendererV2::usedAttributes()
{
  QSet<QString> attributes;

  // mAttrName can contain either attribute name or an expression.
  // Sometimes it is not possible to distinguish between those two,
  // e.g. "a - b" can be both a valid attribute name or expression.
  // Since we do not have access to fields here, try both options.
  attributes << mAttrName;

  QgsExpression testExpr( mAttrName );
  if ( !testExpr.hasParserError() )
    attributes.unite( testExpr.referencedColumns().toSet() );

  if ( mRotation.data() ) attributes.unite( mRotation->referencedColumns().toSet() );
  if ( mSizeScale.data() ) attributes.unite( mSizeScale->referencedColumns().toSet() );

  QgsCategoryList::const_iterator catIt = mCategories.constBegin();
  for ( ; catIt != mCategories.constEnd(); ++catIt )
  {
    QgsSymbolV2* catSymbol = catIt->symbol();
    if ( catSymbol )
    {
      attributes.unite( catSymbol->usedAttributes() );
    }
  }
  return attributes.toList();
}

void QgsStyleV2ManagerDialog::populateSymbols( const QStringList& symbolNames, bool check )
{
  QStandardItemModel* model = qobject_cast<QStandardItemModel*>( listItems->model() );
  model->clear();

  int type = currentItemType();

  for ( int i = 0; i < symbolNames.count(); ++i )
  {
    QString name = symbolNames[i];
    QgsSymbolV2* symbol = mStyle->symbol( name );
    if ( symbol && symbol->type() == type )
    {
      QStandardItem* item = new QStandardItem( name );
      QIcon icon = QgsSymbolLayerV2Utils::symbolPreviewIcon( symbol, listItems->iconSize() );
      item->setIcon( icon );
      item->setData( name ); // used to find out original name when user edited the name
      item->setCheckable( check );
      item->setToolTip( name );
      // add to model
      model->appendRow( item );
    }
    delete symbol;
  }
  selectedSymbolsChanged( QItemSelection(), QItemSelection() );
  symbolSelected( listItems->currentIndex() );
}

QgsSymbolV2* QgsCategorizedSymbolRendererV2::symbolForFeature( QgsFeature& feature )
{
  QgsSymbolV2* symbol = originalSymbolForFeature( feature );
  if ( !symbol )
    return 0;

  if ( !mRotation.data() && !mSizeScale.data() )
    return symbol; // no data-defined rotation/scaling - just return the symbol

  // find out rotation, size scale
  const double rotation = mRotation.data() ? mRotation->evaluate( feature ).toDouble() : 0;
  const double sizeScale = mSizeScale.data() ? mSizeScale->evaluate( feature ).toDouble() : 1.;

  // take a temporary symbol (or create it if doesn't exist)
  QgsSymbolV2* tempSymbol = mTempSymbols[symbol];

  // modify the temporary symbol and return it
  if ( tempSymbol->type() == QgsSymbolV2::Marker )
  {
    QgsMarkerSymbolV2* markerSymbol = static_cast<QgsMarkerSymbolV2*>( tempSymbol );
    if ( mRotation.data() ) markerSymbol->setAngle( rotation );
    markerSymbol->setSize( sizeScale * static_cast<QgsMarkerSymbolV2*>( symbol )->size() );
    markerSymbol->setScaleMethod( mScaleMethod );
  }
  else if ( tempSymbol->type() == QgsSymbolV2::Line )
  {
    QgsLineSymbolV2* lineSymbol = static_cast<QgsLineSymbolV2*>( tempSymbol );
    lineSymbol->setWidth( sizeScale * static_cast<QgsLineSymbolV2*>( symbol )->width() );
  }

  return tempSymbol;
}

void QgsGraduatedSymbolRendererV2Widget::changeSelectedSymbols()
{
  QItemSelectionModel* m = viewGraduated->selectionModel();
  QModelIndexList selectedIndexes = m->selectedRows( 1 );
  if ( m && selectedIndexes.size() > 0 )
  {
    QgsSymbolV2* newSymbol = mGraduatedSymbol->clone();
    QgsSymbolV2SelectorDialog dlg( newSymbol, mStyle, mLayer, this );
    if ( !dlg.exec() )
    {
      delete newSymbol;
      return;
    }

    foreach ( QModelIndex idx, selectedIndexes )
    {
      if ( idx.isValid() )
      {
        int rangeIdx = idx.row();
        QgsSymbolV2* newRangeSymbol = newSymbol->clone();
        newRangeSymbol->setColor( mRenderer->ranges()[rangeIdx].symbol()->color() );
        mRenderer->updateRangeSymbol( rangeIdx, newRangeSymbol );
      }
    }
  }

void QgsGraduatedSymbolRendererV2::startRender( QgsRenderContext& context, const QgsFields& fields )
{
  mCounting = context.rendererScale() == 0.0;

  // find out classification attribute index from name
  mAttrNum = fields.fieldNameIndex( mAttrName );

  if ( mAttrNum == -1 )
  {
    mExpression.reset( new QgsExpression( mAttrName ) );
    mExpression->prepare( &context.expressionContext() );
  }

  QgsRangeList::iterator it = mRanges.begin();
  for ( ; it != mRanges.end(); ++it )
  {
    if ( !it->symbol() )
      continue;

    it->symbol()->startRender( context, &fields );

    if ( mRotation.data() || mSizeScale.data() )
    {
      QgsSymbolV2* tempSymbol = it->symbol()->clone();
      tempSymbol->setRenderHints(( mRotation.data() ? QgsSymbolV2::DataDefinedRotation : 0 ) |
                                 ( mSizeScale.data() ? QgsSymbolV2::DataDefinedSizeScale : 0 ) );
      tempSymbol->startRender( context, &fields );
      mTempSymbols[ it->symbol()] = tempSymbol;
    }
  }
  return;
}

void QgsCategorizedSymbolRendererV2::startRender( QgsRenderContext& context, const QgsVectorLayer *vlayer )
{
  // make sure that the hash table is up to date
  rebuildHash();

  // find out classification attribute index from name
  mAttrNum = vlayer ? vlayer->fieldNameIndex( mAttrName ) : -1;
  if ( mAttrNum == -1 )
  {
    mExpression.reset( new QgsExpression( mAttrName ) );
    mExpression->prepare( vlayer->pendingFields() );
  }

  QgsCategoryList::iterator it = mCategories.begin();
  for ( ; it != mCategories.end(); ++it )
  {
    it->symbol()->startRender( context, vlayer );

    if ( mRotation.data() || mSizeScale.data() )
    {
      QgsSymbolV2* tempSymbol = it->symbol()->clone();
      tempSymbol->setRenderHints(( mRotation.data() ? QgsSymbolV2::DataDefinedRotation : 0 ) |
                                 ( mSizeScale.data() ? QgsSymbolV2::DataDefinedSizeScale : 0 ) );
      tempSymbol->startRender( context, vlayer );
      mTempSymbols[ it->value().toString()] = tempSymbol;
    }
  }

}

void QgsCategorizedSymbolRendererV2::startRender( QgsRenderContext& context, const QgsFields& fields )
{
  mCounting = context.rendererScale() == 0.0;

  // make sure that the hash table is up to date
  rebuildHash();

  // find out classification attribute index from name
  mAttrNum = fields.fieldNameIndex( mAttrName );
  if ( mAttrNum == -1 )
  {
    mExpression.reset( new QgsExpression( mAttrName ) );
    mExpression->prepare( &context.expressionContext() );
  }

  Q_FOREACH ( const QgsRendererCategoryV2& cat, mCategories )
  {
    cat.symbol()->startRender( context, &fields );

    if ( mRotation.data() || mSizeScale.data() )
    {
      QgsSymbolV2* tempSymbol = cat.symbol()->clone();
      tempSymbol->setRenderHints(( mRotation.data() ? QgsSymbolV2::DataDefinedRotation : 0 ) |
                                 ( mSizeScale.data() ? QgsSymbolV2::DataDefinedSizeScale : 0 ) );
      tempSymbol->startRender( context, &fields );
      mTempSymbols[ cat.symbol()] = tempSymbol;
    }
  }

void QgsSymbolLevelsV2Dialog::populateTable()
{
  for ( int row = 0; row < mList.count(); row++ )
  {
    QgsSymbolV2* sym = mList[row].second;
    QString label = mList[row].first;
    QTableWidgetItem *itemLabel = new QTableWidgetItem( label );
    itemLabel->setFlags( itemLabel->flags() ^ Qt::ItemIsEditable );
    tableLevels->setItem( row, 0, itemLabel );
    for ( int layer = 0; layer < mMaxLayers; layer++ )
    {
      QTableWidgetItem* item;
      if ( layer >= sym->symbolLayerCount() )
      {
        item = new QTableWidgetItem();
        item->setFlags( Qt::ItemFlags() );
      }
      else
      {
        QgsSymbolLayerV2* sl = sym->symbolLayer( layer );
        QIcon icon = QgsSymbolLayerV2Utils::symbolLayerPreviewIcon( sl, QgsSymbolV2::MM, QSize( 16, 16 ) );
        item = new QTableWidgetItem( icon, QString::number( sl->renderingPass() ) );
      }
      tableLevels->setItem( row, layer + 1, item );
      tableLevels->resizeColumnToContents( 0 );
    }
  }

}

void QgsCategorizedSymbolRendererV2::startRender( QgsRenderContext& context, const QgsVectorLayer *vlayer )
{
  // make sure that the hash table is up to date
  rebuildHash();

  // find out classification attribute index from name
  mAttrNum = vlayer ? vlayer->fieldNameIndex( mAttrName ) : -1;

  mRotationFieldIdx  = ( mRotationField.isEmpty()  ? -1 : vlayer->fieldNameIndex( mRotationField ) );
  mSizeScaleFieldIdx = ( mSizeScaleField.isEmpty() ? -1 : vlayer->fieldNameIndex( mSizeScaleField ) );

  QgsCategoryList::iterator it = mCategories.begin();
  for ( ; it != mCategories.end(); ++it )
  {
    it->symbol()->startRender( context, vlayer );

    if ( mRotationFieldIdx != -1 || mSizeScaleFieldIdx != -1 )
    {
      QgsSymbolV2* tempSymbol = it->symbol()->clone();
      tempSymbol->setRenderHints(( mRotationFieldIdx != -1 ? QgsSymbolV2::DataDefinedRotation : 0 ) |
                                 ( mSizeScaleFieldIdx != -1 ? QgsSymbolV2::DataDefinedSizeScale : 0 ) );
      tempSymbol->startRender( context, vlayer );
      mTempSymbols[ it->value().toString()] = tempSymbol;
    }
  }

}

QList<QString> QgsGraduatedSymbolRendererV2::usedAttributes()
{
  QSet<QString> attributes;
  attributes.insert( mAttrName );
  if ( !mRotationField.isEmpty() )
  {
    attributes.insert( mRotationField );
  }
  if ( !mSizeScaleField.isEmpty() )
  {
    attributes.insert( mSizeScaleField );
  }

  QgsSymbolV2* symbol = 0;
  QgsRangeList::const_iterator range_it = mRanges.constBegin();
  for ( ; range_it != mRanges.constEnd(); ++range_it )
  {
    symbol = range_it->symbol();
    if ( symbol )
    {
      attributes.unite( symbol->usedAttributes() );
    }
  }
  return attributes.toList();
}

QgsSymbolV2* QgsFillSymbolV2::clone() const
{
  QgsSymbolV2* cloneSymbol = new QgsFillSymbolV2( cloneLayers() );
  cloneSymbol->setOutputUnit( mOutputUnit );
  cloneSymbol->setAlpha( mAlpha );
  return cloneSymbol;
}

QgsSymbolV2* QgsMarkerSymbolV2::clone() const
{
  QgsSymbolV2* cloneSymbol = new QgsMarkerSymbolV2( cloneLayers() );
  cloneSymbol->setAlpha( mAlpha );
  cloneSymbol->setLayer( mLayer );
  cloneSymbol->setClipFeaturesToExtent( mClipFeaturesToExtent );
  return cloneSymbol;
}

void QgsSymbolLevelsV2Dialog::renderingPassChanged( int row, int column )
{
  if ( row < 0 || row >= mList.count() )
    return;
  QgsSymbolV2* sym = mList[row].second;
  if ( column < 0 || column >= sym->symbolLayerCount() )
    return;
  sym->symbolLayer( column )->setRenderingPass( tableLevels->item( row, column )->text().toInt() );
}

QgsSymbolV2* QgsCategorizedSymbolRendererV2::symbolForFeature( QgsFeature& feature )
{
  const QgsAttributeMap& attrMap = feature.attributeMap();
  QgsAttributeMap::const_iterator ita = attrMap.find( mAttrNum );
  if ( ita == attrMap.end() )
  {
    QgsDebugMsg( "attribute '" + mAttrName + "' (index " + QString::number( mAttrNum ) + ") required by renderer not found" );
    return NULL;
  }

  // find the right symbol for the category
  QgsSymbolV2* symbol = symbolForValue( *ita );
  if ( symbol == NULL )
  {
    // if no symbol found use default one
    //return symbolForValue( QVariant( "" ) );
    // What is default? Empty string may be a legal value, and features not found
    // should not be rendered using empty string value category symbology.
    // We also need to get NULL in that case so that willRenderFeature()
    // may be used to count features.
    return 0;
  }

  if ( mRotationFieldIdx == -1 && mSizeScaleFieldIdx == -1 )
    return symbol; // no data-defined rotation/scaling - just return the symbol

  // find out rotation, size scale
  double rotation = 0;
  double sizeScale = 1;
  if ( mRotationFieldIdx != -1 )
    rotation = attrMap[mRotationFieldIdx].toDouble();
  if ( mSizeScaleFieldIdx != -1 )
    sizeScale = attrMap[mSizeScaleFieldIdx].toDouble();

  // take a temporary symbol (or create it if doesn't exist)
  QgsSymbolV2* tempSymbol = mTempSymbols[ita->toString()];

  // modify the temporary symbol and return it
  if ( tempSymbol->type() == QgsSymbolV2::Marker )
  {
    QgsMarkerSymbolV2* markerSymbol = static_cast<QgsMarkerSymbolV2*>( tempSymbol );
    if ( mRotationFieldIdx != -1 )
      markerSymbol->setAngle( rotation );
    if ( mSizeScaleFieldIdx != -1 )
      markerSymbol->setSize( sizeScale * static_cast<QgsMarkerSymbolV2*>( symbol )->size() );
    markerSymbol->setScaleMethod( mScaleMethod );
  }
  else if ( tempSymbol->type() == QgsSymbolV2::Line )
  {
    QgsLineSymbolV2* lineSymbol = static_cast<QgsLineSymbolV2*>( tempSymbol );
    if ( mSizeScaleFieldIdx != -1 )
      lineSymbol->setWidth( sizeScale * static_cast<QgsLineSymbolV2*>( symbol )->width() );
  }

  return tempSymbol;
}