C++ const_iterator::toDouble方法代码示例

QgsSymbolV2* QgsGraduatedSymbolRendererV2::symbolForFeature( QgsFeature& feature )
{
  const QgsAttributeMap& attrMap = feature.attributeMap();
  QgsAttributeMap::const_iterator ita = attrMap.find( mAttrNum );
  if ( ita == attrMap.end() )
  {
    QgsDebugMsg( "attribute required by renderer not found: " + mAttrName + "(index " + QString::number( mAttrNum ) + ")" );
    return NULL;
  }

  // find the right category
  QgsSymbolV2* symbol = symbolForValue( ita->toDouble() );
  if ( symbol == NULL )
    return NULL;

  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[symbol];

  // 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;
}

bool QgsGPXProvider::addFeature( QgsFeature& f )
{
  unsigned char* geo = f.geometry()->asWkb();
  QGis::WkbType wkbType = f.geometry()->wkbType();
  bool success = false;
  QgsGPSObject* obj = NULL;
  const QgsAttributeMap& attrs( f.attributeMap() );
  QgsAttributeMap::const_iterator it;

  // is it a waypoint?
  if ( mFeatureType == WaypointType && geo != NULL && wkbType == QGis::WKBPoint )
  {

    // add geometry
    QgsWaypoint wpt;
    std::memcpy( &wpt.lon, geo + 5, sizeof( double ) );
    std::memcpy( &wpt.lat, geo + 13, sizeof( double ) );

    // add waypoint-specific attributes
    for ( it = attrs.begin(); it != attrs.end(); ++it )
    {
      if ( it.key() == EleAttr )
      {
        bool eleIsOK;
        double ele = it->toDouble( &eleIsOK );
        if ( eleIsOK )
          wpt.ele = ele;
      }
      else if ( it.key() == SymAttr )
      {
        wpt.sym = it->toString();
      }
    }

    QgsGPSData::WaypointIterator iter = data->addWaypoint( wpt );
    success = true;
    obj = &( *iter );
  }

  // is it a route?
  if ( mFeatureType == RouteType && geo != NULL && wkbType == QGis::WKBLineString )
  {

    QgsRoute rte;

    // reset bounds
    rte.xMin = std::numeric_limits<double>::max();
    rte.xMax = -std::numeric_limits<double>::max();
    rte.yMin = std::numeric_limits<double>::max();
    rte.yMax = -std::numeric_limits<double>::max();

    // add geometry
    int nPoints;
    std::memcpy( &nPoints, geo + 5, 4 );
    for ( int i = 0; i < nPoints; ++i )
    {
      double lat, lon;
      std::memcpy( &lon, geo + 9 + 16 * i, sizeof( double ) );
      std::memcpy( &lat, geo + 9 + 16 * i + 8, sizeof( double ) );
      QgsRoutepoint rtept;
      rtept.lat = lat;
      rtept.lon = lon;
      rte.points.push_back( rtept );
      rte.xMin = rte.xMin < lon ? rte.xMin : lon;
      rte.xMax = rte.xMax > lon ? rte.xMax : lon;
      rte.yMin = rte.yMin < lat ? rte.yMin : lat;
      rte.yMax = rte.yMax > lat ? rte.yMax : lat;
    }

    // add route-specific attributes
    for ( it = attrs.begin(); it != attrs.end(); ++it )
    {
      if ( it.key() == NumAttr )
      {
        bool numIsOK;
        long num = it->toInt( &numIsOK );
        if ( numIsOK )
          rte.number = num;
      }
    }

    QgsGPSData::RouteIterator iter = data->addRoute( rte );
    success = true;
    obj = &( *iter );
  }

  // is it a track?
  if ( mFeatureType == TrackType && geo != NULL && wkbType == QGis::WKBLineString )
  {

    QgsTrack trk;
    QgsTrackSegment trkseg;

    // reset bounds
    trk.xMin = std::numeric_limits<double>::max();
    trk.xMax = -std::numeric_limits<double>::max();
    trk.yMin = std::numeric_limits<double>::max();
    trk.yMax = -std::numeric_limits<double>::max();

    // add geometry
//.........这里部分代码省略.........