/// <summary>
/// Returns the next feature at worldPos.
/// </summary>
/// <param name="worldPos"></param>
/// <param name="limit"></param>
/// <param name="outLayer"></param>
/// the layer containing the next feature; null if no next feature is found.
/// <param name="feature"></param>
/// <param name="condition"></param>
/// <returns>the next feature at worldPos, null if there is no next feature.</returns>
public IFeature GetNextFeatureAtPosition(ICoordinate worldPos, float limit, out Layer outLayer, IFeature feature,
Func <ILayer, bool> condition)
{
IEnvelope envelope = GetEnvelope(worldPos, limit);
IFeature nextFeature = null;
bool featureFound = false;
outLayer = null;
foreach (ILayer mapLayer in Map.GetAllVisibleLayers(false))
{
var vectorLayer = mapLayer as VectorLayer;
IPoint point = GeometryFactory.CreatePoint(worldPos);
if (vectorLayer == null || !vectorLayer.IsSelectable)
{
continue;
}
if ((null != condition) && (!condition(vectorLayer)))
{
continue;
}
FeatureCollection provider = vectorLayer.DataSource as FeatureCollection;
// this will skip shapefile layers
if (null != provider)
{
IList objectsAt = provider.GetFeatures(envelope);
foreach (IFeature featureAt in objectsAt)
{
// GetFeatures(envelope) uses the geometry bounds; this results in more
// geometries than we actually are interested in (especially linestrings and polygons).
double distance = featureAt.Geometry.Distance(point);
if (distance >= limit)
{
continue;
}
if (featureFound)
{
nextFeature = featureAt;
outLayer = vectorLayer;
return(nextFeature);
}
if (featureAt == feature)
{
featureFound = true;
continue;
}
if (null != nextFeature)
{
continue;
}
// If feature is last in collections objectsAt nextfeature is first
nextFeature = featureAt;
outLayer = vectorLayer;
}
}
}
return(nextFeature);
}