com.vividsolutions.jts.geomgraph

Class Label


  • public class Label
extends Object
    A Label indicates the topological relationship of a component of a topology graph to a given Geometry. This class supports labels for relationships to two Geometrys, which is sufficient for algorithms for binary operations.

    Topology graphs support the concept of labeling nodes and edges in the graph. The label of a node or edge specifies its topological relationship to one or more geometries. (In fact, since JTS operations have only two arguments labels are required for only two geometries). A label for a node or edge has one or two elements, depending on whether the node or edge occurs in one or both of the input Geometrys. Elements contain attributes which categorize the topological location of the node or edge relative to the parent Geometry; that is, whether the node or edge is in the interior, boundary or exterior of the Geometry. Attributes have a value from the set {Interior, Boundary, Exterior}. In a node each element has a single attribute <On>. For an edge each element has a triplet of attributes <Left, On, Right>.

    It is up to the client code to associate the 0 and 1 TopologyLocations with specific geometries.

    • Constructor Summary

      Constructors

      Constructor and Description
      Label(int onLoc)
      Construct a Label with a single location for both Geometries.
      Label(int geomIndex, int onLoc)
      Construct a Label with a single location for both Geometries.
      Label(int onLoc, int leftLoc, int rightLoc)
      Construct a Label with On, Left and Right locations for both Geometries.
      Label(int geomIndex, int onLoc, int leftLoc, int rightLoc)
      Construct a Label with On, Left and Right locations for both Geometries.
      Label(Label lbl)
      Construct a Label with the same values as the argument Label.

    • Constructor Detail

      • Label

        public Label(int onLoc)
        Construct a Label with a single location for both Geometries. Initialize the locations to Null

      • Label

        public Label(int geomIndex,
             int onLoc)
        Construct a Label with a single location for both Geometries. Initialize the location for the Geometry index.

      • Label

        public Label(int onLoc,
             int leftLoc,
             int rightLoc)
        Construct a Label with On, Left and Right locations for both Geometries. Initialize the locations for both Geometries to the given values.

      • Label

        public Label(int geomIndex,
             int onLoc,
             int leftLoc,
             int rightLoc)
        Construct a Label with On, Left and Right locations for both Geometries. Initialize the locations for the given Geometry index.

      • Label

        public Label(Label lbl)
        Construct a Label with the same values as the argument Label.

    • Method Detail

      • toLineLabel

        public static Label toLineLabel(Label label)

      • flip

        public void flip()

      • getLocation

        public int getLocation(int geomIndex,
                       int posIndex)

      • getLocation

        public int getLocation(int geomIndex)

      • setLocation

        public void setLocation(int geomIndex,
                        int posIndex,
                        int location)

      • setLocation

        public void setLocation(int geomIndex,
                        int location)

      • setAllLocations

        public void setAllLocations(int geomIndex,
                            int location)

      • setAllLocationsIfNull

        public void setAllLocationsIfNull(int geomIndex,
                                  int location)

      • setAllLocationsIfNull

        public void setAllLocationsIfNull(int location)

      • merge

        public void merge(Label lbl)
        Merge this label with another one. Merging updates any null attributes of this label with the attributes from lbl

      • getGeometryCount

        public int getGeometryCount()

      • isNull

        public boolean isNull(int geomIndex)

      • isAnyNull

        public boolean isAnyNull(int geomIndex)

      • isArea

        public boolean isArea()

      • isArea

        public boolean isArea(int geomIndex)

      • isLine

        public boolean isLine(int geomIndex)

      • isEqualOnSide

        public boolean isEqualOnSide(Label lbl,
                             int side)

      • allPositionsEqual

        public boolean allPositionsEqual(int geomIndex,
                                 int loc)

      • toLine

        public void toLine(int geomIndex)
        Converts one GeometryLocation to a Line location

      • toString

        public String toString()