Package org.geotools.geometry

Class Position2D

  • All Implemented Interfaces:
    Serializable, Cloneable, Position, Cloneable
    public class Position2D
extends Point2D.Double
implements Position, Serializable, Cloneable
    Holds the coordinates for a two-dimensional position within some coordinate reference system.

    Note 1:

    This class inherits x and y fields. But despite their names, they don't need to be oriented toward East and North. The (x,y) axis can have any orientation and should be understood as "ordinate 0" and "ordinate 1" values instead. This is not specific to this implementation; in Java2D too, the visual axis orientation depend on the affine transform in the graphics context.

    The rational for avoiding axis orientation restriction is that other Position implementation do not have such restriction, and it would be hard to generalize (what to do with North-East direction?).

    Note 2:

    Do not mix instances of this class with ordinary Point2D instances in a HashSet or as HashMap keys. It is not possible to meet both Point2D.hashCode() and Position.hashCode() contract, and this class choose to implements the later. Concequently, hashCode() is inconsistent with Point2D.equals(java.lang.Object) (but is consistent with Position.equals(java.lang.Object)).

    In other words, it is safe to add instances of DirectPosition2D in a HashSet<DirectPosition>, but it is unsafe to add them in a HashSet<Point2D>. Collections that do not rely on Object.hashCode(), like ArrayList, are safe in all cases.

    Since:
    2.0
    Author:
    Martin Desruisseaux (IRD)
    See Also:
    Position1D, GeneralPosition, Point2D, Serialized Form

    • Nested Class Summary

      • Nested classes/interfaces inherited from class Point2D

        Point2D.Double, Point2D.Float

    • Field Summary

      • Fields inherited from class Point2D.Double

        x, y

    • Constructor Summary

      Constructors 
      Constructor Description
      Position2D()
      Constructs a position initialized to (0,0) with a null coordinate reference system.
      Position2D​(double x, double y)
      Constructs a 2D position from the specified ordinates.
      Position2D​(Point2D point)
      Constructs a position from the specified Point2D.
      Position2D​(Position point)
      Constructs a position initialized to the same values than the specified point.
      Position2D​(CoordinateReferenceSystem crs)
      Constructs a position with the specified coordinate reference system.
      Position2D​(CoordinateReferenceSystem crs, double x, double y)
      Constructs a 2D position from the specified ordinates in the specified CRS.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      Position2D clone()
      Returns a clone of this point.
      boolean equals​(Object object)
      Compares this point with the specified object for equality.
      double[] getCoordinate()
      Returns a sequence of numbers that hold the coordinate of this position in its reference system.
      CoordinateReferenceSystem getCoordinateReferenceSystem()
      Returns the coordinate reference system in which the coordinate is given.
      int getDimension()
      The length of coordinate sequence (the number of entries).
      Position getDirectPosition()
      Returns always this, the direct position for this position.
      double getOrdinate​(int dimension)
      Returns the ordinate at the specified dimension.
      int hashCode()
      Returns a hash value for this coordinate.
      void setCoordinateReferenceSystem​(CoordinateReferenceSystem crs)
      Set the coordinate reference system in which the coordinate is given.
      void setLocation​(Position position)
      Set this coordinate to the specified direct position.
      void setOrdinate​(int dimension, double value)
      Sets the ordinate value along the specified dimension.
      Point2D toPoint2D()
      Returns a Point2D with the same coordinate as this direct position.
      String toString()
      Returns a string representation of this coordinate.

      • Methods inherited from class Point2D.Double

        getX, getY, setLocation

      • Methods inherited from class Point2D

        distance, distance, distance, distanceSq, distanceSq, distanceSq, setLocation

      • Methods inherited from class Object

        finalize, getClass, notify, notifyAll, wait, wait, wait

    • Constructor Detail

      • Position2D

        public Position2D()
        Constructs a position initialized to (0,0) with a null coordinate reference system.

      • Position2D

        public Position2D​(CoordinateReferenceSystem crs)
        Constructs a position with the specified coordinate reference system.
        Parameters:
        crs - The coordinate reference system, or null.

      • Position2D

        public Position2D​(double x,
                  double y)
        Constructs a 2D position from the specified ordinates. Despite their name, the (x,y) coordinates don't need to be oriented toward (East, North). Those parameter names simply match the x and y fields. See the class javadoc for details.
        Parameters:
        x - The x value.
        y - The y value.

      • Position2D

        public Position2D​(CoordinateReferenceSystem crs,
                  double x,
                  double y)
        Constructs a 2D position from the specified ordinates in the specified CRS. Despite their name, the (x,y) coordinates don't need to be oriented toward (East, North). Those parameter names simply match the x and y fields. The actual axis orientations are determined by the specified CRS. See the class javadoc for details.
        Parameters:
        crs - The coordinate reference system, or null.
        x - The x value.
        y - The y value.

      • Position2D

        public Position2D​(Point2D point)
        Constructs a position from the specified Point2D.
        Parameters:
        point - The point to copy.

      • Position2D

        public Position2D​(Position point)
        Constructs a position initialized to the same values than the specified point.
        Parameters:
        point - The point to copy.

    • Method Detail

      • getDirectPosition

        public Position getDirectPosition()
        Returns always this, the direct position for this position.
        Specified by:
        getDirectPosition in interface Position
        Returns:
        The direct position (may be this).
        Since:
        2.5

      • setCoordinateReferenceSystem

        public void setCoordinateReferenceSystem​(CoordinateReferenceSystem crs)
        Set the coordinate reference system in which the coordinate is given.
        Parameters:
        crs - The new coordinate reference system, or null.

      • getDimension

        public final int getDimension()
        The length of coordinate sequence (the number of entries). This is always 2 for DirectPosition2D objects.
        Specified by:
        getDimension in interface Position
        Returns:
        The dimensionality of this position.

      • getCoordinate

        public double[] getCoordinate()
        Returns a sequence of numbers that hold the coordinate of this position in its reference system.
        Specified by:
        getCoordinate in interface Position
        Returns:
        The coordinates

      • getOrdinate

        public final double getOrdinate​(int dimension)
                         throws IndexOutOfBoundsException
        Returns the ordinate at the specified dimension.
        Specified by:
        getOrdinate in interface Position
        Parameters:
        dimension - The dimension in the range 0 to 1 inclusive.
        Returns:
        The coordinate at the specified dimension.
        Throws:
        IndexOutOfBoundsException - if the specified dimension is out of bounds.

      • setOrdinate

        public final void setOrdinate​(int dimension,
                              double value)
                       throws IndexOutOfBoundsException
        Sets the ordinate value along the specified dimension.
        Specified by:
        setOrdinate in interface Position
        Parameters:
        dimension - the dimension for the ordinate of interest.
        value - the ordinate value of interest.
        Throws:
        IndexOutOfBoundsException - if the specified dimension is out of bounds.

      • toPoint2D

        public Point2D toPoint2D()
        Returns a Point2D with the same coordinate as this direct position.
        Returns:
        This position as a point.

      • toString

        public String toString()
        Returns a string representation of this coordinate. The default implementation formats this coordinate using a shared instance of CoordinateFormat. This is okay for occasional formatting (for example for debugging purpose). But if there is a lot of positions to format, users will get better performance and more control by using their own instance of CoordinateFormat.
        Overrides:
        toString in class Point2D.Double

      • hashCode

        public int hashCode()
        Returns a hash value for this coordinate. This method implements the Position.hashCode() contract, not the Point2D.hashCode() contract.
        Specified by:
        hashCode in interface Position
        Overrides:
        hashCode in class Point2D
        Returns:
        A hash code value for this position.

      • equals

        public boolean equals​(Object object)
        Compares this point with the specified object for equality. If the given object implements the Position interface, then the comparaison is performed as specified in its Position.equals(java.lang.Object) contract. Otherwise the comparaison is performed as specified in Point2D.equals(java.lang.Object).
        Specified by:
        equals in interface Position
        Overrides:
        equals in class Point2D
        Parameters:
        object - The object to compare with this position.
        Returns:
        true if the given object is equals to this position.

      • clone

        public Position2D clone()
        Returns a clone of this point.
        Specified by:
        clone in interface Cloneable
        Overrides:
        clone in class Point2D
        Returns:
        A clone of this position.
        See Also:
        Object.clone()