Class ObservablePolylineUtil

java.lang.Object
com.luciad.geometries.observable.ObservablePolylineUtil

public final class ObservablePolylineUtil extends Object
This class provides utility methods for Observable instance for Polyline.
  • Method Details Link icon

    • derivePointAtIndex Link icon

      @NotNull public static Observable<@Nullable Point> derivePointAtIndex(@NotNull Observable<@Nullable Polyline> observablePolyline, long index)
      Derives an Observable Point from the given observable polyline that represents the point at the given index.

      This observable point will be updated when the given observable polyline changes.

      Notes:

      • When the observable polyline contains a null value, the observable point instance will contain a null value too.
      • When the given index >= point count, the observable point instance will contain a null value.
      • Observable#setValue will throw an exception for derived instances.
      Parameters:
      observablePolyline - an observable polyline from which to derive the point
      index - the point index
      Returns:
      a derived Observable
    • derivePointAtStart Link icon

      @NotNull public static Observable<@Nullable Point> derivePointAtStart(@NotNull Observable<@Nullable Polyline> observablePolyline)
      Derives an Observable Point from the given observable polyline that represents the start point.

      This observable point will be updated when the given observable polyline changes.

      Notes:

      • When the observable polyline contains a null value, the observable point instance will contain a null value too.
      • Observable#setValue will throw an exception for derived instances.
      Parameters:
      observablePolyline - an observable polyline from which to derive the point
      Returns:
      a derived Observable
    • derivePointAtEnd Link icon

      @NotNull public static Observable<@Nullable Point> derivePointAtEnd(@NotNull Observable<@Nullable Polyline> observablePolyline)
      Derives an Observable Point from the given observable polyline that represents the end point of the polyline (regardless of the point count).

      This observable point will be updated when the given observable polyline changes.

      Notes:

      • When the observable polyline contains a null value, the observable point instance will contain a null value too.
      • Observable#setValue will throw an exception for derived instances.
      Parameters:
      observablePolyline - an observable polyline from which to derive the point
      Returns:
      a derived Observable
    • derivePointOnSegment Link icon

      @NotNull public static Observable<@Nullable Point> derivePointOnSegment(@NotNull Observable<@Nullable Polyline> observablePolyline, long segmentIndex, double parameter)
      Derives an Observable Point from the given observable polyline that represents a point on a segment of the polyline.

      This observable point will be updated when the given observable polyline changes.

      Notes:

      • When the observable polyline contains a null value, the observable point instance will contain a null value too.
      • When the given segmentIndex >= point count - 1, the observable point instance will contain a null value.
      • Observable#setValue will throw an exception for derived instances.
      Parameters:
      observablePolyline - an observable polyline from which to derive the point
      segmentIndex - a segment index: a value between [0, pointCount - 2]. For example: segment index 0 corresponds with the segment between the points with index 0 and 1.
      parameter - a parameter value between [0, 1] that determines which point of the segment is chosen. This can for example be 0.5, to get the middle of the segment
      Returns:
      a derived Observable