Package org.geotools.api.style

Interface Symbolizer

All Known Subinterfaces:
ExtensionSymbolizer, LineSymbolizer, PointSymbolizer, PolygonSymbolizer, RasterSymbolizer, TextSymbolizer
All Known Implementing Classes:
AbstractSymbolizer, LineSymbolizerImpl, PointSymbolizerImpl, PolygonSymbolizerImpl, RasterSymbolizerImpl, TextSymbolizerImpl, VendorSymbolizerImpl
public interface Symbolizer
Abstract superclass of the symbolizers defined by the Symbology Encoding specification.

Please note you are not free to create your own subtype o Symbolizer - we are limited to LineSymbolizer, PointSymbolizer, PolygonSymbolizer, RasterSymbolizer and TextSymbolizer.

Geometry types other than inherently linear types can also be used. If a point geometry is used, it should be interpreted as a line of "epsilon" (arbitrarily small) length with a horizontal orientation centered on the point, and should be rendered with two end caps. If a polygon is used (or other "area" type), then its closed outline is used as the line string (with no end caps). If a raster geometry is used, its coverage-area outline is used for the line, rendered with no end caps.

Since:
GeoAPI 2.2
Author:
Open Geospatial Consortium, Johann Sorel (Geomatys), Chris Dillard (SYS Technologies)

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    accept(StyleVisitor visitor)
     
    Object
    accept(TraversingStyleVisitor visitor, Object extraData)
    Calls the visit method of a StyleVisitor
    Description
    getDescription()
    Returns the description of this symbolizer.
    Expression
    getGeometry()
    This defines the geometry to be used for styling.
    The property is optional and if it is absent (null) then the "default" geometry property of the feature should be used.
    Typically, features only have one geometry so, in general, the need to select one is not required.
    The expression can also build a new geometry out of existing attributes or transform an existing geometry.
    String
    getGeometryPropertyName()
    Returns the name of the geometry feature attribute to use for drawing.
    String
    getName()
    Returns a name for this symbolizer.
    Map<String,String>
    getOptions()
    Map of vendor options for the symbolizer.
    Unit<Length>
    getUnitOfMeasure()
    Returns a measure unit.
    boolean
    hasOption(String key)
    Determines if a vendor option with the specific key has been set on this symbolizer.
    void
    setDescription(Description description)
    Tile and Abstract of Symbolzer.
    void
    setGeometry(Expression geometry)
    Sets the expression used for styling.
    void
    setGeometryPropertyName(String geometryPropertyName)
    A shortcut to define the geometry expression as a PropertyName Typically, features only have one geometry so, in general, the need to select one is not required.
    void
    setName(String name)
    Name of symbolizer; not always human readable.
    void
    setUnitOfMeasure(Unit<Length> uom)
    Defines a measure unit for the symbolizer.

  • Method Details

    • getUnitOfMeasure

      Unit<Length> getUnitOfMeasure()
      Returns a measure unit. This parameter is inherited from GML. Renderers shall use the unit to correctly render symbols.

      Recommended uom definitions are :

      • metre
      • foot
      • pixel

      Returns:
      can be null. If the unit is null than we shall use a the pixel unit

    • setDescription

      void setDescription(Description description)
      Tile and Abstract of Symbolzer.
      Since:
      SymbologyEncoding 1.1

    • setName

      void setName(String name)
      Name of symbolizer; not always human readable.

      Please consider getDescription().getTitle() as an alternative if presenting this symbolizer in a user interface.

      Since:
      SymbologyEncoding 1.1

    • getGeometryPropertyName

      String getGeometryPropertyName()
      Returns the name of the geometry feature attribute to use for drawing. May return null (or Expression.NIL) if this symbol is to use the default geometry attribute, whatever it may be. Using null in this fashion is similar to a PropertyName using the XPath expression ".".

      The content of the element gives the property name in XPath syntax. In principle, a fixed geometry could be defined using GML or operators could be defined for computing the geometry from references or literals. However, using a feature property directly is by far the most commonly useful method.

      Returns:
      Geometry attribute name, or null to indicate default geometry

    • getName

      String getName()
      Returns a name for this symbolizer. This can be any string that uniquely identifies this style within a given canvas. It is not meant to be human-friendly. (The "title" property is meant to be human friendly.)
      Returns:
      a name for this style.

    • accept

      void accept(StyleVisitor visitor)

    • setUnitOfMeasure

      void setUnitOfMeasure(Unit<Length> uom)
      Defines a measure unit for the symbolizer. This parameter is inherited from GML. Renderers shall use the unit to correctly render symbols.

      Recommended uom definitions are :

      • metre
      • foot
      • pixel

      Parameters:
      uom - can be null, which indicates usage of the pixel unit.
      Since:
      SymbologyEncoding 1.1

    • getDescription

      Description getDescription()
      Returns the description of this symbolizer.
      Returns:
      Description with usual informations used for user interfaces.

    • accept

      Object accept(TraversingStyleVisitor visitor, Object extraData)
      Calls the visit method of a StyleVisitor
      Parameters:
      visitor - the style visitor
      Returns:
      value produced

    • setGeometryPropertyName

      void setGeometryPropertyName(String geometryPropertyName)
      A shortcut to define the geometry expression as a PropertyName Typically, features only have one geometry so, in general, the need to select one is not required. Note: this moves a little away from the SLD spec which provides an XPath reference to a Geometry object, but does follow it in spirit.

    • getGeometry

      Expression getGeometry()
      This defines the geometry to be used for styling.
      The property is optional and if it is absent (null) then the "default" geometry property of the feature should be used.
      Typically, features only have one geometry so, in general, the need to select one is not required.
      The expression can also build a new geometry out of existing attributes or transform an existing geometry. For geometry transformations that do change the geometry locations or that make up geometries out of non geometric attributes it is advised that the Expression implements the SpatialTransformationFunction interface

    • setGeometry

      void setGeometry(Expression geometry)
      Sets the expression used for styling. See getGeometry() for further details.

    • hasOption

      boolean hasOption(String key)
      Determines if a vendor option with the specific key has been set on this symbolizer.

    • getOptions

      Map<String,String> getOptions()
      Map of vendor options for the symbolizer.

      Client code looking for the existence of a single option should use hasOption(String)