org.opengis.sld

Interface StyleVisitor

@Extension
public interface StyleVisitor

Interface that can be implemented by objects that want to perform some action on style objects. The visitor design pattern is used to avoid runtime type checking of objects that descend from a common superclass. So instead of code that looks like this, with costly instanceof checks:

 Symbol s = ... ;
 if (s instanceof LineSymbol) {
   // Do Line stuff
 }
 else if (s instanceof PointSymbol) {
   // Do Point stuff
 }
 ...
 

you can implement the SymbolVisitor interface and the object itself will invoke the appropriate method:

 class MyVisitor implements SymbolVisitor {
   public Object visit(LineSymbol symbol, Object userData) {
     // Do Line stuff
   }
   public Object visit(PointSymbol symbol, Object userData) {
     // Do Point stuff
   }
   ...
 }
 ...
 Symbol s = ... ;
 MyVisitor visitor = new MyVisitor(...);
 Object o = s.accept(visitor, myData);
 

Since:

GeoAPI 2.0

Method Summary

Modifier and Type	Method and Description
java.lang.Object	visit(ExternalGraphic externalGraphic, java.lang.Object userData)
java.lang.Object	visit(LinePlacement placement, java.lang.Object userData)
java.lang.Object	visit(LineSymbol symbol, java.lang.Object userData)
java.lang.Object	visit(Mark mark, java.lang.Object userData)
java.lang.Object	visit(PointPlacement placement, java.lang.Object userData)
java.lang.Object	visit(PointSymbol symbol, java.lang.Object userData)
java.lang.Object	visit(PolygonSymbol symbol, java.lang.Object userData)
java.lang.Object	visit(TextSymbol symbol, java.lang.Object userData)

Method Detail

visit

java.lang.Object visit(LineSymbol symbol,
                       java.lang.Object userData)

visit

java.lang.Object visit(PointSymbol symbol,
                       java.lang.Object userData)

visit

java.lang.Object visit(PolygonSymbol symbol,
                       java.lang.Object userData)

visit

java.lang.Object visit(TextSymbol symbol,
                       java.lang.Object userData)

visit

java.lang.Object visit(ExternalGraphic externalGraphic,
                       java.lang.Object userData)

visit

java.lang.Object visit(Mark mark,
                       java.lang.Object userData)

visit

java.lang.Object visit(LinePlacement placement,
                       java.lang.Object userData)

visit

java.lang.Object visit(PointPlacement placement,
                       java.lang.Object userData)