java - How to decorate a TableCellRenderer with Graphics related instructions? -

i'm implemting tablecellrenderers using decorator design-pattern. works nice , long need decorate returned component decorated renderer in such manner can performed inside scope of gettablecellrenderercomponent(..).
how can decorate returned component such cases need graphics object in paint process? in particular - inside paintcomponent(graphics g) method?
example, when want draw line simple setborder(..) not suffice:

import java.awt.color; import java.awt.component;  import javax.swing.jtable; import javax.swing.table.tablecellrenderer; import javax.swing.table.defaulttablecellrenderer;   public class mytablecellrendererdecorator extends defaulttablecellrenderer {      private tablecellrenderer decoratedrenderer;     private component decoratedcomponent;      public mytablecellrendererdecorator(tablecellrenderer decoratedrenderer) {         super();         this.decoratedrenderer = decoratedrenderer;     }      @override     public component gettablecellrenderercomponent(jtable table, object value,             boolean isselected, boolean hasfocus, int row, int column) {          this.decoratedcomponent = decoratedrenderer.gettablecellrenderercomponent(table, value,             isselected, hasfocus, row, column);          //an example decoration works fine         decoratedcomponent.setbackground(color.red);          return decoratedcomponent;     }      /**      * code not executed, because paint called on returned component      * gettablecellrenderercomponent() , not on jlabel in renderer subclasses.      */     @override     public void paintcomponent(graphics g) {         decoratedcomponent.paint(g);         //an example needed decoration in paintcomponent()         rectangle bounds = g.getclipbounds();         g.setcolor(color.blue);         g.drawline(0, 0, bounds.width, bounds.height);     } } 

i had 2 different solutions in mind:
1. introduce interface called decoratedtablecellrenderer:

import javax.swing.table.tablecellrenderer;  public interface decoratedtablecellrenderer extends tablecellrenderer {      public void setpostpaintcomponentrunnable(runnable postpaintcomponentrunnable); } 

so mytablecellrendererdecorator receive decoratedtablecellrenderer in constructor instead of simple tablecellrenderer, , responsability decorating inside paintcomponent moves decorated class. if assume renderer jcomponent paints itself, can done overriding paintcomponent(..) , applying postpaintcomponentrunnable.run() after own paint code.
but, if want support such decoration renderers apply on tablecellrenderer in may not able modify?
2. using java's reflection , dynamic proxy instantiate new componentui delegate decoratedcomponent, perform each method original componentui object, decorated version of paint(graphics g, jcomponent c).
keep decoration responsibilty in decorating class, dynamic proxies hard read , maintain in perspective, happy if find more elegant idea.

as turns out, original sample code gave close correct because, in fact, returned component this. is, gettablecellrenderercomponent returns defaulttablecellrenderer called on, overridden methods in subclass of defaulttablecellrenderer called during painting of component.

here's code defaulttablecellrenderer shows i'm talking about:

public component gettablecellrenderercomponent(jtable table, object value,                       boolean isselected, boolean hasfocus, int row, int column) {     //...     return this; } 

therefore, if override paint(graphics gfx) method , call super classes gettablecellrenderercomponent able draw whatever want in cell.

so gettablecellrenderercomponent should read this:

@override public component gettablecellrenderercomponent(jtable table, object value,         boolean isselected, boolean hasfocus, int row, int column) {      jlabel component = super.gettablecellrenderercomponent(table, value,         isselected, hasfocus, row, column);      //an example decoration works fine     component.setbackground(color.red);      return component; } 

and use paint method in subclass of defaulttablecellrenderer instead of paintcomponent this:

/**  * code executed.  */ @override public void paint(graphics g) {     super.paint(g);     //an example needed decoration in paintcomponent()     rectangle bounds = g.getclipbounds();     g.setcolor(color.blue);     g.drawline(0, 0, bounds.width, bounds.height); }