package net.sf.tacos.model;

 import java.util.Collection;

 /**

  * @author phraktle

  */

 public interface ITreeContentProvider extends IContentProvider {

     /**

      * Returns all child elements of a parent. The returned collection is not

      * modified by the viewer.

      * 

      * @param parentElement

      * @return Collection of child nodes (never null)

      */

     public Collection getChildren(Object parentElement);

     /**

      * @param parentElement

      * @return

      */

     public boolean hasChildren(Object parentElement);

     /**

      * Returns the parent of the given element, or <code>null</code> if the

      * the parent can't be determined. Revealing a specific element will not

      * work in this case.

      * 

      * @param childElement

      * @return parent or null

      */

     public Object getParent(Object childElement);

 }