/*
    * Copyright (C) 2007-2012 Argeo GmbH
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *         http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.argeo.eclipse.ui;
  
  import org.eclipse.jface.viewers.ITreeContentProvider;
  import org.eclipse.jface.viewers.Viewer;
  
  /**
   * Tree content provider dealing with tree objects and providing reasonable
   * defaults.
   */
  public abstract class AbstractTreeContentProvider implements
  		ITreeContentProvider {
  	private static final long serialVersionUID = 8246126401957763868L;
  
  	/** Does nothing */
  	public void dispose() {
  	}
  
  	/** Does nothing */
  	public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
  	}
  
  	public Object[] getChildren(Object element) {
  		if (element instanceof TreeParent) {
  			return ((TreeParent) element).getChildren();
  		}
  		return new Object[0];
  	}
  
  	public Object getParent(Object element) {
  		if (element instanceof TreeParent) {
  			return ((TreeParent) element).getParent();
  		}
  		return null;
  	}
  
  	public boolean hasChildren(Object element) {
  		if (element instanceof TreeParent) {
  			return ((TreeParent) element).hasChildren();
  		}
  		return false;
  	}
  }