branchtreenode.java

Java的面向对象数据库系统的源代码

/*
 * Copyright 2001 (C) MetaStuff, Ltd. All Rights Reserved.
 * 
 * This software is open source. 
 * See the bottom of this file for the licence.
 * 
 * $Id: BranchTreeNode.java,v 1.2 2003/06/10 16:18:35 per_nyfelt Exp $
 */

package org.dom4j.swing;

import org.dom4j.Branch;
import org.dom4j.CharacterData;
import org.dom4j.Node;

import javax.swing.tree.TreeNode;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;

/** <p><code>BranchTreeNode</code> implements the Swing TreeNode interface
  * to bind dom4j XML Branch nodes (i.e. Document and Element nodes) to a Swing TreeModel.</p>
  *
  * @author <a href="mailto:[e-mail]">James Strachan</a> ([e-mail])
  * @author Jakob Jenkov
  * @version $Revision: 1.2 $ 
  */
public class BranchTreeNode extends LeafTreeNode {

    /** Stores the child tree nodes */
    protected List children;

    
    public BranchTreeNode() {
    }
    
    public BranchTreeNode(Branch xmlNode) {
        super(xmlNode);
    }
    
    public BranchTreeNode(TreeNode parent, Branch xmlNode) {
        super( parent, xmlNode );
    }
    

    // TreeNode methods
    //-------------------------------------------------------------------------                
    public Enumeration children() {
        return new Enumeration() {
            int index = -1;
            
            public boolean hasMoreElements() {
                return index + 1 < getChildCount();
            }
            
            public Object nextElement() {
                return getChildAt( ++index );
            }
        };
    }
    
    public boolean getAllowsChildren() {
        return true;
    }
    
    public TreeNode getChildAt(int childIndex) {
        return (TreeNode) getChildList().get(childIndex);
    }
    
    public int getChildCount() {
        return getChildList().size();
    }
    
    public int getIndex(TreeNode node) {
        return getChildList().indexOf(node);
    }
    
    public boolean isLeaf() {
        return getXmlBranch().nodeCount() <= 0;
    }
    
    public String toString() {
        return xmlNode.getName();
    }

    
    // Implementation methods
    //-------------------------------------------------------------------------                
    
    /** Uses Lazy Initialization pattern to create a List of children */
    protected List getChildList() {
        // for now lets just create the children once, the first time they 
        // are asked for.
        // XXXX - we may wish to detect inconsistencies here....
        if ( children == null ) {
            children = createChildList();
        }
        return children;
    }
    
    
    /** Factory method to create List of children TreeNodes */
    protected List createChildList() {
        // add attributes and content as children?
        Branch branch = getXmlBranch();
        int size = branch.nodeCount();
        List children = new ArrayList( size );
        for ( int i = 0; i < size; i++ ) {
            Node node = branch.node(i);
            
            // ignore whitespace text nodes
            if ( node instanceof CharacterData ) {
                String text = node.getText();
                if ( text == null ) {
                    continue;
                }
                text = text.trim();
                if ( text.length() <= 0 ) {
                    continue;
                }
            }
            children.add( createChildTreeNode( node ) );
        }
        return children;
    }

    /** Factory method to create child tree nodes for a given XML node type
      */
    protected TreeNode createChildTreeNode( Node xmlNode ) {
        if ( xmlNode instanceof Branch ) {
            return new BranchTreeNode( this, (Branch) xmlNode );
        }
        else { 
            return new LeafTreeNode( this, xmlNode );
        }
            
    }
    protected Branch getXmlBranch() {
        return (Branch) xmlNode;
    }
}




/*
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided
 * that the following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright
 *    statements and notices.  Redistributions must also contain a
 *    copy of this document.
 *
 * 2. Redistributions in binary form must reproduce the
 *    above copyright notice, this list of conditions and the
 *    following disclaimer in the documentation and/or other
 *    materials provided with the distribution.
 *
 * 3. The name "DOM4J" must not be used to endorse or promote
 *    products derived from this Software without prior written
 *    permission of MetaStuff, Ltd.  For written permission,
 *    please contact [e-mail].
 *
 * 4. Products derived from this Software may not be called "DOM4J"
 *    nor may "DOM4J" appear in their names without prior written
 *    permission of MetaStuff, Ltd. DOM4J is a registered
 *    trademark of MetaStuff, Ltd.
 *
 * 5. Due credit should be given to the DOM4J Project
 *    (http://dom4j.org/).
 *
 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
 * METASTUFF, LTD. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Copyright 2001 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * $Id: BranchTreeNode.java,v 1.2 2003/06/10 16:18:35 per_nyfelt Exp $
 */