f@0: /*  
f@0:  CCmI Editor - A Collaborative Cross-Modal Diagram Editing Tool
f@0:   
f@0:  Copyright (C) 2011  Queen Mary University of London (http://ccmi.eecs.qmul.ac.uk/)
f@0: 
f@0:  This program is free software: you can redistribute it and/or modify
f@0:  it under the terms of the GNU General Public License as published by
f@0:  the Free Software Foundation, either version 3 of the License, or
f@0:  (at your option) any later version.
f@0: 
f@0:  This program is distributed in the hope that it will be useful,
f@0:  but WITHOUT ANY WARRANTY; without even the implied warranty of
f@0:  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
f@0:  GNU General Public License for more details.
f@0: 
f@0:  You should have received a copy of the GNU General Public License
f@0:  along with this program.  If not, see <http://www.gnu.org/licenses/>.
f@0: */
f@0: package uk.ac.qmul.eecs.ccmi.checkboxtree;
f@0: 
f@0: import java.awt.event.MouseAdapter;
f@0: import java.awt.event.MouseEvent;
f@0: import java.io.IOException;
f@0: import java.io.InputStream;
f@0: import java.util.Enumeration;
f@0: 
f@0: import javax.swing.JTree;
f@0: import javax.swing.tree.DefaultMutableTreeNode;
f@0: import javax.swing.tree.DefaultTreeModel;
f@0: import javax.swing.tree.TreePath;
f@0: import javax.xml.parsers.ParserConfigurationException;
f@0: import javax.xml.parsers.SAXParser;
f@0: import javax.xml.parsers.SAXParserFactory;
f@0: 
f@0: import org.xml.sax.SAXException;
f@0: 
f@0: 
f@0: /**
f@0:  * A JTree containing {@code CheckBoxTreeNode} nodes. The tree is built according to an XML file
f@0:  * passed as argument to the constructor.
f@0:  * The XML file hierarchical structure reflects the structure of the tree. XML tag name can be 
f@0:  * either {@code selectable} or {@code unselectable}. The former representing tree nodes with a check
f@0:  * box associated to it, and the latter a normal tree node, much as a {@link DefaultMutableTreeNode}. 
f@0:  * Either tags must have an attribute {@code value}, representing the name of the node which will be displayed
f@0:  * in the tree. Here is an example of a simple XML file, representing a tree with the tree root (non selectable) having
f@0:  * three children, the first of which has, in turn, a child. all the descendants of the root are selectable, but the 
f@0:  * first child.   
f@0:  *    
f@0:  * <pre>
f@0:  * {@code
f@0:  * 	<?xml version="1.0" encoding="utf-8"?>
f@0:  *  <unselectable value="root">
f@0:  *   <unselectable value="first child"/>
f@0:  *   <selectable value="second child"/>
f@0:  *   <selectable value "third child">
f@0:  *     <selectable value="grand child"/>
f@0:  *   </selectable>
f@0:  *  </unselectable>
f@0:  * }
f@0:  * </pre>   
f@0:  * 
f@0:  * @see CheckBoxTreeNode 
f@0:  */
f@0: @SuppressWarnings("serial")
f@0: public class CheckBoxTree extends JTree {
f@0: 	public CheckBoxTree(InputStream stream, SetProperties values){
f@0: 		super(new DefaultTreeModel(new DefaultMutableTreeNode()));
f@0: 		this.properties = values;
f@0: 		getAccessibleContext().setAccessibleName("tree");
f@0: 		treeModel =  (DefaultTreeModel)getModel();
f@0: 		setCellRenderer(new CheckBoxTreeCellRenderer());
f@0: 		buildTree(stream);
f@0: 		/* mouse listener to toggle the selected tree node */
f@0: 		addMouseListener(new MouseAdapter(){
f@0: 			@Override
f@0: 			public void mousePressed(MouseEvent e){
f@0: 				TreePath path = getPathForLocation(e.getX(),e.getY());
f@0: 				if(path == null)
f@0: 					return;
f@0: 				CheckBoxTreeNode treeNode = (CheckBoxTreeNode)path.getLastPathComponent();
f@0: 				toggleSelection(treeNode);
f@0: 			}
f@0: 		});
f@0: 	}
f@0: 	
f@0: 	/**
f@0: 	 * Builds a CheckBoxTree out of an xml file passed as argument. All the nodes 
f@0: 	 * of the tree are marked unchecked. 
f@0: 	 * 
f@0: 	 * @param stream an input stream to an xml file
f@0: 	 */
f@0: 	public CheckBoxTree(InputStream stream){
f@0: 		this(stream,null);
f@0: 	}
f@0: 	
f@0: 	/* use a sax parser to build the tree, if an error occurs during the parsing it just stops */
f@0: 	private void buildTree(InputStream stream){
f@0: 		SAXParserFactory factory = SAXParserFactory.newInstance();
f@0: 		try {
f@0: 			SAXParser saxParser = factory.newSAXParser();
f@0: 			XMLHandler handler = new XMLHandler((DefaultTreeModel)getModel(),properties);
f@0: 			saxParser.parse(stream, handler);
f@0: 		} catch (IOException e) {
f@0: 			e.printStackTrace();
f@0: 			return;
f@0: 		} catch (ParserConfigurationException e) {
f@0: 			e.printStackTrace();
f@0: 			return;
f@0: 		} catch (SAXException e) {
f@0: 			e.printStackTrace();
f@0: 			return;
f@0: 		}
f@0: 	}
f@0: 	
f@0: 	/**
f@0: 	 * Returns a reference to the properties holding which nodes of the tree are currently checked.  
f@0: 	 * @return the properties or {@code null} if the constructor with no properties was used. 
f@0: 	 */
f@0: 	public SetProperties getProperties(){
f@0: 		return properties;
f@0: 	}
f@0: 	
f@0: 	/**
f@0: 	 * Toggle the check box of the tree node passed as argument. If the tree node 
f@0: 	 * is not a leaf, then all its descendants will get the new value it. That is, 
f@0: 	 * if the tree node becomes selected as a result of the call, then all the descendants 
f@0: 	 * will become in turn selected (regardless of their previous state). If it becomes
f@0: 	 * unselected, the descendants will become unselected as well.   
f@0: 	 * 
f@0: 	 * @param treeNode the tree node to toggle
f@0: 	 */
f@0: 	public void toggleSelection(CheckBoxTreeNode treeNode){
f@0: 		if(treeNode.isSelectable()){
f@0: 			boolean selection = !treeNode.isSelected();
f@0: 			treeNode.setSelected(selection);
f@0: 			if(selection)
f@0: 				properties.add(treeNode.getPathAsString());
f@0: 			else
f@0: 				properties.remove(treeNode.getPathAsString());
f@0: 			treeModel.nodeChanged(treeNode);
f@0: 			if(!treeNode.isLeaf()){
f@0: 				for( @SuppressWarnings("unchecked")
f@0: 					Enumeration<CheckBoxTreeNode> enumeration = treeNode.depthFirstEnumeration(); enumeration.hasMoreElements();){
f@0: 					CheckBoxTreeNode t = enumeration.nextElement();
f@0: 					t.setSelected(selection);
f@0: 					if(selection)
f@0: 						properties.add(t.getPathAsString());
f@0: 					else
f@0: 						properties.remove(t.getPathAsString());
f@0: 					treeModel.nodeChanged(t);
f@0: 				}
f@0: 			}
f@0: 		}
f@0: 	}
f@0: 	
f@0: 	private SetProperties properties;
f@0: 	private DefaultTreeModel treeModel; 
f@0: }