DomItemModel.java

package com.delcyon.capo.webapp.models;

import org.w3c.dom.Attr;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import com.delcyon.capo.xml.XPath;
import com.delcyon.capo.xml.cdom.CNodeList;

import eu.webtoolkit.jwt.ItemDataRole;
import eu.webtoolkit.jwt.Orientation;
import eu.webtoolkit.jwt.WAbstractItemModel;
import eu.webtoolkit.jwt.WModelIndex;
/**
 * 
 * @author jeremiah
 *To implement a custom model, you need to reimplement the following methods:

getIndex() and getParent() methods that allow one to navigate the model
getColumnCount() and getRowCount() to specify the top level geometry and the nested geometry at every item
getData() to return the data for an item
optionally, getHeaderData() to return row and column header data
optionally, getFlags() to indicate data options
 */
public class DomItemModel extends WAbstractItemModel
{

	public enum DomUse
	{
		NAVIGATION,
		ATTRIBUTES
	}
	private Element rootElement;
	private DomUse domUse = null;
	private String xpathFilter = "child::*";
	
	public DomItemModel(Element rootElement,DomUse domUse)
	{
		this.rootElement = rootElement;
		this.domUse = domUse;
	}
	
	private NodeList getChildNodes(Node parentNode)
	{
		if(parentNode == null)
		{
			return new CNodeList();
		}
		else if (xpathFilter != null)
		{
			try
			{
				return XPath.selectNodes(parentNode, xpathFilter);
			} catch (Exception e)
			{				
				e.printStackTrace();
			}
		}
		
		return parentNode.getChildNodes();
		
	}
	
	@Override
	public Object getHeaderData(int column, Orientation orientation, int role)
	{
		if(domUse == DomUse.ATTRIBUTES && ItemDataRole.DisplayRole == role)
		{
			if(column == 0)
			{
				return "name";
			}
			else
			{
				return "value";
			}
		}
	    else if(rootElement != null && ItemDataRole.DisplayRole == role)
	    {
	        return rootElement.getLocalName();
	    }
	    else
	    {
	        return null;
	    }
	}
	
	@Override
	public int getColumnCount(WModelIndex parent)
	{
		if (domUse == DomUse.NAVIGATION)
		{
			return 1;
		}
		else if (domUse == DomUse.ATTRIBUTES)
		{
			return 2;
		}
		else
		{
			return rootElement.getAttributes().getLength();
		}
	}

	@Override
	public int getRowCount(WModelIndex parent)
	{
		Node parentNode = null;
		if(parent == null)
		{
			parentNode = rootElement;						
		}
		else
		{
			parentNode = (Node) parent.getInternalPointer();
		}
		
		if (domUse == DomUse.ATTRIBUTES)
		{
			if(parentNode instanceof Element)
			{
				//System.out.println("row count = "+((Element)parentNode).getAttributes().getLength());
				return ((Element)parentNode).getAttributes().getLength();
			}
			else
			{
				return 0;
			}
		}
		else
		{
			
			return getChildNodes(parentNode).getLength();
		}
	}

	//this is really about what happens when given a child, trying to figure out it's parents index
	//column will ALWAYS be 0
	@Override
	public WModelIndex getParent(WModelIndex index)
	{
		Node node = (Node) index.getInternalPointer();
		if(node.getParentNode() == null)
		{
			return null;
		}
		
		if(node instanceof Attr)
		{
			node = node.getParentNode();
		}
		
		//if (node instanceof Element)
		{
			int count = -1;
			Node startNode = node.getParentNode();
			do
			{
				count++;
				startNode = startNode.getPreviousSibling();
			}while(startNode != null);
			
			return createIndex(count, 0, node.getParentNode());
		}
		//else 
	}

	@Override
	public Object getData(WModelIndex index, int role)
	{
		if (role == ItemDataRole.DisplayRole)
		{	
			if (domUse == DomUse.ATTRIBUTES)
			{
				Attr attr = (Attr) index.getInternalPointer();
				if (index.getColumn() == 0)
				{
					return attr.getLocalName();
				}
				else
				{
					return attr.getValue();
				}
			}
			else
			{
				String nodeValue = ((Node)index.getInternalPointer()).getNodeValue();

				if (nodeValue == null)
				{
					nodeValue = ((Node) index.getInternalPointer()).getLocalName();
				}
				return nodeValue;
			}
		}
		else
		{
			return null;
		}
	}

	@Override
	//we're making in index here using the our id as the ptr in create index
	public WModelIndex getIndex(int row, int column, WModelIndex parent)
	{
		if (domUse == DomUse.ATTRIBUTES)
		{
			//only put in some data if it's a valid row were looking at. It can become and invalid row if were swapping out models where the previous model has more rows than this one. 
			if(rootElement != null && row < rootElement.getAttributes().getLength())
			{
				return createIndex(row, column, rootElement.getAttributes().item(row));
			}
			else
			{
				return createIndex(row, column, null);	 
			}
		}
		else
		{
			Element parentElement = null;
			if (parent != null)
			{
				parentElement = (Element) parent.getInternalPointer();
			}
			else
			{
				parentElement = rootElement;
			}

			if (getChildNodes(parentElement).getLength() > 0)
			{
				Node childElement = getChildNodes(parentElement).item(row);
				if (column > 0)
				{
					Attr attr = (Attr) childElement.getAttributes().item(column);
					return createIndex(row, column, attr);
				}
				else
				{
					return createIndex(row, column, childElement);	
				}
			}
			return null;
		}
	}

}