EDIT

package eu.etaxonomy.taxeditor.prototype2.view.propertysheetsupport;

import java.util.TreeMap;

import org.eclipse.core.databinding.DataBindingContext;

import org.eclipse.core.databinding.UpdateValueStrategy;

import org.eclipse.core.databinding.observable.value.IObservableValue;

import org.eclipse.core.runtime.Assert;

import org.eclipse.jface.databinding.swt.SWTObservables;

import org.eclipse.jface.viewers.CellEditor;

import org.eclipse.jface.viewers.EditingSupport;

import org.eclipse.jface.viewers.TextCellEditor;

import org.eclipse.jface.viewers.ViewerCell;

import org.eclipse.swt.SWT;

import eu.etaxonomy.taxeditor.prototype2.model.PropertySheetNode;

import eu.etaxonomy.taxeditor.prototype2.view.PropertySheetViewer;

public class PropertySheetValueEditingSupport extends EditingSupport {

	private TreeMap<String,CellEditor> cellEditors;

	private PropertySheetViewer viewer;

	private DataBindingContext bindingContext;

	public PropertySheetValueEditingSupport(PropertySheetViewer viewer) {

		super(viewer);

		this.viewer = viewer;

		this.bindingContext = viewer.getBindingContext();

		this.cellEditors = new TreeMap<String, CellEditor>();

	}		

	protected boolean canEdit(Object element) {

		return ((PropertySheetNode) element).isEditable();

	}

	protected CellEditor getCellEditor(Object element) {

		String elementString = element.toString();

		if (cellEditors.get(elementString) == null)

			cellEditors.put(elementString, new TextCellEditor(viewer.getTree()));

		return cellEditors.get(elementString);

	}

	protected Object getValue(Object element) {

		return (PropertySheetNode) element;

	}

	protected void setValue(Object element, Object value) {

		((PropertySheetNode) element).setPropertyValue(value.toString());

		this.getViewer().update(element, null);

	}

	protected void initializeCellEditorValue(CellEditor cellEditor, ViewerCell cell) {

		PropertySheetNode node = (PropertySheetNode) getValue(cell.getElement());

		// an empty string instead of a null makes the field editable

		cellEditor.setValue(node.getPropertyValue() == null ? "" : node.getPropertyValue());

		// if node element is observing a value, bind it to its TreeItem

		IObservableValue observeNodeValue = node.getObserveValue();

		if (observeNodeValue != null) {

	        Assert.isNotNull(bindingContext,

            	"Editing support: PropertySheetViewer's binding context must be explicitly set.");

			IObservableValue observeCellValue = SWTObservables.observeText(cellEditor.getControl(), SWT.Modify);

			bindingContext.bindValue(observeNodeValue, observeCellValue,

					new UpdateValueStrategy(UpdateValueStrategy.POLICY_CONVERT), null);

		}

	}		

}