jsf/plugins/org.eclipse.jst.pagedesigner/src/org/eclipse/jst/pagedesigner/utils/SelectionHelper.java - jsf/webtools.jsf - Git at Google

 /*******************************************************************************
  * Copyright (c) 2006 Sybase, Inc. and others.
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *     Sybase, Inc. - initial API and implementation
  *******************************************************************************/
 package org.eclipse.jst.pagedesigner.utils;

 import java.util.ArrayList;
 import java.util.List;

 import org.eclipse.gef.EditPart;
 import org.eclipse.jface.text.ITextSelection;
 import org.eclipse.jface.text.TextSelection;
 import org.eclipse.jface.viewers.ISelection;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.jface.viewers.StructuredSelection;
 import org.eclipse.jst.jsf.core.internal.tld.CMUtil;
 import org.eclipse.jst.pagedesigner.dom.DOMPosition;
 import org.eclipse.jst.pagedesigner.dom.DOMPositionHelper;
 import org.eclipse.jst.pagedesigner.dom.DOMRefPosition;
 import org.eclipse.jst.pagedesigner.dom.DOMRefPosition2;
 import org.eclipse.jst.pagedesigner.dom.DOMUtil;
 import org.eclipse.jst.pagedesigner.dom.EditValidateUtil;
 import org.eclipse.jst.pagedesigner.dom.IDOMPosition;
 import org.eclipse.jst.pagedesigner.parts.NodeEditPart;
 import org.eclipse.jst.pagedesigner.viewer.DesignPosition;
 import org.eclipse.jst.pagedesigner.viewer.DesignRange;
 import org.eclipse.jst.pagedesigner.viewer.IHTMLGraphicalViewer;
 import org.eclipse.wst.sse.core.internal.provisional.IStructuredModel;
 import org.eclipse.wst.sse.core.internal.provisional.IndexedRegion;
 import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocumentRegion;
 import org.eclipse.wst.xml.core.internal.contentmodel.CMElementDeclaration;
 import org.eclipse.wst.xml.core.internal.provisional.document.IDOMModel;
 import org.eclipse.wst.xml.core.internal.provisional.document.IDOMNode;
 import org.eclipse.wst.xml.core.internal.regions.DOMRegionContext;
 import org.w3c.dom.CharacterData;
 import org.w3c.dom.Element;
 import org.w3c.dom.Node;
 import org.w3c.dom.Text;

 /**
  * @author mengbo
  * @version 1.5
  */
 public class SelectionHelper {
 	/**
 	 * convert the text selection to a Node. Will use the start offset of the
 	 * text selection.
 	 *
 	 * @param model
 	 * @param textSel
 	 * @return
 	 */
 	public static Node toNode(IStructuredModel model, ITextSelection textSel) {
 		// FIXME: currently always normalize to a single node. should also
 		// consider change into DesignRange
 		// on text selection, find the appropriate Node
 		Object inode = model.getIndexedRegion(textSel.getOffset());
 		if (inode instanceof Node) {
 			return (Node) inode;
 		}
         return null;
 	}

 	/**
 	 * convert a structured selection of NodeEditPart or Node into the first
 	 * node.
 	 *
 	 * @param selection
 	 * @return
 	 */
 	public static Node toNode(IStructuredSelection selection) {
 		if (selection.isEmpty()) {
 			return null;
 		}
 		Object first = selection.getFirstElement();
 		if (first instanceof Node) {
 			return (Node) first;
 		} else if (first instanceof NodeEditPart) {
 			return ((NodeEditPart) first).getIDOMNode();
 		} else {
 			return null;
 		}
 	}

 	/**
 	 * convert a DesignRange into a single node.
 	 *
 	 * @param range
 	 * @return
 	 */
 	public static Node toNode(DesignRange range) {
 		if (range.isValid()) {
 			Node node1 = range.getStartPosition().getContainerNode();
 			Node node2 = range.getEndPosition().getContainerNode();
 			return DOMUtil.findCommonAncester(node1, node2);
 		}
         return null;
 	}

 	/**
 	 * @param model
 	 * @param region
 	 *            if null, then will calculate it using offset.
 	 * @param offset
 	 *            offset in source.
 	 * @return
 	 */
 	public static IDOMPosition toDOMPosition(IDOMModel model,
 			IndexedRegion region, int offset) {
 		if (region == null) {
 			region = model.getIndexedRegion(offset);
 		}
 		if (region == null && offset > 0) {
 			// in case this is at end of file.
 			offset = offset - 1;
 			region = model.getIndexedRegion(offset);
 			if (region != null) {
 				if (region.getEndOffset() >= offset + 1) {
 					offset += 1; // restore offset.
 				}
 			}
 		}
 		if (region == null) {
 			return new DOMPosition(model.getDocument(), 0);
 		}
 		IDOMNode node = (IDOMNode) region;
 		int start = node.getStartOffset();
 		if (offset <= start) {
 			return new DOMRefPosition(node, false);
 		}
 		int end = node.getEndOffset();
 		if (offset >= end) {
 			return new DOMRefPosition(node, true);
 		}
 		if (node instanceof CharacterData) {
 			String data = ((CharacterData) node).getData();
 			String source = node.getSource();
 			if (data.equals(source)) {
 				return new DOMPosition(node, offset - start);
 			}
 			IStructuredDocumentRegion r = node
 					.getFirstStructuredDocumentRegion();
 			int countedData = 0;
 			// TODO: dead? int offsetInNode = offset - start;
 			while (r != null) {
 				if (DOMRegionContext.XML_CHAR_REFERENCE.equals(r.getType())
 						|| DOMRegionContext.XML_ENTITY_REFERENCE.equals(r
 								.getType())) {
 					countedData += 1; // FIXME: what if the entity reference's
 					// corresponding data is more than 1
 					// char?
 					// where can we get that information?
 					if (r.getEnd() >= offset) {
 						return new DOMPosition(node, countedData);
 					}
 				} else {
 					if (r.getEnd() >= offset) {
 						return new DOMPosition(node, countedData + offset
 								- r.getStart());
 					}
 					countedData += r.getLength();
 				}
 				r = r.getNext();
 			}
 			return new DOMRefPosition(node, true);
 		} else if (node instanceof Element) {
 			CMElementDeclaration cm = CMUtil
 					.getElementDeclaration((Element) node);
 			if (cm != null && cm.getContentType() == CMElementDeclaration.EMPTY) {
 				// this node can't have children.
 				return new DOMRefPosition(node, true);
 			}
 			IStructuredDocumentRegion startRegion = node
 					.getStartStructuredDocumentRegion();
 			if (startRegion == null) {
 				return new DOMRefPosition(node, true);
 			}
             int startRegionEnd = node.getStartStructuredDocumentRegion()
             		.getEnd();
             if (offset <= startRegionEnd) {
             	// it is in the start tag region. So put position at first
             	// child position.
             	return new DOMRefPosition2(node, false);
             }
             return new DOMRefPosition2(node, true);
 		} else {
 			return new DOMRefPosition(node, true);
 		}
 		// XXX: the implementation in EditModelQuery seemed to be very complex.
 		// Need revisit that
 		// and refactor the implementation to this class later. (lium)
 	}

 	/**
 	 * Give a text selection with offset and length, convert it into a Designer
 	 * selection (IStrucuturedSelection of editpart or DesignerRange). If the
 	 * text selection include just a single element node, we'll create a
 	 * IStructuredSelection, otherwise we'll create a DesignerRange.
 	 *
 	 * @param graphicViewer
 	 * @param offset
 	 * @param length
 	 */
 	public static ISelection convertToDesignerSelection(
 			IHTMLGraphicalViewer graphicViewer, int offset, int length) {
 		IDOMModel model = graphicViewer.getModel();
 		IndexedRegion region1 = model.getIndexedRegion(offset);
 		IndexedRegion region2 = model.getIndexedRegion(offset + length);
 		IDOMNode node1 = (IDOMNode) region1;

 		if (node1 == null) {
 			IDOMPosition endOfDoc = new DOMRefPosition2(model.getDocument(),
 					true);
 			DesignPosition p = DOMPositionHelper.toDesignPosition(endOfDoc);
 			return new DesignRange(p, p);
 		}

 		if ((region1 == region2 || node1.getEndOffset() == offset + length)
 				&& !(node1 instanceof Text)) {
 			// ok, we selected a single node.
 			EditPart part = (EditPart) node1.getAdapterFor(EditPart.class);
 			if (part != null) {
 				return new StructuredSelection(part);
 			}
 		}

 		// when we reach here, we'll create a DesignerRange
 		IDOMPosition position1 = toDOMPosition(model, region1, offset);
 		IDOMPosition position2 = (length == 0 ? position1 : toDOMPosition(
 				model, region2, offset + length));

 		if (position1 == null || position2 == null) {
 			return new DesignRange(null, null);
 		}
 		DesignPosition p1 = DOMPositionHelper.toDesignPosition(position1);
 		DesignPosition p2 = (length == 0 ? p1 : DOMPositionHelper
 				.toDesignPosition(position2));
 		if (p1 == null || p2 == null) {
 			return new DesignRange(null, null);
 		}

 		return new DesignRange(p1, p2);

 	}

 	/**
 	 * convert a IDOMPosition into index in the source.
 	 *
 	 * @param p
 	 * @return
 	 */
 	private static int getIndexedRegionLocation(IDOMPosition p) {
 		if (!EditValidateUtil.validPosition(p)) {
 			return 0;
 		}

 		IDOMNode parent = (IDOMNode) p.getContainerNode();
 		if (p.isText()) {
 			String text = ((CharacterData) parent).getData();
 			String source = parent.getSource();
 			if (text.length() == source.length()) {
 				// no entity reference.
 				return parent.getStartOffset() + p.getOffset();
 			}
 			// CR404708. Need to handle entity reference in the text.
 			int offset = p.getOffset();
 			int counted = 0;
 			IStructuredDocumentRegion r = parent
 					.getFirstStructuredDocumentRegion();
 			while (r != null && counted < offset) {
 				if (DOMRegionContext.XML_CHAR_REFERENCE.equals(r.getType())
 						|| DOMRegionContext.XML_ENTITY_REFERENCE.equals(r
 								.getType())) {
 					counted++;
 					if (counted >= offset) {
 						return r.getEndOffset();
 					}
 				} else {
 					int length = r.getLength();
 					if (counted + length >= offset) {
 						return r.getStartOffset() + offset - counted;
 					}
 					counted += length;
 				}
 				r = r.getNext();
 			}
 			return parent.getStartOffset() + p.getOffset();
 		}
         IDOMNode previous = (IDOMNode) p.getPreviousSiblingNode();
         if (previous != null) {
         	return previous.getEndOffset();
         }
         IDOMNode next = (IDOMNode) p.getNextSiblingNode();
         if (next != null) {
         	return next.getStartOffset();
         }
         IStructuredDocumentRegion r = parent
         		.getStartStructuredDocumentRegion();
         if (r != null) {
         	return r.getEnd();
         }
         // r == null normally means the parent is the document node.
         return parent.getEndOffset();
 	}

 	/**
 	 * convert design selection of structured selection of NodeEditPart into
 	 * structured selection of Node
 	 *
 	 * @param sel
 	 * @return
 	 */
 	public static IStructuredSelection convertFromDesignSelection(
 			IStructuredSelection sel) {
 		List list = sel.toList();
 		if (list != null) {
 			List result = new ArrayList(list.size());
 			for (int i = 0, size = list.size(); i < size; i++) {
 				NodeEditPart part = (NodeEditPart) list.get(i);
 				result.add(part.getIDOMNode());
 			}
 			return new StructuredSelection(result);
 		}
         return new StructuredSelection();
 	}

 	/**
 	 *
 	 * @param selection
 	 *            selection from designer, could be IStructuredSelection of
 	 *            NodeEditPart, or DesignRange.
 	 * @return
 	 */
 	public static ITextSelection convertFromDesignSelection(DesignRange range) {
 		if (range.isValid()) {
 			IDOMPosition start = DOMPositionHelper.toDOMPosition(range
 					.getStartPosition());
 			IDOMPosition end = DOMPositionHelper.toDOMPosition(range
 					.getEndPosition());
 			// We should not encounter invalid position.
 			if (EditValidateUtil.validPosition(start)
 					&& EditValidateUtil.validPosition(end)) {
 				int offset = getIndexedRegionLocation(start);
 				int endoffset = getIndexedRegionLocation(end);
 				if (offset > endoffset) {
 					int temp = offset;
 					offset = endoffset;
 					endoffset = temp;
 				}
 				return new TextSelection(offset, endoffset - offset);
 			}
 		}
         return new TextSelection(0, 0);
 	}

 	public static ITextSelection convertFromDesignSelectionToTextSelection(
 			ISelection selection) {
 		if (selection instanceof IStructuredSelection) {
 			IStructuredSelection nodes = convertFromDesignSelection((IStructuredSelection) selection);
 			IDOMNode node = (IDOMNode) nodes.getFirstElement();
 			if (node != null && node.getNodeType() != Node.DOCUMENT_NODE) {
 				return new TextSelection(node.getStartOffset(), node
 						.getEndOffset()
 						- node.getStartOffset());
 			}
 		} else if (selection instanceof DesignRange) {
 			return convertFromDesignSelection((DesignRange) selection);
 		}
         return new TextSelection(0, 0);
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2006 Sybase, Inc. and others.
	*
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* Sybase, Inc. - initial API and implementation
	*******************************************************************************/
	package org.eclipse.jst.pagedesigner.utils;

	import java.util.ArrayList;
	import java.util.List;

	import org.eclipse.gef.EditPart;
	import org.eclipse.jface.text.ITextSelection;
	import org.eclipse.jface.text.TextSelection;
	import org.eclipse.jface.viewers.ISelection;
	import org.eclipse.jface.viewers.IStructuredSelection;
	import org.eclipse.jface.viewers.StructuredSelection;
	import org.eclipse.jst.jsf.core.internal.tld.CMUtil;
	import org.eclipse.jst.pagedesigner.dom.DOMPosition;
	import org.eclipse.jst.pagedesigner.dom.DOMPositionHelper;
	import org.eclipse.jst.pagedesigner.dom.DOMRefPosition;
	import org.eclipse.jst.pagedesigner.dom.DOMRefPosition2;
	import org.eclipse.jst.pagedesigner.dom.DOMUtil;
	import org.eclipse.jst.pagedesigner.dom.EditValidateUtil;
	import org.eclipse.jst.pagedesigner.dom.IDOMPosition;
	import org.eclipse.jst.pagedesigner.parts.NodeEditPart;
	import org.eclipse.jst.pagedesigner.viewer.DesignPosition;
	import org.eclipse.jst.pagedesigner.viewer.DesignRange;
	import org.eclipse.jst.pagedesigner.viewer.IHTMLGraphicalViewer;
	import org.eclipse.wst.sse.core.internal.provisional.IStructuredModel;
	import org.eclipse.wst.sse.core.internal.provisional.IndexedRegion;
	import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocumentRegion;
	import org.eclipse.wst.xml.core.internal.contentmodel.CMElementDeclaration;
	import org.eclipse.wst.xml.core.internal.provisional.document.IDOMModel;
	import org.eclipse.wst.xml.core.internal.provisional.document.IDOMNode;
	import org.eclipse.wst.xml.core.internal.regions.DOMRegionContext;
	import org.w3c.dom.CharacterData;
	import org.w3c.dom.Element;
	import org.w3c.dom.Node;
	import org.w3c.dom.Text;

	/**
	* @author mengbo
	* @version 1.5
	*/
	public class SelectionHelper {
	/**
	* convert the text selection to a Node. Will use the start offset of the
	* text selection.
	*
	* @param model
	* @param textSel
	* @return
	*/
	public static Node toNode(IStructuredModel model, ITextSelection textSel) {
	// FIXME: currently always normalize to a single node. should also
	// consider change into DesignRange
	// on text selection, find the appropriate Node
	Object inode = model.getIndexedRegion(textSel.getOffset());
	if (inode instanceof Node) {
	return (Node) inode;
	}
	return null;
	}

	/**
	* convert a structured selection of NodeEditPart or Node into the first
	* node.
	*
	* @param selection
	* @return
	*/
	public static Node toNode(IStructuredSelection selection) {
	if (selection.isEmpty()) {
	return null;
	}
	Object first = selection.getFirstElement();
	if (first instanceof Node) {
	return (Node) first;
	} else if (first instanceof NodeEditPart) {
	return ((NodeEditPart) first).getIDOMNode();
	} else {
	return null;
	}
	}

	/**
	* convert a DesignRange into a single node.
	*
	* @param range
	* @return
	*/
	public static Node toNode(DesignRange range) {
	if (range.isValid()) {
	Node node1 = range.getStartPosition().getContainerNode();
	Node node2 = range.getEndPosition().getContainerNode();
	return DOMUtil.findCommonAncester(node1, node2);
	}
	return null;
	}

	/**
	* @param model
	* @param region
	* if null, then will calculate it using offset.
	* @param offset
	* offset in source.
	* @return
	*/
	public static IDOMPosition toDOMPosition(IDOMModel model,
	IndexedRegion region, int offset) {
	if (region == null) {
	region = model.getIndexedRegion(offset);
	}
	if (region == null && offset > 0) {
	// in case this is at end of file.
	offset = offset - 1;
	region = model.getIndexedRegion(offset);
	if (region != null) {
	if (region.getEndOffset() >= offset + 1) {
	offset += 1; // restore offset.
	}
	}
	}
	if (region == null) {
	return new DOMPosition(model.getDocument(), 0);
	}
	IDOMNode node = (IDOMNode) region;
	int start = node.getStartOffset();
	if (offset <= start) {
	return new DOMRefPosition(node, false);
	}
	int end = node.getEndOffset();
	if (offset >= end) {
	return new DOMRefPosition(node, true);
	}
	if (node instanceof CharacterData) {
	String data = ((CharacterData) node).getData();
	String source = node.getSource();
	if (data.equals(source)) {
	return new DOMPosition(node, offset - start);
	}
	IStructuredDocumentRegion r = node
	.getFirstStructuredDocumentRegion();
	int countedData = 0;
	// TODO: dead? int offsetInNode = offset - start;
	while (r != null) {
	if (DOMRegionContext.XML_CHAR_REFERENCE.equals(r.getType())
	\|\| DOMRegionContext.XML_ENTITY_REFERENCE.equals(r
	.getType())) {
	countedData += 1; // FIXME: what if the entity reference's
	// corresponding data is more than 1
	// char?
	// where can we get that information?
	if (r.getEnd() >= offset) {
	return new DOMPosition(node, countedData);
	}
	} else {
	if (r.getEnd() >= offset) {
	return new DOMPosition(node, countedData + offset
	- r.getStart());
	}
	countedData += r.getLength();
	}
	r = r.getNext();
	}
	return new DOMRefPosition(node, true);
	} else if (node instanceof Element) {
	CMElementDeclaration cm = CMUtil
	.getElementDeclaration((Element) node);
	if (cm != null && cm.getContentType() == CMElementDeclaration.EMPTY) {
	// this node can't have children.
	return new DOMRefPosition(node, true);
	}
	IStructuredDocumentRegion startRegion = node
	.getStartStructuredDocumentRegion();
	if (startRegion == null) {
	return new DOMRefPosition(node, true);
	}
	int startRegionEnd = node.getStartStructuredDocumentRegion()
	.getEnd();
	if (offset <= startRegionEnd) {
	// it is in the start tag region. So put position at first
	// child position.
	return new DOMRefPosition2(node, false);
	}
	return new DOMRefPosition2(node, true);
	} else {
	return new DOMRefPosition(node, true);
	}
	// XXX: the implementation in EditModelQuery seemed to be very complex.
	// Need revisit that
	// and refactor the implementation to this class later. (lium)
	}

	/**
	* Give a text selection with offset and length, convert it into a Designer
	* selection (IStrucuturedSelection of editpart or DesignerRange). If the
	* text selection include just a single element node, we'll create a
	* IStructuredSelection, otherwise we'll create a DesignerRange.
	*
	* @param graphicViewer
	* @param offset
	* @param length
	*/
	public static ISelection convertToDesignerSelection(
	IHTMLGraphicalViewer graphicViewer, int offset, int length) {
	IDOMModel model = graphicViewer.getModel();
	IndexedRegion region1 = model.getIndexedRegion(offset);
	IndexedRegion region2 = model.getIndexedRegion(offset + length);
	IDOMNode node1 = (IDOMNode) region1;

	if (node1 == null) {
	IDOMPosition endOfDoc = new DOMRefPosition2(model.getDocument(),
	true);
	DesignPosition p = DOMPositionHelper.toDesignPosition(endOfDoc);
	return new DesignRange(p, p);
	}

	if ((region1 == region2 \|\| node1.getEndOffset() == offset + length)
	&& !(node1 instanceof Text)) {
	// ok, we selected a single node.
	EditPart part = (EditPart) node1.getAdapterFor(EditPart.class);
	if (part != null) {
	return new StructuredSelection(part);
	}
	}

	// when we reach here, we'll create a DesignerRange
	IDOMPosition position1 = toDOMPosition(model, region1, offset);
	IDOMPosition position2 = (length == 0 ? position1 : toDOMPosition(
	model, region2, offset + length));

	if (position1 == null \|\| position2 == null) {
	return new DesignRange(null, null);
	}
	DesignPosition p1 = DOMPositionHelper.toDesignPosition(position1);
	DesignPosition p2 = (length == 0 ? p1 : DOMPositionHelper
	.toDesignPosition(position2));
	if (p1 == null \|\| p2 == null) {
	return new DesignRange(null, null);
	}

	return new DesignRange(p1, p2);

	}

	/**
	* convert a IDOMPosition into index in the source.
	*
	* @param p
	* @return
	*/
	private static int getIndexedRegionLocation(IDOMPosition p) {
	if (!EditValidateUtil.validPosition(p)) {
	return 0;
	}

	IDOMNode parent = (IDOMNode) p.getContainerNode();
	if (p.isText()) {
	String text = ((CharacterData) parent).getData();
	String source = parent.getSource();
	if (text.length() == source.length()) {
	// no entity reference.
	return parent.getStartOffset() + p.getOffset();
	}
	// CR404708. Need to handle entity reference in the text.
	int offset = p.getOffset();
	int counted = 0;
	IStructuredDocumentRegion r = parent
	.getFirstStructuredDocumentRegion();
	while (r != null && counted < offset) {
	if (DOMRegionContext.XML_CHAR_REFERENCE.equals(r.getType())
	\|\| DOMRegionContext.XML_ENTITY_REFERENCE.equals(r
	.getType())) {
	counted++;
	if (counted >= offset) {
	return r.getEndOffset();
	}
	} else {
	int length = r.getLength();
	if (counted + length >= offset) {
	return r.getStartOffset() + offset - counted;
	}
	counted += length;
	}
	r = r.getNext();
	}
	return parent.getStartOffset() + p.getOffset();
	}
	IDOMNode previous = (IDOMNode) p.getPreviousSiblingNode();
	if (previous != null) {
	return previous.getEndOffset();
	}
	IDOMNode next = (IDOMNode) p.getNextSiblingNode();
	if (next != null) {
	return next.getStartOffset();
	}
	IStructuredDocumentRegion r = parent
	.getStartStructuredDocumentRegion();
	if (r != null) {
	return r.getEnd();
	}
	// r == null normally means the parent is the document node.
	return parent.getEndOffset();
	}

	/**
	* convert design selection of structured selection of NodeEditPart into
	* structured selection of Node
	*
	* @param sel
	* @return
	*/
	public static IStructuredSelection convertFromDesignSelection(
	IStructuredSelection sel) {
	List list = sel.toList();
	if (list != null) {
	List result = new ArrayList(list.size());
	for (int i = 0, size = list.size(); i < size; i++) {
	NodeEditPart part = (NodeEditPart) list.get(i);
	result.add(part.getIDOMNode());
	}
	return new StructuredSelection(result);
	}
	return new StructuredSelection();
	}

	/**
	*
	* @param selection
	* selection from designer, could be IStructuredSelection of
	* NodeEditPart, or DesignRange.
	* @return
	*/
	public static ITextSelection convertFromDesignSelection(DesignRange range) {
	if (range.isValid()) {
	IDOMPosition start = DOMPositionHelper.toDOMPosition(range
	.getStartPosition());
	IDOMPosition end = DOMPositionHelper.toDOMPosition(range
	.getEndPosition());
	// We should not encounter invalid position.
	if (EditValidateUtil.validPosition(start)
	&& EditValidateUtil.validPosition(end)) {
	int offset = getIndexedRegionLocation(start);
	int endoffset = getIndexedRegionLocation(end);
	if (offset > endoffset) {
	int temp = offset;
	offset = endoffset;
	endoffset = temp;
	}
	return new TextSelection(offset, endoffset - offset);
	}
	}
	return new TextSelection(0, 0);
	}

	public static ITextSelection convertFromDesignSelectionToTextSelection(
	ISelection selection) {
	if (selection instanceof IStructuredSelection) {
	IStructuredSelection nodes = convertFromDesignSelection((IStructuredSelection) selection);
	IDOMNode node = (IDOMNode) nodes.getFirstElement();
	if (node != null && node.getNodeType() != Node.DOCUMENT_NODE) {
	return new TextSelection(node.getStartOffset(), node
	.getEndOffset()
	- node.getStartOffset());
	}
	} else if (selection instanceof DesignRange) {
	return convertFromDesignSelection((DesignRange) selection);
	}
	return new TextSelection(0, 0);
	}
	}