content: /*******************************************************************************
   * Copyright (c) 2000, 2007 IBM Corporation 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:
   *     IBM Corporation - initial API and implementation
   *******************************************************************************/
  package org.eclipse.wst.jsdt.internal.corext.refactoring.changes;
  
  import org.eclipse.core.runtime.Assert;
  import org.eclipse.ltk.core.refactoring.CategorizedTextEditGroup;
  import org.eclipse.ltk.core.refactoring.GroupCategorySet;
  import org.eclipse.ltk.core.refactoring.TextChange;
  import org.eclipse.ltk.core.refactoring.TextEditChangeGroup;
  import org.eclipse.text.edits.MalformedTreeException;
  import org.eclipse.text.edits.MultiTextEdit;
  import org.eclipse.text.edits.TextEdit;
  import org.eclipse.text.edits.TextEditGroup;
  
  
  /**
   * A utility class to provide compatibility with the old
   * text change API of adding text edits directly and auto
   * inserting them into the tree.
   */
  public class TextChangeCompatibility {
  
  	public static void addTextEdit(TextChange change, String name, TextEdit edit) throws MalformedTreeException {
  		Assert.isNotNull(change);
  		Assert.isNotNull(name);
  		Assert.isNotNull(edit);
  		TextEdit root= change.getEdit();
  		if (root == null) {
  			root= new MultiTextEdit();
  			change.setEdit(root);
  		}
  		insert(root, edit);
  		change.addTextEditGroup(new TextEditGroup(name, edit));
  	}
  	
  	public static void addTextEdit(TextChange change, String name, TextEdit edit, GroupCategorySet groupCategories) throws MalformedTreeException {
  		Assert.isNotNull(change);
  		Assert.isNotNull(name);
  		Assert.isNotNull(edit);
  		TextEdit root= change.getEdit();
  		if (root == null) {
  			root= new MultiTextEdit();
  			change.setEdit(root);
  		}
  		insert(root, edit);
  		change.addTextEditChangeGroup(new TextEditChangeGroup(
  			change,
  			new CategorizedTextEditGroup(name, edit, groupCategories)));
  	}
  	
  	public static void insert(TextEdit parent, TextEdit edit) throws MalformedTreeException {
  		if (!parent.hasChildren()) {
  			parent.addChild(edit);
  			return;
  		}
  		TextEdit[] children= parent.getChildren();
  		// First dive down to find the right parent.
  		for (int i= 0; i < children.length; i++) {
  			TextEdit child= children[i];
  			if (covers(child, edit)) {
  				insert(child, edit);
  				return;
  			}
  		}
  		// We have the right parent. Now check if some of the children have to
  		// be moved under the new edit since it is covering it.
  		int removed= 0;
  		for (int i= 0; i < children.length; i++) {
  			TextEdit child= children[i];
  			if (covers(edit, child)) {
  				parent.removeChild(i - removed++);
  				edit.addChild(child);
  			}
  		}
  		parent.addChild(edit);
  	}
  	
  	private static boolean covers(TextEdit thisEdit, TextEdit otherEdit) {
  		if (thisEdit.getLength() == 0)	// an insertion point can't cover anything
  			return false;
  		
  		int thisOffset= thisEdit.getOffset();
  		int thisEnd= thisEdit.getExclusiveEnd();	
  		if (otherEdit.getLength() == 0) {
  			int otherOffset= otherEdit.getOffset();
  			return thisOffset < otherOffset && otherOffset < thisEnd;
  		} else {
  			int otherOffset= otherEdit.getOffset();
  			int otherEnd= otherEdit.getExclusiveEnd();
  			return thisOffset <= otherOffset && otherEnd <= thisEnd;
  		}
  	}		
  	
  }
  