content: /*******************************************************************************
   * Copyright (c) 2000, 2008 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.ui.refactoring.actions;
  
  import org.eclipse.jface.text.ITextSelection;
  import org.eclipse.wst.jsdt.core.IClassFile;
  import org.eclipse.wst.jsdt.core.IJavaScriptUnit;
  import org.eclipse.wst.jsdt.core.IJavaScriptElement;
  import org.eclipse.wst.jsdt.core.IType;
  import org.eclipse.wst.jsdt.core.JavaScriptModelException;
  import org.eclipse.wst.jsdt.internal.ui.actions.SelectionConverter;
  import org.eclipse.wst.jsdt.internal.ui.javaeditor.JavaEditor;
  import org.eclipse.wst.jsdt.internal.ui.javaeditor.JavaTextSelection;
  
  /**
   * Helper class for refactoring actions
   */
  public class RefactoringActions {
  
  	/**
  	 * Converts the given selection into a type using the following rules:
  	 * <ul>
  	 *   <li>if the selection is enclosed by a type than that type is returned.</li>
  	 *   <li>if the selection is inside a compilation unit or class file than the 
  	 *       primary type is returned.</li>
  	 *   <li>otherwise <code>null</code> is returned.
  	 * </ul>
  	 */
  	public static IType getEnclosingOrPrimaryType(JavaTextSelection selection) throws JavaScriptModelException {
  		final IJavaScriptElement element= selection.resolveEnclosingElement();
  		if (element != null)
  			return convertToEnclosingOrPrimaryType(element);
  		return null;
  	}
  	public static IType getEnclosingOrPrimaryType(JavaEditor editor) throws JavaScriptModelException {
  		return convertToEnclosingOrPrimaryType(SelectionConverter.resolveEnclosingElement(
  			editor, (ITextSelection)editor.getSelectionProvider().getSelection()));
  	}
  
  	private static IType convertToEnclosingOrPrimaryType(IJavaScriptElement element) throws JavaScriptModelException {
  		if (element instanceof IType)
  			return (IType)element;
  		IType result= (IType)element.getAncestor(IJavaScriptElement.TYPE);
  		if (result != null)
  			return result;
  		if (element instanceof IJavaScriptUnit)
  			return ((IJavaScriptUnit)element).findPrimaryType();
  		if (element instanceof IClassFile) 
  			return ((IClassFile)element).getType();
  		return null;
  	}
  	
  	/**
  	 * Converts the given selection into a type using the following rules:
  	 * <ul>
  	 *   <li>if the selection is enclosed by a type than that type is returned.</li>
  	 *   <li>otherwise <code>null</code> is returned.
  	 * </ul>
  	 */
  	public static IType getEnclosingType(JavaTextSelection selection) throws JavaScriptModelException {
  		return convertToEnclosingType(selection.resolveEnclosingElement());
  	}
  	public static IType getEnclosingType(JavaEditor editor) throws JavaScriptModelException {
  		return convertToEnclosingType(SelectionConverter.resolveEnclosingElement(
  			editor, (ITextSelection)editor.getSelectionProvider().getSelection()));
  	}
  	
  	private static IType convertToEnclosingType(IJavaScriptElement element) {
  		if (element == null)
  			return null;
  		if (! (element instanceof IType))
  			element= element.getAncestor(IJavaScriptElement.TYPE);
  		return (IType)element;
  	}
  }
  