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.dom.fragments;
  
  import org.eclipse.core.runtime.Assert;
  import org.eclipse.wst.jsdt.core.IBuffer;
  import org.eclipse.wst.jsdt.core.ToolFactory;
  import org.eclipse.wst.jsdt.core.compiler.IScanner;
  import org.eclipse.wst.jsdt.core.compiler.ITerminalSymbols;
  import org.eclipse.wst.jsdt.core.compiler.InvalidInputException;
  import org.eclipse.wst.jsdt.internal.corext.SourceRange;
  
  /**
   * This class houses a collection of static methods which do not refer to,
   * or otherwise depend on, other classes in this package.  Each 
   * package-visible method is called by more than one other class in this
   * package.  Since they do not depend on other classes in this package, 
   * they could be moved to some less specialized package.
   */
  class Util {
  	static boolean rangeIncludesNonWhitespaceOutsideRange(SourceRange selection, SourceRange nodes, IBuffer buffer) {
  		if(!selection.covers(nodes))
  			return false;
  
  		//TODO: skip leading comments. Consider that leading line comment must be followed by newline!
  		if(!isJustWhitespace(selection.getOffset(), nodes.getOffset(), buffer))
  			return true;
  		if(!isJustWhitespaceOrComment(nodes.getOffset() + nodes.getLength(), selection.getOffset() + selection.getLength(), buffer))				
  			return true;
  		return false;		
  	}
  	private static boolean isJustWhitespace(int start, int end, IBuffer buffer) {
  		if (start == end)
  			return true;
  		Assert.isTrue(start <= end);
  		return 0 == buffer.getText(start, end - start).trim().length();
  	}
  	private static boolean isJustWhitespaceOrComment(int start, int end, IBuffer buffer) {
  		if (start == end)
  			return true;
  		Assert.isTrue(start <= end);
  		String trimmedText= buffer.getText(start, end - start).trim();
  		if (0 == trimmedText.length()) {
  			return true;
  		} else {
  			IScanner scanner= ToolFactory.createScanner(false, false, false, null);
  			scanner.setSource(trimmedText.toCharArray());
  			try {
  				return scanner.getNextToken() == ITerminalSymbols.TokenNameEOF;
  			} catch (InvalidInputException e) {
  				return false;
  			}
  		}
  	}
  }
  