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.util;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import org.eclipse.core.runtime.CoreException;
  import org.eclipse.jface.text.BadLocationException;
  import org.eclipse.jface.text.IDocument;
  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.dom.ASTNode;
  import org.eclipse.wst.jsdt.core.dom.rewrite.TargetSourceRangeComputer;
  import org.eclipse.wst.jsdt.core.formatter.IndentManipulation;
  import org.eclipse.wst.jsdt.internal.corext.dom.TokenScanner;
  
  public class SelectionAwareSourceRangeComputer extends TargetSourceRangeComputer {
  
  	private ASTNode[] fSelectedNodes;
  	private IDocument fDocument;
  	private int fSelectionStart;
  	private int fSelectionLength;
  	
  	private Map/*<ASTNode, SourceRange>*/ fRanges;
  	
  	public SelectionAwareSourceRangeComputer(ASTNode[] selectedNodes, IDocument document, int selectionStart, int selectionLength) throws BadLocationException, CoreException {
  		fSelectedNodes= selectedNodes;
  		fDocument= document;
  		fSelectionStart= selectionStart;
  		fSelectionLength= selectionLength;
  	}
  	
  	public SourceRange computeSourceRange(ASTNode node) {
  		try {
  			if (fRanges == null)
  				initializeRanges();
  			SourceRange result= (SourceRange)fRanges.get(node);
  			if (result != null)
  				return result;
  			return super.computeSourceRange(node);
  		} catch (BadLocationException e) {
  			// fall back to standard implementation
  			fRanges= new HashMap();
  		} catch (CoreException e) {
  			// fall back to standard implementation
  			fRanges= new HashMap();
  		}
  		return super.computeSourceRange(node);
  	}
  
  	private void initializeRanges() throws BadLocationException, CoreException {
  		fRanges= new HashMap();
  		if (fSelectedNodes.length == 0)
  			return;
  		
  		fRanges.put(fSelectedNodes[0], super.computeSourceRange(fSelectedNodes[0]));
  		int last= fSelectedNodes.length - 1;
  		fRanges.put(fSelectedNodes[last], super.computeSourceRange(fSelectedNodes[last]));
  		
  		IScanner scanner= ToolFactory.createScanner(true, false, false, false);
  		String documentPortionToScan= fDocument.get(fSelectionStart, fSelectionLength);
  		scanner.setSource(documentPortionToScan.toCharArray());
  		TokenScanner tokenizer= new TokenScanner(scanner);
  		int pos= tokenizer.getNextStartOffset(0, false);
  		
  		ASTNode currentNode= fSelectedNodes[0];
  		int newStart= Math.min(fSelectionStart + pos, currentNode.getStartPosition());
  		SourceRange range= (SourceRange)fRanges.get(currentNode);
  		fRanges.put(currentNode, new SourceRange(newStart, range.getLength() + range.getStartPosition() - newStart));
  		
  		currentNode= fSelectedNodes[last];
  		int scannerStart= currentNode.getStartPosition() + currentNode.getLength() - fSelectionStart;
  		tokenizer.setOffset(scannerStart);
  		pos= scannerStart;
  		int token= -1;
  		try {
  			while (true) {
  				token= tokenizer.readNext(false);
  				pos= tokenizer.getCurrentEndOffset();
  			}
  		} catch (CoreException e) {
  		}
  		if (token == ITerminalSymbols.TokenNameCOMMENT_LINE) {
  			int index= pos - 1;
  			while(index >= 0 && IndentManipulation.isLineDelimiterChar(documentPortionToScan.charAt(index))) {
  				pos--;
  				index--;
  			}
  		}
  		
  		int newEnd= Math.max(fSelectionStart + pos, currentNode.getStartPosition() + currentNode.getLength());
  		range= (SourceRange)fRanges.get(currentNode);
  		fRanges.put(currentNode, new SourceRange(range.getStartPosition(), newEnd - range.getStartPosition()));
  	}
  }
  