| /******************************************************************************* |
| * Copyright (c) 2006, 2012 Oracle 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: |
| * Oracle Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.bpel.ui.editors.xpath; |
| |
| import java.io.IOException; |
| |
| import org.eclipse.jface.text.BadLocationException; |
| import org.eclipse.jface.text.IDocument; |
| |
| /** |
| * Reads from a document either forwards or backwards. May be configured to skip |
| * comments and strings. |
| * |
| * @author Michal Chmielewski (michal.chmielewski@oracle.com) |
| * @date Oct 27, 2006 |
| * |
| */ |
| |
| public class XPathCodeReader { |
| |
| /** The EOF character */ |
| public static final int EOF = -1; |
| |
| private boolean fSkipStrings = false; |
| |
| private boolean fForward = false; |
| |
| private IDocument fDocument; |
| |
| private int fOffset; |
| |
| private int fEnd = -1; |
| |
| |
| /** |
| * Return an XPathCodeReader. |
| * |
| */ |
| |
| public XPathCodeReader() { |
| |
| } |
| |
| /** |
| * Returns the offset of the last read character. Should only be called |
| * after read has been called. |
| * @return offset |
| */ |
| |
| public int getOffset() { |
| return fForward ? fOffset - 1 : fOffset; |
| } |
| |
| /** |
| * |
| * @param document |
| * @param offset |
| * @param length |
| * @param skipStrings |
| */ |
| |
| public void configureForwardReader (IDocument document, int offset, int length, boolean skipStrings) { |
| fDocument = document; |
| fOffset = offset; |
| fSkipStrings = skipStrings; |
| |
| fForward = true; |
| fEnd = Math.min(fDocument.getLength(), fOffset + length); |
| } |
| |
| /** |
| * |
| * @param document |
| * @param offset |
| * @param skipStrings |
| * @throws IOException |
| */ |
| |
| public void configureBackwardReader(IDocument document, int offset, boolean skipStrings) throws IOException { |
| fDocument = document; |
| fOffset = offset; |
| fSkipStrings = skipStrings; |
| |
| fForward = false; |
| try { |
| fDocument.getLineOfOffset(fOffset); |
| } catch (BadLocationException x) { |
| throw new IOException(x.getMessage()); |
| } |
| } |
| |
| /** |
| * |
| */ |
| public void close() { |
| fDocument = null; |
| } |
| |
| /** |
| * @return the next character read, in either the forward or reverse direction. |
| * @throws IOException if bad location (passed start or end) |
| * |
| */ |
| |
| public int read() throws IOException { |
| try { |
| return fForward ? readForwards() : readBackwards(); |
| } catch (BadLocationException x) { |
| throw new IOException(x.getMessage()); |
| } |
| } |
| |
| private void gotoStringEnd(char delimiter) throws BadLocationException { |
| while (fOffset < fEnd) { |
| char current = fDocument.getChar(fOffset++); |
| if (current == '\\') { |
| // ignore escaped characters |
| ++fOffset; |
| } else if (current == delimiter) { |
| return; |
| } |
| } |
| } |
| |
| @SuppressWarnings("unused") |
| private void gotoLineEnd() throws BadLocationException { |
| int line = fDocument.getLineOfOffset(fOffset); |
| fOffset = fDocument.getLineOffset(line + 1); |
| } |
| |
| |
| private int readForwards() throws BadLocationException { |
| while (fOffset < fEnd) { |
| char current = fDocument.getChar(fOffset++); |
| |
| switch (current) { |
| |
| case '"': |
| case '\'': |
| |
| if (fSkipStrings) { |
| gotoStringEnd(current); |
| continue; |
| } |
| |
| return current; |
| } |
| |
| return current; |
| } |
| |
| return EOF; |
| } |
| |
| |
| private void gotoStringStart(char delimiter) throws BadLocationException { |
| while (0 < fOffset) { |
| char current = fDocument.getChar(fOffset); |
| if (current == delimiter) { |
| if (!(0 <= fOffset && fDocument.getChar(fOffset - 1) == '\\')) |
| return; |
| } |
| --fOffset; |
| } |
| } |
| |
| private int readBackwards() throws BadLocationException { |
| |
| while (0 < fOffset) { |
| --fOffset; |
| |
| char current = fDocument.getChar(fOffset); |
| switch (current) { |
| |
| case '"': |
| case '\'': |
| |
| if (fSkipStrings) { |
| --fOffset; |
| gotoStringStart(current); |
| continue; |
| } |
| |
| return current; |
| } |
| |
| return current; |
| } |
| |
| return EOF; |
| } |
| } |