| /******************************************************************************* |
| * Copyright (c) 2000, 2011 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.jdt.internal.ui.text; |
| |
| |
| import java.io.IOException; |
| |
| import org.eclipse.jface.internal.text.html.SingleCharReader; |
| |
| 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. |
| */ |
| public class JavaCodeReader extends SingleCharReader { |
| |
| /** The EOF character */ |
| public static final int EOF= -1; |
| |
| private boolean fSkipComments= false; |
| private boolean fSkipStrings= false; |
| private boolean fForward= false; |
| |
| private IDocument fDocument; |
| private int fOffset; |
| |
| private int fEnd= -1; |
| private int fCachedLineNumber= -1; |
| private int fCachedLineOffset= -1; |
| |
| |
| public JavaCodeReader() { |
| } |
| |
| /** |
| * Returns the offset of the last read character. Should only be called after read has been called. |
| */ |
| public int getOffset() { |
| return fForward ? fOffset -1 : fOffset; |
| } |
| |
| public void configureForwardReader(IDocument document, int offset, int length, boolean skipComments, boolean skipStrings) throws IOException { |
| fDocument= document; |
| fOffset= offset; |
| fSkipComments= skipComments; |
| fSkipStrings= skipStrings; |
| |
| fForward= true; |
| fEnd= Math.min(fDocument.getLength(), fOffset + length); |
| } |
| |
| public void configureBackwardReader(IDocument document, int offset, boolean skipComments, boolean skipStrings) throws IOException { |
| fDocument= document; |
| fOffset= offset; |
| fSkipComments= skipComments; |
| fSkipStrings= skipStrings; |
| |
| fForward= false; |
| try { |
| fCachedLineNumber= fDocument.getLineOfOffset(fOffset); |
| } catch (BadLocationException x) { |
| throw new IOException(x.getMessage()); |
| } |
| } |
| |
| /* |
| * @see Reader#close() |
| */ |
| @Override |
| public void close() throws IOException { |
| fDocument= null; |
| } |
| |
| /* |
| * @see SingleCharReader#read() |
| */ |
| @Override |
| public int read() throws IOException { |
| try { |
| return fForward ? readForwards() : readBackwards(); |
| } catch (BadLocationException x) { |
| throw new IOException(x.getMessage()); |
| } |
| } |
| |
| private void gotoCommentEnd() throws BadLocationException { |
| while (fOffset < fEnd) { |
| char current= fDocument.getChar(fOffset++); |
| if (current == '*') { |
| if (fOffset < fEnd && fDocument.getChar(fOffset) == '/') { |
| ++ fOffset; |
| return; |
| } |
| } |
| } |
| } |
| |
| 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; |
| } |
| } |
| } |
| |
| 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 '/': |
| |
| if (fSkipComments && fOffset < fEnd) { |
| char next= fDocument.getChar(fOffset); |
| if (next == '*') { |
| // a comment starts, advance to the comment end |
| ++ fOffset; |
| gotoCommentEnd(); |
| continue; |
| } else if (next == '/') { |
| // '//'-comment starts, advance to the line end |
| gotoLineEnd(); |
| continue; |
| } |
| } |
| |
| return current; |
| |
| case '"': |
| case '\'': |
| |
| if (fSkipStrings) { |
| gotoStringEnd(current); |
| continue; |
| } |
| |
| return current; |
| } |
| |
| return current; |
| } |
| |
| return EOF; |
| } |
| |
| private void handleSingleLineComment() throws BadLocationException { |
| int line= fDocument.getLineOfOffset(fOffset); |
| if (line < fCachedLineNumber) { |
| fCachedLineNumber= line; |
| fCachedLineOffset= fDocument.getLineOffset(line); |
| int offset= fOffset; |
| while (fCachedLineOffset < offset) { |
| char current= fDocument.getChar(offset--); |
| if (current == '/' && fCachedLineOffset <= offset && fDocument.getChar(offset) == '/') { |
| fOffset= offset; |
| return; |
| } |
| } |
| } |
| } |
| |
| private void gotoCommentStart() throws BadLocationException { |
| while (0 < fOffset) { |
| char current= fDocument.getChar(fOffset--); |
| if (current == '*' && 0 <= fOffset && fDocument.getChar(fOffset) == '/') |
| return; |
| } |
| } |
| |
| 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; |
| |
| handleSingleLineComment(); |
| |
| char current= fDocument.getChar(fOffset); |
| switch (current) { |
| case '/': |
| |
| if (fSkipComments && fOffset > 1) { |
| char next= fDocument.getChar(fOffset - 1); |
| if (next == '*') { |
| // a comment ends, advance to the comment start |
| fOffset -= 2; |
| gotoCommentStart(); |
| continue; |
| } |
| } |
| |
| return current; |
| |
| case '"': |
| case '\'': |
| |
| if (fSkipStrings) { |
| -- fOffset; |
| gotoStringStart(current); |
| continue; |
| } |
| |
| return current; |
| } |
| |
| return current; |
| } |
| |
| return EOF; |
| } |
| } |
| |