--- /dev/null
+/*******************************************************************************
+ * Copyright (c) 2000, 2006 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 org.eclipse.core.runtime.Assert;
+
+import org.eclipse.jface.text.BadLocationException;
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.rules.ICharacterScanner;
+
+import org.eclipse.jdt.internal.ui.JavaPlugin;
+
+
+
+/**
+ * A buffered document scanner. The buffer always contains a section
+ * of a fixed size of the document to be scanned.
+ */
+
+public final class BufferedDocumentScanner implements ICharacterScanner {
+
+ /** The document being scanned. */
+ private IDocument fDocument;
+ /** The offset of the document range to scan. */
+ private int fRangeOffset;
+ /** The length of the document range to scan. */
+ private int fRangeLength;
+ /** The delimiters of the document. */
+ private char[][] fDelimiters;
+
+ /** The buffer. */
+ private final char[] fBuffer;
+ /** The offset of the buffer within the document. */
+ private int fBufferOffset;
+ /** The valid length of the buffer for access. */
+ private int fBufferLength;
+ /** The offset of the scanner within the buffer. */
+ private int fOffset;
+
+
+ /**
+ * Creates a new buffered document scanner.
+ * The buffer size is set to the given number of characters.
+ *
+ * @param size the buffer size
+ */
+ public BufferedDocumentScanner(int size) {
+ Assert.isTrue(size >= 1);
+ fBuffer= new char[size];
+ }
+
+ /**
+ * Fills the buffer with the contents of the document starting at the given offset.
+ *
+ * @param offset the document offset at which the buffer starts
+ */
+ private final void updateBuffer(int offset) {
+
+ fBufferOffset= offset;
+
+ if (fBufferOffset + fBuffer.length > fRangeOffset + fRangeLength)
+ fBufferLength= fRangeLength - (fBufferOffset - fRangeOffset);
+ else
+ fBufferLength= fBuffer.length;
+
+ try {
+ final String content= fDocument.get(fBufferOffset, fBufferLength);
+ content.getChars(0, fBufferLength, fBuffer, 0);
+ } catch (BadLocationException e) {
+ }
+ }
+
+ /**
+ * Configures the scanner by providing access to the document range over which to scan.
+ *
+ * @param document the document to scan
+ * @param offset the offset of the document range to scan
+ * @param length the length of the document range to scan
+ */
+ public final void setRange(IDocument document, int offset, int length) {
+
+ fDocument= document;
+ fRangeOffset= offset;
+ fRangeLength= length;
+
+ String[] delimiters= document.getLegalLineDelimiters();
+ fDelimiters= new char[delimiters.length][];
+ for (int i= 0; i < delimiters.length; i++)
+ fDelimiters[i]= delimiters[i].toCharArray();
+
+ updateBuffer(offset);
+ fOffset= 0;
+ }
+
+ /*
+ * @see ICharacterScanner#read()
+ */
+ public final int read() {
+
+ if (fOffset == fBufferLength) {
+ int end= fBufferOffset + fBufferLength;
+ if (end == fDocument.getLength() || end == fRangeOffset + fRangeLength)
+ return EOF;
+ else {
+ updateBuffer(fBufferOffset + fBufferLength);
+ fOffset= 0;
+ }
+ }
+
+ try {
+ return fBuffer[fOffset++];
+ } catch (ArrayIndexOutOfBoundsException ex) {
+ StringBuffer buf= new StringBuffer();
+ buf.append("Detailed state of 'BufferedDocumentScanner:'"); //$NON-NLS-1$
+ buf.append("\n\tfOffset= "); //$NON-NLS-1$
+ buf.append(fOffset);
+ buf.append("\n\tfBufferOffset= "); //$NON-NLS-1$
+ buf.append(fBufferOffset);
+ buf.append("\n\tfBufferLength= "); //$NON-NLS-1$
+ buf.append(fBufferLength);
+ buf.append("\n\tfRangeOffset= "); //$NON-NLS-1$
+ buf.append(fRangeOffset);
+ buf.append("\n\tfRangeLength= "); //$NON-NLS-1$
+ buf.append(fRangeLength);
+ JavaPlugin.logErrorMessage(buf.toString());
+ throw ex;
+ }
+ }
+
+ /*
+ * @see ICharacterScanner#unread
+ */
+ public final void unread() {
+
+ if (fOffset == 0) {
+ if (fBufferOffset == fRangeOffset) {
+ // error: BOF
+ } else {
+ updateBuffer(fBufferOffset - fBuffer.length);
+ fOffset= fBuffer.length - 1;
+ }
+ } else {
+ --fOffset;
+ }
+ }
+
+ /*
+ * @see ICharacterScanner#getColumn()
+ */
+ public final int getColumn() {
+
+ try {
+ final int offset= fBufferOffset + fOffset;
+ final int line= fDocument.getLineOfOffset(offset);
+ final int start= fDocument.getLineOffset(line);
+ return offset - start;
+ } catch (BadLocationException e) {
+ }
+
+ return -1;
+ }
+
+ /*
+ * @see ICharacterScanner#getLegalLineDelimiters()
+ */
+ public final char[][] getLegalLineDelimiters() {
+ return fDelimiters;
+ }
+}
git://git.uio.no / ifi-stolz-refaktor.git / blobdiff