| /******************************************************************************* |
| * Copyright (c) 2000, 2006 IBM Corporation and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * 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 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 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() |
| */ |
| @Override |
| public 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) { |
| StringBuilder buf= new StringBuilder(); |
| 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 |
| */ |
| @Override |
| public void unread() { |
| |
| if (fOffset == 0) { |
| if (fBufferOffset == fRangeOffset) { |
| // error: BOF |
| } else { |
| updateBuffer(fBufferOffset - fBuffer.length); |
| fOffset= fBuffer.length - 1; |
| } |
| } else { |
| --fOffset; |
| } |
| } |
| |
| /* |
| * @see ICharacterScanner#getColumn() |
| */ |
| @Override |
| public 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() |
| */ |
| @Override |
| public char[][] getLegalLineDelimiters() { |
| return fDelimiters; |
| } |
| } |