| /******************************************************************************* |
| * 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.ui.editors.text; |
| |
| import java.io.IOException; |
| import java.io.Reader; |
| |
| import org.eclipse.core.runtime.Assert; |
| |
| import org.eclipse.jface.text.BadLocationException; |
| import org.eclipse.jface.text.DocumentEvent; |
| import org.eclipse.jface.text.IDocument; |
| import org.eclipse.jface.text.IDocumentListener; |
| |
| |
| /** |
| * A <code>Reader</code> that reads from an <code>IDocument</code>. |
| * The reader ensures that its content is the same as the document |
| * content when the stream was created. |
| * <p> |
| * Note that {@link #close()} must be called to release any acquired |
| * resources. |
| * </p> |
| * |
| * @since 3.1 |
| */ |
| class DocumentReader extends Reader { |
| |
| /** |
| * Document based character sequence. |
| */ |
| private static class DocumentCharSequence implements CharSequence { |
| |
| /** Document */ |
| private IDocument fDocument; |
| |
| /** |
| * Initialize with the sequence of characters in the given |
| * document. |
| * |
| * @param document the document |
| */ |
| public DocumentCharSequence(IDocument document) { |
| fDocument= document; |
| } |
| |
| @Override |
| public int length() { |
| return fDocument.getLength(); |
| } |
| |
| @Override |
| public char charAt(int index) { |
| try { |
| return fDocument.getChar(index); |
| } catch (BadLocationException x) { |
| throw new IndexOutOfBoundsException(x.getLocalizedMessage()); |
| } |
| } |
| |
| @Override |
| public CharSequence subSequence(int start, int end) { |
| try { |
| return fDocument.get(start, end - start); |
| } catch (BadLocationException x) { |
| throw new IndexOutOfBoundsException(x.getLocalizedMessage()); |
| } |
| } |
| } |
| |
| /** |
| * Internal document listener. |
| */ |
| private class InternalDocumentListener implements IDocumentListener { |
| |
| @Override |
| public void documentAboutToBeChanged(DocumentEvent event) { |
| handleDocumentAboutToBeChanged(); |
| } |
| |
| @Override |
| public void documentChanged(DocumentEvent event) { |
| } |
| } |
| |
| /** The character sequence. */ |
| private volatile CharSequence fCharSequence; |
| |
| /** Document length. */ |
| private int fLength; |
| |
| /** The current offset. */ |
| private int fOffset= 0; |
| |
| /** The document. */ |
| private IDocument fDocument; |
| |
| /** The document listener. */ |
| private IDocumentListener fDocumentListener= new InternalDocumentListener(); |
| |
| /** |
| * Creates a new document input stream and initializes |
| * the stream to read from the given document. |
| * |
| * @param document the document |
| */ |
| public DocumentReader(IDocument document) { |
| Assert.isNotNull(document); |
| fDocument= document; |
| fCharSequence= new DocumentCharSequence(fDocument); |
| fDocument.addDocumentListener(fDocumentListener); |
| fLength= fCharSequence.length(); |
| } |
| |
| @Override |
| public void close() throws IOException { |
| synchronized (this) { |
| fCharSequence= null; |
| } |
| releaseDocument(); |
| } |
| |
| /** |
| * Copies the document prior to modification and removes the document listener. |
| */ |
| private void handleDocumentAboutToBeChanged() { |
| IDocument document= fDocument; |
| if (fCharSequence == null || document == null) |
| return; |
| String content= document.get(); |
| synchronized (this) { |
| if (fCharSequence == null) |
| return; |
| fCharSequence= content; |
| } |
| releaseDocument(); |
| } |
| |
| /** |
| * Removes the document listener. |
| */ |
| private synchronized void releaseDocument() { |
| if (fDocument != null) |
| fDocument.removeDocumentListener(fDocumentListener); |
| fDocument= null; |
| fDocumentListener= null; |
| } |
| |
| @Override |
| public int read(char[] cbuf, int off, int len) throws IOException { |
| int i= 0; |
| try { |
| for (; i < len && fOffset < fLength; i++) |
| cbuf[off + i]= fCharSequence.charAt(fOffset++); |
| if (i > 0) |
| return i; |
| |
| return -1; |
| } catch (NullPointerException x) { |
| throw new IOException(TextEditorMessages.DocumentInputStream_error_streamClosed); |
| } catch (IndexOutOfBoundsException x) { |
| return i-1; |
| } |
| } |
| } |