org.eclipse.jdt.debug.ui/ui/org/eclipse/jdt/internal/debug/ui/JDISourceViewer.java

/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.debug.ui;


import java.util.ArrayList;
import java.util.List;

import org.eclipse.jdt.internal.ui.text.JavaPartitionScanner;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.ITypedRegion;
import org.eclipse.jface.text.contentassist.IContentAssistant;
import org.eclipse.jface.text.source.IVerticalRuler;
import org.eclipse.jface.text.source.SourceViewer;
import org.eclipse.swt.custom.BidiSegmentEvent;
import org.eclipse.swt.custom.BidiSegmentListener;
import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.widgets.Composite;

public class JDISourceViewer extends SourceViewer {

	public JDISourceViewer(Composite parent, IVerticalRuler ruler, int styles) {
		super(parent, ruler, styles);
		StyledText text= this.getTextWidget();
		text.addBidiSegmentListener(new  BidiSegmentListener() {
			public void lineGetSegments(BidiSegmentEvent event) {
				try {
					event.segments= getBidiLineSegments(event.lineOffset);
				} catch (BadLocationException x) {
					// ignore
				}
			}
		});
	}

	public IContentAssistant getContentAssistant() {
		return fContentAssistant;
	}
	
	/**
	 * Returns a segmentation of the line of the given document appropriate for bidi rendering.
	 * The default implementation returns only the string literals of a Java code line as segments.
	 * 
	 * @param document the document
	 * @param lineOffset the offset of the line
	 * @return the line's bidi segmentation
	 * @throws BadLocationException in case lineOffset is not valid in document
	 */
	protected int[] getBidiLineSegments(int lineOffset) throws BadLocationException {
		IDocument document= getDocument();
		if (document == null) {
			return null;
		}
		IRegion line= document.getLineInformationOfOffset(lineOffset);
		ITypedRegion[] linePartitioning= document.computePartitioning(lineOffset, line.getLength());
		
		List segmentation= new ArrayList();
		for (int i= 0; i < linePartitioning.length; i++) {
			if (JavaPartitionScanner.JAVA_STRING.equals(linePartitioning[i].getType()))
				segmentation.add(linePartitioning[i]);
		}
		
		
		if (segmentation.size() == 0) 
			return null;
			
		int size= segmentation.size();
		int[] segments= new int[size * 2 + 1];
		
		int j= 0;
		for (int i= 0; i < size; i++) {
			ITypedRegion segment= (ITypedRegion) segmentation.get(i);
			
			if (i == 0)
				segments[j++]= 0;
				
			int offset= segment.getOffset() - lineOffset;
			if (offset > segments[j - 1])
				segments[j++]= offset;
				
			if (offset + segment.getLength() >= line.getLength())
				break;
				
			segments[j++]= offset + segment.getLength();
		}
		
		if (j < segments.length) {
			int[] result= new int[j];
			System.arraycopy(segments, 0, result, 0, j);
			segments= result;
		}
		
		return segments;
	}	
}