org.eclipse.jface.text/src/org/eclipse/jface/text/source/ChangeRulerColumn.java - platform/eclipse.platform.text - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2004 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.jface.text.source;

 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.StyledText;
 import org.eclipse.swt.events.DisposeEvent;
 import org.eclipse.swt.events.DisposeListener;
 import org.eclipse.swt.events.MouseEvent;
 import org.eclipse.swt.events.MouseListener;
 import org.eclipse.swt.events.MouseMoveListener;
 import org.eclipse.swt.events.PaintEvent;
 import org.eclipse.swt.events.PaintListener;
 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.Font;
 import org.eclipse.swt.graphics.GC;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.widgets.Canvas;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Display;

 import org.eclipse.jface.text.Assert;
 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IRegion;
 import org.eclipse.jface.text.ITextListener;
 import org.eclipse.jface.text.ITextViewer;
 import org.eclipse.jface.text.ITextViewerExtension5;
 import org.eclipse.jface.text.IViewportListener;
 import org.eclipse.jface.text.TextEvent;

 /**
  * A vertical ruler column displaying line numbers and serving as a UI for quick diff.
  * Clients instantiate and configure object of this class.
  *
  * @since 3.0
  */
 public final class ChangeRulerColumn implements IVerticalRulerColumn, IVerticalRulerInfo, IVerticalRulerInfoExtension, IChangeRulerColumn {

 	/**
 	 * Handles all the mouse interaction in this line number ruler column.
 	 */
 	class MouseHandler implements MouseListener, MouseMoveListener {

 		/*
 		 * @see org.eclipse.swt.events.MouseListener#mouseUp(org.eclipse.swt.events.MouseEvent)
 		 */
 		public void mouseUp(MouseEvent event) {
 		}

 		/*
 		 * @see org.eclipse.swt.events.MouseListener#mouseDown(org.eclipse.swt.events.MouseEvent)
 		 */
 		public void mouseDown(MouseEvent event) {
 			fParentRuler.setLocationOfLastMouseButtonActivity(event.x, event.y);
 		}

 		/*
 		 * @see org.eclipse.swt.events.MouseListener#mouseDoubleClick(org.eclipse.swt.events.MouseEvent)
 		 */
 		public void mouseDoubleClick(MouseEvent event) {
 			fParentRuler.setLocationOfLastMouseButtonActivity(event.x, event.y);
 		}

 		/*
 		 * @see org.eclipse.swt.events.MouseMoveListener#mouseMove(org.eclipse.swt.events.MouseEvent)
 		 */
 		public void mouseMove(MouseEvent e) {
 		}

 	}

 	/**
 	 * Internal listener class.
 	 */
 	class InternalListener implements IViewportListener, ITextListener {

 		/*
 		 * @see IViewportListener#viewportChanged(int)
 		 */
 		public void viewportChanged(int verticalPosition) {
 			if (verticalPosition != fScrollPos)
 				redraw();
 		}

 		/*
 		 * @see ITextListener#textChanged(TextEvent)
 		 */
 		public void textChanged(TextEvent event) {

 			if (!event.getViewerRedrawState())
 				return;

 			if (fSensitiveToTextChanges || event.getDocumentEvent() == null)
 				postRedraw();

 		}
 	}

 	/**
 	 * Internal listener class that will update the ruler when the underlying model changes.
 	 */
 	class AnnotationListener implements IAnnotationModelListener {
 		/*
 		 * @see org.eclipse.jface.text.source.IAnnotationModelListener#modelChanged(org.eclipse.jface.text.source.IAnnotationModel)
 		 */
 		public void modelChanged(IAnnotationModel model) {
 			postRedraw();
 		}
 	}

 	/** This column's parent ruler */
 	private CompositeRuler fParentRuler;
 	/** Cached text viewer */
 	private ITextViewer fCachedTextViewer;
 	/** Cached text widget */
 	private StyledText fCachedTextWidget;
 	/** The columns canvas */
 	private Canvas fCanvas;
 	/** Cache for the actual scroll position in pixels */
 	private int fScrollPos;
 	/** The drawable for double buffering */
 	private Image fBuffer;
 	/** The internal listener */
 	private InternalListener fInternalListener= new InternalListener();
 	/** Indicates whether this column reacts on text change events */
 	private boolean fSensitiveToTextChanges= false;
 	/** The foreground color */
 	private Color fForeground;
 	/** The background color */
 	private Color fBackground;
 	/** Color for changed lines */
 	private Color fAddedColor;
 	/** Color for added lines */
 	private Color fChangedColor;
 	/** Color for the deleted line indicator */
 	private Color fDeletedColor;
 	/** The ruler's annotation model. */
 	private IAnnotationModel fAnnotationModel;
 	/** The ruler's hover */
 	private IAnnotationHover fHover;
 	/** The internal listener */
 	private AnnotationListener fAnnotationListener= new AnnotationListener();
 	/** The width of the change ruler column. */
 	private int fWidth= 5;


 	/**
 	 * Returns the System background color for list widgets.
 	 *
 	 * @param display the display the drawing occurs on
 	 * @return the System background color for list widgets
 	 */
 	protected Color getBackground(Display display) {
 		if (fBackground == null)
 			return display.getSystemColor(SWT.COLOR_LIST_BACKGROUND);
 		return fBackground;
 	}

 	/*
 	 * @see IVerticalRulerColumn#createControl(CompositeRuler, Composite)
 	 */
 	public Control createControl(CompositeRuler parentRuler, Composite parentControl) {

 		fParentRuler= parentRuler;
 		fCachedTextViewer= parentRuler.getTextViewer();
 		fCachedTextWidget= fCachedTextViewer.getTextWidget();

 		fCanvas= new Canvas(parentControl, SWT.NONE);
 		fCanvas.setBackground(getBackground(fCanvas.getDisplay()));
 		fCanvas.setForeground(fForeground);

 		fCanvas.addPaintListener(new PaintListener() {
 			public void paintControl(PaintEvent event) {
 				if (fCachedTextViewer != null)
 					doubleBufferPaint(event.gc);
 			}
 		});

 		fCanvas.addDisposeListener(new DisposeListener() {
 			public void widgetDisposed(DisposeEvent e) {
 				handleDispose();
 				fCachedTextViewer= null;
 				fCachedTextWidget= null;
 			}
 		});

 		MouseHandler mouseHandler= new MouseHandler();

 		fCanvas.addMouseListener(mouseHandler);

 		fCanvas.addMouseMoveListener(mouseHandler);

 		if (fCachedTextViewer != null) {

 			fCachedTextViewer.addViewportListener(fInternalListener);
 			fCachedTextViewer.addTextListener(fInternalListener);
 		}

 		return fCanvas;
 	}

 	/**
 	 * Disposes the column's resources.
 	 */
 	protected void handleDispose() {

 		if (fAnnotationModel != null) {
 			fAnnotationModel.removeAnnotationModelListener(fAnnotationListener);
 			fAnnotationModel= null;
 		}

 		if (fCachedTextViewer != null) {
 			fCachedTextViewer.removeViewportListener(fInternalListener);
 			fCachedTextViewer.removeTextListener(fInternalListener);
 		}

 		if (fBuffer != null) {
 			fBuffer.dispose();
 			fBuffer= null;
 		}
 	}

 	/**
 	 * Double buffer drawing.
 	 *
 	 * @param dest the GC to draw into
 	 */
 	private void doubleBufferPaint(GC dest) {

 		Point size= fCanvas.getSize();

 		if (size.x <= 0 || size.y <= 0)
 			return;

 		if (fBuffer != null) {
 			Rectangle r= fBuffer.getBounds();
 			if (r.width != size.x || r.height != size.y) {
 				fBuffer.dispose();
 				fBuffer= null;
 			}
 		}
 		if (fBuffer == null)
 			fBuffer= new Image(fCanvas.getDisplay(), size.x, size.y);

 		GC gc= new GC(fBuffer);
 		gc.setFont(fCanvas.getFont());
 		if (fForeground != null)
 			gc.setForeground(fForeground);

 		try {
 			gc.setBackground(getBackground(fCanvas.getDisplay()));
 			gc.fillRectangle(0, 0, size.x, size.y);

 			if (fCachedTextViewer instanceof ITextViewerExtension5)
 				doPaint1(gc);
 			else
 				doPaint(gc);

 		} finally {
 			gc.dispose();
 		}

 		dest.drawImage(fBuffer, 0, 0);
 	}

 	/**
 	 * Returns the viewport height in lines.
 	 *
 	 * @return the viewport height in lines
 	 */
 	protected int getVisibleLinesInViewport() {
 		Rectangle clArea= fCachedTextWidget.getClientArea();
 		if (!clArea.isEmpty())
 			return clArea.height / fCachedTextWidget.getLineHeight();
 		return -1;
 	}

 	/**
 	 * Draws the ruler column.
 	 *
 	 * @param gc the GC to draw into
 	 */
 	private void doPaint(GC gc) {

 		if (fCachedTextViewer == null)
 			return;

 		if (fCachedTextWidget == null)
 			return;


 		int firstLine= 0;

 		int topLine= fCachedTextViewer.getTopIndex() -1;
 		int bottomLine= fCachedTextViewer.getBottomIndex() + 1;

 		try {

 			IRegion region= fCachedTextViewer.getVisibleRegion();
 			IDocument doc= fCachedTextViewer.getDocument();

 			if (doc == null)
 				return;

 			firstLine= doc.getLineOfOffset(region.getOffset());
 			if (firstLine > topLine)
 				topLine= firstLine;

 			int lastLine= doc.getLineOfOffset(region.getOffset() + region.getLength());
 			if (lastLine < bottomLine)
 				bottomLine= lastLine;

 		} catch (BadLocationException x) {
 			return;
 		}

 		fSensitiveToTextChanges= bottomLine - topLine < getVisibleLinesInViewport();

 		int lineheight= fCachedTextWidget.getLineHeight();
 		fScrollPos= fCachedTextWidget.getTopPixel();
 		int canvasheight= fCanvas.getSize().y;

 		int y= ((topLine - firstLine) * lineheight) - fScrollPos + fCachedTextViewer.getTopInset();
 		for (int line= topLine; line <= bottomLine; line++, y+= lineheight) {

 			if (y >= canvasheight)
 				break;

 			paintLine(line, y, lineheight, gc, fCachedTextWidget.getDisplay());
 		}
 	}

 	/**
 	 * Draws the ruler column. Uses <code>ITextViewerExtension5</code> for the
 	 * implementation. Will replace <code>doPinat(GC)</code>.
 	 *
 	 * @param gc the GC to draw into
 	 */
 	private void doPaint1(GC gc) {

 		if (fCachedTextViewer == null)
 			return;

 		ITextViewerExtension5 extension= (ITextViewerExtension5) fCachedTextViewer;

 		int firstLine= 0;


 		int widgetTopLine= fCachedTextWidget.getTopIndex();
 		if (widgetTopLine > 0)
 			-- widgetTopLine;

 		int topLine= extension.widgetLine2ModelLine(widgetTopLine);
 		int bottomLine= fCachedTextViewer.getBottomIndex();
 		if (bottomLine >= 0)
 			++ bottomLine;

 		try {

 			IRegion region= extension.getModelCoverage();
 			IDocument doc= fCachedTextViewer.getDocument();

 			if (doc == null)
 				 return;

 			firstLine= doc.getLineOfOffset(region.getOffset());
 			if (firstLine > topLine || topLine == -1)
 				topLine= firstLine;

 			int lastLine= doc.getLineOfOffset(region.getOffset() + region.getLength());
 			if (lastLine < bottomLine || bottomLine == -1)
 				bottomLine= lastLine;

 		} catch (BadLocationException x) {
 			return;
 		}

 		fSensitiveToTextChanges= bottomLine - topLine < getVisibleLinesInViewport();

 		int lineheight= fCachedTextWidget.getLineHeight();
 		fScrollPos= fCachedTextWidget.getTopPixel();
 		int canvasheight= fCanvas.getSize().y;

 		int y= (widgetTopLine * lineheight) - fScrollPos + fCachedTextViewer.getTopInset();
 		for (int modelLine= topLine; modelLine <= bottomLine; modelLine++) {

 			if (y >= canvasheight)
 				break;

 			int widgetLine= extension.modelLine2WidgetLine(modelLine);
 			if (widgetLine == -1)
 				continue;

 			paintLine(modelLine, y, lineheight, gc, fCachedTextWidget.getDisplay());

 			y+= lineheight;
 		}
 	}

 	/*
 	 * @see IVerticalRulerColumn#redraw()
 	 */
 	public void redraw() {

 		if (fCanvas != null && !fCanvas.isDisposed()) {
 			GC gc= new GC(fCanvas);
 			doubleBufferPaint(gc);
 			gc.dispose();
 		}
 	}

 	/*
 	 * @see IVerticalRulerColumn#setFont(Font)
 	 */
 	public void setFont(Font font) {
 	}

 	/**
 	 * Returns the parent (composite) ruler of this ruler column.
 	 *
 	 * @return the parent ruler
 	 * @since 3.0
 	 */
 	protected CompositeRuler getParentRuler() {
 		return fParentRuler;
 	}

 	/*
 	 * @see org.eclipse.jface.text.source.LineNumberRulerColumn#paintLineHook(int, int, int, org.eclipse.swt.graphics.GC)
 	 */
 	protected void paintLine(int line, int y, int lineheight, GC gc, Display display) {
 		ILineDiffInfo info= getDiffInfo(line);

 		if (info != null) {
 			// width of the column
 			int width= getWidth();

 			// draw background color if special
 			if (hasSpecialColor(info)) {
 				gc.setBackground(getColor(info, display));
 				gc.fillRectangle(0, y, width, lineheight);
 			}

 			/* Deletion Indicator: Simply a horizontal line */
 			int delBefore= info.getRemovedLinesAbove();
 			int delBelow= info.getRemovedLinesBelow();
 			if (delBefore > 0 || delBelow > 0) {
 				Color deletionColor= getDeletionColor(display);
 				gc.setForeground(deletionColor);

 				if (delBefore > 0) {
 					gc.drawLine(0, y, width, y);
 				}

 				if (delBelow > 0) {
 					gc.drawLine(0, y + lineheight - 1, width, y + lineheight - 1);
 				}
 			}
 		}
 	}

 	/**
 	 * Returns whether the line background differs from the default.
 	 *
 	 * @param info the info being queried
 	 * @return <code>true</code> if <code>info</code> describes either a changed or an added line.
 	 */
 	private boolean hasSpecialColor(ILineDiffInfo info) {
 		return info.getChangeType() == ILineDiffInfo.ADDED || info.getChangeType() == ILineDiffInfo.CHANGED;
 	}

 	/**
 	 * Retrieves the <code>ILineDiffInfo</code> for <code>line</code> from the model.
 	 * There are optimizations for direct access and sequential access patterns.
 	 *
 	 * @param line the line we want the info for.
 	 * @return the <code>ILineDiffInfo</code> for <code>line</code>, or <code>null</code>.
 	 */
 	private ILineDiffInfo getDiffInfo(int line) {
 		if (fAnnotationModel == null)
 			return null;

 		// assume direct access
 		if (fAnnotationModel instanceof ILineDiffer) {
 			ILineDiffer differ= (ILineDiffer)fAnnotationModel;
 			return differ.getLineInfo(line);
 		}

 		return null;
 	}

 	/**
 	 * Returns the color for deleted lines.
 	 *
 	 * @param display the display
 	 * @return the color to be used for the deletion indicator
 	 */
 	private Color getDeletionColor(Display display) {
 		return fDeletedColor == null ? getBackground(display) : fDeletedColor;
 	}

 	/**
 	 * Returns the color for the given line diff info.
 	 *
 	 * @param info the <code>ILineDiffInfo</code> being queried
 	 * @param display the display that the drawing occurs on
 	 * @return the correct background color for the line type being described by <code>info</code>
 	 */
 	private Color getColor(ILineDiffInfo info, Display display) {
 		Assert.isTrue(info != null && info.getChangeType() != ILineDiffInfo.UNCHANGED);
 		Color ret= null;
 		switch (info.getChangeType()) {
 			case ILineDiffInfo.CHANGED :
 				ret= fChangedColor;
 				break;
 			case ILineDiffInfo.ADDED :
 				ret= fAddedColor;
 				break;
 		}
 		return ret == null ? getBackground(display) : ret;
 	}

 	/*
 	 * @see org.eclipse.jface.text.source.IVerticalRulerInfo#getLineOfLastMouseButtonActivity()
 	 */
 	public int getLineOfLastMouseButtonActivity() {
 		return getParentRuler().getLineOfLastMouseButtonActivity();
 	}

 	/*
 	 * @see org.eclipse.jface.text.source.IVerticalRulerInfo#toDocumentLineNumber(int)
 	 */
 	public int toDocumentLineNumber(int y_coordinate) {
 		return getParentRuler().toDocumentLineNumber(y_coordinate);
 	}

 	/*
 	 * @see org.eclipse.jface.text.source.IVerticalRulerInfoExtension#getHover()
 	 */
 	public IAnnotationHover getHover() {
 		return fHover;
 	}

 	/*
 	 * @see org.eclipse.jface.text.source.IChangeRulerColumn#setHover(org.eclipse.jface.text.source.IAnnotationHover)
 	 */
 	public void setHover(IAnnotationHover hover) {
 		fHover= hover;
 	}

 	/*
 	 * @see IVerticalRulerColumn#setModel(IAnnotationModel)
 	 */
 	public void setModel(IAnnotationModel model) {
 		IAnnotationModel newModel;
 		if (model instanceof IAnnotationModelExtension) {
 			newModel= ((IAnnotationModelExtension)model).getAnnotationModel(QUICK_DIFF_MODEL_ID);
 		} else {
 			newModel= model;
 		}
 		if (fAnnotationModel != newModel) {
 			if (fAnnotationModel != null) {
 				fAnnotationModel.removeAnnotationModelListener(fAnnotationListener);
 			}
 			fAnnotationModel= newModel;
 			if (fAnnotationModel != null) {
 				fAnnotationModel.addAnnotationModelListener(fAnnotationListener);
 			}
 			redraw();
 		}
 	}

 	/*
 	 * @see org.eclipse.jface.text.source.IChangeRulerColumn#setBackground(org.eclipse.swt.graphics.Color)
 	 */
 	public void setBackground(Color background) {
 		fBackground= background;
 		if (fCanvas != null && !fCanvas.isDisposed())
 			fCanvas.setBackground(getBackground(fCanvas.getDisplay()));
 	}

 	/*
 	 * @see org.eclipse.jface.text.source.IChangeRulerColumn#setAddedColor(org.eclipse.swt.graphics.Color)
 	 */
 	public void setAddedColor(Color addedColor) {
 		fAddedColor= addedColor;
 	}

 	/*
 	 * @see org.eclipse.jface.text.source.IChangeRulerColumn#setChangedColor(org.eclipse.swt.graphics.Color)
 	 */
 	public void setChangedColor(Color changedColor) {
 		fChangedColor= changedColor;
 	}

 	/*
 	 * @see org.eclipse.jface.text.source.IChangeRulerColumn#setDeletedColor(org.eclipse.swt.graphics.Color)
 	 */
 	public void setDeletedColor(Color deletedColor) {
 		fDeletedColor= deletedColor;
 	}

 	/*
 	 * @see org.eclipse.jface.text.source.IVerticalRulerInfoExtension#getModel()
 	 */
 	public IAnnotationModel getModel() {
 		return fAnnotationModel;
 	}

 	/*
 	 * @see IVerticalRulerColumn#getControl()
 	 */
 	public Control getControl() {
 		return fCanvas;
 	}

 	/*
 	 * @see org.eclipse.jface.text.source.IVerticalRulerInfo#getWidth()
 	 */
 	public int getWidth() {
 		return fWidth;
 	}

 	/**
 	 * Triggers a redraw in the display thread.
 	 */
 	protected final void postRedraw() {
 		if (fCanvas != null && !fCanvas.isDisposed()) {
 			Display d= fCanvas.getDisplay();
 			if (d != null) {
 				d.asyncExec(new Runnable() {
 					public void run() {
 						redraw();
 					}
 				});
 			}
 		}
 	}

 	/*
 	 * @see org.eclipse.jface.text.source.IVerticalRulerInfoExtension#addVerticalRulerListener(org.eclipse.jface.text.source.IVerticalRulerListener)
 	 */
 	public void addVerticalRulerListener(IVerticalRulerListener listener) {
 		throw new UnsupportedOperationException();
 	}

 	/*
 	 * @see org.eclipse.jface.text.source.IVerticalRulerInfoExtension#removeVerticalRulerListener(org.eclipse.jface.text.source.IVerticalRulerListener)
 	 */
 	public void removeVerticalRulerListener(IVerticalRulerListener listener) {
 		throw new UnsupportedOperationException();
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2004 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.jface.text.source;

	import org.eclipse.swt.SWT;
	import org.eclipse.swt.custom.StyledText;
	import org.eclipse.swt.events.DisposeEvent;
	import org.eclipse.swt.events.DisposeListener;
	import org.eclipse.swt.events.MouseEvent;
	import org.eclipse.swt.events.MouseListener;
	import org.eclipse.swt.events.MouseMoveListener;
	import org.eclipse.swt.events.PaintEvent;
	import org.eclipse.swt.events.PaintListener;
	import org.eclipse.swt.graphics.Color;
	import org.eclipse.swt.graphics.Font;
	import org.eclipse.swt.graphics.GC;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.graphics.Rectangle;
	import org.eclipse.swt.widgets.Canvas;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Display;

	import org.eclipse.jface.text.Assert;
	import org.eclipse.jface.text.BadLocationException;
	import org.eclipse.jface.text.IDocument;
	import org.eclipse.jface.text.IRegion;
	import org.eclipse.jface.text.ITextListener;
	import org.eclipse.jface.text.ITextViewer;
	import org.eclipse.jface.text.ITextViewerExtension5;
	import org.eclipse.jface.text.IViewportListener;
	import org.eclipse.jface.text.TextEvent;

	/**
	* A vertical ruler column displaying line numbers and serving as a UI for quick diff.
	* Clients instantiate and configure object of this class.
	*
	* @since 3.0
	*/
	public final class ChangeRulerColumn implements IVerticalRulerColumn, IVerticalRulerInfo, IVerticalRulerInfoExtension, IChangeRulerColumn {

	/**
	* Handles all the mouse interaction in this line number ruler column.
	*/
	class MouseHandler implements MouseListener, MouseMoveListener {

	/*
	* @see org.eclipse.swt.events.MouseListener#mouseUp(org.eclipse.swt.events.MouseEvent)
	*/
	public void mouseUp(MouseEvent event) {
	}

	/*
	* @see org.eclipse.swt.events.MouseListener#mouseDown(org.eclipse.swt.events.MouseEvent)
	*/
	public void mouseDown(MouseEvent event) {
	fParentRuler.setLocationOfLastMouseButtonActivity(event.x, event.y);
	}

	/*
	* @see org.eclipse.swt.events.MouseListener#mouseDoubleClick(org.eclipse.swt.events.MouseEvent)
	*/
	public void mouseDoubleClick(MouseEvent event) {
	fParentRuler.setLocationOfLastMouseButtonActivity(event.x, event.y);
	}

	/*
	* @see org.eclipse.swt.events.MouseMoveListener#mouseMove(org.eclipse.swt.events.MouseEvent)
	*/
	public void mouseMove(MouseEvent e) {
	}

	}

	/**
	* Internal listener class.
	*/
	class InternalListener implements IViewportListener, ITextListener {

	/*
	* @see IViewportListener#viewportChanged(int)
	*/
	public void viewportChanged(int verticalPosition) {
	if (verticalPosition != fScrollPos)
	redraw();
	}

	/*
	* @see ITextListener#textChanged(TextEvent)
	*/
	public void textChanged(TextEvent event) {

	if (!event.getViewerRedrawState())
	return;

	if (fSensitiveToTextChanges \|\| event.getDocumentEvent() == null)
	postRedraw();

	}
	}

	/**
	* Internal listener class that will update the ruler when the underlying model changes.
	*/
	class AnnotationListener implements IAnnotationModelListener {
	/*
	* @see org.eclipse.jface.text.source.IAnnotationModelListener#modelChanged(org.eclipse.jface.text.source.IAnnotationModel)
	*/
	public void modelChanged(IAnnotationModel model) {
	postRedraw();
	}
	}

	/** This column's parent ruler */
	private CompositeRuler fParentRuler;
	/** Cached text viewer */
	private ITextViewer fCachedTextViewer;
	/** Cached text widget */
	private StyledText fCachedTextWidget;
	/** The columns canvas */
	private Canvas fCanvas;
	/** Cache for the actual scroll position in pixels */
	private int fScrollPos;
	/** The drawable for double buffering */
	private Image fBuffer;
	/** The internal listener */
	private InternalListener fInternalListener= new InternalListener();
	/** Indicates whether this column reacts on text change events */
	private boolean fSensitiveToTextChanges= false;
	/** The foreground color */
	private Color fForeground;
	/** The background color */
	private Color fBackground;
	/** Color for changed lines */
	private Color fAddedColor;
	/** Color for added lines */
	private Color fChangedColor;
	/** Color for the deleted line indicator */
	private Color fDeletedColor;
	/** The ruler's annotation model. */
	private IAnnotationModel fAnnotationModel;
	/** The ruler's hover */
	private IAnnotationHover fHover;
	/** The internal listener */
	private AnnotationListener fAnnotationListener= new AnnotationListener();
	/** The width of the change ruler column. */
	private int fWidth= 5;


	/**
	* Returns the System background color for list widgets.
	*
	* @param display the display the drawing occurs on
	* @return the System background color for list widgets
	*/
	protected Color getBackground(Display display) {
	if (fBackground == null)
	return display.getSystemColor(SWT.COLOR_LIST_BACKGROUND);
	return fBackground;
	}

	/*
	* @see IVerticalRulerColumn#createControl(CompositeRuler, Composite)
	*/
	public Control createControl(CompositeRuler parentRuler, Composite parentControl) {

	fParentRuler= parentRuler;
	fCachedTextViewer= parentRuler.getTextViewer();
	fCachedTextWidget= fCachedTextViewer.getTextWidget();

	fCanvas= new Canvas(parentControl, SWT.NONE);
	fCanvas.setBackground(getBackground(fCanvas.getDisplay()));
	fCanvas.setForeground(fForeground);

	fCanvas.addPaintListener(new PaintListener() {
	public void paintControl(PaintEvent event) {
	if (fCachedTextViewer != null)
	doubleBufferPaint(event.gc);
	}
	});

	fCanvas.addDisposeListener(new DisposeListener() {
	public void widgetDisposed(DisposeEvent e) {
	handleDispose();
	fCachedTextViewer= null;
	fCachedTextWidget= null;
	}
	});

	MouseHandler mouseHandler= new MouseHandler();

	fCanvas.addMouseListener(mouseHandler);

	fCanvas.addMouseMoveListener(mouseHandler);

	if (fCachedTextViewer != null) {

	fCachedTextViewer.addViewportListener(fInternalListener);
	fCachedTextViewer.addTextListener(fInternalListener);
	}

	return fCanvas;
	}

	/**
	* Disposes the column's resources.
	*/
	protected void handleDispose() {

	if (fAnnotationModel != null) {
	fAnnotationModel.removeAnnotationModelListener(fAnnotationListener);
	fAnnotationModel= null;
	}

	if (fCachedTextViewer != null) {
	fCachedTextViewer.removeViewportListener(fInternalListener);
	fCachedTextViewer.removeTextListener(fInternalListener);
	}

	if (fBuffer != null) {
	fBuffer.dispose();
	fBuffer= null;
	}
	}

	/**
	* Double buffer drawing.
	*
	* @param dest the GC to draw into
	*/
	private void doubleBufferPaint(GC dest) {

	Point size= fCanvas.getSize();

	if (size.x <= 0 \|\| size.y <= 0)
	return;

	if (fBuffer != null) {
	Rectangle r= fBuffer.getBounds();
	if (r.width != size.x \|\| r.height != size.y) {
	fBuffer.dispose();
	fBuffer= null;
	}
	}
	if (fBuffer == null)
	fBuffer= new Image(fCanvas.getDisplay(), size.x, size.y);

	GC gc= new GC(fBuffer);
	gc.setFont(fCanvas.getFont());
	if (fForeground != null)
	gc.setForeground(fForeground);

	try {
	gc.setBackground(getBackground(fCanvas.getDisplay()));
	gc.fillRectangle(0, 0, size.x, size.y);

	if (fCachedTextViewer instanceof ITextViewerExtension5)
	doPaint1(gc);
	else
	doPaint(gc);

	} finally {
	gc.dispose();
	}

	dest.drawImage(fBuffer, 0, 0);
	}

	/**
	* Returns the viewport height in lines.
	*
	* @return the viewport height in lines
	*/
	protected int getVisibleLinesInViewport() {
	Rectangle clArea= fCachedTextWidget.getClientArea();
	if (!clArea.isEmpty())
	return clArea.height / fCachedTextWidget.getLineHeight();
	return -1;
	}

	/**
	* Draws the ruler column.
	*
	* @param gc the GC to draw into
	*/
	private void doPaint(GC gc) {

	if (fCachedTextViewer == null)
	return;

	if (fCachedTextWidget == null)
	return;


	int firstLine= 0;

	int topLine= fCachedTextViewer.getTopIndex() -1;
	int bottomLine= fCachedTextViewer.getBottomIndex() + 1;

	try {

	IRegion region= fCachedTextViewer.getVisibleRegion();
	IDocument doc= fCachedTextViewer.getDocument();

	if (doc == null)
	return;

	firstLine= doc.getLineOfOffset(region.getOffset());
	if (firstLine > topLine)
	topLine= firstLine;

	int lastLine= doc.getLineOfOffset(region.getOffset() + region.getLength());
	if (lastLine < bottomLine)
	bottomLine= lastLine;

	} catch (BadLocationException x) {
	return;
	}

	fSensitiveToTextChanges= bottomLine - topLine < getVisibleLinesInViewport();

	int lineheight= fCachedTextWidget.getLineHeight();
	fScrollPos= fCachedTextWidget.getTopPixel();
	int canvasheight= fCanvas.getSize().y;

	int y= ((topLine - firstLine) * lineheight) - fScrollPos + fCachedTextViewer.getTopInset();
	for (int line= topLine; line <= bottomLine; line++, y+= lineheight) {

	if (y >= canvasheight)
	break;

	paintLine(line, y, lineheight, gc, fCachedTextWidget.getDisplay());
	}
	}

	/**
	* Draws the ruler column. Uses <code>ITextViewerExtension5</code> for the
	* implementation. Will replace <code>doPinat(GC)</code>.
	*
	* @param gc the GC to draw into
	*/
	private void doPaint1(GC gc) {

	if (fCachedTextViewer == null)
	return;

	ITextViewerExtension5 extension= (ITextViewerExtension5) fCachedTextViewer;

	int firstLine= 0;


	int widgetTopLine= fCachedTextWidget.getTopIndex();
	if (widgetTopLine > 0)
	-- widgetTopLine;

	int topLine= extension.widgetLine2ModelLine(widgetTopLine);
	int bottomLine= fCachedTextViewer.getBottomIndex();
	if (bottomLine >= 0)
	++ bottomLine;

	try {

	IRegion region= extension.getModelCoverage();
	IDocument doc= fCachedTextViewer.getDocument();

	if (doc == null)
	return;

	firstLine= doc.getLineOfOffset(region.getOffset());
	if (firstLine > topLine \|\| topLine == -1)
	topLine= firstLine;

	int lastLine= doc.getLineOfOffset(region.getOffset() + region.getLength());
	if (lastLine < bottomLine \|\| bottomLine == -1)
	bottomLine= lastLine;

	} catch (BadLocationException x) {
	return;
	}

	fSensitiveToTextChanges= bottomLine - topLine < getVisibleLinesInViewport();

	int lineheight= fCachedTextWidget.getLineHeight();
	fScrollPos= fCachedTextWidget.getTopPixel();
	int canvasheight= fCanvas.getSize().y;

	int y= (widgetTopLine * lineheight) - fScrollPos + fCachedTextViewer.getTopInset();
	for (int modelLine= topLine; modelLine <= bottomLine; modelLine++) {

	if (y >= canvasheight)
	break;

	int widgetLine= extension.modelLine2WidgetLine(modelLine);
	if (widgetLine == -1)
	continue;

	paintLine(modelLine, y, lineheight, gc, fCachedTextWidget.getDisplay());

	y+= lineheight;
	}
	}

	/*
	* @see IVerticalRulerColumn#redraw()
	*/
	public void redraw() {

	if (fCanvas != null && !fCanvas.isDisposed()) {
	GC gc= new GC(fCanvas);
	doubleBufferPaint(gc);
	gc.dispose();
	}
	}

	/*
	* @see IVerticalRulerColumn#setFont(Font)
	*/
	public void setFont(Font font) {
	}

	/**
	* Returns the parent (composite) ruler of this ruler column.
	*
	* @return the parent ruler
	* @since 3.0
	*/
	protected CompositeRuler getParentRuler() {
	return fParentRuler;
	}

	/*
	* @see org.eclipse.jface.text.source.LineNumberRulerColumn#paintLineHook(int, int, int, org.eclipse.swt.graphics.GC)
	*/
	protected void paintLine(int line, int y, int lineheight, GC gc, Display display) {
	ILineDiffInfo info= getDiffInfo(line);

	if (info != null) {
	// width of the column
	int width= getWidth();

	// draw background color if special
	if (hasSpecialColor(info)) {
	gc.setBackground(getColor(info, display));
	gc.fillRectangle(0, y, width, lineheight);
	}

	/* Deletion Indicator: Simply a horizontal line */
	int delBefore= info.getRemovedLinesAbove();
	int delBelow= info.getRemovedLinesBelow();
	if (delBefore > 0 \|\| delBelow > 0) {
	Color deletionColor= getDeletionColor(display);
	gc.setForeground(deletionColor);

	if (delBefore > 0) {
	gc.drawLine(0, y, width, y);
	}

	if (delBelow > 0) {
	gc.drawLine(0, y + lineheight - 1, width, y + lineheight - 1);
	}
	}
	}
	}

	/**
	* Returns whether the line background differs from the default.
	*
	* @param info the info being queried
	* @return <code>true</code> if <code>info</code> describes either a changed or an added line.
	*/
	private boolean hasSpecialColor(ILineDiffInfo info) {
	return info.getChangeType() == ILineDiffInfo.ADDED \|\| info.getChangeType() == ILineDiffInfo.CHANGED;
	}

	/**
	* Retrieves the <code>ILineDiffInfo</code> for <code>line</code> from the model.
	* There are optimizations for direct access and sequential access patterns.
	*
	* @param line the line we want the info for.
	* @return the <code>ILineDiffInfo</code> for <code>line</code>, or <code>null</code>.
	*/
	private ILineDiffInfo getDiffInfo(int line) {
	if (fAnnotationModel == null)
	return null;

	// assume direct access
	if (fAnnotationModel instanceof ILineDiffer) {
	ILineDiffer differ= (ILineDiffer)fAnnotationModel;
	return differ.getLineInfo(line);
	}

	return null;
	}

	/**
	* Returns the color for deleted lines.
	*
	* @param display the display
	* @return the color to be used for the deletion indicator
	*/
	private Color getDeletionColor(Display display) {
	return fDeletedColor == null ? getBackground(display) : fDeletedColor;
	}

	/**
	* Returns the color for the given line diff info.
	*
	* @param info the <code>ILineDiffInfo</code> being queried
	* @param display the display that the drawing occurs on
	* @return the correct background color for the line type being described by <code>info</code>
	*/
	private Color getColor(ILineDiffInfo info, Display display) {
	Assert.isTrue(info != null && info.getChangeType() != ILineDiffInfo.UNCHANGED);
	Color ret= null;
	switch (info.getChangeType()) {
	case ILineDiffInfo.CHANGED :
	ret= fChangedColor;
	break;
	case ILineDiffInfo.ADDED :
	ret= fAddedColor;
	break;
	}
	return ret == null ? getBackground(display) : ret;
	}

	/*
	* @see org.eclipse.jface.text.source.IVerticalRulerInfo#getLineOfLastMouseButtonActivity()
	*/
	public int getLineOfLastMouseButtonActivity() {
	return getParentRuler().getLineOfLastMouseButtonActivity();
	}

	/*
	* @see org.eclipse.jface.text.source.IVerticalRulerInfo#toDocumentLineNumber(int)
	*/
	public int toDocumentLineNumber(int y_coordinate) {
	return getParentRuler().toDocumentLineNumber(y_coordinate);
	}

	/*
	* @see org.eclipse.jface.text.source.IVerticalRulerInfoExtension#getHover()
	*/
	public IAnnotationHover getHover() {
	return fHover;
	}

	/*
	* @see org.eclipse.jface.text.source.IChangeRulerColumn#setHover(org.eclipse.jface.text.source.IAnnotationHover)
	*/
	public void setHover(IAnnotationHover hover) {
	fHover= hover;
	}

	/*
	* @see IVerticalRulerColumn#setModel(IAnnotationModel)
	*/
	public void setModel(IAnnotationModel model) {
	IAnnotationModel newModel;
	if (model instanceof IAnnotationModelExtension) {
	newModel= ((IAnnotationModelExtension)model).getAnnotationModel(QUICK_DIFF_MODEL_ID);
	} else {
	newModel= model;
	}
	if (fAnnotationModel != newModel) {
	if (fAnnotationModel != null) {
	fAnnotationModel.removeAnnotationModelListener(fAnnotationListener);
	}
	fAnnotationModel= newModel;
	if (fAnnotationModel != null) {
	fAnnotationModel.addAnnotationModelListener(fAnnotationListener);
	}
	redraw();
	}
	}

	/*
	* @see org.eclipse.jface.text.source.IChangeRulerColumn#setBackground(org.eclipse.swt.graphics.Color)
	*/
	public void setBackground(Color background) {
	fBackground= background;
	if (fCanvas != null && !fCanvas.isDisposed())
	fCanvas.setBackground(getBackground(fCanvas.getDisplay()));
	}

	/*
	* @see org.eclipse.jface.text.source.IChangeRulerColumn#setAddedColor(org.eclipse.swt.graphics.Color)
	*/
	public void setAddedColor(Color addedColor) {
	fAddedColor= addedColor;
	}

	/*
	* @see org.eclipse.jface.text.source.IChangeRulerColumn#setChangedColor(org.eclipse.swt.graphics.Color)
	*/
	public void setChangedColor(Color changedColor) {
	fChangedColor= changedColor;
	}

	/*
	* @see org.eclipse.jface.text.source.IChangeRulerColumn#setDeletedColor(org.eclipse.swt.graphics.Color)
	*/
	public void setDeletedColor(Color deletedColor) {
	fDeletedColor= deletedColor;
	}

	/*
	* @see org.eclipse.jface.text.source.IVerticalRulerInfoExtension#getModel()
	*/
	public IAnnotationModel getModel() {
	return fAnnotationModel;
	}

	/*
	* @see IVerticalRulerColumn#getControl()
	*/
	public Control getControl() {
	return fCanvas;
	}

	/*
	* @see org.eclipse.jface.text.source.IVerticalRulerInfo#getWidth()
	*/
	public int getWidth() {
	return fWidth;
	}

	/**
	* Triggers a redraw in the display thread.
	*/
	protected final void postRedraw() {
	if (fCanvas != null && !fCanvas.isDisposed()) {
	Display d= fCanvas.getDisplay();
	if (d != null) {
	d.asyncExec(new Runnable() {
	public void run() {
	redraw();
	}
	});
	}
	}
	}

	/*
	* @see org.eclipse.jface.text.source.IVerticalRulerInfoExtension#addVerticalRulerListener(org.eclipse.jface.text.source.IVerticalRulerListener)
	*/
	public void addVerticalRulerListener(IVerticalRulerListener listener) {
	throw new UnsupportedOperationException();
	}

	/*
	* @see org.eclipse.jface.text.source.IVerticalRulerInfoExtension#removeVerticalRulerListener(org.eclipse.jface.text.source.IVerticalRulerListener)
	*/
	public void removeVerticalRulerListener(IVerticalRulerListener listener) {
	throw new UnsupportedOperationException();
	}
	}