/*******************************************************************************
 * 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.ui.texteditor;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.eclipse.swt.custom.StyledText;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.RGB;

import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.text.CursorLinePainter;
import org.eclipse.jface.text.IPainter;
import org.eclipse.jface.text.ITextViewerExtension2;
import org.eclipse.jface.text.ITextViewerExtension4;
import org.eclipse.jface.text.MarginPainter;
import org.eclipse.jface.text.source.AnnotationPainter;
import org.eclipse.jface.text.source.IAnnotationAccess;
import org.eclipse.jface.text.source.ICharacterPairMatcher;
import org.eclipse.jface.text.source.IOverviewRuler;
import org.eclipse.jface.text.source.ISharedTextColors;
import org.eclipse.jface.text.source.ISourceViewer;
import org.eclipse.jface.text.source.MatchingCharacterPainter;

import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.preference.PreferenceConverter;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;

/**
 * Support for source viewer decoration.
 * 
 * @since 2.1
 */
public class SourceViewerDecorationSupport {
	
	
	/*
	 * @see IPropertyChangeListener
	 */
	private class FontPropertyChangeListener implements IPropertyChangeListener {
		/*
		 * @see IPropertyChangeListener#propertyChange(org.eclipse.jface.util.PropertyChangeEvent)
		 */
		public void propertyChange(PropertyChangeEvent event) {
			if (fSymbolicFontName != null && fSymbolicFontName.equals(event.getProperty()))
				fMarginPainter.initialize();
		}
	}

	
	/** The viewer */
	private ISourceViewer fSourceViewer;
	/** The viewer's overview ruler */
	private IOverviewRuler fOverviewRuler;
	/** The annotation access */
	private IAnnotationAccess fAnnotationAccess;
	/** The shared color manager */
	private ISharedTextColors fSharedTextColors;
	
	/** The editor's line painter */
	private CursorLinePainter fCursorLinePainter;
	/** The editor's margin ruler painter */
	private MarginPainter fMarginPainter;
	/** The editor's annotation painter */
	private AnnotationPainter fAnnotationPainter;
	/** The editor's peer character painter */
	private MatchingCharacterPainter fMatchingCharacterPainter;
	/** The character painter's pair matcher */
	private ICharacterPairMatcher fCharacterPairMatcher;
	
	/** Table of annotation type preference infos */
	private Map fAnnotationTypeKeyMap= new HashMap();
	/** Preference key for the cursor line highlighting */
	private String fCursorLinePainterEnableKey;
	/** Preference key for the cursor line background color */
	private String fCursorLinePainterColorKey;
	/** Preference key for the margin painter */	
	private String fMarginPainterEnableKey;
	/** Preference key for the margin painter color */
	private String fMarginPainterColorKey;
	/** Preference key for the margin painter column */
	private String fMarginPainterColumnKey;
	/** Preference key for the matching character painter */
	private String fMatchingCharacterPainterEnableKey;
	/** Preference key for the matching character painter color */
	private String fMatchingCharacterPainterColorKey;
	/** The property change listener */
	private IPropertyChangeListener fPropertyChangeListener;
	/** The preference store */
	private IPreferenceStore fPreferenceStore;
	/** The symbolic font name */
	private String fSymbolicFontName;
	/** The font change listener */
	private FontPropertyChangeListener fFontPropertyChangeListener;


	/**
	 * Creates a new decoration support for the given viewer.
	 * 
	 * @param sourceViewer the source viewer
	 * @param overviewRuler the viewer's overview ruler
	 * @param annotationAccess the annotation access
	 * @param sharedTextColors the shared text color manager
	 */
	public SourceViewerDecorationSupport(ISourceViewer sourceViewer, IOverviewRuler overviewRuler, IAnnotationAccess annotationAccess, ISharedTextColors sharedTextColors) {
		fSourceViewer= sourceViewer;
		fOverviewRuler= overviewRuler;
		fAnnotationAccess= annotationAccess;
		fSharedTextColors= sharedTextColors;
	}
	
	/**
	 * Installs this decoration support on th given preference store. It assumes
	 * that this support has completely been configured.
	 * 
	 * @param store the preference store
	 */
	public void install(IPreferenceStore store) {
		
		fPreferenceStore= store;
		if (fPreferenceStore != null) {
			fPropertyChangeListener= new IPropertyChangeListener() {
				public void propertyChange(PropertyChangeEvent event) {
					handlePreferenceStoreChanged(event);
				}
			};
			fPreferenceStore.addPropertyChangeListener(fPropertyChangeListener);
		}
		
		updateTextDecorations();
		updateOverviewDecorations();
	}

	/**
	 * Updates the text docorations for all configured annotation types.
	 */
	private void updateTextDecorations() {
		
		StyledText widget= fSourceViewer.getTextWidget();
		if (widget == null || widget.isDisposed())
			return;
		
		if (areMatchingCharactersShown())
			showMatchingCharacters();
		else
			hideMatchingCharacters();
			
		if (isCursorLineShown())
			showCursorLine();
		else
			hideCursorLine();
		
		if (isMarginShown())
			showMargin();
		else
			hideMargin();
		
		Iterator e= fAnnotationTypeKeyMap.keySet().iterator();
		while (e.hasNext()) {
			Object type= e.next();
			if (areAnnotationsShown(type))
				showAnnotations(type, false);
			else
				hideAnnotations(type, false);
			if (areAnnotationsHighlighted(type))
				showAnnotations(type, true);
			else
				hideAnnotations(type, true);
		}
	}
	
	/**
	 * Updates the annotation overview for all configured annotation types.
	 */
	public void updateOverviewDecorations() {
		Iterator e= fAnnotationTypeKeyMap.keySet().iterator();
		while (e.hasNext()) {
			Object type= e.next();
			if (isAnnotationOverviewShown(type))
				showAnnotationOverview(type);
			else
				hideAnnotationOverview(type);
		}
	}
	
	/**
	 * Uninstalls this support from the preference store it has previously been
	 * installed on. If there is no such preference store, this call is without
	 * effect.
	 */
	public void uninstall() {
		
		if (fPreferenceStore != null) {
			fPreferenceStore.removePropertyChangeListener(fPropertyChangeListener);
			fPropertyChangeListener= null;
			fPreferenceStore= null;
		}
		
		if (fFontPropertyChangeListener != null) {		
			JFaceResources.getFontRegistry().removeListener(fFontPropertyChangeListener);
			fFontPropertyChangeListener= null;
		}
	}
	
	/**
	 * Disposes this decoration support. Internally calls
	 * <code>uninstall</code>.
	 */
	public void dispose() {
		uninstall();
		updateTextDecorations();
		updateOverviewDecorations();
	}
	
	/**
	 * Sets the character pair matcher for the matching character painter.
	 * 
	 * @param pairMatcher
	 */
	public void setCharacterPairMatcher(ICharacterPairMatcher pairMatcher) {
		fCharacterPairMatcher= pairMatcher;
	}
	
	/**
	 * Sets the preference keys for the annotation painter.
	 * 
	 * @param type the annotation type
	 * @param colorKey the preference key for the color
	 * @param editorKey the preference key for the presentation in the text area
	 * @param overviewRulerKey the preference key for the presentation in the overview  ruler
	 * @param layer the layer
	 */
	public void setAnnotationPainterPreferenceKeys(Object type, String colorKey, String editorKey, String overviewRulerKey, int layer) {
		AnnotationPreference info= new AnnotationPreference(type, colorKey, editorKey, overviewRulerKey, layer);
		fAnnotationTypeKeyMap.put(type, info);
	}
	
	/**
	 * Sets the preference info for the annotation painter.
	 * @param info the preference info to be set
	 */
	public void setAnnotationPreference(AnnotationPreference info) {
		fAnnotationTypeKeyMap.put(info.getAnnotationType(), info);
	}
	
	/**
	 * Sets the preference keys for the cursor line painter.
	 * @param enableKey the preference key for the cursor line painter
	 * @param colorKey the preference key for the color used by the cursor line
	 *        painter
	 */
	public void setCursorLinePainterPreferenceKeys(String enableKey, String colorKey) {
		fCursorLinePainterEnableKey= enableKey;
		fCursorLinePainterColorKey= colorKey;
	}
	
	/**
	 * Sets the preference keys for the margin painter.
	 * @param enableKey the preference key for the margin painter
	 * @param colorKey the preference key for the color used by the margin
	 *         painter
	 * @param columnKey the preference key for the margin column
	 */
	public void setMarginPainterPreferenceKeys(String enableKey, String colorKey, String columnKey) {
		fMarginPainterEnableKey= enableKey;
		fMarginPainterColorKey= colorKey;
		fMarginPainterColumnKey= columnKey;
	}
	
	/**
	 * Sets the preference keys for the matching character painter.
	 * @param enableKey the preference key for the matching character painter
	 * @param colorKey the preference key for the color used by the matching
	 *         character  painter
	 */
	public void setMatchingCharacterPainterPreferenceKeys(String enableKey, String colorKey) {
		fMatchingCharacterPainterEnableKey= enableKey;
		fMatchingCharacterPainterColorKey= colorKey;
	}
	
	/**
	 * Sets the symbolic font name that is used for computing the margin width.
	 * @param symbolicFontName
	 */
	public void setSymbolicFontName(String symbolicFontName) {
		fSymbolicFontName= symbolicFontName;
	}
	
	/**
	 * Returns the annotation preference for the given key.
	 * 
	 * @param preferenceKey the preference key string
	 * @return the annotation preference
	 */
	private AnnotationPreference getAnnotationPreferenceInfo(String preferenceKey) {
		Iterator e= fAnnotationTypeKeyMap.values().iterator();
		while (e.hasNext()) {
			AnnotationPreference info= (AnnotationPreference) e.next();
			if (info != null && info.isPreferenceKey(preferenceKey)) 
				return info;
		}
		return null;
	}
	
	
	/*
	 * @see AbstractTextEditor#handlePreferenceStoreChanged(PropertyChangeEvent)
 	 */
	protected void handlePreferenceStoreChanged(PropertyChangeEvent event) {
		
		String p= event.getProperty();		
		
		if (fMatchingCharacterPainterEnableKey != null && fMatchingCharacterPainterEnableKey.equals(p) && fCharacterPairMatcher != null) {
			if (areMatchingCharactersShown())
				showMatchingCharacters();
			else
				hideMatchingCharacters();
			return;
		}
		
		if (fMatchingCharacterPainterColorKey != null && fMatchingCharacterPainterColorKey.equals(p)) {
			if (fMatchingCharacterPainter != null) {
				fMatchingCharacterPainter.setColor(getColor(fMatchingCharacterPainterColorKey));
				fMatchingCharacterPainter.paint(IPainter.CONFIGURATION);
			}
			return;
		}
		
		if (fCursorLinePainterEnableKey.equals(p)) {
			if (isCursorLineShown())
				showCursorLine();
			else
				hideCursorLine();
			return;
		}
		
		if (fCursorLinePainterColorKey.equals(p)) {
			if (fCursorLinePainter != null) {
				hideCursorLine();
				showCursorLine();
			}					
			return;
		}
		
		if (fMarginPainterEnableKey.equals(p)) {
			if (isMarginShown())
				showMargin();
			else
				hideMargin();
			return;
		}
		
		if (fMarginPainterColorKey.equals(p)) {
			if (fMarginPainter != null) {
				fMarginPainter.setMarginRulerColor(getColor(fMarginPainterColorKey));
				fMarginPainter.paint(IPainter.CONFIGURATION);
			}
			return;
		}
		
		if (fMarginPainterColumnKey.equals(p)) {
			if (fMarginPainter != null && fPreferenceStore != null) {
				fMarginPainter.setMarginRulerColumn(fPreferenceStore.getInt(fMarginPainterColumnKey));
				fMarginPainter.paint(IPainter.CONFIGURATION);
			}
			return;
		}
		
		AnnotationPreference info= getAnnotationPreferenceInfo(p);
		if (info != null) {
			
			if (info.getColorPreferenceKey().equals(p)) {
				Color color= getColor(info.getColorPreferenceKey());
				if (fAnnotationPainter != null) {
					fAnnotationPainter.setAnnotationTypeColor(info.getAnnotationType(), color);
					fAnnotationPainter.paint(IPainter.CONFIGURATION);
				}
				setAnnotationOverviewColor(info.getAnnotationType(), color);
				return;
			}
			
			if (info.getTextPreferenceKey().equals(p)) {
				if (areAnnotationsShown(info.getAnnotationType()))
					showAnnotations(info.getAnnotationType(), false);
				else
					hideAnnotations(info.getAnnotationType(), false);
				return;
			}
			
			if (info.getHighlightPreferenceKey() != null && info.getHighlightPreferenceKey().equals(p)) {
				if (areAnnotationsHighlighted(info.getAnnotationType()))
					showAnnotations(info.getAnnotationType(), true);
				else
					hideAnnotations(info.getAnnotationType(), true);
				return;
			}
			
			if (info.getOverviewRulerPreferenceKey().equals(p)) {
				if (isAnnotationOverviewShown(info.getAnnotationType()))
					showAnnotationOverview(info.getAnnotationType());
				else
					hideAnnotationOverview(info.getAnnotationType());
				return;
			}
		}			
				
	}
	
	/**
	 * Returns the shared color for the given key.
	 * 
	 * @param key the color key string
	 * @return the shared color for the given key
	 */
	private Color getColor(String key) {
		if (fPreferenceStore != null) {
			RGB rgb= PreferenceConverter.getColor(fPreferenceStore, key);
			return getColor(rgb);
		}
		return null;
	}
	
	/**
	 * Returns the shared color for the given RGB.
	 * 
	 * @param rgb the rgb
	 * @return the shared color for the given rgb
	 */
	private Color getColor(RGB rgb) {
		return fSharedTextColors.getColor(rgb);
	}
	
	/**
	 * Returns the color of the given annotation type.
	 * 
	 * @param annotationType the annotation type
	 * @return the color of the annotation type
	 */
	private Color getAnnotationTypeColor(Object annotationType) {
		AnnotationPreference info= (AnnotationPreference) fAnnotationTypeKeyMap.get(annotationType);
		if (info != null)
			return getColor( info.getColorPreferenceKey());
		return null;
	}
	

	/**
	 * Returns the layer of the given annotation type.
	 * 
	 * @param annotationType the annotation type
	 * @return the layer
	 */
	private int getAnnotationTypeLayer(Object annotationType) {
		AnnotationPreference info= (AnnotationPreference) fAnnotationTypeKeyMap.get(annotationType);
		if (info != null)
			return info.getPresentationLayer();
		return 0;
	}
	
	/**
	 * Enables showing of matching characters.
	 */
	private void showMatchingCharacters() {
		if (fMatchingCharacterPainter == null) {
			if (fSourceViewer instanceof ITextViewerExtension2) {
				fMatchingCharacterPainter= new MatchingCharacterPainter(fSourceViewer, fCharacterPairMatcher);
				fMatchingCharacterPainter.setColor(getColor(fMatchingCharacterPainterColorKey));
				ITextViewerExtension2 extension= (ITextViewerExtension2) fSourceViewer;
				extension.addPainter(fMatchingCharacterPainter);
			}
		}
	}

	/**
	 * Disables showing of matching characters.
	 */
	private void hideMatchingCharacters() {
		if (fMatchingCharacterPainter != null) {
			if (fSourceViewer instanceof ITextViewerExtension2) {
				ITextViewerExtension2 extension= (ITextViewerExtension2) fSourceViewer;
				extension.removePainter(fMatchingCharacterPainter);
				fMatchingCharacterPainter.deactivate(true);
				fMatchingCharacterPainter.dispose();
				fMatchingCharacterPainter= null;
			}
		}
	}
	
	/**
	 * Tells whether matching charaters are shown.
	 * 
	 * @return <code>true</code> if the matching characters are shown
	 */
	private boolean areMatchingCharactersShown() {
		if (fPreferenceStore != null && fMatchingCharacterPainterEnableKey != null)
			return fPreferenceStore.getBoolean(fMatchingCharacterPainterEnableKey);
		return false;
	}
	
	/**
	 * Shows the cursor line.
	 */	
	private void showCursorLine() {
		if (fCursorLinePainter == null) {
			if (fSourceViewer instanceof ITextViewerExtension2) {
				fCursorLinePainter= new CursorLinePainter(fSourceViewer);
				fCursorLinePainter.setHighlightColor(getColor(fCursorLinePainterColorKey));
				ITextViewerExtension2 extension= (ITextViewerExtension2) fSourceViewer;
				extension.addPainter(fCursorLinePainter);
			}
		}
	}

	/**
	 * Hides the cursor line.
	 */	
	private void hideCursorLine() {
		if (fCursorLinePainter != null) {
			if (fSourceViewer instanceof ITextViewerExtension2) {
				ITextViewerExtension2 extension= (ITextViewerExtension2) fSourceViewer;
				extension.removePainter(fCursorLinePainter);
				fCursorLinePainter.deactivate(true);
				fCursorLinePainter.dispose();
				fCursorLinePainter= null;
			}
		}
	}
	
	/**
	 * Tells whether the cursor line is shown.
	 * 
	 * @return <code>true</code> f the cursor line is shown
	 */
	private boolean isCursorLineShown() {
		if (fPreferenceStore != null)
			return fPreferenceStore.getBoolean(fCursorLinePainterEnableKey);
		return false;
	}
	
	/**
	 * Shows the margin.
	 */	
	private void showMargin() {
		if (fMarginPainter == null) {
			if (fSourceViewer instanceof ITextViewerExtension2) {
				fMarginPainter= new MarginPainter(fSourceViewer);
				fMarginPainter.setMarginRulerColor(getColor(fMarginPainterColorKey));
				if (fPreferenceStore != null)
					fMarginPainter.setMarginRulerColumn(fPreferenceStore.getInt(fMarginPainterColumnKey));
				ITextViewerExtension2 extension= (ITextViewerExtension2) fSourceViewer;
				extension.addPainter(fMarginPainter);
				
				fFontPropertyChangeListener= new FontPropertyChangeListener();
				JFaceResources.getFontRegistry().addListener(fFontPropertyChangeListener);
			}
		}
	}

	/**
	 * Hides the margin.
	 */	
	private void hideMargin() {
		if (fMarginPainter != null) {
			if (fSourceViewer instanceof ITextViewerExtension2) {
				JFaceResources.getFontRegistry().removeListener(fFontPropertyChangeListener);
				fFontPropertyChangeListener= null;
				
				ITextViewerExtension2 extension= (ITextViewerExtension2) fSourceViewer;
				extension.removePainter(fMarginPainter);
				fMarginPainter.deactivate(true);
				fMarginPainter.dispose();
				fMarginPainter= null;
			}
		}
	}

	/**
	 * Tells whether the margin is shown.
	 * 
	 * @return <code>true</code> if the margin is shown
	 */	
	private boolean isMarginShown() {
		if (fPreferenceStore != null)
			return fPreferenceStore.getBoolean(fMarginPainterEnableKey);
		return false;
	}
	
	/**
	 * Enables annotations in the source viewer for the given annotation type.
	 * 
	 * @param annotationType the annotation type
	 * @param highlighting <code>true</code> if highlighting <code>false</code> if painting squiggles
	 */
	private void showAnnotations(Object annotationType, boolean highlighting) {
		if (fSourceViewer instanceof ITextViewerExtension2) {
			if (fAnnotationPainter == null) {
				fAnnotationPainter= new AnnotationPainter(fSourceViewer, fAnnotationAccess);
				if (fSourceViewer instanceof ITextViewerExtension4)
					((ITextViewerExtension4)fSourceViewer).addTextPresentationListener(fAnnotationPainter);
				ITextViewerExtension2 extension= (ITextViewerExtension2) fSourceViewer;
				extension.addPainter(fAnnotationPainter);
			}
			fAnnotationPainter.setAnnotationTypeColor(annotationType, getAnnotationTypeColor(annotationType));
			if (highlighting)
				fAnnotationPainter.addHighlightAnnotationType(annotationType);
			else
				fAnnotationPainter.addAnnotationType(annotationType);
			fAnnotationPainter.paint(IPainter.CONFIGURATION);
		}
	}
	
	/**
	 * Shuts down the annotation painter.
	 */
	private void shutdownAnnotationPainter() {
		if (!fAnnotationPainter.isPaintingAnnotations()) {
			if (fSourceViewer instanceof ITextViewerExtension2) {
				ITextViewerExtension2 extension= (ITextViewerExtension2) fSourceViewer;
				extension.removePainter(fAnnotationPainter);
			}
			if (fSourceViewer instanceof ITextViewerExtension4)
				((ITextViewerExtension4)fSourceViewer).removeTextPresentationListener(fAnnotationPainter);
			
			fAnnotationPainter.deactivate(true);
			fAnnotationPainter.dispose();
			fAnnotationPainter= null;
		} else {
			fAnnotationPainter.paint(IPainter.CONFIGURATION);
		}
	}

	/**
	 * Hides annotations in the source viewer for the given annotation type.
	 * 
	 * @param annotationType the annotation type
	 * @param highlighting <code>true</code> if highlighting <code>false</code> if painting squiggles
	 * @since 3.0
	 */
	private void hideAnnotations(Object annotationType, boolean highlighting) {
		if (fAnnotationPainter != null) {
			if (highlighting)
				fAnnotationPainter.removeHighlightAnnotationType(annotationType);
			else
				fAnnotationPainter.removeAnnotationType(annotationType);
			fAnnotationPainter.paint(IPainter.CONFIGURATION);
			shutdownAnnotationPainter();
		}
	}
	
	/**
	 * Tells whether annotations are shown in the source viewer for the given type.
	 * 
	 * @param annotationType the annotation type
	 * @return <code>true</code> if the annotations are shown
	 */	
	private boolean areAnnotationsShown(Object annotationType) {
		if (fPreferenceStore != null) {
			AnnotationPreference info= (AnnotationPreference) fAnnotationTypeKeyMap.get(annotationType);
			if (info != null)
				return fPreferenceStore.getBoolean(info.getTextPreferenceKey());
		}
		return false;
	}
	
	/**
	 * Tells whether annotations are highlighted in the source viewer for the given type.
	 * 
	 * @param annotationType the annotation type
	 * @return <code>true</code> if the annotations are highlighted
	 * @since 3.0
	 */	
	private boolean areAnnotationsHighlighted(Object annotationType) {
		if (fPreferenceStore != null) {
			AnnotationPreference info= (AnnotationPreference)fAnnotationTypeKeyMap.get(annotationType);
			if (info != null)
				return info.getHighlightPreferenceKey() != null && fPreferenceStore.getBoolean(info.getHighlightPreferenceKey());
		}
		return false;
	}
	
	/**
	 * Tells whether annotation overview is enabled for the given type.
	 * 
	 * @param annotationType the annotation type
	 * @return <code>true</code> if the annotation overview is shown
	 */	
	private boolean isAnnotationOverviewShown(Object annotationType) {
		if (fPreferenceStore != null) {
			if (fOverviewRuler != null) {
				AnnotationPreference info= (AnnotationPreference) fAnnotationTypeKeyMap.get(annotationType);
				if (info != null)
					return fPreferenceStore.getBoolean(info.getOverviewRulerPreferenceKey());
			}
		}
		return false;
	}

	/**
	 * Enable annotation overview for the given annotation type.
	 * 
	 * @param annotationType the annotation type
	 */	
	private void showAnnotationOverview(Object annotationType) {
		if (fOverviewRuler != null) {
			fOverviewRuler.setAnnotationTypeColor(annotationType, getAnnotationTypeColor(annotationType));
			fOverviewRuler.setAnnotationTypeLayer(annotationType, getAnnotationTypeLayer(annotationType));
			fOverviewRuler.addAnnotationType(annotationType);
			fOverviewRuler.update();
		}
	}
	
	/**
	 * Hides the annotation overview for the given type.
	 * @param annotationType the annotation type
	 */
	private void hideAnnotationOverview(Object annotationType) {
		if (fOverviewRuler != null) {
			fOverviewRuler.removeAnnotationType(annotationType);
			fOverviewRuler.update();
		}
	}
	
	/**
	 * Hides the annotation overview.
	 * @param annotationType the annotation type
	 */
	public void hideAnnotationOverview() {
		if (fOverviewRuler != null) {
			Iterator e= fAnnotationTypeKeyMap.keySet().iterator();
			while (e.hasNext())
				fOverviewRuler.removeAnnotationType(e.next());
			fOverviewRuler.update();
		}
	}
	
	/**
	 * Sets the annotion overview color for the given annotation type.
	 * 
	 * @param annotationType the annotation type
	 * @param color the color
	 */
	private void setAnnotationOverviewColor(Object annotationType, Color color) {
		if (fOverviewRuler != null) {
			fOverviewRuler.setAnnotationTypeColor(annotationType, color);
			fOverviewRuler.update();
		}
	}	
}