core/plugins/org.eclipse.dltk.ui/src/org/eclipse/dltk/internal/ui/editor/ScriptSourceViewer.java - dltk/org.eclipse.dltk.core - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2017 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
  * 			Alex Panchenko <alex@xored.com>
  *******************************************************************************/
 package org.eclipse.dltk.internal.ui.editor;

 import java.util.ArrayList;

 import org.eclipse.core.runtime.Assert;
 import org.eclipse.dltk.ui.text.ScriptSourceViewerConfiguration;
 import org.eclipse.jface.preference.IPreferenceStore;
 import org.eclipse.jface.preference.PreferenceConverter;
 import org.eclipse.jface.resource.JFaceResources;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IRegion;
 import org.eclipse.jface.text.ITextPresentationListener;
 import org.eclipse.jface.text.Region;
 import org.eclipse.jface.text.information.IInformationPresenter;
 import org.eclipse.jface.text.reconciler.IReconciler;
 import org.eclipse.jface.text.source.IOverviewRuler;
 import org.eclipse.jface.text.source.IVerticalRuler;
 import org.eclipse.jface.text.source.SourceViewerConfiguration;
 import org.eclipse.jface.text.source.projection.ProjectionViewer;
 import org.eclipse.jface.util.IPropertyChangeListener;
 import org.eclipse.jface.util.PropertyChangeEvent;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.StyleRange;
 import org.eclipse.swt.custom.StyledText;
 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.RGB;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.ui.texteditor.AbstractDecoratedTextEditorPreferenceConstants;
 import org.eclipse.ui.texteditor.AbstractTextEditor;

 public class ScriptSourceViewer extends ProjectionViewer implements
 		IPropertyChangeListener {

 	/**
 	 * Text operation code for requesting the outline for the current input.
 	 */
 	public static final int SHOW_OUTLINE = 51;

 	/**
 	 * Text operation code for requesting the outline for the element at the
 	 * current position.
 	 */
 	public static final int OPEN_STRUCTURE = 52;

 	/**
 	 * Text operation code for requesting the hierarchy for the current input.
 	 */
 	public static final int SHOW_HIERARCHY = 53;

 	private IInformationPresenter fOutlinePresenter;

 	private IInformationPresenter fStructurePresenter;

 	private IInformationPresenter fHierarchyPresenter;

 	/**
 	 * This viewer's foreground color.
 	 */
 	private Color fForegroundColor;

 	/**
 	 * The viewer's background color.
 	 */
 	private Color fBackgroundColor;

 	/**
 	 * This viewer's selection foreground color.
 	 */
 	private Color fSelectionForegroundColor;

 	/**
 	 * The viewer's selection background color.
 	 */
 	private Color fSelectionBackgroundColor;

 	/**
 	 * The preference store.
 	 */
 	private IPreferenceStore fPreferenceStore;

 	/**
 	 * Is this source viewer configured?
 	 */
 	private boolean fIsConfigured;

 	// /**
 	// * The backspace manager of this viewer.
 	// *
 	// */
 	// private SmartBackspaceManager fBackspaceManager;

 	/**
 	 * Whether to delay setting the visual document until the projection has
 	 * been computed.
 	 * <p>
 	 * Added for performance optimization.
 	 * </p>
 	 *
 	 * @see #prepareDelayedProjection()
 	 */
 	private boolean fIsSetVisibleDocumentDelayed = false;

 	public ScriptSourceViewer(Composite parent, IVerticalRuler verticalRuler,
 			IOverviewRuler overviewRuler, boolean showAnnotationsOverview,
 			int styles, IPreferenceStore store) {
 		super(parent, verticalRuler, overviewRuler, showAnnotationsOverview,
 				styles);
 		setPreferenceStore(store);
 	}

 	@Override
 	public void doOperation(int operation) {
 		if (getTextWidget() == null)
 			return;

 		switch (operation) {
 		case SHOW_OUTLINE:
 			if (fOutlinePresenter != null)
 				fOutlinePresenter.showInformation();
 			return;
 		case OPEN_STRUCTURE:
 			if (fStructurePresenter != null)
 				fStructurePresenter.showInformation();
 			return;
 		case SHOW_HIERARCHY:
 			if (fHierarchyPresenter != null)
 				fHierarchyPresenter.showInformation();
 			return;
 		}

 		super.doOperation(operation);
 	}

 	@Override
 	public boolean canDoOperation(int operation) {
 		if (operation == SHOW_OUTLINE)
 			return fOutlinePresenter != null;
 		if (operation == OPEN_STRUCTURE)
 			return fStructurePresenter != null;
 		if (operation == SHOW_HIERARCHY)
 			return fHierarchyPresenter != null;

 		return super.canDoOperation(operation);
 	}

 	@Override
 	public void configure(SourceViewerConfiguration configuration) {

 		/*
 		 * Prevent access to colors disposed in unconfigure(), see:
 		 * https://bugs.eclipse.org/bugs/show_bug.cgi?id=53641
 		 * https://bugs.eclipse.org/bugs/show_bug.cgi?id=86177
 		 */
 		StyledText textWidget = getTextWidget();
 		if (textWidget != null && !textWidget.isDisposed()) {
 			Color foregroundColor = textWidget.getForeground();
 			if (foregroundColor != null && foregroundColor.isDisposed())
 				textWidget.setForeground(null);
 			Color backgroundColor = textWidget.getBackground();
 			if (backgroundColor != null && backgroundColor.isDisposed())
 				textWidget.setBackground(null);
 		}

 		super.configure(configuration);
 		if (configuration instanceof ScriptSourceViewerConfiguration) {
 			ScriptSourceViewerConfiguration dltkSVCconfiguration = (ScriptSourceViewerConfiguration) configuration;
 			fOutlinePresenter = dltkSVCconfiguration.getOutlinePresenter(this,
 					false);
 			if (fOutlinePresenter != null)
 				fOutlinePresenter.install(this);

 			fStructurePresenter = dltkSVCconfiguration.getOutlinePresenter(
 					this, true);
 			if (fStructurePresenter != null)
 				fStructurePresenter.install(this);

 			fHierarchyPresenter = dltkSVCconfiguration.getHierarchyPresenter(
 					this, true);
 			if (fHierarchyPresenter != null)
 				fHierarchyPresenter.install(this);
 			if (textWidget != null) {
 				textWidget.setFont(JFaceResources.getFont(dltkSVCconfiguration
 						.getFontPropertyPreferenceKey()));
 			}
 		}

 		if (fPreferenceStore != null) {
 			fPreferenceStore.addPropertyChangeListener(this);
 			initializeViewerColors();
 		}

 		fIsConfigured = true;
 	}

 	public void initializeViewerColors() {
 		if (fPreferenceStore != null) {

 			StyledText styledText = getTextWidget();

 			// ----------- foreground color --------------------
 			Color color = fPreferenceStore
 					.getBoolean(AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND_SYSTEM_DEFAULT) ? null
 					: createColor(fPreferenceStore,
 							AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND,
 							styledText.getDisplay());
 			styledText.setForeground(color);

 			if (fForegroundColor != null)
 				fForegroundColor.dispose();

 			fForegroundColor = color;

 			// ---------- background color ----------------------
 			color = fPreferenceStore
 					.getBoolean(AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND_SYSTEM_DEFAULT) ? null
 					: createColor(fPreferenceStore,
 							AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND,
 							styledText.getDisplay());
 			styledText.setBackground(color);

 			if (fBackgroundColor != null)
 				fBackgroundColor.dispose();

 			fBackgroundColor = color;

 			// ----------- selection foreground color --------------------
 			color = fPreferenceStore
 					.getBoolean(AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_FOREGROUND_DEFAULT_COLOR) ? null
 					: createColor(
 							fPreferenceStore,
 							AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_FOREGROUND_COLOR,
 							styledText.getDisplay());
 			styledText.setSelectionForeground(color);

 			if (fSelectionForegroundColor != null)
 				fSelectionForegroundColor.dispose();

 			fSelectionForegroundColor = color;

 			// ---------- selection background color ----------------------
 			color = fPreferenceStore
 					.getBoolean(AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_BACKGROUND_DEFAULT_COLOR) ? null
 					: createColor(
 							fPreferenceStore,
 							AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_BACKGROUND_COLOR,
 							styledText.getDisplay());
 			styledText.setSelectionBackground(color);

 			if (fSelectionBackgroundColor != null)
 				fSelectionBackgroundColor.dispose();

 			fSelectionBackgroundColor = color;
 		}
 	}

 	/**
 	 * Creates a color from the information stored in the given preference
 	 * store. Returns <code>null</code> if there is no such information
 	 * available.
 	 *
 	 * @param store
 	 *            the store to read from
 	 * @param key
 	 *            the key used for the lookup in the preference store
 	 * @param display
 	 *            the display used create the color
 	 * @return the created color according to the specification in the
 	 *         preference store
 	 */
 	private Color createColor(IPreferenceStore store, String key,
 			Display display) {

 		RGB rgb = null;

 		if (store.contains(key)) {

 			if (store.isDefault(key))
 				rgb = PreferenceConverter.getDefaultColor(store, key);
 			else
 				rgb = PreferenceConverter.getColor(store, key);

 			if (rgb != null)
 				return new Color(display, rgb);
 		}

 		return null;
 	}

 	@Override
 	public void unconfigure() {
 		if (fOutlinePresenter != null) {
 			fOutlinePresenter.uninstall();
 			fOutlinePresenter = null;
 		}
 		if (fStructurePresenter != null) {
 			fStructurePresenter.uninstall();
 			fStructurePresenter = null;
 		}
 		if (fHierarchyPresenter != null) {
 			fHierarchyPresenter.uninstall();
 			fHierarchyPresenter = null;
 		}
 		if (fForegroundColor != null) {
 			fForegroundColor.dispose();
 			fForegroundColor = null;
 		}
 		if (fBackgroundColor != null) {
 			fBackgroundColor.dispose();
 			fBackgroundColor = null;
 		}

 		if (fPreferenceStore != null)
 			fPreferenceStore.removePropertyChangeListener(this);

 		super.unconfigure();

 		fIsConfigured = false;
 	}

 	@Override
 	public Point rememberSelection() {
 		return super.rememberSelection();
 	}

 	@Override
 	public void restoreSelection() {
 		super.restoreSelection();
 	}

 	@Override
 	public void propertyChange(PropertyChangeEvent event) {
 		String property = event.getProperty();
 		if (AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND.equals(property)
 				|| AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND_SYSTEM_DEFAULT
 						.equals(property)
 				|| AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND
 						.equals(property)
 				|| AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND_SYSTEM_DEFAULT
 						.equals(property)
 				|| AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_FOREGROUND_COLOR
 						.equals(property)
 				|| AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_FOREGROUND_DEFAULT_COLOR
 						.equals(property)
 				|| AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_BACKGROUND_COLOR
 						.equals(property)
 				|| AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_BACKGROUND_DEFAULT_COLOR
 						.equals(property)) {
 			initializeViewerColors();
 		}
 	}

 	/**
 	 * Sets the preference store on this viewer.
 	 *
 	 * @param store
 	 *            the preference store
 	 */
 	public void setPreferenceStore(IPreferenceStore store) {
 		if (fIsConfigured && fPreferenceStore != null)
 			fPreferenceStore.removePropertyChangeListener(this);

 		fPreferenceStore = store;

 		if (fIsConfigured && fPreferenceStore != null) {
 			fPreferenceStore.addPropertyChangeListener(this);
 			initializeViewerColors();
 		}
 	}

 	@Override
 	public void resetVisibleRegion() {
 		super.resetVisibleRegion();
 		// re-enable folding if ProjectionViewer failed to due so
 		// TODO: Add editor folding option here.
 		if (fPreferenceStore != null && !isProjectionMode())
 			enableProjection();
 		/*
 		 * && fPreferenceStore.getBoolean(PreferenceConstants.
 		 * EDITOR_FOLDING_ENABLED)
 		 */
 	}

 	@Override
 	protected void createControl(Composite parent, int styles) {

 		// Use LEFT_TO_RIGHT unless otherwise specified.
 		if ((styles & SWT.RIGHT_TO_LEFT) == 0
 				&& (styles & SWT.LEFT_TO_RIGHT) == 0)
 			styles |= SWT.LEFT_TO_RIGHT;

 		super.createControl(parent, styles);

 		// System.err.println("Add backup manager");
 		// fBackspaceManager= new SmartBackspaceManager();
 		// fBackspaceManager.install(this);
 	}

 	@Override
 	protected void handleDispose() {
 		// if (fBackspaceManager != null) {
 		// fBackspaceManager.uninstall();
 		// fBackspaceManager = null;
 		// }

 		super.handleDispose();
 	}

 	/**
 	 * Prepends the text presentation listener at the beginning of the viewer's
 	 * list of text presentation listeners. If the listener is already
 	 * registered with the viewer this call moves the listener to the beginning
 	 * of the list.
 	 *
 	 * @param listener
 	 *            the text presentation listener
 	 */
 	public void prependTextPresentationListener(
 			ITextPresentationListener listener) {

 		Assert.isNotNull(listener);

 		if (fTextPresentationListeners == null)
 			fTextPresentationListeners = new ArrayList();

 		fTextPresentationListeners.remove(listener);
 		fTextPresentationListeners.add(0, listener);
 	}

 	/**
 	 * Sets the given reconciler.
 	 *
 	 * @param reconciler
 	 *            the reconciler
 	 */
 	void setReconciler(IReconciler reconciler) {
 		fReconciler = reconciler;
 	}

 	/**
 	 * Returns the reconciler.
 	 *
 	 * @return the reconciler or <code>null</code> if not set
 	 */
 	IReconciler getReconciler() {
 		return fReconciler;
 	}

 	/**
 	 * Delays setting the visual document until after the projection has been
 	 * computed. This method must only be called before the document is set on
 	 * the viewer.
 	 * <p>
 	 * This is a performance optimization to reduce the computation of the text
 	 * presentation triggered by <code>setVisibleDocument(IDocument)</code>.
 	 * </p>
 	 *
 	 * @see #setVisibleDocument(IDocument)
 	 */
 	void prepareDelayedProjection() {
 		Assert.isTrue(!fIsSetVisibleDocumentDelayed);
 		fIsSetVisibleDocumentDelayed = true;
 	}

 	/**
 	 * {@inheritDoc}
 	 * <p>
 	 * This is a performance optimization to reduce the computation of the text
 	 * presentation triggered by {@link #setVisibleDocument(IDocument)}
 	 * </p>
 	 *
 	 * @see #prepareDelayedProjection()
 	 */
 	@Override
 	protected void setVisibleDocument(IDocument document) {
 		if (fIsSetVisibleDocumentDelayed) {
 			fIsSetVisibleDocumentDelayed = false;
 			IDocument previous = getVisibleDocument();
 			// will set the visible document if anything is folded
 			enableProjection();
 			IDocument current = getVisibleDocument();
 			// if the visible document was not replaced, continue as usual
 			if (current != null && current != previous)
 				return;
 		}

 		super.setVisibleDocument(document);
 	}

 	/**
 	 * {@inheritDoc}
 	 * <p>
 	 * Performance optimization: since we know at this place that none of the
 	 * clients expects the given range to be untouched we reuse the given range
 	 * as return value.
 	 * </p>
 	 */
 	@Override
 	protected StyleRange modelStyleRange2WidgetStyleRange(StyleRange range) {
 		IRegion region = modelRange2WidgetRange(new Region(range.start,
 				range.length));
 		if (region != null) {
 			// don't clone the style range, but simply reuse it.
 			range.start = region.getOffset();
 			range.length = region.getLength();
 			return range;
 		}
 		return null;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2017 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
	* Alex Panchenko <alex@xored.com>
	*******************************************************************************/
	package org.eclipse.dltk.internal.ui.editor;

	import java.util.ArrayList;

	import org.eclipse.core.runtime.Assert;
	import org.eclipse.dltk.ui.text.ScriptSourceViewerConfiguration;
	import org.eclipse.jface.preference.IPreferenceStore;
	import org.eclipse.jface.preference.PreferenceConverter;
	import org.eclipse.jface.resource.JFaceResources;
	import org.eclipse.jface.text.IDocument;
	import org.eclipse.jface.text.IRegion;
	import org.eclipse.jface.text.ITextPresentationListener;
	import org.eclipse.jface.text.Region;
	import org.eclipse.jface.text.information.IInformationPresenter;
	import org.eclipse.jface.text.reconciler.IReconciler;
	import org.eclipse.jface.text.source.IOverviewRuler;
	import org.eclipse.jface.text.source.IVerticalRuler;
	import org.eclipse.jface.text.source.SourceViewerConfiguration;
	import org.eclipse.jface.text.source.projection.ProjectionViewer;
	import org.eclipse.jface.util.IPropertyChangeListener;
	import org.eclipse.jface.util.PropertyChangeEvent;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.custom.StyleRange;
	import org.eclipse.swt.custom.StyledText;
	import org.eclipse.swt.graphics.Color;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.graphics.RGB;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Display;
	import org.eclipse.ui.texteditor.AbstractDecoratedTextEditorPreferenceConstants;
	import org.eclipse.ui.texteditor.AbstractTextEditor;

	public class ScriptSourceViewer extends ProjectionViewer implements
	IPropertyChangeListener {

	/**
	* Text operation code for requesting the outline for the current input.
	*/
	public static final int SHOW_OUTLINE = 51;

	/**
	* Text operation code for requesting the outline for the element at the
	* current position.
	*/
	public static final int OPEN_STRUCTURE = 52;

	/**
	* Text operation code for requesting the hierarchy for the current input.
	*/
	public static final int SHOW_HIERARCHY = 53;

	private IInformationPresenter fOutlinePresenter;

	private IInformationPresenter fStructurePresenter;

	private IInformationPresenter fHierarchyPresenter;

	/**
	* This viewer's foreground color.
	*/
	private Color fForegroundColor;

	/**
	* The viewer's background color.
	*/
	private Color fBackgroundColor;

	/**
	* This viewer's selection foreground color.
	*/
	private Color fSelectionForegroundColor;

	/**
	* The viewer's selection background color.
	*/
	private Color fSelectionBackgroundColor;

	/**
	* The preference store.
	*/
	private IPreferenceStore fPreferenceStore;

	/**
	* Is this source viewer configured?
	*/
	private boolean fIsConfigured;

	// /**
	// * The backspace manager of this viewer.
	// *
	// */
	// private SmartBackspaceManager fBackspaceManager;

	/**
	* Whether to delay setting the visual document until the projection has
	* been computed.
	* <p>
	* Added for performance optimization.
	* </p>
	*
	* @see #prepareDelayedProjection()
	*/
	private boolean fIsSetVisibleDocumentDelayed = false;

	public ScriptSourceViewer(Composite parent, IVerticalRuler verticalRuler,
	IOverviewRuler overviewRuler, boolean showAnnotationsOverview,
	int styles, IPreferenceStore store) {
	super(parent, verticalRuler, overviewRuler, showAnnotationsOverview,
	styles);
	setPreferenceStore(store);
	}

	@Override
	public void doOperation(int operation) {
	if (getTextWidget() == null)
	return;

	switch (operation) {
	case SHOW_OUTLINE:
	if (fOutlinePresenter != null)
	fOutlinePresenter.showInformation();
	return;
	case OPEN_STRUCTURE:
	if (fStructurePresenter != null)
	fStructurePresenter.showInformation();
	return;
	case SHOW_HIERARCHY:
	if (fHierarchyPresenter != null)
	fHierarchyPresenter.showInformation();
	return;
	}

	super.doOperation(operation);
	}

	@Override
	public boolean canDoOperation(int operation) {
	if (operation == SHOW_OUTLINE)
	return fOutlinePresenter != null;
	if (operation == OPEN_STRUCTURE)
	return fStructurePresenter != null;
	if (operation == SHOW_HIERARCHY)
	return fHierarchyPresenter != null;

	return super.canDoOperation(operation);
	}

	@Override
	public void configure(SourceViewerConfiguration configuration) {

	/*
	* Prevent access to colors disposed in unconfigure(), see:
	* https://bugs.eclipse.org/bugs/show_bug.cgi?id=53641
	* https://bugs.eclipse.org/bugs/show_bug.cgi?id=86177
	*/
	StyledText textWidget = getTextWidget();
	if (textWidget != null && !textWidget.isDisposed()) {
	Color foregroundColor = textWidget.getForeground();
	if (foregroundColor != null && foregroundColor.isDisposed())
	textWidget.setForeground(null);
	Color backgroundColor = textWidget.getBackground();
	if (backgroundColor != null && backgroundColor.isDisposed())
	textWidget.setBackground(null);
	}

	super.configure(configuration);
	if (configuration instanceof ScriptSourceViewerConfiguration) {
	ScriptSourceViewerConfiguration dltkSVCconfiguration = (ScriptSourceViewerConfiguration) configuration;
	fOutlinePresenter = dltkSVCconfiguration.getOutlinePresenter(this,
	false);
	if (fOutlinePresenter != null)
	fOutlinePresenter.install(this);

	fStructurePresenter = dltkSVCconfiguration.getOutlinePresenter(
	this, true);
	if (fStructurePresenter != null)
	fStructurePresenter.install(this);

	fHierarchyPresenter = dltkSVCconfiguration.getHierarchyPresenter(
	this, true);
	if (fHierarchyPresenter != null)
	fHierarchyPresenter.install(this);
	if (textWidget != null) {
	textWidget.setFont(JFaceResources.getFont(dltkSVCconfiguration
	.getFontPropertyPreferenceKey()));
	}
	}

	if (fPreferenceStore != null) {
	fPreferenceStore.addPropertyChangeListener(this);
	initializeViewerColors();
	}

	fIsConfigured = true;
	}

	public void initializeViewerColors() {
	if (fPreferenceStore != null) {

	StyledText styledText = getTextWidget();

	// ----------- foreground color --------------------
	Color color = fPreferenceStore
	.getBoolean(AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND_SYSTEM_DEFAULT) ? null
	: createColor(fPreferenceStore,
	AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND,
	styledText.getDisplay());
	styledText.setForeground(color);

	if (fForegroundColor != null)
	fForegroundColor.dispose();

	fForegroundColor = color;

	// ---------- background color ----------------------
	color = fPreferenceStore
	.getBoolean(AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND_SYSTEM_DEFAULT) ? null
	: createColor(fPreferenceStore,
	AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND,
	styledText.getDisplay());
	styledText.setBackground(color);

	if (fBackgroundColor != null)
	fBackgroundColor.dispose();

	fBackgroundColor = color;

	// ----------- selection foreground color --------------------
	color = fPreferenceStore
	.getBoolean(AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_FOREGROUND_DEFAULT_COLOR) ? null
	: createColor(
	fPreferenceStore,
	AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_FOREGROUND_COLOR,
	styledText.getDisplay());
	styledText.setSelectionForeground(color);

	if (fSelectionForegroundColor != null)
	fSelectionForegroundColor.dispose();

	fSelectionForegroundColor = color;

	// ---------- selection background color ----------------------
	color = fPreferenceStore
	.getBoolean(AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_BACKGROUND_DEFAULT_COLOR) ? null
	: createColor(
	fPreferenceStore,
	AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_BACKGROUND_COLOR,
	styledText.getDisplay());
	styledText.setSelectionBackground(color);

	if (fSelectionBackgroundColor != null)
	fSelectionBackgroundColor.dispose();

	fSelectionBackgroundColor = color;
	}
	}

	/**
	* Creates a color from the information stored in the given preference
	* store. Returns <code>null</code> if there is no such information
	* available.
	*
	* @param store
	* the store to read from
	* @param key
	* the key used for the lookup in the preference store
	* @param display
	* the display used create the color
	* @return the created color according to the specification in the
	* preference store
	*/
	private Color createColor(IPreferenceStore store, String key,
	Display display) {

	RGB rgb = null;

	if (store.contains(key)) {

	if (store.isDefault(key))
	rgb = PreferenceConverter.getDefaultColor(store, key);
	else
	rgb = PreferenceConverter.getColor(store, key);

	if (rgb != null)
	return new Color(display, rgb);
	}

	return null;
	}

	@Override
	public void unconfigure() {
	if (fOutlinePresenter != null) {
	fOutlinePresenter.uninstall();
	fOutlinePresenter = null;
	}
	if (fStructurePresenter != null) {
	fStructurePresenter.uninstall();
	fStructurePresenter = null;
	}
	if (fHierarchyPresenter != null) {
	fHierarchyPresenter.uninstall();
	fHierarchyPresenter = null;
	}
	if (fForegroundColor != null) {
	fForegroundColor.dispose();
	fForegroundColor = null;
	}
	if (fBackgroundColor != null) {
	fBackgroundColor.dispose();
	fBackgroundColor = null;
	}

	if (fPreferenceStore != null)
	fPreferenceStore.removePropertyChangeListener(this);

	super.unconfigure();

	fIsConfigured = false;
	}

	@Override
	public Point rememberSelection() {
	return super.rememberSelection();
	}

	@Override
	public void restoreSelection() {
	super.restoreSelection();
	}

	@Override
	public void propertyChange(PropertyChangeEvent event) {
	String property = event.getProperty();
	if (AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND.equals(property)
	\|\| AbstractTextEditor.PREFERENCE_COLOR_FOREGROUND_SYSTEM_DEFAULT
	.equals(property)
	\|\| AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND
	.equals(property)
	\|\| AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND_SYSTEM_DEFAULT
	.equals(property)
	\|\| AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_FOREGROUND_COLOR
	.equals(property)
	\|\| AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_FOREGROUND_DEFAULT_COLOR
	.equals(property)
	\|\| AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_BACKGROUND_COLOR
	.equals(property)
	\|\| AbstractDecoratedTextEditorPreferenceConstants.EDITOR_SELECTION_BACKGROUND_DEFAULT_COLOR
	.equals(property)) {
	initializeViewerColors();
	}
	}

	/**
	* Sets the preference store on this viewer.
	*
	* @param store
	* the preference store
	*/
	public void setPreferenceStore(IPreferenceStore store) {
	if (fIsConfigured && fPreferenceStore != null)
	fPreferenceStore.removePropertyChangeListener(this);

	fPreferenceStore = store;

	if (fIsConfigured && fPreferenceStore != null) {
	fPreferenceStore.addPropertyChangeListener(this);
	initializeViewerColors();
	}
	}

	@Override
	public void resetVisibleRegion() {
	super.resetVisibleRegion();
	// re-enable folding if ProjectionViewer failed to due so
	// TODO: Add editor folding option here.
	if (fPreferenceStore != null && !isProjectionMode())
	enableProjection();
	/*
	* && fPreferenceStore.getBoolean(PreferenceConstants.
	* EDITOR_FOLDING_ENABLED)
	*/
	}

	@Override
	protected void createControl(Composite parent, int styles) {

	// Use LEFT_TO_RIGHT unless otherwise specified.
	if ((styles & SWT.RIGHT_TO_LEFT) == 0
	&& (styles & SWT.LEFT_TO_RIGHT) == 0)
	styles \|= SWT.LEFT_TO_RIGHT;

	super.createControl(parent, styles);

	// System.err.println("Add backup manager");
	// fBackspaceManager= new SmartBackspaceManager();
	// fBackspaceManager.install(this);
	}

	@Override
	protected void handleDispose() {
	// if (fBackspaceManager != null) {
	// fBackspaceManager.uninstall();
	// fBackspaceManager = null;
	// }

	super.handleDispose();
	}

	/**
	* Prepends the text presentation listener at the beginning of the viewer's
	* list of text presentation listeners. If the listener is already
	* registered with the viewer this call moves the listener to the beginning
	* of the list.
	*
	* @param listener
	* the text presentation listener
	*/
	public void prependTextPresentationListener(
	ITextPresentationListener listener) {

	Assert.isNotNull(listener);

	if (fTextPresentationListeners == null)
	fTextPresentationListeners = new ArrayList();

	fTextPresentationListeners.remove(listener);
	fTextPresentationListeners.add(0, listener);
	}

	/**
	* Sets the given reconciler.
	*
	* @param reconciler
	* the reconciler
	*/
	void setReconciler(IReconciler reconciler) {
	fReconciler = reconciler;
	}

	/**
	* Returns the reconciler.
	*
	* @return the reconciler or <code>null</code> if not set
	*/
	IReconciler getReconciler() {
	return fReconciler;
	}

	/**
	* Delays setting the visual document until after the projection has been
	* computed. This method must only be called before the document is set on
	* the viewer.
	* <p>
	* This is a performance optimization to reduce the computation of the text
	* presentation triggered by <code>setVisibleDocument(IDocument)</code>.
	* </p>
	*
	* @see #setVisibleDocument(IDocument)
	*/
	void prepareDelayedProjection() {
	Assert.isTrue(!fIsSetVisibleDocumentDelayed);
	fIsSetVisibleDocumentDelayed = true;
	}

	/**
	* {@inheritDoc}
	* <p>
	* This is a performance optimization to reduce the computation of the text
	* presentation triggered by {@link #setVisibleDocument(IDocument)}
	* </p>
	*
	* @see #prepareDelayedProjection()
	*/
	@Override
	protected void setVisibleDocument(IDocument document) {
	if (fIsSetVisibleDocumentDelayed) {
	fIsSetVisibleDocumentDelayed = false;
	IDocument previous = getVisibleDocument();
	// will set the visible document if anything is folded
	enableProjection();
	IDocument current = getVisibleDocument();
	// if the visible document was not replaced, continue as usual
	if (current != null && current != previous)
	return;
	}

	super.setVisibleDocument(document);
	}

	/**
	* {@inheritDoc}
	* <p>
	* Performance optimization: since we know at this place that none of the
	* clients expects the given range to be untouched we reuse the given range
	* as return value.
	* </p>
	*/
	@Override
	protected StyleRange modelStyleRange2WidgetStyleRange(StyleRange range) {
	IRegion region = modelRange2WidgetRange(new Region(range.start,
	range.length));
	if (region != null) {
	// don't clone the style range, but simply reuse it.
	range.start = region.getOffset();
	range.length = region.getLength();
	return range;
	}
	return null;
	}
	}