org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/RichTextAttributeEditor.java - mylyn/org.eclipse.mylyn.tasks - Git at Google

 /*******************************************************************************
  * Copyright (c) 2004, 2008 Tasktop Technologies 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:
  *     Tasktop Technologies - initial API and implementation
  *     Raphael Ackermann - spell checking support on bug 195514
  *     Jingwen Ou - extensibility improvements
  *     David Green - fix for bug 256702
  *******************************************************************************/

 package org.eclipse.mylyn.internal.tasks.ui.editors;

 import java.util.Iterator;

 import org.eclipse.core.runtime.Assert;
 import org.eclipse.jface.action.Action;
 import org.eclipse.jface.action.IAction;
 import org.eclipse.jface.resource.JFaceResources;
 import org.eclipse.jface.text.Document;
 import org.eclipse.jface.text.ITextListener;
 import org.eclipse.jface.text.TextEvent;
 import org.eclipse.jface.text.source.AnnotationModel;
 import org.eclipse.jface.text.source.IAnnotationAccess;
 import org.eclipse.jface.text.source.SourceViewer;
 import org.eclipse.mylyn.internal.provisional.commons.ui.CommonTextSupport;
 import org.eclipse.mylyn.internal.provisional.commons.ui.CommonThemes;
 import org.eclipse.mylyn.internal.tasks.ui.commands.ViewSourceHandler;
 import org.eclipse.mylyn.internal.tasks.ui.editors.RepositoryTextViewerConfiguration.Mode;
 import org.eclipse.mylyn.internal.tasks.ui.util.TasksUiInternal;
 import org.eclipse.mylyn.tasks.core.TaskRepository;
 import org.eclipse.mylyn.tasks.core.data.TaskAttribute;
 import org.eclipse.mylyn.tasks.core.data.TaskDataModel;
 import org.eclipse.mylyn.tasks.ui.editors.AbstractAttributeEditor;
 import org.eclipse.mylyn.tasks.ui.editors.AbstractRenderingEngine;
 import org.eclipse.mylyn.tasks.ui.editors.AbstractTaskEditorExtension;
 import org.eclipse.mylyn.tasks.ui.editors.LayoutHint;
 import org.eclipse.mylyn.tasks.ui.editors.LayoutHint.ColumnSpan;
 import org.eclipse.mylyn.tasks.ui.editors.LayoutHint.RowSpan;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.StackLayout;
 import org.eclipse.swt.events.DisposeEvent;
 import org.eclipse.swt.events.DisposeListener;
 import org.eclipse.swt.events.FocusAdapter;
 import org.eclipse.swt.events.FocusEvent;
 import org.eclipse.swt.events.FocusListener;
 import org.eclipse.swt.graphics.Font;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Event;
 import org.eclipse.swt.widgets.Listener;
 import org.eclipse.swt.widgets.Menu;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.contexts.IContextActivation;
 import org.eclipse.ui.contexts.IContextService;
 import org.eclipse.ui.editors.text.EditorsUI;
 import org.eclipse.ui.forms.widgets.FormToolkit;
 import org.eclipse.ui.texteditor.AnnotationPreference;
 import org.eclipse.ui.texteditor.DefaultMarkerAnnotationAccess;
 import org.eclipse.ui.texteditor.MarkerAnnotationPreferences;
 import org.eclipse.ui.texteditor.SourceViewerDecorationSupport;
 import org.eclipse.ui.themes.IThemeManager;

 /**
  * A text attribute editor that can switch between a editor, preview and source view.
  *
  * @author Raphael Ackermann
  * @author Steffen Pingel
  * @author Jingwen Ou
  */
 public class RichTextAttributeEditor extends AbstractAttributeEditor {

 	private IContextActivation contextActivation;

 	private final IContextService contextService;

 	private SourceViewer defaultViewer;

 	private Composite editorComposite;

 	private StackLayout editorLayout;

 	private final AbstractTaskEditorExtension extension;

 	private SourceViewer editorViewer;

 	private SourceViewer previewViewer;

 	private final TaskRepository taskRepository;

 	private FormToolkit toolkit;

 	public class ViewSourceAction extends Action {

 		public ViewSourceAction() {
 			super(Messages.RichTextAttributeEditor_Viewer_Source, SWT.TOGGLE);
 			setChecked(false);
 			setEnabled(false);
 		}

 		@Override
 		public void run() {
 			if (isChecked()) {
 				showDefault();
 			} else {
 				showEditor();
 			}
 			if (editorLayout != null) {
 				EditorUtil.reflow(editorLayout.topControl);
 			}
 			ViewSourceHandler.setChecked(isChecked());
 		}

 	}

 	private final IAction viewSourceAction = new ViewSourceAction();

 	private boolean spellCheckingEnabled;

 	private final int style;

 	private Mode mode;

 	private AbstractRenderingEngine renderingEngine;

 	private BrowserPreviewViewer browserViewer;

 	public RichTextAttributeEditor(TaskDataModel manager, TaskRepository taskRepository, TaskAttribute taskAttribute) {
 		this(manager, taskRepository, taskAttribute, SWT.MULTI);
 	}

 	public RichTextAttributeEditor(TaskDataModel manager, TaskRepository taskRepository, TaskAttribute taskAttribute,
 			int style) {
 		this(manager, taskRepository, taskAttribute, style, null, null);
 	}

 	public RichTextAttributeEditor(TaskDataModel manager, TaskRepository taskRepository, TaskAttribute taskAttribute,
 			int style, IContextService contextService, AbstractTaskEditorExtension extension) {
 		super(manager, taskAttribute);
 		this.taskRepository = taskRepository;
 		this.style = style;
 		this.contextService = contextService;
 		this.extension = extension;
 		if ((style & SWT.MULTI) != 0) {
 			setLayoutHint(new LayoutHint(RowSpan.MULTIPLE, ColumnSpan.MULTIPLE));
 		} else {
 			setLayoutHint(new LayoutHint(RowSpan.SINGLE, ColumnSpan.MULTIPLE));
 		}
 		setMode(Mode.DEFAULT);
 	}

 	public Mode getMode() {
 		return mode;
 	}

 	public void setMode(Mode mode) {
 		Assert.isNotNull(mode);
 		this.mode = mode;
 	}

 	private void installListeners(final SourceViewer viewer) {
 		viewer.addTextListener(new ITextListener() {
 			public void textChanged(TextEvent event) {
 				// filter out events caused by text presentation changes, e.g. annotation drawing
 				String value = viewer.getTextWidget().getText();
 				if (!getValue().equals(value)) {
 					setValue(value);
 					EditorUtil.ensureVisible(viewer.getTextWidget());
 				}
 			}
 		});
 		// ensure that tab traverses to next control instead of inserting a tab character unless editing multi-line text
 		if ((style & SWT.MULTI) != 0 && mode != Mode.DEFAULT) {
 			viewer.getTextWidget().addListener(SWT.Traverse, new Listener() {
 				public void handleEvent(Event event) {
 					switch (event.detail) {
 					case SWT.TRAVERSE_TAB_NEXT:
 					case SWT.TRAVERSE_TAB_PREVIOUS:
 						event.doit = true;
 						break;
 					}
 				}
 			});
 		}
 	}

 	public String getValue() {
 		return getAttributeMapper().getValue(getTaskAttribute());
 	}

 	public boolean isSpellCheckingEnabled() {
 		return spellCheckingEnabled;
 	}

 	public void setSpellCheckingEnabled(boolean spellCheckingEnabled) {
 		this.spellCheckingEnabled = spellCheckingEnabled;
 	}

 	public void setValue(String value) {
 		getAttributeMapper().setValue(getTaskAttribute(), value);
 		attributeChanged();
 	}

 	/** Configures annotation model for spell checking. */
 	private void configureAsEditor(SourceViewer viewer, Document document) {
 		AnnotationModel annotationModel = new AnnotationModel();
 		viewer.showAnnotations(false);
 		viewer.showAnnotationsOverview(false);
 		IAnnotationAccess annotationAccess = new DefaultMarkerAnnotationAccess();
 		final SourceViewerDecorationSupport support = new SourceViewerDecorationSupport(viewer, null, annotationAccess,
 				EditorsUI.getSharedTextColors());
 		Iterator<?> e = new MarkerAnnotationPreferences().getAnnotationPreferences().iterator();
 		while (e.hasNext()) {
 			support.setAnnotationPreference((AnnotationPreference) e.next());
 		}
 		support.install(EditorsUI.getPreferenceStore());
 		viewer.getTextWidget().addDisposeListener(new DisposeListener() {
 			public void widgetDisposed(DisposeEvent e) {
 				support.uninstall();
 			}
 		});
 		//viewer.getTextWidget().setIndent(2);
 		viewer.setDocument(document, annotationModel);
 	}

 	private RepositoryTextViewerConfiguration installHyperlinkPresenter(SourceViewer viewer) {
 		RepositoryTextViewerConfiguration configuration = new RepositoryTextViewerConfiguration(taskRepository, false);
 		configuration.setMode(getMode());

 		// do not configure viewer, this has already been done in extension

 		AbstractHyperlinkTextPresentationManager manager;
 		if (getMode() == Mode.DEFAULT) {
 			manager = new HighlightingHyperlinkTextPresentationManager();
 			manager.setHyperlinkDetectors(configuration.getDefaultHyperlinkDetectors(viewer, null));
 			manager.install(viewer);

 			manager = new TaskHyperlinkTextPresentationManager();
 			manager.setHyperlinkDetectors(configuration.getDefaultHyperlinkDetectors(viewer, Mode.TASK));
 			manager.install(viewer);
 		} else if (getMode() == Mode.TASK_RELATION) {
 			manager = new TaskHyperlinkTextPresentationManager();
 			manager.setHyperlinkDetectors(configuration.getDefaultHyperlinkDetectors(viewer, Mode.TASK_RELATION));
 			manager.install(viewer);
 		}

 		return configuration;
 	}

 	private SourceViewer configure(final SourceViewer viewer, boolean readOnly) {
 		// do this before setting the document to not require invalidating the presentation
 		installHyperlinkPresenter(viewer);

 		Document document = new Document(getValue());
 		if (readOnly) {
 			viewer.setDocument(document);
 			if (extension != null) {
 				// setting view source action
 				viewer.getControl().setData(ViewSourceHandler.VIEW_SOURCE_ACTION, viewSourceAction);
 				viewer.getControl().addFocusListener(new FocusAdapter() {
 					@Override
 					public void focusGained(FocusEvent e) {
 						ViewSourceHandler.setChecked(getViewer() == defaultViewer);
 					}
 				});
 			}
 		} else {
 			configureAsEditor(viewer, document);
 			installListeners(viewer);
 			viewer.getControl().setData(FormToolkit.KEY_DRAW_BORDER, FormToolkit.TEXT_BORDER);
 		}

 		// enable cut/copy/paste
 		CommonTextSupport.setTextViewer(viewer.getTextWidget(), viewer);
 		viewer.setEditable(!readOnly);
 		viewer.getTextWidget().setFont(getFont());
 		toolkit.adapt(viewer.getControl(), false, false);

 		return viewer;
 	}

 	@Override
 	public void createControl(Composite parent, FormToolkit toolkit) {
 		this.toolkit = toolkit;

 		int style = this.style;
 		if (!isReadOnly() && (style & TasksUiInternal.SWT_NO_SCROLL) == 0) {
 			style |= SWT.V_SCROLL;
 		}

 		if (extension != null || renderingEngine != null) {
 			editorComposite = new Composite(parent, SWT.NULL);
 			editorLayout = new StackLayout() {
 				@Override
 				protected Point computeSize(Composite composite, int hint, int hint2, boolean flushCache) {
 					return topControl.computeSize(hint, hint2, flushCache);
 				}
 			};
 			editorComposite.setLayout(editorLayout);
 			setControl(editorComposite);

 			if (extension != null) {
 				if (isReadOnly()) {
 					editorViewer = extension.createViewer(taskRepository, editorComposite, style);
 				} else {
 					editorViewer = extension.createEditor(taskRepository, editorComposite, style);
 					editorViewer.getTextWidget().addFocusListener(new FocusListener() {
 						public void focusGained(FocusEvent e) {
 							setContext();
 						}

 						public void focusLost(FocusEvent e) {
 							unsetContext();
 						}
 					});
 					editorViewer.getTextWidget().addDisposeListener(new DisposeListener() {
 						public void widgetDisposed(DisposeEvent e) {
 							unsetContext();
 						}
 					});
 				}
 				configure(editorViewer, isReadOnly());
 				show(editorViewer);
 			} else {
 				defaultViewer = createDefaultEditor(editorComposite, style);
 				configure(defaultViewer, isReadOnly());
 				show(defaultViewer);
 			}

 			viewSourceAction.setEnabled(true);
 		} else {
 			defaultViewer = createDefaultEditor(parent, style);
 			configure(defaultViewer, isReadOnly());
 			setControl(defaultViewer.getControl());

 			viewSourceAction.setEnabled(false);
 		}
 	}

 	private SourceViewer createDefaultEditor(Composite parent, int styles) {
 		SourceViewer defaultEditor = new SourceViewer(parent, null, styles | SWT.WRAP);

 		RepositoryTextViewerConfiguration viewerConfig = new RepositoryTextViewerConfiguration(taskRepository,
 				isSpellCheckingEnabled() && !isReadOnly());
 		viewerConfig.setMode(getMode());
 		defaultEditor.configure(viewerConfig);

 		return defaultEditor;
 	}

 	public SourceViewer getDefaultViewer() {
 		if (defaultViewer == null) {
 			defaultViewer = createDefaultEditor(editorComposite, style);
 			configure(defaultViewer, isReadOnly());

 			// fixed font size
 			defaultViewer.getTextWidget().setFont(JFaceResources.getFontRegistry().get(JFaceResources.TEXT_FONT));
 			// adapt maximize action
 			defaultViewer.getControl().setData(EditorUtil.KEY_TOGGLE_TO_MAXIMIZE_ACTION,
 					editorViewer.getControl().getData(EditorUtil.KEY_TOGGLE_TO_MAXIMIZE_ACTION));
 			// adapt menu to the new viewer
 			installMenu(defaultViewer.getControl(), editorViewer.getControl().getMenu());
 		}
 		return defaultViewer;
 	}

 	private void installMenu(final Control control, Menu menu) {
 		if (menu != null) {
 			control.setMenu(menu);
 			control.addDisposeListener(new DisposeListener() {
 				public void widgetDisposed(DisposeEvent e) {
 					control.setMenu(null);
 				}
 			});
 		}
 	}

 	private Font getFont() {
 		IThemeManager themeManager = PlatformUI.getWorkbench().getThemeManager();
 		Font font = themeManager.getCurrentTheme().getFontRegistry().get(CommonThemes.FONT_EDITOR_COMMENT);
 		return font;
 	}

 	private SourceViewer getPreviewViewer() {
 		if (extension == null) {
 			return null;
 		}

 		// construct as needed
 		if (previewViewer == null) {
 			// previewer should always have a vertical scroll bar if it's editable
 			int previewViewerStyle = style;
 			if (getEditorViewer() != null) {
 				previewViewerStyle |= SWT.V_SCROLL;
 			}
 			previewViewer = extension.createViewer(taskRepository, editorComposite, previewViewerStyle);
 			configure(previewViewer, true);
 			// adapt maximize action
 			previewViewer.getControl().setData(EditorUtil.KEY_TOGGLE_TO_MAXIMIZE_ACTION,
 					editorViewer.getControl().getData(EditorUtil.KEY_TOGGLE_TO_MAXIMIZE_ACTION));
 		}
 		Document document = new Document(editorViewer.getDocument().get());
 		previewViewer.setDocument(document);
 		return previewViewer;
 	}

 	public SourceViewer getEditorViewer() {
 		return editorViewer;
 	}

 	public SourceViewer getViewer() {
 		if (editorLayout == null) {
 			return defaultViewer;
 		}
 		if (defaultViewer != null && editorLayout.topControl == defaultViewer.getControl()) {
 			return defaultViewer;
 		} else if (previewViewer != null && editorLayout.topControl == previewViewer.getControl()) {
 			return previewViewer;
 		} else {
 			return editorViewer;
 		}
 	}

 	private void setContext() {
 		if (contextService == null) {
 			return;
 		}
 		if (contextActivation != null) {
 			contextService.deactivateContext(contextActivation);
 			contextActivation = null;
 		}
 		if (contextService != null && extension.getEditorContextId() != null) {
 			contextActivation = contextService.activateContext(extension.getEditorContextId());
 		}
 	}

 	/**
 	 * Brings <code>viewer</code> to top.
 	 */
 	private void show(SourceViewer viewer) {
 		show(viewer.getControl());
 	}

 	/**
 	 * Brings <code>control</code> to top.
 	 */
 	private void show(Control control) {
 		// no extension is available
 		if (editorComposite == null) {
 			return;
 		}

 		editorLayout.topControl = control;
 		if (editorComposite.getParent().getLayout() instanceof FillWidthLayout) {
 			((FillWidthLayout) editorComposite.getParent().getLayout()).flush();
 		}
 		editorComposite.layout();
 		control.setFocus();
 	}

 	public void showDefault() {
 		show(getDefaultViewer());
 	}

 	public void showPreview() {
 		if (!isReadOnly()) {
 			show(getPreviewViewer());
 		}
 	}

 	public void showEditor() {
 		if (getEditorViewer() != null) {
 			show(getEditorViewer());
 		} else {
 			show(getDefaultViewer());
 		}
 	}

 	private void unsetContext() {
 		if (contextService == null) {
 			return;
 		}
 		if (contextActivation != null) {
 			contextService.deactivateContext(contextActivation);
 			contextActivation = null;
 		}
 	}

 	public boolean hasPreview() {
 		return extension != null && !isReadOnly();
 	}

 	public boolean hasBrowser() {
 		return renderingEngine != null;
 	}

 	private BrowserPreviewViewer getBrowserViewer() {
 		if (editorComposite == null || renderingEngine == null) {
 			return null;
 		}

 		if (browserViewer == null) {
 			browserViewer = new BrowserPreviewViewer(getModel().getTaskRepository(), renderingEngine);
 			browserViewer.createControl(editorComposite, toolkit);
 		}
 		return browserViewer;
 	}

 	public AbstractRenderingEngine getRenderingEngine() {
 		return renderingEngine;
 	}

 	public void setRenderingEngine(AbstractRenderingEngine renderingEngine) {
 		this.renderingEngine = renderingEngine;
 	}

 	public void showBrowser() {
 		BrowserPreviewViewer viewer = getBrowserViewer();
 		viewer.update(getValue());
 		if (viewer != null) {
 			show(viewer.getControl());
 		}
 	}

 	public IAction getViewSourceAction() {
 		return viewSourceAction;
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2004, 2008 Tasktop Technologies 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:
	* Tasktop Technologies - initial API and implementation
	* Raphael Ackermann - spell checking support on bug 195514
	* Jingwen Ou - extensibility improvements
	* David Green - fix for bug 256702
	*******************************************************************************/

	package org.eclipse.mylyn.internal.tasks.ui.editors;

	import java.util.Iterator;

	import org.eclipse.core.runtime.Assert;
	import org.eclipse.jface.action.Action;
	import org.eclipse.jface.action.IAction;
	import org.eclipse.jface.resource.JFaceResources;
	import org.eclipse.jface.text.Document;
	import org.eclipse.jface.text.ITextListener;
	import org.eclipse.jface.text.TextEvent;
	import org.eclipse.jface.text.source.AnnotationModel;
	import org.eclipse.jface.text.source.IAnnotationAccess;
	import org.eclipse.jface.text.source.SourceViewer;
	import org.eclipse.mylyn.internal.provisional.commons.ui.CommonTextSupport;
	import org.eclipse.mylyn.internal.provisional.commons.ui.CommonThemes;
	import org.eclipse.mylyn.internal.tasks.ui.commands.ViewSourceHandler;
	import org.eclipse.mylyn.internal.tasks.ui.editors.RepositoryTextViewerConfiguration.Mode;
	import org.eclipse.mylyn.internal.tasks.ui.util.TasksUiInternal;
	import org.eclipse.mylyn.tasks.core.TaskRepository;
	import org.eclipse.mylyn.tasks.core.data.TaskAttribute;
	import org.eclipse.mylyn.tasks.core.data.TaskDataModel;
	import org.eclipse.mylyn.tasks.ui.editors.AbstractAttributeEditor;
	import org.eclipse.mylyn.tasks.ui.editors.AbstractRenderingEngine;
	import org.eclipse.mylyn.tasks.ui.editors.AbstractTaskEditorExtension;
	import org.eclipse.mylyn.tasks.ui.editors.LayoutHint;
	import org.eclipse.mylyn.tasks.ui.editors.LayoutHint.ColumnSpan;
	import org.eclipse.mylyn.tasks.ui.editors.LayoutHint.RowSpan;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.custom.StackLayout;
	import org.eclipse.swt.events.DisposeEvent;
	import org.eclipse.swt.events.DisposeListener;
	import org.eclipse.swt.events.FocusAdapter;
	import org.eclipse.swt.events.FocusEvent;
	import org.eclipse.swt.events.FocusListener;
	import org.eclipse.swt.graphics.Font;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Event;
	import org.eclipse.swt.widgets.Listener;
	import org.eclipse.swt.widgets.Menu;
	import org.eclipse.ui.PlatformUI;
	import org.eclipse.ui.contexts.IContextActivation;
	import org.eclipse.ui.contexts.IContextService;
	import org.eclipse.ui.editors.text.EditorsUI;
	import org.eclipse.ui.forms.widgets.FormToolkit;
	import org.eclipse.ui.texteditor.AnnotationPreference;
	import org.eclipse.ui.texteditor.DefaultMarkerAnnotationAccess;
	import org.eclipse.ui.texteditor.MarkerAnnotationPreferences;
	import org.eclipse.ui.texteditor.SourceViewerDecorationSupport;
	import org.eclipse.ui.themes.IThemeManager;

	/**
	* A text attribute editor that can switch between a editor, preview and source view.
	*
	* @author Raphael Ackermann
	* @author Steffen Pingel
	* @author Jingwen Ou
	*/
	public class RichTextAttributeEditor extends AbstractAttributeEditor {

	private IContextActivation contextActivation;

	private final IContextService contextService;

	private SourceViewer defaultViewer;

	private Composite editorComposite;

	private StackLayout editorLayout;

	private final AbstractTaskEditorExtension extension;

	private SourceViewer editorViewer;

	private SourceViewer previewViewer;

	private final TaskRepository taskRepository;

	private FormToolkit toolkit;

	public class ViewSourceAction extends Action {

	public ViewSourceAction() {
	super(Messages.RichTextAttributeEditor_Viewer_Source, SWT.TOGGLE);
	setChecked(false);
	setEnabled(false);
	}

	@Override
	public void run() {
	if (isChecked()) {
	showDefault();
	} else {
	showEditor();
	}
	if (editorLayout != null) {
	EditorUtil.reflow(editorLayout.topControl);
	}
	ViewSourceHandler.setChecked(isChecked());
	}

	}

	private final IAction viewSourceAction = new ViewSourceAction();

	private boolean spellCheckingEnabled;

	private final int style;

	private Mode mode;

	private AbstractRenderingEngine renderingEngine;

	private BrowserPreviewViewer browserViewer;

	public RichTextAttributeEditor(TaskDataModel manager, TaskRepository taskRepository, TaskAttribute taskAttribute) {
	this(manager, taskRepository, taskAttribute, SWT.MULTI);
	}

	public RichTextAttributeEditor(TaskDataModel manager, TaskRepository taskRepository, TaskAttribute taskAttribute,
	int style) {
	this(manager, taskRepository, taskAttribute, style, null, null);
	}

	public RichTextAttributeEditor(TaskDataModel manager, TaskRepository taskRepository, TaskAttribute taskAttribute,
	int style, IContextService contextService, AbstractTaskEditorExtension extension) {
	super(manager, taskAttribute);
	this.taskRepository = taskRepository;
	this.style = style;
	this.contextService = contextService;
	this.extension = extension;
	if ((style & SWT.MULTI) != 0) {
	setLayoutHint(new LayoutHint(RowSpan.MULTIPLE, ColumnSpan.MULTIPLE));
	} else {
	setLayoutHint(new LayoutHint(RowSpan.SINGLE, ColumnSpan.MULTIPLE));
	}
	setMode(Mode.DEFAULT);
	}

	public Mode getMode() {
	return mode;
	}

	public void setMode(Mode mode) {
	Assert.isNotNull(mode);
	this.mode = mode;
	}

	private void installListeners(final SourceViewer viewer) {
	viewer.addTextListener(new ITextListener() {
	public void textChanged(TextEvent event) {
	// filter out events caused by text presentation changes, e.g. annotation drawing
	String value = viewer.getTextWidget().getText();
	if (!getValue().equals(value)) {
	setValue(value);
	EditorUtil.ensureVisible(viewer.getTextWidget());
	}
	}
	});
	// ensure that tab traverses to next control instead of inserting a tab character unless editing multi-line text
	if ((style & SWT.MULTI) != 0 && mode != Mode.DEFAULT) {
	viewer.getTextWidget().addListener(SWT.Traverse, new Listener() {
	public void handleEvent(Event event) {
	switch (event.detail) {
	case SWT.TRAVERSE_TAB_NEXT:
	case SWT.TRAVERSE_TAB_PREVIOUS:
	event.doit = true;
	break;
	}
	}
	});
	}
	}

	public String getValue() {
	return getAttributeMapper().getValue(getTaskAttribute());
	}

	public boolean isSpellCheckingEnabled() {
	return spellCheckingEnabled;
	}

	public void setSpellCheckingEnabled(boolean spellCheckingEnabled) {
	this.spellCheckingEnabled = spellCheckingEnabled;
	}

	public void setValue(String value) {
	getAttributeMapper().setValue(getTaskAttribute(), value);
	attributeChanged();
	}

	/** Configures annotation model for spell checking. */
	private void configureAsEditor(SourceViewer viewer, Document document) {
	AnnotationModel annotationModel = new AnnotationModel();
	viewer.showAnnotations(false);
	viewer.showAnnotationsOverview(false);
	IAnnotationAccess annotationAccess = new DefaultMarkerAnnotationAccess();
	final SourceViewerDecorationSupport support = new SourceViewerDecorationSupport(viewer, null, annotationAccess,
	EditorsUI.getSharedTextColors());
	Iterator<?> e = new MarkerAnnotationPreferences().getAnnotationPreferences().iterator();
	while (e.hasNext()) {
	support.setAnnotationPreference((AnnotationPreference) e.next());
	}
	support.install(EditorsUI.getPreferenceStore());
	viewer.getTextWidget().addDisposeListener(new DisposeListener() {
	public void widgetDisposed(DisposeEvent e) {
	support.uninstall();
	}
	});
	//viewer.getTextWidget().setIndent(2);
	viewer.setDocument(document, annotationModel);
	}

	private RepositoryTextViewerConfiguration installHyperlinkPresenter(SourceViewer viewer) {
	RepositoryTextViewerConfiguration configuration = new RepositoryTextViewerConfiguration(taskRepository, false);
	configuration.setMode(getMode());

	// do not configure viewer, this has already been done in extension

	AbstractHyperlinkTextPresentationManager manager;
	if (getMode() == Mode.DEFAULT) {
	manager = new HighlightingHyperlinkTextPresentationManager();
	manager.setHyperlinkDetectors(configuration.getDefaultHyperlinkDetectors(viewer, null));
	manager.install(viewer);

	manager = new TaskHyperlinkTextPresentationManager();
	manager.setHyperlinkDetectors(configuration.getDefaultHyperlinkDetectors(viewer, Mode.TASK));
	manager.install(viewer);
	} else if (getMode() == Mode.TASK_RELATION) {
	manager = new TaskHyperlinkTextPresentationManager();
	manager.setHyperlinkDetectors(configuration.getDefaultHyperlinkDetectors(viewer, Mode.TASK_RELATION));
	manager.install(viewer);
	}

	return configuration;
	}

	private SourceViewer configure(final SourceViewer viewer, boolean readOnly) {
	// do this before setting the document to not require invalidating the presentation
	installHyperlinkPresenter(viewer);

	Document document = new Document(getValue());
	if (readOnly) {
	viewer.setDocument(document);
	if (extension != null) {
	// setting view source action
	viewer.getControl().setData(ViewSourceHandler.VIEW_SOURCE_ACTION, viewSourceAction);
	viewer.getControl().addFocusListener(new FocusAdapter() {
	@Override
	public void focusGained(FocusEvent e) {
	ViewSourceHandler.setChecked(getViewer() == defaultViewer);
	}
	});
	}
	} else {
	configureAsEditor(viewer, document);
	installListeners(viewer);
	viewer.getControl().setData(FormToolkit.KEY_DRAW_BORDER, FormToolkit.TEXT_BORDER);
	}

	// enable cut/copy/paste
	CommonTextSupport.setTextViewer(viewer.getTextWidget(), viewer);
	viewer.setEditable(!readOnly);
	viewer.getTextWidget().setFont(getFont());
	toolkit.adapt(viewer.getControl(), false, false);

	return viewer;
	}

	@Override
	public void createControl(Composite parent, FormToolkit toolkit) {
	this.toolkit = toolkit;

	int style = this.style;
	if (!isReadOnly() && (style & TasksUiInternal.SWT_NO_SCROLL) == 0) {
	style \|= SWT.V_SCROLL;
	}

	if (extension != null \|\| renderingEngine != null) {
	editorComposite = new Composite(parent, SWT.NULL);
	editorLayout = new StackLayout() {
	@Override
	protected Point computeSize(Composite composite, int hint, int hint2, boolean flushCache) {
	return topControl.computeSize(hint, hint2, flushCache);
	}
	};
	editorComposite.setLayout(editorLayout);
	setControl(editorComposite);

	if (extension != null) {
	if (isReadOnly()) {
	editorViewer = extension.createViewer(taskRepository, editorComposite, style);
	} else {
	editorViewer = extension.createEditor(taskRepository, editorComposite, style);
	editorViewer.getTextWidget().addFocusListener(new FocusListener() {
	public void focusGained(FocusEvent e) {
	setContext();
	}

	public void focusLost(FocusEvent e) {
	unsetContext();
	}
	});
	editorViewer.getTextWidget().addDisposeListener(new DisposeListener() {
	public void widgetDisposed(DisposeEvent e) {
	unsetContext();
	}
	});
	}
	configure(editorViewer, isReadOnly());
	show(editorViewer);
	} else {
	defaultViewer = createDefaultEditor(editorComposite, style);
	configure(defaultViewer, isReadOnly());
	show(defaultViewer);
	}

	viewSourceAction.setEnabled(true);
	} else {
	defaultViewer = createDefaultEditor(parent, style);
	configure(defaultViewer, isReadOnly());
	setControl(defaultViewer.getControl());

	viewSourceAction.setEnabled(false);
	}
	}

	private SourceViewer createDefaultEditor(Composite parent, int styles) {
	SourceViewer defaultEditor = new SourceViewer(parent, null, styles \| SWT.WRAP);

	RepositoryTextViewerConfiguration viewerConfig = new RepositoryTextViewerConfiguration(taskRepository,
	isSpellCheckingEnabled() && !isReadOnly());
	viewerConfig.setMode(getMode());
	defaultEditor.configure(viewerConfig);

	return defaultEditor;
	}

	public SourceViewer getDefaultViewer() {
	if (defaultViewer == null) {
	defaultViewer = createDefaultEditor(editorComposite, style);
	configure(defaultViewer, isReadOnly());

	// fixed font size
	defaultViewer.getTextWidget().setFont(JFaceResources.getFontRegistry().get(JFaceResources.TEXT_FONT));
	// adapt maximize action
	defaultViewer.getControl().setData(EditorUtil.KEY_TOGGLE_TO_MAXIMIZE_ACTION,
	editorViewer.getControl().getData(EditorUtil.KEY_TOGGLE_TO_MAXIMIZE_ACTION));
	// adapt menu to the new viewer
	installMenu(defaultViewer.getControl(), editorViewer.getControl().getMenu());
	}
	return defaultViewer;
	}

	private void installMenu(final Control control, Menu menu) {
	if (menu != null) {
	control.setMenu(menu);
	control.addDisposeListener(new DisposeListener() {
	public void widgetDisposed(DisposeEvent e) {
	control.setMenu(null);
	}
	});
	}
	}

	private Font getFont() {
	IThemeManager themeManager = PlatformUI.getWorkbench().getThemeManager();
	Font font = themeManager.getCurrentTheme().getFontRegistry().get(CommonThemes.FONT_EDITOR_COMMENT);
	return font;
	}

	private SourceViewer getPreviewViewer() {
	if (extension == null) {
	return null;
	}

	// construct as needed
	if (previewViewer == null) {
	// previewer should always have a vertical scroll bar if it's editable
	int previewViewerStyle = style;
	if (getEditorViewer() != null) {
	previewViewerStyle \|= SWT.V_SCROLL;
	}
	previewViewer = extension.createViewer(taskRepository, editorComposite, previewViewerStyle);
	configure(previewViewer, true);
	// adapt maximize action
	previewViewer.getControl().setData(EditorUtil.KEY_TOGGLE_TO_MAXIMIZE_ACTION,
	editorViewer.getControl().getData(EditorUtil.KEY_TOGGLE_TO_MAXIMIZE_ACTION));
	}
	Document document = new Document(editorViewer.getDocument().get());
	previewViewer.setDocument(document);
	return previewViewer;
	}

	public SourceViewer getEditorViewer() {
	return editorViewer;
	}

	public SourceViewer getViewer() {
	if (editorLayout == null) {
	return defaultViewer;
	}
	if (defaultViewer != null && editorLayout.topControl == defaultViewer.getControl()) {
	return defaultViewer;
	} else if (previewViewer != null && editorLayout.topControl == previewViewer.getControl()) {
	return previewViewer;
	} else {
	return editorViewer;
	}
	}

	private void setContext() {
	if (contextService == null) {
	return;
	}
	if (contextActivation != null) {
	contextService.deactivateContext(contextActivation);
	contextActivation = null;
	}
	if (contextService != null && extension.getEditorContextId() != null) {
	contextActivation = contextService.activateContext(extension.getEditorContextId());
	}
	}

	/**
	* Brings <code>viewer</code> to top.
	*/
	private void show(SourceViewer viewer) {
	show(viewer.getControl());
	}

	/**
	* Brings <code>control</code> to top.
	*/
	private void show(Control control) {
	// no extension is available
	if (editorComposite == null) {
	return;
	}

	editorLayout.topControl = control;
	if (editorComposite.getParent().getLayout() instanceof FillWidthLayout) {
	((FillWidthLayout) editorComposite.getParent().getLayout()).flush();
	}
	editorComposite.layout();
	control.setFocus();
	}

	public void showDefault() {
	show(getDefaultViewer());
	}

	public void showPreview() {
	if (!isReadOnly()) {
	show(getPreviewViewer());
	}
	}

	public void showEditor() {
	if (getEditorViewer() != null) {
	show(getEditorViewer());
	} else {
	show(getDefaultViewer());
	}
	}

	private void unsetContext() {
	if (contextService == null) {
	return;
	}
	if (contextActivation != null) {
	contextService.deactivateContext(contextActivation);
	contextActivation = null;
	}
	}

	public boolean hasPreview() {
	return extension != null && !isReadOnly();
	}

	public boolean hasBrowser() {
	return renderingEngine != null;
	}

	private BrowserPreviewViewer getBrowserViewer() {
	if (editorComposite == null \|\| renderingEngine == null) {
	return null;
	}

	if (browserViewer == null) {
	browserViewer = new BrowserPreviewViewer(getModel().getTaskRepository(), renderingEngine);
	browserViewer.createControl(editorComposite, toolkit);
	}
	return browserViewer;
	}

	public AbstractRenderingEngine getRenderingEngine() {
	return renderingEngine;
	}

	public void setRenderingEngine(AbstractRenderingEngine renderingEngine) {
	this.renderingEngine = renderingEngine;
	}

	public void showBrowser() {
	BrowserPreviewViewer viewer = getBrowserViewer();
	viewer.update(getValue());
	if (viewer != null) {
	show(viewer.getControl());
	}
	}

	public IAction getViewSourceAction() {
	return viewSourceAction;
	}

	}