/*******************************************************************************
 * Copyright (c) 2006 Sybase, Inc. 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:
 *     Sybase, Inc. - initial API and implementation
 *******************************************************************************/
package org.eclipse.jst.pagedesigner.editors;

import java.util.List;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.Platform;
import org.eclipse.gef.DefaultEditDomain;
import org.eclipse.gef.EditPart;
import org.eclipse.gef.GraphicalViewer;
import org.eclipse.gef.dnd.TemplateTransferDragSourceListener;
import org.eclipse.gef.editparts.ScalableRootEditPart;
import org.eclipse.gef.palette.PaletteRoot;
import org.eclipse.gef.ui.actions.ActionRegistry;
import org.eclipse.gef.ui.actions.UpdateAction;
import org.eclipse.gef.ui.palette.FlyoutPaletteComposite.FlyoutPreferences;
import org.eclipse.gef.ui.palette.PaletteViewer;
import org.eclipse.gef.ui.palette.PaletteViewerProvider;
import org.eclipse.gef.ui.parts.GraphicalEditorWithFlyoutPalette;
import org.eclipse.gef.ui.parts.GraphicalViewerKeyHandler;
import org.eclipse.gef.ui.views.palette.PaletteViewerPage;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.action.IMenuListener;
import org.eclipse.jface.action.IMenuManager;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jst.pagedesigner.IJMTConstants;
import org.eclipse.jst.pagedesigner.PDPlugin;
import org.eclipse.jst.pagedesigner.actions.container.ContainerActionGroup;
import org.eclipse.jst.pagedesigner.actions.menuextension.CustomedContextMenuActionGroup;
import org.eclipse.jst.pagedesigner.actions.range.RangeActionGroup;
import org.eclipse.jst.pagedesigner.actions.single.SingleElementActionGroup;
import org.eclipse.jst.pagedesigner.commands.CopyAction;
import org.eclipse.jst.pagedesigner.commands.CutAction;
import org.eclipse.jst.pagedesigner.commands.DeleteAction;
import org.eclipse.jst.pagedesigner.commands.PasteAction;
import org.eclipse.jst.pagedesigner.dnd.internal.LocalSelectionDropTargetListener;
import org.eclipse.jst.pagedesigner.dnd.internal.PDTemplateTransferDropTargetListener;
import org.eclipse.jst.pagedesigner.dnd.internal.ResouceDropTargetListener;
import org.eclipse.jst.pagedesigner.editors.actions.ActionsMessages;
import org.eclipse.jst.pagedesigner.editors.actions.DesignerUndoRedoAction;
import org.eclipse.jst.pagedesigner.editors.actions.RelatedViewActionGroup;
import org.eclipse.jst.pagedesigner.editors.actions.SkinsMenuItemBuilder;
import org.eclipse.jst.pagedesigner.editors.palette.DesignerPaletteCustomizer;
import org.eclipse.jst.pagedesigner.editors.palette.DesignerPaletteRootFactory;
import org.eclipse.jst.pagedesigner.editors.palette.DesignerPaletteViewerProvider;
import org.eclipse.jst.pagedesigner.editors.palette.IPaletteFactory;
import org.eclipse.jst.pagedesigner.jsp.core.internal.pagevar.DocumentPageVariableAdapter;
import org.eclipse.jst.pagedesigner.jsp.core.pagevar.adapter.PageVariableAdapterFactory;
import org.eclipse.jst.pagedesigner.parts.CSSStyleAdapterFactory;
import org.eclipse.jst.pagedesigner.parts.DocumentEditPart;
import org.eclipse.jst.pagedesigner.parts.HTMLEditPartsFactory;
import org.eclipse.jst.pagedesigner.parts.RefresherFactory;
import org.eclipse.jst.pagedesigner.utils.SelectionHelper;
import org.eclipse.jst.pagedesigner.viewer.IHTMLGraphicalViewer;
import org.eclipse.swt.events.MouseAdapter;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.ui.IEditorInput;
import org.eclipse.ui.IFileEditorInput;
import org.eclipse.ui.IPageLayout;
import org.eclipse.ui.ISharedImages;
import org.eclipse.ui.IWorkbenchCommandConstants;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.actions.ActionContext;
import org.eclipse.wst.sse.core.internal.PropagatingAdapter;
import org.eclipse.wst.sse.core.internal.provisional.IModelStateListener;
import org.eclipse.wst.sse.core.internal.provisional.INodeAdapterFactory;
import org.eclipse.wst.sse.core.internal.provisional.IStructuredModel;
import org.eclipse.wst.sse.core.internal.undo.IDocumentSelectionMediator;
import org.eclipse.wst.sse.core.internal.undo.UndoDocumentEvent;
import org.eclipse.wst.xml.core.internal.provisional.document.IDOMDocument;
import org.eclipse.wst.xml.core.internal.provisional.document.IDOMModel;

/**
 * @author mengbo
 */
public class SimpleGraphicalEditor extends GraphicalEditorWithFlyoutPalette implements
		IDesignViewer, IDocumentSelectionMediator {

	private HTMLEditor _delegate;

	private IHTMLGraphicalViewer _viewer;

	private IStructuredModel _model;

	/** Palette component, holding the tools and shapes. */
	private PaletteRoot _palette;
	
	private PaletteViewerPage _paletteViewerPage;

	private SelectionSynchronizer _synchronizer = new SelectionSynchronizer(
			this);

	private IModelStateListener _internalModelListener = new IModelStateListener() {
		public void modelAboutToBeChanged(IStructuredModel model) {
            // do nothing
		}

		public void modelChanged(IStructuredModel model) {
			updateActionsWhenModelChange();
		}

		public void modelDirtyStateChanged(IStructuredModel model,
				boolean isDirty) {
            // do nothing
		}

		public void modelResourceDeleted(IStructuredModel model) {
            // do nothing
		}

		public void modelResourceMoved(IStructuredModel oldModel,
				IStructuredModel newModel) {
            // do nothing
		}

		public void modelAboutToBeReinitialized(IStructuredModel structuredModel) {
            // do nothing
		}

		public void modelReinitialized(IStructuredModel structuredModel) {
            // do nothing
		}
	};

	private PaletteViewerProvider _paletteViewerProvider;

	/**
	 * TODO: why isn't this private?
	 */
	protected IPaletteFactory _paletteViewerPageFactory;

	/**
	 * @param delegate
	 * @param editdomain
	 */
	public SimpleGraphicalEditor(HTMLEditor delegate,
			DefaultEditDomain editdomain) {
		_delegate = delegate;
		initPaletteFactory();
		this.setEditDomain(editdomain);		
	}

	protected void createGraphicalViewer(Composite parent) {
		_viewer = IHTMLGraphicalViewer.Factory.createGraphicalViewer(this);
		Control control = _viewer.createControl(parent);
		PlatformUI.getWorkbench().getHelpSystem().setHelp(control,
				PDPlugin.getResourceString("SimpleGraphicalEditor.help.id")); //$NON-NLS-1$
		setGraphicalViewer(_viewer);
		configureGraphicalViewer();
		hookGraphicalViewer();
		initializeGraphicalViewer();
		initializeContextMenu();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.gef.ui.parts.GraphicalEditor#dispose()
	 */
	public void dispose() {
		if (_model != null) {
			_model.getUndoManager().disconnect(this);
		}

		super.dispose();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.gef.ui.parts.GraphicalEditor#initializeGraphicalViewer()
	 */
	protected void initializeGraphicalViewer() {
		ScalableRootEditPart rootEditPart = new ScalableRootEditPart();
		_viewer.setRootEditPart(rootEditPart);

		_viewer.getViewport().setContentsTracksWidth(true);

		_viewer.setKeyHandler(new GraphicalViewerKeyHandler(_viewer));

		// initialize the viewer with input
		// IStructuredModel sModel =
		// StructuredModelManager.getModelManager().createUnManagedStructuredModelFor(ContentTypeIdForHTML.ContentTypeID_HTML);
		// IDOMDocument designDoc = ((IDOMModel)sModel).getDocument();
		// HTMLEditPartsFactory factory = new HTMLEditPartsFactory(designDoc);
		HTMLEditPartsFactory factory = new HTMLEditPartsFactory(null);

		_viewer.setEditPartFactory(factory);

		// for sync with source view.

		_viewer.addDropTargetListener(new LocalSelectionDropTargetListener(
				_viewer));
		_viewer.addDropTargetListener(new PDTemplateTransferDropTargetListener(
				_viewer));
		_viewer.addDropTargetListener(new ResouceDropTargetListener(_viewer));
		
		// add double click support.
		_viewer.getControl().addMouseListener(new MouseAdapter() {
			public void mouseDoubleClick(MouseEvent e) {
				try {
					getSite().getPage().showView(IPageLayout.ID_PROP_SHEET);
				} catch (PartInitException e1) {
					// ignore
				}
			}
		});
        
        super.initializeGraphicalViewer();
	}

	/**
	 * 
	 */
	protected void initializeContextMenu() {
		Control gviewer = _viewer.getControl();
		MenuManager menuMgr = new MenuManager();
		menuMgr.setRemoveAllWhenShown(true);
		Menu menu = menuMgr.createContextMenu(gviewer);
		gviewer.setMenu(menu);
		menuMgr.addMenuListener(new ContextMenuListener());
		getSite().registerContextMenu(
				"HTMLVisualEditor.contextMenu", menuMgr, _viewer); //$NON-NLS-1$
	}

	private void updateActionsWhenModelChange() {
		// update undo/redo action
		IAction action = this.getAction(IWorkbenchCommandConstants.EDIT_UNDO);
		((UpdateAction) action).update();

		action = this.getAction(IWorkbenchCommandConstants.EDIT_REDO);
		((UpdateAction) action).update();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.gef.ui.parts.GraphicalEditor#createActions()
	 */
	protected void createActions() {
		super.createActions();
		ActionRegistry registry = getActionRegistry();
		ISharedImages sharedImages = PlatformUI.getWorkbench()
				.getSharedImages();

		IAction action;

		action = new DesignerUndoRedoAction(true, this);
		action.setImageDescriptor(sharedImages
				.getImageDescriptor(ISharedImages.IMG_TOOL_UNDO));
		action.setDisabledImageDescriptor(sharedImages
				.getImageDescriptor(ISharedImages.IMG_TOOL_UNDO_DISABLED));
		action.setActionDefinitionId(IWorkbenchCommandConstants.EDIT_UNDO);
		action.setId(IWorkbenchCommandConstants.EDIT_UNDO);
		getSite().getKeyBindingService().registerAction(action);
		registry.registerAction(action);

		action = new DesignerUndoRedoAction(false, this);
		action.setImageDescriptor(sharedImages
				.getImageDescriptor(ISharedImages.IMG_TOOL_REDO));
		action.setDisabledImageDescriptor(sharedImages
				.getImageDescriptor(ISharedImages.IMG_TOOL_REDO_DISABLED));
		action.setActionDefinitionId(IWorkbenchCommandConstants.EDIT_REDO);
		action.setId(IWorkbenchCommandConstants.EDIT_REDO);
		getSite().getKeyBindingService().registerAction(action);
		registry.registerAction(action);

		action = new DeleteAction(this);
		action.setImageDescriptor(sharedImages
				.getImageDescriptor(ISharedImages.IMG_TOOL_DELETE));
		action.setDisabledImageDescriptor(sharedImages
				.getImageDescriptor(ISharedImages.IMG_TOOL_DELETE_DISABLED));
		action.setActionDefinitionId(IWorkbenchCommandConstants.EDIT_DELETE);
		action.setId(IWorkbenchCommandConstants.EDIT_DELETE);
		getSite().getKeyBindingService().registerAction(action);
		this.getSelectionActions().add(action.getId());
		registry.registerAction(action);

		action = new CopyAction(this);
		action.setImageDescriptor(sharedImages
				.getImageDescriptor(ISharedImages.IMG_TOOL_COPY));
		action.setDisabledImageDescriptor(sharedImages
				.getImageDescriptor(ISharedImages.IMG_TOOL_COPY_DISABLED));
		action.setActionDefinitionId(IWorkbenchCommandConstants.EDIT_COPY);
		action.setId(IWorkbenchCommandConstants.EDIT_COPY);
		getSite().getKeyBindingService().registerAction(action);
		this.getSelectionActions().add(action.getId());
		registry.registerAction(action);

		action = new CutAction(this);
		action.setImageDescriptor(sharedImages
				.getImageDescriptor(ISharedImages.IMG_TOOL_CUT));
		action.setDisabledImageDescriptor(sharedImages
				.getImageDescriptor(ISharedImages.IMG_TOOL_CUT_DISABLED));
		action.setActionDefinitionId(IWorkbenchCommandConstants.EDIT_CUT);
		action.setId(IWorkbenchCommandConstants.EDIT_CUT);
		getSite().getKeyBindingService().registerAction(action);
		this.getSelectionActions().add(action.getId());
		registry.registerAction(action);

		action = new PasteAction(this);
		action.setImageDescriptor(sharedImages
				.getImageDescriptor(ISharedImages.IMG_TOOL_PASTE));
		action.setDisabledImageDescriptor(sharedImages
				.getImageDescriptor(ISharedImages.IMG_TOOL_PASTE_DISABLED));
		action.setActionDefinitionId(IWorkbenchCommandConstants.EDIT_PASTE);
		action.setId(IWorkbenchCommandConstants.EDIT_PASTE);
		getSite().getKeyBindingService().registerAction(action);
		this.getSelectionActions().add(action.getId());
		registry.registerAction(action);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.ISaveablePart#doSave(org.eclipse.core.runtime.IProgressMonitor)
	 */
	public void doSave(IProgressMonitor monitor) {
		if (_delegate != null) {
			_delegate.doSave(monitor);
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.ISaveablePart#doSaveAs()
	 */
	public void doSaveAs() {
		if (_delegate != null) {
			_delegate.doSaveAs();
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.ISaveablePart#isDirty()
	 */
	public boolean isDirty() {
		if (_delegate != null) {
			return _delegate.isDirty();
		}
        return false;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.ISaveablePart#isSaveAsAllowed()
	 */
	public boolean isSaveAsAllowed() {
		if (_delegate != null) {
			return _delegate.isSaveAsAllowed();
		}
        return false;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see com.sybase.html.editor.IDesignViewer#setModel(com.ibm.sse.model.IStructuredModel)
	 */
	public void setModel(IStructuredModel model) {
		if (_model != null) {
			if (_model.getUndoManager() != null)
				_model.getUndoManager().disconnect(this);
			_model.removeModelStateListener(_internalModelListener);
		}

		this._model = model;

		if (_model != null) {
			_model.addModelStateListener(_internalModelListener);
			if (_model.getUndoManager() != null) {
				_model.getUndoManager().connect(this);
				updateActionsWhenModelChange();
			}
		}

		if (model instanceof IDOMModel) {
			IDOMDocument doc = ((IDOMModel) model).getDocument();
			PropagatingAdapter adapter = (PropagatingAdapter) doc
					.getAdapterFor(PropagatingAdapter.class);
			if (adapter != null) {
				INodeAdapterFactory factory = RefresherFactory.getInstance();
				adapter.addAdaptOnCreateFactory(factory);
				adapter.initializeForFactory(factory, doc);
				// CSSStyleAdapterFactory fac2 =
				// CSSStyleAdapterFactory.getInstance();
				// adapter.addAdaptOnCreateFactory(fac2);
				// adapter.initializeForFactory(fac2, doc);
			}
			((IDOMModel) model).getFactoryRegistry().addFactory(
					CSSStyleAdapterFactory.getInstance());

			// _viewer.getDestDocumentForDesign().getModel().getFactoryRegistry().addFactory(CSSStyleAdapterFactory.getInstance());
			((IDOMModel) model).getFactoryRegistry().addFactory(
					new PageVariableAdapterFactory());
			doc.addAdapter(new DocumentPageVariableAdapter(doc));
			_viewer.setContents(((IDOMModel) model).getDocument());
		} else {
			_viewer.setContents((EditPart) null);
		}
	}

	/**
	 * @return the selection synchronizer
	 */
	protected SelectionSynchronizer getSynchronizer() {
		return _synchronizer;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.gef.ui.parts.GraphicalEditor#updateActions(java.util.List)
	 */
	protected void updateActions(List actionIds) {
		super.updateActions(actionIds);
	}

	/**
	 * @param id
	 * @return the action for the id
	 */
	public IAction getAction(Object id) {
		// lium: following lines commented out, see comments in
		// DesignerUndoRedoAction
		// if (ITextEditorActionConstants.UNDO.equals(id) ||
		// ITextEditorActionConstants.REDO.equals(id))
		// {
		// return _delegate.getTextEditor().getAction((String) id);
		// }
		return getActionRegistry().getAction(id);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.gef.ui.parts.GraphicalEditorWithFlyoutPalette#getPalettePreferences()
	 */
	protected FlyoutPreferences getPalettePreferences() {
		return DesignerPaletteRootFactory.createPalettePreferences();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.gef.ui.parts.GraphicalEditorWithFlyoutPalette#getPaletteRoot()
	 */
	protected PaletteRoot getPaletteRoot() {
		if (_palette == null) {
			if (_paletteViewerPageFactory != null) {
	            _palette = _paletteViewerPageFactory.createPaletteRoot(_delegate.getEditorInput());
	        } 
            if (_palette == null) {
            	_palette = DesignerPaletteRootFactory
            		.createPaletteRoot(getCurrentFile(_delegate.getEditorInput()));
            }
		}
		return _palette;

	}

    /*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.gef.ui.parts.GraphicalEditorWithFlyoutPalette#createPaletteViewerProvider()
	 */
    protected PaletteViewerProvider createPaletteViewerProvider() {
    	if (_paletteViewerProvider == null) {
    		if (_paletteViewerPageFactory != null) {
    			_paletteViewerProvider = _paletteViewerPageFactory.createPaletteViewerProvider(getEditDomain());
    		}
    		if (_paletteViewerProvider == null) {//if still null
    			return new DesignerPaletteViewerProvider(getEditDomain()) {
    				protected void configurePaletteViewer(PaletteViewer viewer) {
    					super.configurePaletteViewer(viewer);
    					viewer.setCustomizer(new DesignerPaletteCustomizer());

    					// create a drag source listener for this palette viewer
    					// together with an appropriate transfer drop target listener,
    					// this will enable
    					// model element creation by dragging a
    					// CombinatedTemplateCreationEntries
    					// from the palette into the editor
    					// @see ShapesEditor#createTransferDropTargetListener()
    					viewer
    							.addDragSourceListener(new TemplateTransferDragSourceListener(
    									viewer));
    				}
    			};
    		}
    	}
    	return _paletteViewerProvider;
    }

    /**
     * @return the palette viewer page
     */
    protected PaletteViewerPage createPaletteViewerPage() {
        if (_paletteViewerPageFactory != null) {
        	_paletteViewerPage = _paletteViewerPageFactory.createPaletteViewerPage(createPaletteViewerProvider());
        } 
        if (_paletteViewerPage == null) {
            DefaultEditDomain editDomain = getEditDomain();
//            PaletteItemManager manager = PaletteItemManager
//                    .getInstance(getCurrentFile(getEditorInput()));
//            manager.reset();
            PaletteRoot paletteRoot = getPaletteRoot();
            editDomain.setPaletteRoot(paletteRoot);
            
//            _paletteViewerPage = (PaletteViewerPage) super.getAdapter(PalettePage.class);
            // if possible, try to use the 
            if (_paletteViewerPage == null)
            {
                PaletteViewerProvider provider = getPaletteViewerProvider2();
                _paletteViewerPage = new PaletteViewerPage(provider);
            }
        }
    	return _paletteViewerPage;
    }
    
    PaletteViewerProvider getPaletteViewerProvider2()
    {
        return getPaletteViewerProvider();
    }
    
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jst.pagedesigner.editors.IDesignViewer#getGraphicViewer()
	 */
	public IHTMLGraphicalViewer getGraphicViewer() {
		return _viewer;
	}

	/**
	 * @return the html editor delegate
	 */
	public HTMLEditor getHTMLEditor() {
		return _delegate;
	}

//	private IProject getCurrentProject(IEditorInput input) {
//		IProject curProject = null;
//		IFile inputFile = null;
//		if (input instanceof IFileEditorInput) {
//			inputFile = ((IFileEditorInput) input).getFile();
//			curProject = inputFile.getProject();
//		}
//		return curProject;
//	}

	private IFile getCurrentFile(IEditorInput input) {
		IFile inputFile = null;
		if (input instanceof IFileEditorInput) {
			inputFile = ((IFileEditorInput) input).getFile();
		}
		return inputFile;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.ISelectionListener#selectionChanged(org.eclipse.ui.IWorkbenchPart,
	 *      org.eclipse.jface.viewers.ISelection)
	 */
	public void selectionChanged(IWorkbenchPart part, ISelection selection) {
		if (_viewer != null) {
			GraphicalViewer viewerViewer = getGraphicalViewer();
			if (viewerViewer != null && viewerViewer.getControl() != null
					&& viewerViewer.getControl().isFocusControl()) {
				updateActions(getSelectionActions());
				if (selection instanceof IStructuredSelection && //
						!(((IStructuredSelection) selection).getFirstElement() instanceof DocumentEditPart)) {
					((IHTMLGraphicalViewer) viewerViewer)
							.updateRangeSelection(selection);
				}
			}
		} else {
			super.selectionChanged(part, selection);
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.wst.sse.core.internal.undo.IDocumentSelectionMediator#getDocument()
	 */
	public IDocument getDocument() {
		if (_model != null) {
			return _model.getStructuredDocument();
		}
		return null;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.wst.sse.core.internal.undo.IDocumentSelectionMediator#undoOperationSelectionChanged(org.eclipse.wst.sse.core.internal.undo.UndoDocumentEvent)
	 */
	public void undoOperationSelectionChanged(UndoDocumentEvent event) {
		IDocumentSelectionMediator requester = event.getRequester();
		if (this == requester) {
			// ok, the undo/redo operation is initialized by designer page.
			// we should set selection in designer.
			// However, when this method is called, the modelChanged event is
			// not fired yet, so the
			// editpart hasn't refreshed yet. So we register a
			// modelStateListener, and do the selection
			// in modelChangedEvent. (lium)
			final int offset = event.getOffset();
			final int length = event.getLength();

			_model.addModelStateListener(new IModelStateListener() {
				public void modelAboutToBeChanged(IStructuredModel model) {
                    // nothing to do
				}

				public void modelChanged(IStructuredModel model) {
					_model.removeModelStateListener(this);
					ISelection sel = SelectionHelper
							.convertToDesignerSelection(getGraphicViewer(),
									offset, length);
					if (sel != null) {
						getGraphicViewer().setSelection(sel);
					}
				}

				public void modelDirtyStateChanged(IStructuredModel model,
						boolean isDirty) {
                    // do  nothing
				}

				public void modelResourceDeleted(IStructuredModel model) {
                    // do nothign
				}

				public void modelResourceMoved(IStructuredModel oldModel,
						IStructuredModel newModel) {
                    // do nothing
				}

				public void modelAboutToBeReinitialized(
						IStructuredModel structuredModel) {
                    // do nothing
				}

				public void modelReinitialized(IStructuredModel structuredModel) {
                    // do nothing
				}
			});
		}
	}
 
    private final class ContextMenuListener implements IMenuListener 
    {
        public void menuAboutToShow(IMenuManager menuMgr1) 
        {
            // add standarized sub-menus
            addEditSubMenu(menuMgr1);
            addSelectSubMenu(menuMgr1);
            addInsertSubMenu(menuMgr1);
            /*
             * Bug 172959 - [WPE] WPE context menu Navigate->Java->Value doesn't work..
             * 
            addNavigateSubMenu(menuMgr1);
            */
            addStyleSubMenu(menuMgr1);
            
            // add separators that mark standard append locations in the main
            // context menu
            PageDesignerActionConstants.addStandardActionGroups(menuMgr1);

            // TODO: Run/Debug?
            
            // insert ElementEdit contributed menu items
            final ContainerActionGroup containerActionGroup = 
                new ContainerActionGroup();
            ActionContext context = new ActionContext(_viewer
                    .getSelection());
            context.setInput(_viewer);
            containerActionGroup.setContext(context);
            containerActionGroup.fillContextMenu(menuMgr1);
            containerActionGroup.setContext(null);

            // TODO: TableActionGroup

            // if on a text context, (instead of a ElementEditPart),
            // add text styling actions
            final RangeActionGroup rangeActionGroup = new RangeActionGroup();
            context = new ActionContext(_viewer.getSelection());
            context.setInput(_viewer);
            rangeActionGroup.setContext(context);
            rangeActionGroup.fillContextMenu(menuMgr1);
            rangeActionGroup.setContext(null);

            // Add actions for single ElementEditPart's that are common
            // to all
            final SingleElementActionGroup singleActionGroup = 
                new SingleElementActionGroup();
            singleActionGroup.setContext(new ActionContext(_viewer
                    .getSelection()));
            singleActionGroup.fillContextMenu(menuMgr1);
            singleActionGroup.setContext(null);

            // add "Show In" actions...
            final RelatedViewActionGroup viewMenu = new RelatedViewActionGroup(getEditDomain());
            context = new ActionContext(_viewer.getSelection());
            viewMenu.setContext(context);
            viewMenu.fillContextMenu(menuMgr1);

            // add extension point contributed menu actions
            CustomedContextMenuActionGroup customedMenu = new CustomedContextMenuActionGroup();
            customedMenu.setContext(new ActionContext(_viewer
                    .getSelection()));
            customedMenu.setModel(_model);
            customedMenu.setParentControl(_viewer.getControl());
            customedMenu.fillContextMenu(menuMgr1);
            customedMenu.setContext(null);
            customedMenu.setParentControl(null);
            customedMenu.setModel(null);

            //add skins menu
            IEditorInput editorInput = _delegate.getEditorInput();
			if (editorInput instanceof IFileEditorInput) {
				IFile file = ((IFileEditorInput)editorInput).getFile();
				IProject project = file.getProject();
				if (project != null) {
					SkinsMenuItemBuilder builder = new SkinsMenuItemBuilder(project);
					builder.buildMenuManagers(menuMgr1);
        }
			}
        }

        /*
         * Bug 172959 - [WPE] WPE context menu Navigate->Java->Value doesn't work..
         * 
        private void addNavigateSubMenu(IMenuManager menu) {
            final IMenuManager  navigateSubmenu = 
                new MenuManager(ActionsMessages.getString("Navigate.Menu")  //$NON-NLS-1$
                        , PageDesignerActionConstants.NAVIGATE_SUBMENU_ID);
            menu.add(navigateSubmenu);
            PageDesignerActionConstants.addStandardNavigateActionGroups(navigateSubmenu);
        }
         */

        private void addEditSubMenu(IMenuManager menu)
        {
            final IMenuManager  editSubmenu 
                = new MenuManager(ActionsMessages.getString("Edit.Menu")  //$NON-NLS-1$
                        , PageDesignerActionConstants.EDIT_SUBMENU_ID);
            menu.add(editSubmenu);
            PageDesignerActionConstants.addStandardEditActionGroups(editSubmenu);
            
            // FIXME: for UNDO/REDO, maybe need also wrap them in
            // DesignerCommand.
            // otherwise don't have validate() called after the source
            // change.
            editSubmenu.appendToGroup(PageDesignerActionConstants.GROUP_UNDO,
                    getAction(IWorkbenchCommandConstants.EDIT_UNDO));
            editSubmenu.appendToGroup(PageDesignerActionConstants.GROUP_UNDO,
                    getAction(IWorkbenchCommandConstants.EDIT_REDO));

            editSubmenu.appendToGroup(PageDesignerActionConstants.GROUP_EDIT,
                    getAction(IWorkbenchCommandConstants.EDIT_CUT));
            editSubmenu.appendToGroup(PageDesignerActionConstants.GROUP_EDIT,
                    getAction(IWorkbenchCommandConstants.EDIT_COPY));
            editSubmenu.appendToGroup(PageDesignerActionConstants.GROUP_EDIT,
                    getAction(IWorkbenchCommandConstants.EDIT_PASTE));
            editSubmenu.appendToGroup(PageDesignerActionConstants.GROUP_EDIT,
                    getAction(IWorkbenchCommandConstants.EDIT_DELETE));

        }
        
        private void addStyleSubMenu(IMenuManager menu)
        {
            final IMenuManager  styleSubmenu = 
                new MenuManager(ActionsMessages.getString("Style.Menu")  //$NON-NLS-1$
                        , PageDesignerActionConstants.STYLE_SUBMENU_ID);
            menu.add(styleSubmenu);
            PageDesignerActionConstants.addStandardStyleActionGroups(styleSubmenu);
        }
        private void addInsertSubMenu(IMenuManager menu) {
            final IMenuManager  insertSubmenu = 
                new MenuManager(ActionsMessages.getString("Insert.Menu")  //$NON-NLS-1$
                        , PageDesignerActionConstants.INSERT_SUBMENU_ID);
            menu.add(insertSubmenu);
            PageDesignerActionConstants.addStandardInsertActionGroups(insertSubmenu);
        }
        
        private void addSelectSubMenu(IMenuManager menu)
        {
            final IMenuManager  selectSubMenu = 
                new MenuManager(ActionsMessages.getString("Select.Menu")  //$NON-NLS-1$
                        , PageDesignerActionConstants.SELECT_SUBMENU_ID);
            menu.add(selectSubMenu);
            PageDesignerActionConstants.addStandardSelectActionGroups(selectSubMenu);
        }
    }

    
    /**
     * @return the palette viewer page
     */
    public PaletteViewerPage getPaletteViewerPage() {
        if (_paletteViewerPage == null) {
        	_paletteViewerPage = createPaletteViewerPage();
		}
		return _paletteViewerPage;
	}

    /**
     * @return the palette factory
     */
    protected IPaletteFactory initPaletteFactory()
    {   	
    	if (_paletteViewerPageFactory == null) {
	        //List<IElementEditFactory> result = new ArrayList<IElementEditFactory>();
	        IExtensionPoint extensionPoint = Platform.getExtensionRegistry()
	                .getExtensionPoint(PDPlugin.getPluginId(),
	                        IJMTConstants.EXTENSION_POINT_PAGEDESIGNER);
	        IExtension[] extensions = extensionPoint.getExtensions();
	
	        for (int i = 0; i < extensions.length; i++)
	        {
	            IExtension ext = extensions[i];
	            IConfigurationElement[] elementEditElement = ext
	                    .getConfigurationElements();
	
	            for (int j = 0; j < elementEditElement.length; j++)
	            {
	                final IConfigurationElement element = elementEditElement[j];
	                if (element.getName().equals(
	                        IJMTConstants.PALETTE_FACTORY))
	                {
	                    elementEditElement[j].getAttribute("class"); //$NON-NLS-1$
	                    Object obj;
	                    try
	                    {
	                        obj = elementEditElement[j]
	                                .createExecutableExtension("class"); //$NON-NLS-1$
	
	                        // TODO: we need a policy based solution here,
	                        // but this will do for now
	                        if (obj instanceof IPaletteFactory)
	                        {
	                        	_paletteViewerPageFactory = (IPaletteFactory) obj;
	                        }
	                    } 
	                    catch (CoreException e)
	                    {
	                        PDPlugin.log("Problem loading element edit extension for "+element.toString(), e); //$NON-NLS-1$
	                    }
	                }
	            }
	        }
    	}
        return _paletteViewerPageFactory;
    }
//    
//    @Override
//	public Object getAdapter(Class type) {
//    	if (type == PalettePage.class) {
//    		return getPaletteViewerPage();
//    	}
//		return super.getAdapter(type);
//	}


}