plugins/org.eclipse.bpmn2.modeler.ui/src/org/eclipse/bpmn2/modeler/ui/editor/BPMN2MultiPageEditor.java - bpmn2-modeler/org.eclipse.bpmn2-modeler - Git at Google

 /*******************************************************************************
  * Copyright (c) 2011, 2012 Red Hat, Inc.
  *  All rights reserved.
  * This program is 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:
  * Red Hat, Inc. - initial API and implementation
  *
  * @author Bob Brodt
  ******************************************************************************/

 package org.eclipse.bpmn2.modeler.ui.editor;

 import java.util.ArrayList;
 import java.util.List;

 import org.eclipse.bpmn2.BaseElement;
 import org.eclipse.bpmn2.di.BPMNDiagram;
 import org.eclipse.bpmn2.modeler.core.adapters.ExtendedPropertiesProvider;
 import org.eclipse.bpmn2.modeler.core.utils.ModelUtil;
 import org.eclipse.bpmn2.modeler.ui.Bpmn2DiagramEditorInput;
 import org.eclipse.core.resources.IMarker;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.graphiti.mm.pictograms.PictogramElement;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.CTabFolder;
 import org.eclipse.swt.custom.CTabFolder2Listener;
 import org.eclipse.swt.custom.CTabFolderEvent;
 import org.eclipse.swt.custom.CTabItem;
 import org.eclipse.swt.events.SelectionAdapter;
 import org.eclipse.swt.events.SelectionEvent;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.ui.IEditorInput;
 import org.eclipse.ui.IEditorPart;
 import org.eclipse.ui.IEditorSite;
 import org.eclipse.ui.PartInitException;
 import org.eclipse.ui.ide.IDE;
 import org.eclipse.ui.ide.IGotoMarker;
 import org.eclipse.ui.part.FileEditorInput;
 import org.eclipse.ui.part.MultiPageEditorPart;
 import org.eclipse.ui.part.MultiPageEditorSite;

 /**
  * This class implements a multi-page version of the BPMN2 Modeler (BPMN2Editor class).
  * To revert back to the original, single-page version simply change the editor extension
  * point in plugin.xml (see comments there).
  *
  * This is still in the experimental phase and currently only supports a single diagram
  * per .bpmn file. An optional second page, which displays the XML source, can be created
  * from the context menu. The source view is not yet synchronized to the design view and
  * can only show the XML as of the last "Save" i.e. the current state of the file on disk,
  * not the in-memory model. Design/Source view synchronization will be implemented in a
  * future version, but direct editing of the XML will not be supported - it will remain
  * "view only".
  *
  * Future versions will support multiple diagrams per .bpmn file with the ability to add
  * and remove pages containing different diagram types. It should be possible for the user
  * to create a single file that contains a mix of Process, Collaboration and Choreography
  * diagrams. Whether or not these types of files are actually deployable and/or executable
  * is another story ;)
  */
 public class BPMN2MultiPageEditor extends MultiPageEditorPart implements IGotoMarker {

 	DesignEditor designEditor;
 	SourceViewer sourceViewer;
 	private CTabFolder tabFolder;
 	private int defaultTabHeight;
 	private List<BPMNDiagram> bpmnDiagrams = new ArrayList<BPMNDiagram>();
 	private List<PictogramElement[]> currentSelections = new ArrayList<PictogramElement[]>();
 	private int currentPageIndex = -1;

 	public BPMN2MultiPageEditor() {
 		super();
 	}

 	@Override
 	protected IEditorSite createSite(IEditorPart editor) {
 		if (editor instanceof DesignEditor)
 			return new DesignEditorSite(this, editor);
 		return new MultiPageEditorSite(this, editor);
 	}

 	@Override
 	public String getTitle() {
 		if (designEditor!=null)
 			return designEditor.getTitle();
 		return super.getTitle();
 	}

 	@Override
 	public String getPartName() {
 		if (designEditor!=null)
 			return designEditor.getPartName();
 		return super.getPartName();
 	}

 	@Override
     public void setInput(IEditorInput input) {
     	super.setInput(input);
     	Display.getDefault().asyncExec(new Runnable() {
 			@Override
 			public void run() {
 		    	setTitleToolTip( getTitleToolTip() );
 			}
     	});
     }

     /**
      * Method declared on IEditorPart.
      *
      * @param marker Marker to look for
      */
     @Override
     public void gotoMarker(IMarker marker) {
         if (getActivePage() < 0) {
             setActivePage(0);
         }
         IDE.gotoMarker(getEditor(getActivePage()), marker);
     }
 	/* (non-Javadoc)
 	 * @see org.eclipse.ui.part.MultiPageEditorPart#createPages()
 	 */
 	@Override
 	protected void createPages() {
 		tabFolder = (CTabFolder)getContainer();
 		tabFolder.addCTabFolder2Listener( new CTabFolder2Listener() {

 			@Override
 			public void close(CTabFolderEvent event) {
 				if (event.item.getData() == sourceViewer)
 					removeSourceViewer();
 			}

 			@Override
 			public void minimize(CTabFolderEvent event) {
 			}

 			@Override
 			public void maximize(CTabFolderEvent event) {
 			}

 			@Override
 			public void restore(CTabFolderEvent event) {
 			}

 			@Override
 			public void showList(CTabFolderEvent event) {
 			}

 		});
 		tabFolder.addSelectionListener( new SelectionAdapter() {
 			@Override
 			public void widgetSelected(SelectionEvent e) {
 				int pageIndex = tabFolder.getSelectionIndex();
 				if (pageIndex>=0 && pageIndex<bpmnDiagrams.size() && designEditor!=null) {
 					BPMNDiagram bpmnDiagram = bpmnDiagrams.get(pageIndex);
 					designEditor.selectBpmnDiagram(bpmnDiagram);
 				}
 			}
 		});

 		// defer editor layout until all pages have been created
 		tabFolder.setLayoutDeferred(true);

 		createDesignEditor();

 		Display.getDefault().asyncExec(new Runnable() {
 			public void run() {
 				setActivePage(0);
 				designEditor.selectBpmnDiagram(bpmnDiagrams.get(0));
 				tabFolder.setLayoutDeferred(false);
 				tabFolder.setTabPosition(SWT.TOP);
 				updateTabs();
 			}
 		});
 	}

 	protected void createDesignEditor() {
 		if (designEditor==null) {
 			designEditor = new DesignEditor(this, this);

 			try {
 				int pageIndex = tabFolder.getItemCount();
 				if (sourceViewer!=null)
 					--pageIndex;
 				addPage(pageIndex, designEditor, BPMN2MultiPageEditor.this.getEditorInput());
 				defaultTabHeight = tabFolder.getTabHeight();
 				setPageText(pageIndex,ExtendedPropertiesProvider.getTextValue( designEditor.getBpmnDiagram() ));

 				defaultTabHeight = tabFolder.getTabHeight();

 				updateTabs();
 			}
 			catch (Exception e) {
 				e.printStackTrace();
 			}
 		}
 	}

 	public DesignEditor getDesignEditor() {
 		return designEditor;
 	}

 	protected void addDesignPage(final BPMNDiagram bpmnDiagram) {
 		createDesignEditor();
 		Display.getDefault().asyncExec(new Runnable() {
 			public void run() {
 				try {

 					int pageIndex = tabFolder.getItemCount();
 					if (sourceViewer!=null)
 						--pageIndex;
 					Bpmn2DiagramEditorInput input = (Bpmn2DiagramEditorInput)designEditor.getEditorInput();
 					input.setBpmnDiagram(bpmnDiagram);
 					addPage(pageIndex, designEditor, input);
 					CTabItem oldItem = tabFolder.getItem(pageIndex-1);
 					CTabItem newItem = tabFolder.getItem(pageIndex);
 					newItem.setControl( oldItem.getControl() );
 					BaseElement bpmnElement = bpmnDiagram.getPlane().getBpmnElement();
 					String name = ModelUtil.getName(bpmnElement);
 					if (name==null)
 						name = ExtendedPropertiesProvider.getTextValue(bpmnDiagram);
 					setPageText(pageIndex,name);

 					setActivePage(pageIndex);
 					updateTabs();
 				}
 				catch (Exception e) {
 					e.printStackTrace();
 				}
 			}
 		});
 	}

 	public void showDesignPage(final BPMNDiagram bpmnDiagram) {
 		final int pageIndex = bpmnDiagrams.indexOf(bpmnDiagram);
 		if (pageIndex>=0) {
 			if (getDesignEditor().getBpmnDiagram()!=bpmnDiagram) {
 				setActivePage(pageIndex);
 			}
 		}
 		else {
 			designEditor.showDesignPage(bpmnDiagram);
 		}
 	}

 	protected void removeDesignPage(final BPMNDiagram bpmnDiagram) {
 		final int pageIndex = bpmnDiagrams.indexOf(bpmnDiagram);
 		if (pageIndex>0) {
 			// go back to "Design" page - the only page that can't be removed
 			Display.getCurrent().asyncExec( new Runnable() {
 				@Override
 				public void run() {
 					setActivePage(0);

 					IEditorPart editor = getEditor(pageIndex);
 					if (editor instanceof DesignEditor) {
 						((DesignEditor)editor).deleteBpmnDiagram(bpmnDiagram);
 					}

 					// need to manage this ourselves so that the CTabFolder doesn't
 					// dispose our editor site (a child of the CTabItem.control)
 					tabFolder.getItem(pageIndex).setControl(null);

 					removePage(pageIndex);

 					tabFolder.getSelection().getControl().setVisible(true);
 				}
 			});
 		}
 	}

 	public int getDesignPageCount() {
 		int count = getPageCount();
 		if (sourceViewer!=null)
 			--count;
 		return count;
 	}

 	protected void createSourceViewer() {
 		if (sourceViewer==null) {
 			sourceViewer = new SourceViewer(this);

 			try {
 				int pageIndex = tabFolder.getItemCount();
 				FileEditorInput input = new FileEditorInput(designEditor.getModelFile());
 				addPage(pageIndex, sourceViewer, input);
 				tabFolder.getItem(pageIndex).setShowClose(true);

 				setPageText(pageIndex,Messages.BPMN2MultiPageEditor_Source_Tab);
 				setActivePage(pageIndex);

 				updateTabs();
 			}
 			catch (Exception e) {
 				e.printStackTrace();
 				if (sourceViewer!=null)
 					sourceViewer.dispose();
 			}
 		}
 	}

 	public SourceViewer getSourceViewer() {
 		return sourceViewer;
 	}

 	public void removeSourceViewer() {
 		// there will only be one source page and it will always be the last page in the tab folder
 		if (sourceViewer!=null) {
 			int pageIndex = tabFolder.getItemCount() - 1;
 			if (pageIndex>0) {
 				removePage(pageIndex);
 				sourceViewer = null;
 			}
 		}
 	}

 	public void addPage(int pageIndex, IEditorPart editor, IEditorInput input)
 			throws PartInitException {
 		super.addPage(pageIndex,editor,input);
 		if (editor instanceof DesignEditor) {
 			bpmnDiagrams.add(pageIndex,((DesignEditor)editor).getBpmnDiagram());
 			currentSelections.add(new PictogramElement[]{});
 		}
 	}

 	@Override
 	public void removePage(int pageIndex) {
 		Object page = tabFolder.getItem(pageIndex).getData();
 		super.removePage(pageIndex);
 		updateTabs();
 		if (page instanceof DesignEditor) {
 			bpmnDiagrams.remove(pageIndex);
 			currentSelections.remove(pageIndex);
 		}
 	}

 	@Override
 	protected void pageChange(final int newPageIndex) {
 		if (currentPageIndex>=0 && currentPageIndex<tabFolder.getItemCount()) {
 			IEditorPart editor = getEditor(currentPageIndex);
 			if (editor instanceof DesignEditor) {
 				final DesignEditor de = (DesignEditor) editor;
 				PictogramElement selections[] = de.getSelectedPictogramElements();
 				currentSelections.set(currentPageIndex, selections);
 			}
 		}
 		currentPageIndex = newPageIndex;

 		super.pageChange(newPageIndex);

 		IEditorPart editor = getEditor(newPageIndex);
 		if (editor instanceof DesignEditor) {
 			final DesignEditor de = (DesignEditor) editor;
 			BPMNDiagram bpmnDiagram = bpmnDiagrams.get(newPageIndex);
 			final PictogramElement selections[] = currentSelections.get(newPageIndex);
 			de.pageChange(bpmnDiagram);

 			if (selections!=null) {
 				Display.getCurrent().asyncExec(new Runnable() {
 					@Override
 					public void run() {
 						de.selectPictogramElements(selections);
 					}
 				});
 			}
 		}
 	}

 	public int getPageCount() {
 		return tabFolder.getItemCount();
 	}

 	public CTabItem getTabItem(int pageIndex) {
 		return tabFolder.getItem(pageIndex);
 	}

 	public BPMNDiagram getBpmnDiagram(int i) {
 		if (i>=0 && i<bpmnDiagrams.size()) {
 			return bpmnDiagrams.get(i);
 		}
 		return null;
 	}

 	private void updateTabs() {
 		if (!tabFolder.getLayoutDeferred()) {
 			if (tabFolder.getItemCount()==1) {
 				tabFolder.setTabHeight(0);
 			}
 			else
 				tabFolder.setTabHeight(defaultTabHeight);
 		}
 		tabFolder.layout();
 	}

 	public CTabFolder getTabFolder() {
 		return tabFolder;
 	}

 	/* (non-Javadoc)
 	 * @see org.eclipse.ui.part.EditorPart#doSave(org.eclipse.core.runtime.IProgressMonitor)
 	 */
 	@Override
 	public void doSave(IProgressMonitor monitor) {
 		designEditor.doSave(monitor);
 	}

 	/* (non-Javadoc)
 	 * @see org.eclipse.ui.part.EditorPart#doSaveAs()
 	 */
 	@Override
 	public void doSaveAs() {
 		IEditorPart activeEditor = getActiveEditor();
 		activeEditor.doSaveAs();
 	}

 	/* (non-Javadoc)
 	 * @see org.eclipse.ui.part.EditorPart#isSaveAsAllowed()
 	 */
 	@Override
 	public boolean isSaveAsAllowed() {

 		/*
 		 * Depending upon the active page in multipage editor, call the saveAsAllowed.
 		 * It helps to see whether a particular editor allows 'save as' feature
 		 */
 		IEditorPart activeEditor = getActiveEditor();
 		if (activeEditor!=null)
 			return activeEditor.isSaveAsAllowed();
 		return false;
 	}

 	@Override
 	public void dispose() {
 		designEditor.dispose();
 		if (sourceViewer!=null)
 			sourceViewer.dispose();
 	}

 	@Override
 	public IEditorPart getActiveEditor() {
 		return super.getActiveEditor();
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2011, 2012 Red Hat, Inc.
	* All rights reserved.
	* This program is 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:
	* Red Hat, Inc. - initial API and implementation
	*
	* @author Bob Brodt
	******************************************************************************/

	package org.eclipse.bpmn2.modeler.ui.editor;

	import java.util.ArrayList;
	import java.util.List;

	import org.eclipse.bpmn2.BaseElement;
	import org.eclipse.bpmn2.di.BPMNDiagram;
	import org.eclipse.bpmn2.modeler.core.adapters.ExtendedPropertiesProvider;
	import org.eclipse.bpmn2.modeler.core.utils.ModelUtil;
	import org.eclipse.bpmn2.modeler.ui.Bpmn2DiagramEditorInput;
	import org.eclipse.core.resources.IMarker;
	import org.eclipse.core.runtime.IProgressMonitor;
	import org.eclipse.graphiti.mm.pictograms.PictogramElement;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.custom.CTabFolder;
	import org.eclipse.swt.custom.CTabFolder2Listener;
	import org.eclipse.swt.custom.CTabFolderEvent;
	import org.eclipse.swt.custom.CTabItem;
	import org.eclipse.swt.events.SelectionAdapter;
	import org.eclipse.swt.events.SelectionEvent;
	import org.eclipse.swt.widgets.Display;
	import org.eclipse.ui.IEditorInput;
	import org.eclipse.ui.IEditorPart;
	import org.eclipse.ui.IEditorSite;
	import org.eclipse.ui.PartInitException;
	import org.eclipse.ui.ide.IDE;
	import org.eclipse.ui.ide.IGotoMarker;
	import org.eclipse.ui.part.FileEditorInput;
	import org.eclipse.ui.part.MultiPageEditorPart;
	import org.eclipse.ui.part.MultiPageEditorSite;

	/**
	* This class implements a multi-page version of the BPMN2 Modeler (BPMN2Editor class).
	* To revert back to the original, single-page version simply change the editor extension
	* point in plugin.xml (see comments there).
	*
	* This is still in the experimental phase and currently only supports a single diagram
	* per .bpmn file. An optional second page, which displays the XML source, can be created
	* from the context menu. The source view is not yet synchronized to the design view and
	* can only show the XML as of the last "Save" i.e. the current state of the file on disk,
	* not the in-memory model. Design/Source view synchronization will be implemented in a
	* future version, but direct editing of the XML will not be supported - it will remain
	* "view only".
	*
	* Future versions will support multiple diagrams per .bpmn file with the ability to add
	* and remove pages containing different diagram types. It should be possible for the user
	* to create a single file that contains a mix of Process, Collaboration and Choreography
	* diagrams. Whether or not these types of files are actually deployable and/or executable
	* is another story ;)
	*/
	public class BPMN2MultiPageEditor extends MultiPageEditorPart implements IGotoMarker {

	DesignEditor designEditor;
	SourceViewer sourceViewer;
	private CTabFolder tabFolder;
	private int defaultTabHeight;
	private List<BPMNDiagram> bpmnDiagrams = new ArrayList<BPMNDiagram>();
	private List<PictogramElement[]> currentSelections = new ArrayList<PictogramElement[]>();
	private int currentPageIndex = -1;

	public BPMN2MultiPageEditor() {
	super();
	}

	@Override
	protected IEditorSite createSite(IEditorPart editor) {
	if (editor instanceof DesignEditor)
	return new DesignEditorSite(this, editor);
	return new MultiPageEditorSite(this, editor);
	}

	@Override
	public String getTitle() {
	if (designEditor!=null)
	return designEditor.getTitle();
	return super.getTitle();
	}

	@Override
	public String getPartName() {
	if (designEditor!=null)
	return designEditor.getPartName();
	return super.getPartName();
	}

	@Override
	public void setInput(IEditorInput input) {
	super.setInput(input);
	Display.getDefault().asyncExec(new Runnable() {
	@Override
	public void run() {
	setTitleToolTip( getTitleToolTip() );
	}
	});
	}

	/**
	* Method declared on IEditorPart.
	*
	* @param marker Marker to look for
	*/
	@Override
	public void gotoMarker(IMarker marker) {
	if (getActivePage() < 0) {
	setActivePage(0);
	}
	IDE.gotoMarker(getEditor(getActivePage()), marker);
	}
	/* (non-Javadoc)
	* @see org.eclipse.ui.part.MultiPageEditorPart#createPages()
	*/
	@Override
	protected void createPages() {
	tabFolder = (CTabFolder)getContainer();
	tabFolder.addCTabFolder2Listener( new CTabFolder2Listener() {

	@Override
	public void close(CTabFolderEvent event) {
	if (event.item.getData() == sourceViewer)
	removeSourceViewer();
	}

	@Override
	public void minimize(CTabFolderEvent event) {
	}

	@Override
	public void maximize(CTabFolderEvent event) {
	}

	@Override
	public void restore(CTabFolderEvent event) {
	}

	@Override
	public void showList(CTabFolderEvent event) {
	}

	});
	tabFolder.addSelectionListener( new SelectionAdapter() {
	@Override
	public void widgetSelected(SelectionEvent e) {
	int pageIndex = tabFolder.getSelectionIndex();
	if (pageIndex>=0 && pageIndex<bpmnDiagrams.size() && designEditor!=null) {
	BPMNDiagram bpmnDiagram = bpmnDiagrams.get(pageIndex);
	designEditor.selectBpmnDiagram(bpmnDiagram);
	}
	}
	});

	// defer editor layout until all pages have been created
	tabFolder.setLayoutDeferred(true);

	createDesignEditor();

	Display.getDefault().asyncExec(new Runnable() {
	public void run() {
	setActivePage(0);
	designEditor.selectBpmnDiagram(bpmnDiagrams.get(0));
	tabFolder.setLayoutDeferred(false);
	tabFolder.setTabPosition(SWT.TOP);
	updateTabs();
	}
	});
	}

	protected void createDesignEditor() {
	if (designEditor==null) {
	designEditor = new DesignEditor(this, this);

	try {
	int pageIndex = tabFolder.getItemCount();
	if (sourceViewer!=null)
	--pageIndex;
	addPage(pageIndex, designEditor, BPMN2MultiPageEditor.this.getEditorInput());
	defaultTabHeight = tabFolder.getTabHeight();
	setPageText(pageIndex,ExtendedPropertiesProvider.getTextValue( designEditor.getBpmnDiagram() ));

	defaultTabHeight = tabFolder.getTabHeight();

	updateTabs();
	}
	catch (Exception e) {
	e.printStackTrace();
	}
	}
	}

	public DesignEditor getDesignEditor() {
	return designEditor;
	}

	protected void addDesignPage(final BPMNDiagram bpmnDiagram) {
	createDesignEditor();
	Display.getDefault().asyncExec(new Runnable() {
	public void run() {
	try {

	int pageIndex = tabFolder.getItemCount();
	if (sourceViewer!=null)
	--pageIndex;
	Bpmn2DiagramEditorInput input = (Bpmn2DiagramEditorInput)designEditor.getEditorInput();
	input.setBpmnDiagram(bpmnDiagram);
	addPage(pageIndex, designEditor, input);
	CTabItem oldItem = tabFolder.getItem(pageIndex-1);
	CTabItem newItem = tabFolder.getItem(pageIndex);
	newItem.setControl( oldItem.getControl() );
	BaseElement bpmnElement = bpmnDiagram.getPlane().getBpmnElement();
	String name = ModelUtil.getName(bpmnElement);
	if (name==null)
	name = ExtendedPropertiesProvider.getTextValue(bpmnDiagram);
	setPageText(pageIndex,name);

	setActivePage(pageIndex);
	updateTabs();
	}
	catch (Exception e) {
	e.printStackTrace();
	}
	}
	});
	}

	public void showDesignPage(final BPMNDiagram bpmnDiagram) {
	final int pageIndex = bpmnDiagrams.indexOf(bpmnDiagram);
	if (pageIndex>=0) {
	if (getDesignEditor().getBpmnDiagram()!=bpmnDiagram) {
	setActivePage(pageIndex);
	}
	}
	else {
	designEditor.showDesignPage(bpmnDiagram);
	}
	}

	protected void removeDesignPage(final BPMNDiagram bpmnDiagram) {
	final int pageIndex = bpmnDiagrams.indexOf(bpmnDiagram);
	if (pageIndex>0) {
	// go back to "Design" page - the only page that can't be removed
	Display.getCurrent().asyncExec( new Runnable() {
	@Override
	public void run() {
	setActivePage(0);

	IEditorPart editor = getEditor(pageIndex);
	if (editor instanceof DesignEditor) {
	((DesignEditor)editor).deleteBpmnDiagram(bpmnDiagram);
	}

	// need to manage this ourselves so that the CTabFolder doesn't
	// dispose our editor site (a child of the CTabItem.control)
	tabFolder.getItem(pageIndex).setControl(null);

	removePage(pageIndex);

	tabFolder.getSelection().getControl().setVisible(true);
	}
	});
	}
	}

	public int getDesignPageCount() {
	int count = getPageCount();
	if (sourceViewer!=null)
	--count;
	return count;
	}

	protected void createSourceViewer() {
	if (sourceViewer==null) {
	sourceViewer = new SourceViewer(this);

	try {
	int pageIndex = tabFolder.getItemCount();
	FileEditorInput input = new FileEditorInput(designEditor.getModelFile());
	addPage(pageIndex, sourceViewer, input);
	tabFolder.getItem(pageIndex).setShowClose(true);

	setPageText(pageIndex,Messages.BPMN2MultiPageEditor_Source_Tab);
	setActivePage(pageIndex);

	updateTabs();
	}
	catch (Exception e) {
	e.printStackTrace();
	if (sourceViewer!=null)
	sourceViewer.dispose();
	}
	}
	}

	public SourceViewer getSourceViewer() {
	return sourceViewer;
	}

	public void removeSourceViewer() {
	// there will only be one source page and it will always be the last page in the tab folder
	if (sourceViewer!=null) {
	int pageIndex = tabFolder.getItemCount() - 1;
	if (pageIndex>0) {
	removePage(pageIndex);
	sourceViewer = null;
	}
	}
	}

	public void addPage(int pageIndex, IEditorPart editor, IEditorInput input)
	throws PartInitException {
	super.addPage(pageIndex,editor,input);
	if (editor instanceof DesignEditor) {
	bpmnDiagrams.add(pageIndex,((DesignEditor)editor).getBpmnDiagram());
	currentSelections.add(new PictogramElement[]{});
	}
	}

	@Override
	public void removePage(int pageIndex) {
	Object page = tabFolder.getItem(pageIndex).getData();
	super.removePage(pageIndex);
	updateTabs();
	if (page instanceof DesignEditor) {
	bpmnDiagrams.remove(pageIndex);
	currentSelections.remove(pageIndex);
	}
	}

	@Override
	protected void pageChange(final int newPageIndex) {
	if (currentPageIndex>=0 && currentPageIndex<tabFolder.getItemCount()) {
	IEditorPart editor = getEditor(currentPageIndex);
	if (editor instanceof DesignEditor) {
	final DesignEditor de = (DesignEditor) editor;
	PictogramElement selections[] = de.getSelectedPictogramElements();
	currentSelections.set(currentPageIndex, selections);
	}
	}
	currentPageIndex = newPageIndex;

	super.pageChange(newPageIndex);

	IEditorPart editor = getEditor(newPageIndex);
	if (editor instanceof DesignEditor) {
	final DesignEditor de = (DesignEditor) editor;
	BPMNDiagram bpmnDiagram = bpmnDiagrams.get(newPageIndex);
	final PictogramElement selections[] = currentSelections.get(newPageIndex);
	de.pageChange(bpmnDiagram);

	if (selections!=null) {
	Display.getCurrent().asyncExec(new Runnable() {
	@Override
	public void run() {
	de.selectPictogramElements(selections);
	}
	});
	}
	}
	}

	public int getPageCount() {
	return tabFolder.getItemCount();
	}

	public CTabItem getTabItem(int pageIndex) {
	return tabFolder.getItem(pageIndex);
	}

	public BPMNDiagram getBpmnDiagram(int i) {
	if (i>=0 && i<bpmnDiagrams.size()) {
	return bpmnDiagrams.get(i);
	}
	return null;
	}

	private void updateTabs() {
	if (!tabFolder.getLayoutDeferred()) {
	if (tabFolder.getItemCount()==1) {
	tabFolder.setTabHeight(0);
	}
	else
	tabFolder.setTabHeight(defaultTabHeight);
	}
	tabFolder.layout();
	}

	public CTabFolder getTabFolder() {
	return tabFolder;
	}

	/* (non-Javadoc)
	* @see org.eclipse.ui.part.EditorPart#doSave(org.eclipse.core.runtime.IProgressMonitor)
	*/
	@Override
	public void doSave(IProgressMonitor monitor) {
	designEditor.doSave(monitor);
	}

	/* (non-Javadoc)
	* @see org.eclipse.ui.part.EditorPart#doSaveAs()
	*/
	@Override
	public void doSaveAs() {
	IEditorPart activeEditor = getActiveEditor();
	activeEditor.doSaveAs();
	}

	/* (non-Javadoc)
	* @see org.eclipse.ui.part.EditorPart#isSaveAsAllowed()
	*/
	@Override
	public boolean isSaveAsAllowed() {

	/*
	* Depending upon the active page in multipage editor, call the saveAsAllowed.
	* It helps to see whether a particular editor allows 'save as' feature
	*/
	IEditorPart activeEditor = getActiveEditor();
	if (activeEditor!=null)
	return activeEditor.isSaveAsAllowed();
	return false;
	}

	@Override
	public void dispose() {
	designEditor.dispose();
	if (sourceViewer!=null)
	sourceViewer.dispose();
	}

	@Override
	public IEditorPart getActiveEditor() {
	return super.getActiveEditor();
	}
	}