plugins/org.eclipse.eef.ide.ui.ext.widgets.reference/src/org/eclipse/eef/ide/ui/ext/widgets/reference/internal/EEFExtEObjectCreationPage.java - eef/org.eclipse.eef - Git at Google

 /*******************************************************************************
  * Copyright (c) 2016 Obeo.
  * 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:
  *    Obeo - initial API and implementation
  *******************************************************************************/
 package org.eclipse.eef.ide.ui.ext.widgets.reference.internal;

 import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;

 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.eef.common.api.utils.Util;
 import org.eclipse.eef.core.api.EditingContextAdapter;
 import org.eclipse.eef.ide.ui.ext.widgets.reference.api.IEEFExtReferenceViewerFilterProvider.ContextKind;
 import org.eclipse.emf.common.notify.Adapter;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.EReference;
 import org.eclipse.emf.ecore.EStructuralFeature;
 import org.eclipse.emf.edit.command.CommandParameter;
 import org.eclipse.emf.edit.provider.ComposedAdapterFactory;
 import org.eclipse.emf.edit.provider.IEditingDomainItemProvider;
 import org.eclipse.emf.edit.provider.ReflectiveItemProviderAdapterFactory;
 import org.eclipse.emf.edit.ui.provider.AdapterFactoryContentProvider;
 import org.eclipse.emf.edit.ui.provider.AdapterFactoryLabelProvider;
 import org.eclipse.jface.viewers.ArrayContentProvider;
 import org.eclipse.jface.viewers.ComboViewer;
 import org.eclipse.jface.viewers.DelegatingStyledCellLabelProvider;
 import org.eclipse.jface.viewers.ISelection;
 import org.eclipse.jface.viewers.ISelectionChangedListener;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.jface.viewers.SelectionChangedEvent;
 import org.eclipse.jface.viewers.StructuredSelection;
 import org.eclipse.jface.viewers.StructuredViewer;
 import org.eclipse.jface.viewers.TreeViewer;
 import org.eclipse.jface.viewers.ViewerFilter;
 import org.eclipse.jface.wizard.WizardPage;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.layout.GridLayout;
 import org.eclipse.swt.widgets.Combo;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Label;
 import org.eclipse.swt.widgets.Tree;

 /**
  * This page is used to create a new EObject for the given reference.
  *
  * @author sbegaudeau
  */
 public class EEFExtEObjectCreationPage extends WizardPage {

 	/**
 	 * The target.
 	 */
 	private EObject target;

 	/**
 	 * The EReference.
 	 */
 	private EReference eReference;

 	/**
 	 * The editing context adapter.
 	 */
 	private EditingContextAdapter editingContextAdapter;

 	/**
 	 * The {@link ComposedAdapterFactory} used to retrieve the label and image of the various EObjects visible in the
 	 * user interface.
 	 */
 	private ComposedAdapterFactory composedAdapterFactory;

 	/**
 	 * The combo viewer used to select the EClass of the element to create.
 	 */
 	private ComboViewer eClassInstanceComboViewer;

 	/**
 	 * This listener will react to selection changes in the combo viewer.
 	 */
 	private ISelectionChangedListener eClassInstanceComboViewerListener;

 	/**
 	 * The tree viewer used to select the container of the new EObject to create.
 	 */
 	private TreeViewer eContainerTreeViewer;

 	/**
 	 * This listener will react to selection changes in the tree viewer.
 	 */
 	private ISelectionChangedListener eContainerTreeViewerListener;

 	/**
 	 * The combo viewer used to select the containment reference to use for the creation of the EObject.
 	 */
 	private ComboViewer eContainementReferenceComboViewer;

 	/**
 	 * This listener will react to selection changes in the combo viewer.
 	 */
 	private ISelectionChangedListener eContainmentReferenceComboViewerListener;

 	/**
 	 * The constructor.
 	 *
 	 * @param target
 	 *            The target
 	 * @param eReference
 	 *            The EReference
 	 * @param editingContextAdapter
 	 *            The editing context adapter
 	 */
 	public EEFExtEObjectCreationPage(EObject target, EReference eReference, EditingContextAdapter editingContextAdapter) {
 		super(Messages.ReferenceCreationWizardPage_title);
 		this.target = target;
 		this.eReference = eReference;
 		this.editingContextAdapter = editingContextAdapter;

 		this.setTitle(Messages.ReferenceCreationWizardPage_title);
 		this.setDescription(Messages.ReferenceCreationWizardPage_description);
 	}

 	/**
 	 * {@inheritDoc}
 	 *
 	 * @see org.eclipse.jface.dialogs.IDialogPage#createControl(org.eclipse.swt.widgets.Composite)
 	 */
 	@Override
 	public void createControl(Composite parent) {
 		this.initializeDialogUnits(parent);

 		Composite control = new Composite(parent, SWT.NONE);
 		control.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
 		this.setControl(control);

 		GridLayout gridLayout = new GridLayout(2, false);
 		control.setLayout(gridLayout);

 		this.composedAdapterFactory = new ComposedAdapterFactory(ComposedAdapterFactory.Descriptor.Registry.INSTANCE);
 		this.composedAdapterFactory.addAdapterFactory(new ReflectiveItemProviderAdapterFactory());

 		if (this.eReference.isContainment()) {
 			this.createEObjectEClassComboViewer(control);
 			this.initializeContainmentInput(this.target, this.eReference);
 		} else {
 			this.createContainerTreeViewer(control);
 			this.createContainmentFeatureComboViewer(control);
 			this.createEObjectEClassComboViewer(control);
 			this.initializeNonContainmentInput();
 		}
 		this.determinePageCompletion();
 	}

 	/**
 	 * Initializes the input of the page for a containment EReference.
 	 *
 	 * @param eObject
 	 *            The EObject to consider
 	 * @param eContainementReference
 	 *            The containment EReference to consider
 	 */
 	private void initializeContainmentInput(EObject eObject, EReference eContainementReference) {
 		List<Object> values = new ArrayList<>();
 		Adapter adapter = this.composedAdapterFactory.adapt(eObject, IEditingDomainItemProvider.class);
 		if (adapter instanceof IEditingDomainItemProvider) {
 			IEditingDomainItemProvider itemProviderAdapter = (IEditingDomainItemProvider) adapter;
 			Collection<?> newChildDescriptors = itemProviderAdapter.getNewChildDescriptors(eObject, this.editingContextAdapter.getEditingDomain(),
 					null);
 			for (Object newChildDescriptor : newChildDescriptors) {
 				if (newChildDescriptor instanceof CommandParameter) {
 					CommandParameter commandParameter = (CommandParameter) newChildDescriptor;
 					Object value = commandParameter.getValue();
 					if (commandParameter.getEReference().equals(eContainementReference) && value instanceof EObject
 							&& this.eReference.getEReferenceType().isSuperTypeOf(((EObject) value).eClass())) {
 						values.add(commandParameter.getValue());
 					}
 				}
 			}
 		}

 		this.eClassInstanceComboViewer.setInput(values);
 		if (values.size() > 0) {
 			this.eClassInstanceComboViewer.setSelection(new StructuredSelection(values.get(0)));
 		} else {
 			this.eClassInstanceComboViewer.setSelection(new StructuredSelection());
 		}
 	}

 	/**
 	 * Initializes the input of the page for a non containment EReference.
 	 */
 	private void initializeNonContainmentInput() {
 		this.eContainerTreeViewer.setInput(this.editingContextAdapter.getEditingDomain().getResourceSet());
 	}

 	/**
 	 * Creates the tree viewer.
 	 *
 	 * @param parent
 	 *            The parent composite
 	 */
 	private void createContainerTreeViewer(Composite parent) {
 		Label label = new Label(parent, SWT.NONE);
 		label.setText(Messages.ReferenceCreationWizardPage_eContainerSelectionLabel);
 		label.setLayoutData(new GridData(SWT.LEFT, SWT.CENTER, false, false, 2, 1));

 		this.eContainerTreeViewer = new TreeViewer(new Tree(parent, SWT.SINGLE | SWT.FULL_SELECTION | SWT.BORDER));
 		this.eContainerTreeViewer.setLabelProvider(new DelegatingStyledCellLabelProvider(
 				new AdapterFactoryLabelProvider.StyledLabelProvider(this.composedAdapterFactory, this.eContainerTreeViewer)));
 		this.eContainerTreeViewer.setContentProvider(new AdapterFactoryContentProvider(this.composedAdapterFactory));
 		this.eContainerTreeViewer.getTree().setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 2, 1));
 		this.eContainerTreeViewer.setAutoExpandLevel(2);

 		List<ViewerFilter> viewFilters = EEFExtReferenceUIPlugin.getPlugin().getViewFilters(ContextKind.CONTAINER_SELECTION);
 		this.eContainerTreeViewer.setFilters(viewFilters.toArray(new ViewerFilter[viewFilters.size()]));

 		this.eContainerTreeViewerListener = new ISelectionChangedListener() {
 			@Override
 			public void selectionChanged(SelectionChangedEvent event) {
 				EEFExtEObjectCreationPage.this.handleEContainerSelectionChanged();
 			}
 		};
 		this.eContainerTreeViewer.addSelectionChangedListener(this.eContainerTreeViewerListener);
 	}

 	/**
 	 * This methods is called when the selection changes in the EContainer tree viewer.
 	 */
 	protected void handleEContainerSelectionChanged() {
 		EObject eContainer = this.getEObject(this.eContainerTreeViewer);
 		if (eContainer != null) {
 			List<EReference> eReferences = this.getValidContainmentReferences(eContainer);
 			this.eContainementReferenceComboViewer.setInput(eReferences);
 			if (eReferences.size() > 0) {
 				this.eContainementReferenceComboViewer.setSelection(new StructuredSelection(eReferences.get(0)));
 			} else {
 				this.eContainementReferenceComboViewer.setSelection(new StructuredSelection());
 				this.eClassInstanceComboViewer.setSelection(new StructuredSelection());
 			}
 		} else {
 			this.eContainementReferenceComboViewer.setSelection(new StructuredSelection());
 			this.eClassInstanceComboViewer.setSelection(new StructuredSelection());
 		}
 		this.determinePageCompletion();
 	}

 	/**
 	 * Returns the currently selected EObject in the given viewer.
 	 *
 	 * @param viewer
 	 *            The viewer
 	 *
 	 * @return The currently selected EObject in the given viewer, or <code>null</code> if the current selection is
 	 *         empty or not an EObject (for example an EResource)
 	 */
 	private EObject getEObject(StructuredViewer viewer) {
 		ISelection selection = viewer.getSelection();
 		if (selection instanceof IStructuredSelection) {
 			IStructuredSelection structuredSelection = (IStructuredSelection) selection;
 			Object object = structuredSelection.getFirstElement();
 			if (object instanceof EObject) {
 				return (EObject) object;
 			}
 		}
 		return null;
 	}

 	/**
 	 * Returns a list of all the containment references of the given EObject which have a type compatible with the type
 	 * of the current EReference.
 	 *
 	 * @param eObject
 	 *            The EObject
 	 * @return A list of EReference
 	 */
 	private List<EReference> getValidContainmentReferences(EObject eObject) {
 		List<EReference> eReferences = new ArrayList<>();

 		List<EStructuralFeature> eAllStructuralFeatures = eObject.eClass().getEAllStructuralFeatures();
 		for (EStructuralFeature eStructuralFeature : eAllStructuralFeatures) {
 			if (eStructuralFeature instanceof EReference) {
 				EReference reference = (EReference) eStructuralFeature;
 				if (reference.isContainment() && reference.getEReferenceType().isSuperTypeOf(this.eReference.getEReferenceType())) {
 					eReferences.add(reference);
 				}
 			}
 		}
 		return eReferences;
 	}

 	/**
 	 * Creates the combo viewer to display the possible containment EReferences to use to create the new EObject.
 	 *
 	 * @param parent
 	 *            The parent composite
 	 */
 	private void createContainmentFeatureComboViewer(Composite parent) {
 		Label label = new Label(parent, SWT.NONE);
 		label.setText(Messages.ReferenceCreationWizardPage_eContainerToUseLabel);
 		label.setLayoutData(new GridData(SWT.LEFT, SWT.CENTER, false, false));

 		this.eContainementReferenceComboViewer = new ComboViewer(new Combo(parent, SWT.DROP_DOWN | SWT.READ_ONLY));
 		this.eContainementReferenceComboViewer.setLabelProvider(new AdapterFactoryLabelProvider(this.composedAdapterFactory));
 		this.eContainementReferenceComboViewer.setContentProvider(new ArrayContentProvider());
 		this.eContainementReferenceComboViewer.getCombo().setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false));

 		this.eContainmentReferenceComboViewerListener = new ISelectionChangedListener() {
 			@Override
 			public void selectionChanged(SelectionChangedEvent event) {
 				EEFExtEObjectCreationPage.this.handleEContainmentReferenceSelectionChange();
 			}
 		};
 		this.eContainementReferenceComboViewer.addSelectionChangedListener(this.eContainmentReferenceComboViewerListener);
 	}

 	/**
 	 * This methods is called when the selection changes in the containment EReference combo viewer.
 	 */
 	private void handleEContainmentReferenceSelectionChange() {
 		EObject eContainer = this.getEObject(this.eContainerTreeViewer);
 		if (eContainer != null) {
 			EObject eContainmentReference = this.getEObject(this.eContainementReferenceComboViewer);
 			if (eContainmentReference instanceof EReference) {
 				this.initializeContainmentInput(eContainer, (EReference) eContainmentReference);
 			}
 		}
 		this.determinePageCompletion();
 	}

 	/**
 	 * Creates the combo viewer used to display the EClass of the possible EObjects that can be created.
 	 *
 	 * @param parent
 	 *            The parent composite
 	 */
 	private void createEObjectEClassComboViewer(Composite parent) {
 		Label label = new Label(parent, SWT.NONE);
 		label.setText(Messages.ReferenceCreationWizardPage_eClassToCreateLabel);
 		label.setLayoutData(new GridData(SWT.LEFT, SWT.CENTER, false, false));

 		this.eClassInstanceComboViewer = new ComboViewer(new Combo(parent, SWT.DROP_DOWN | SWT.READ_ONLY));
 		this.eClassInstanceComboViewer.setLabelProvider(new AdapterFactoryLabelProvider(this.composedAdapterFactory) {
 			@Override
 			public String getText(Object object) {
 				String result = super.getText(object);
 				if (Util.isBlank(result) && object instanceof EObject) {
 					AdapterFactoryLabelProvider labelProvider = new AdapterFactoryLabelProvider(composedAdapterFactory);
 					result = labelProvider.getText(((EObject) object).eClass());
 				}

 				return result;
 			}
 		});
 		this.eClassInstanceComboViewer.setContentProvider(new ArrayContentProvider());
 		this.eClassInstanceComboViewer.getCombo().setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false));

 		this.eClassInstanceComboViewerListener = new ISelectionChangedListener() {
 			@Override
 			public void selectionChanged(SelectionChangedEvent event) {
 				EEFExtEObjectCreationPage.this.determinePageCompletion();
 			}
 		};
 		this.eClassInstanceComboViewer.addSelectionChangedListener(this.eClassInstanceComboViewerListener);
 	}

 	/**
 	 * Determines if the page is complete or not.
 	 */
 	private void determinePageCompletion() {
 		this.setMessage(null);

 		boolean isPageComplete = false;
 		if (this.eReference.isContainment()) {
 			isPageComplete = this.isCompleteViewer(true, this.eClassInstanceComboViewer, Messages.ReferenceCreationWizardPage_missingEClassToCreate);
 		} else {
 			String message = MessageFormat.format(Messages.ReferenceCreationWizardPage_missingEContainer,
 					this.eReference.getEReferenceType().getName());
 			isPageComplete = this.isCompleteViewer(true, this.eContainerTreeViewer, message);
 			isPageComplete = this.isCompleteViewer(isPageComplete, this.eContainementReferenceComboViewer,
 					Messages.ReferenceCreationWizardPage_missingContainmentEReference);
 			isPageComplete = this.isCompleteViewer(isPageComplete, this.eClassInstanceComboViewer,
 					Messages.ReferenceCreationWizardPage_missingEClassToCreate);
 		}
 		this.setPageComplete(isPageComplete);
 	}

 	/**
 	 * Verifies if the given viewer is complete and if not, set the given error message.
 	 *
 	 * @param isCurrentlyComplete
 	 *            The currently completion status
 	 * @param viewer
 	 *            The viewer
 	 * @param errorMessage
 	 *            The error message
 	 * @return <code>true</code> if the wizard is currently complete and the viewer too, <code>false</code> otherwise
 	 */
 	private boolean isCompleteViewer(boolean isCurrentlyComplete, StructuredViewer viewer, String errorMessage) {
 		boolean isComplete = isCurrentlyComplete;
 		if (isCurrentlyComplete) {
 			boolean isViewerComplete = this.getEObject(viewer) != null;
 			isComplete = isComplete && isViewerComplete;

 			if (!isViewerComplete) {
 				this.setMessage(errorMessage, ERROR);
 			}
 		}
 		return isComplete;
 	}

 	/**
 	 * Creates the EObject.
 	 *
 	 * @param monitor
 	 *            The {@link IProgressMonitor}
 	 */
 	public void performFinish(IProgressMonitor monitor) {
 		EObject eObject = this.getEObject(this.eClassInstanceComboViewer);
 		if (eObject != null) {
 			if (this.eReference.isContainment() && this.eReference.isMany()) {
 				this.performFinishMultiValuedContainmentReference(eObject);
 			} else if (this.eReference.isContainment() && !this.eReference.isMany()) {
 				this.performFinistMonoValuedContainmentReference(eObject);
 			} else if (!this.eReference.isContainment() && this.eReference.isMany()) {
 				this.performFinistMultiValuedNonContainmentReference(eObject);
 			} else if (!this.eReference.isContainment() && !this.eReference.isMany()) {
 				this.performFinistMonoValuedNonContainmentReference(eObject);
 			}
 		}
 	}

 	/**
 	 * Performs the creation of the object for a multi-valued containment reference. In this case, the operation is
 	 * quite simple, we will just retrieve the collection containing the values of the reference and add the new
 	 * element, value, at the end.
 	 *
 	 * @param value
 	 *            The element to create
 	 */
 	private void performFinishMultiValuedContainmentReference(EObject value) {
 		this.eContainmentAdd(this.target, this.eReference, value);
 	}

 	/**
 	 * Performs the creation of the object for a mono-valued containment reference. In this case, the easiest one, we
 	 * will just create set the value for the reference.
 	 *
 	 * @param value
 	 *            The element to create
 	 */
 	private void performFinistMonoValuedContainmentReference(EObject value) {
 		this.target.eSet(this.eReference, value);
 	}

 	/**
 	 * Performs the creation of the object for a multi-valued reference. In this case, we will create the object in a
 	 * mono or multi-valued containment reference and then add it to the multi-valued reference of our current object.
 	 *
 	 * @param value
 	 *            The element to create
 	 */
 	private void performFinistMultiValuedNonContainmentReference(EObject value) {
 		EObject eContainer = this.getEObject(this.eContainerTreeViewer);
 		EObject eContainmentReferenceEObject = this.getEObject(this.eContainementReferenceComboViewer);
 		if (eContainer != null && eContainmentReferenceEObject instanceof EReference) {
 			EReference eContainmentReference = (EReference) eContainmentReferenceEObject;

 			if (eContainmentReference.isMany()) {
 				this.eContainmentAdd(eContainer, (EReference) eContainmentReferenceEObject, value);
 			} else {
 				eContainer.eSet(eContainmentReference, value);
 			}

 			this.eContainmentAdd(this.target, this.eReference, value);
 		}
 	}

 	/**
 	 * Performs the creation of the object for a mono-valued reference. In this case, we will create the object in a
 	 * mono or multi-valued containment reference and then add it to the mono-valued reference of our current object.
 	 *
 	 * @param value
 	 *            The element to create
 	 */
 	private void performFinistMonoValuedNonContainmentReference(EObject value) {
 		EObject eContainer = this.getEObject(this.eContainerTreeViewer);
 		EObject eContainmentReferenceEObject = this.getEObject(this.eContainementReferenceComboViewer);
 		if (eContainer != null && eContainmentReferenceEObject instanceof EReference) {
 			EReference eContainmentReference = (EReference) eContainmentReferenceEObject;

 			if (eContainmentReference.isMany()) {
 				this.eContainmentAdd(eContainer, (EReference) eContainmentReferenceEObject, value);
 			} else {
 				eContainer.eSet(eContainmentReference, value);
 			}

 			this.target.eSet(this.eReference, value);
 		}
 	}

 	/**
 	 * Adds the given eObject to the value of the given EReference for the given container EObject.
 	 *
 	 * @param eContainer
 	 *            The container
 	 * @param eContainmentReference
 	 *            The containment EReference
 	 * @param eObject
 	 *            The EObject
 	 */
 	private void eContainmentAdd(EObject eContainer, EReference eContainmentReference, EObject eObject) {
 		Object value = eContainer.eGet(eContainmentReference);
 		if (value instanceof EList<?>) {
 			// sbegaudeau: Yes I know, @SuppressWarnings are bad but we really need this one in order to prevent the
 			// creation of a new list which would fire, as a side effect, a modification notification for all the
 			// siblings of the newly created object. We do not want anyone to believe that those objects have been
 			// modified
 			@SuppressWarnings("unchecked")
 			EList<EObject> objects = (EList<EObject>) value;
 			objects.add(eObject);
 		}
 	}

 	/**
 	 * {@inheritDoc}
 	 *
 	 * @see org.eclipse.jface.dialogs.DialogPage#dispose()
 	 */
 	@Override
 	public void dispose() {
 		super.dispose();

 		this.composedAdapterFactory.dispose();
 		this.eClassInstanceComboViewer.removeSelectionChangedListener(this.eClassInstanceComboViewerListener);
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2016 Obeo.
	* 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:
	* Obeo - initial API and implementation
	*******************************************************************************/
	package org.eclipse.eef.ide.ui.ext.widgets.reference.internal;

	import java.text.MessageFormat;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.List;

	import org.eclipse.core.runtime.IProgressMonitor;
	import org.eclipse.eef.common.api.utils.Util;
	import org.eclipse.eef.core.api.EditingContextAdapter;
	import org.eclipse.eef.ide.ui.ext.widgets.reference.api.IEEFExtReferenceViewerFilterProvider.ContextKind;
	import org.eclipse.emf.common.notify.Adapter;
	import org.eclipse.emf.common.util.EList;
	import org.eclipse.emf.ecore.EObject;
	import org.eclipse.emf.ecore.EReference;
	import org.eclipse.emf.ecore.EStructuralFeature;
	import org.eclipse.emf.edit.command.CommandParameter;
	import org.eclipse.emf.edit.provider.ComposedAdapterFactory;
	import org.eclipse.emf.edit.provider.IEditingDomainItemProvider;
	import org.eclipse.emf.edit.provider.ReflectiveItemProviderAdapterFactory;
	import org.eclipse.emf.edit.ui.provider.AdapterFactoryContentProvider;
	import org.eclipse.emf.edit.ui.provider.AdapterFactoryLabelProvider;
	import org.eclipse.jface.viewers.ArrayContentProvider;
	import org.eclipse.jface.viewers.ComboViewer;
	import org.eclipse.jface.viewers.DelegatingStyledCellLabelProvider;
	import org.eclipse.jface.viewers.ISelection;
	import org.eclipse.jface.viewers.ISelectionChangedListener;
	import org.eclipse.jface.viewers.IStructuredSelection;
	import org.eclipse.jface.viewers.SelectionChangedEvent;
	import org.eclipse.jface.viewers.StructuredSelection;
	import org.eclipse.jface.viewers.StructuredViewer;
	import org.eclipse.jface.viewers.TreeViewer;
	import org.eclipse.jface.viewers.ViewerFilter;
	import org.eclipse.jface.wizard.WizardPage;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.layout.GridData;
	import org.eclipse.swt.layout.GridLayout;
	import org.eclipse.swt.widgets.Combo;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Label;
	import org.eclipse.swt.widgets.Tree;

	/**
	* This page is used to create a new EObject for the given reference.
	*
	* @author sbegaudeau
	*/
	public class EEFExtEObjectCreationPage extends WizardPage {

	/**
	* The target.
	*/
	private EObject target;

	/**
	* The EReference.
	*/
	private EReference eReference;

	/**
	* The editing context adapter.
	*/
	private EditingContextAdapter editingContextAdapter;

	/**
	* The {@link ComposedAdapterFactory} used to retrieve the label and image of the various EObjects visible in the
	* user interface.
	*/
	private ComposedAdapterFactory composedAdapterFactory;

	/**
	* The combo viewer used to select the EClass of the element to create.
	*/
	private ComboViewer eClassInstanceComboViewer;

	/**
	* This listener will react to selection changes in the combo viewer.
	*/
	private ISelectionChangedListener eClassInstanceComboViewerListener;

	/**
	* The tree viewer used to select the container of the new EObject to create.
	*/
	private TreeViewer eContainerTreeViewer;

	/**
	* This listener will react to selection changes in the tree viewer.
	*/
	private ISelectionChangedListener eContainerTreeViewerListener;

	/**
	* The combo viewer used to select the containment reference to use for the creation of the EObject.
	*/
	private ComboViewer eContainementReferenceComboViewer;

	/**
	* This listener will react to selection changes in the combo viewer.
	*/
	private ISelectionChangedListener eContainmentReferenceComboViewerListener;

	/**
	* The constructor.
	*
	* @param target
	* The target
	* @param eReference
	* The EReference
	* @param editingContextAdapter
	* The editing context adapter
	*/
	public EEFExtEObjectCreationPage(EObject target, EReference eReference, EditingContextAdapter editingContextAdapter) {
	super(Messages.ReferenceCreationWizardPage_title);
	this.target = target;
	this.eReference = eReference;
	this.editingContextAdapter = editingContextAdapter;

	this.setTitle(Messages.ReferenceCreationWizardPage_title);
	this.setDescription(Messages.ReferenceCreationWizardPage_description);
	}

	/**
	* {@inheritDoc}
	*
	* @see org.eclipse.jface.dialogs.IDialogPage#createControl(org.eclipse.swt.widgets.Composite)
	*/
	@Override
	public void createControl(Composite parent) {
	this.initializeDialogUnits(parent);

	Composite control = new Composite(parent, SWT.NONE);
	control.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
	this.setControl(control);

	GridLayout gridLayout = new GridLayout(2, false);
	control.setLayout(gridLayout);

	this.composedAdapterFactory = new ComposedAdapterFactory(ComposedAdapterFactory.Descriptor.Registry.INSTANCE);
	this.composedAdapterFactory.addAdapterFactory(new ReflectiveItemProviderAdapterFactory());

	if (this.eReference.isContainment()) {
	this.createEObjectEClassComboViewer(control);
	this.initializeContainmentInput(this.target, this.eReference);
	} else {
	this.createContainerTreeViewer(control);
	this.createContainmentFeatureComboViewer(control);
	this.createEObjectEClassComboViewer(control);
	this.initializeNonContainmentInput();
	}
	this.determinePageCompletion();
	}

	/**
	* Initializes the input of the page for a containment EReference.
	*
	* @param eObject
	* The EObject to consider
	* @param eContainementReference
	* The containment EReference to consider
	*/
	private void initializeContainmentInput(EObject eObject, EReference eContainementReference) {
	List<Object> values = new ArrayList<>();
	Adapter adapter = this.composedAdapterFactory.adapt(eObject, IEditingDomainItemProvider.class);
	if (adapter instanceof IEditingDomainItemProvider) {
	IEditingDomainItemProvider itemProviderAdapter = (IEditingDomainItemProvider) adapter;
	Collection<?> newChildDescriptors = itemProviderAdapter.getNewChildDescriptors(eObject, this.editingContextAdapter.getEditingDomain(),
	null);
	for (Object newChildDescriptor : newChildDescriptors) {
	if (newChildDescriptor instanceof CommandParameter) {
	CommandParameter commandParameter = (CommandParameter) newChildDescriptor;
	Object value = commandParameter.getValue();
	if (commandParameter.getEReference().equals(eContainementReference) && value instanceof EObject
	&& this.eReference.getEReferenceType().isSuperTypeOf(((EObject) value).eClass())) {
	values.add(commandParameter.getValue());
	}
	}
	}
	}

	this.eClassInstanceComboViewer.setInput(values);
	if (values.size() > 0) {
	this.eClassInstanceComboViewer.setSelection(new StructuredSelection(values.get(0)));
	} else {
	this.eClassInstanceComboViewer.setSelection(new StructuredSelection());
	}
	}

	/**
	* Initializes the input of the page for a non containment EReference.
	*/
	private void initializeNonContainmentInput() {
	this.eContainerTreeViewer.setInput(this.editingContextAdapter.getEditingDomain().getResourceSet());
	}

	/**
	* Creates the tree viewer.
	*
	* @param parent
	* The parent composite
	*/
	private void createContainerTreeViewer(Composite parent) {
	Label label = new Label(parent, SWT.NONE);
	label.setText(Messages.ReferenceCreationWizardPage_eContainerSelectionLabel);
	label.setLayoutData(new GridData(SWT.LEFT, SWT.CENTER, false, false, 2, 1));

	this.eContainerTreeViewer = new TreeViewer(new Tree(parent, SWT.SINGLE \| SWT.FULL_SELECTION \| SWT.BORDER));
	this.eContainerTreeViewer.setLabelProvider(new DelegatingStyledCellLabelProvider(
	new AdapterFactoryLabelProvider.StyledLabelProvider(this.composedAdapterFactory, this.eContainerTreeViewer)));
	this.eContainerTreeViewer.setContentProvider(new AdapterFactoryContentProvider(this.composedAdapterFactory));
	this.eContainerTreeViewer.getTree().setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 2, 1));
	this.eContainerTreeViewer.setAutoExpandLevel(2);

	List<ViewerFilter> viewFilters = EEFExtReferenceUIPlugin.getPlugin().getViewFilters(ContextKind.CONTAINER_SELECTION);
	this.eContainerTreeViewer.setFilters(viewFilters.toArray(new ViewerFilter[viewFilters.size()]));

	this.eContainerTreeViewerListener = new ISelectionChangedListener() {
	@Override
	public void selectionChanged(SelectionChangedEvent event) {
	EEFExtEObjectCreationPage.this.handleEContainerSelectionChanged();
	}
	};
	this.eContainerTreeViewer.addSelectionChangedListener(this.eContainerTreeViewerListener);
	}

	/**
	* This methods is called when the selection changes in the EContainer tree viewer.
	*/
	protected void handleEContainerSelectionChanged() {
	EObject eContainer = this.getEObject(this.eContainerTreeViewer);
	if (eContainer != null) {
	List<EReference> eReferences = this.getValidContainmentReferences(eContainer);
	this.eContainementReferenceComboViewer.setInput(eReferences);
	if (eReferences.size() > 0) {
	this.eContainementReferenceComboViewer.setSelection(new StructuredSelection(eReferences.get(0)));
	} else {
	this.eContainementReferenceComboViewer.setSelection(new StructuredSelection());
	this.eClassInstanceComboViewer.setSelection(new StructuredSelection());
	}
	} else {
	this.eContainementReferenceComboViewer.setSelection(new StructuredSelection());
	this.eClassInstanceComboViewer.setSelection(new StructuredSelection());
	}
	this.determinePageCompletion();
	}

	/**
	* Returns the currently selected EObject in the given viewer.
	*
	* @param viewer
	* The viewer
	*
	* @return The currently selected EObject in the given viewer, or <code>null</code> if the current selection is
	* empty or not an EObject (for example an EResource)
	*/
	private EObject getEObject(StructuredViewer viewer) {
	ISelection selection = viewer.getSelection();
	if (selection instanceof IStructuredSelection) {
	IStructuredSelection structuredSelection = (IStructuredSelection) selection;
	Object object = structuredSelection.getFirstElement();
	if (object instanceof EObject) {
	return (EObject) object;
	}
	}
	return null;
	}

	/**
	* Returns a list of all the containment references of the given EObject which have a type compatible with the type
	* of the current EReference.
	*
	* @param eObject
	* The EObject
	* @return A list of EReference
	*/
	private List<EReference> getValidContainmentReferences(EObject eObject) {
	List<EReference> eReferences = new ArrayList<>();

	List<EStructuralFeature> eAllStructuralFeatures = eObject.eClass().getEAllStructuralFeatures();
	for (EStructuralFeature eStructuralFeature : eAllStructuralFeatures) {
	if (eStructuralFeature instanceof EReference) {
	EReference reference = (EReference) eStructuralFeature;
	if (reference.isContainment() && reference.getEReferenceType().isSuperTypeOf(this.eReference.getEReferenceType())) {
	eReferences.add(reference);
	}
	}
	}
	return eReferences;
	}

	/**
	* Creates the combo viewer to display the possible containment EReferences to use to create the new EObject.
	*
	* @param parent
	* The parent composite
	*/
	private void createContainmentFeatureComboViewer(Composite parent) {
	Label label = new Label(parent, SWT.NONE);
	label.setText(Messages.ReferenceCreationWizardPage_eContainerToUseLabel);
	label.setLayoutData(new GridData(SWT.LEFT, SWT.CENTER, false, false));

	this.eContainementReferenceComboViewer = new ComboViewer(new Combo(parent, SWT.DROP_DOWN \| SWT.READ_ONLY));
	this.eContainementReferenceComboViewer.setLabelProvider(new AdapterFactoryLabelProvider(this.composedAdapterFactory));
	this.eContainementReferenceComboViewer.setContentProvider(new ArrayContentProvider());
	this.eContainementReferenceComboViewer.getCombo().setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false));

	this.eContainmentReferenceComboViewerListener = new ISelectionChangedListener() {
	@Override
	public void selectionChanged(SelectionChangedEvent event) {
	EEFExtEObjectCreationPage.this.handleEContainmentReferenceSelectionChange();
	}
	};
	this.eContainementReferenceComboViewer.addSelectionChangedListener(this.eContainmentReferenceComboViewerListener);
	}

	/**
	* This methods is called when the selection changes in the containment EReference combo viewer.
	*/
	private void handleEContainmentReferenceSelectionChange() {
	EObject eContainer = this.getEObject(this.eContainerTreeViewer);
	if (eContainer != null) {
	EObject eContainmentReference = this.getEObject(this.eContainementReferenceComboViewer);
	if (eContainmentReference instanceof EReference) {
	this.initializeContainmentInput(eContainer, (EReference) eContainmentReference);
	}
	}
	this.determinePageCompletion();
	}

	/**
	* Creates the combo viewer used to display the EClass of the possible EObjects that can be created.
	*
	* @param parent
	* The parent composite
	*/
	private void createEObjectEClassComboViewer(Composite parent) {
	Label label = new Label(parent, SWT.NONE);
	label.setText(Messages.ReferenceCreationWizardPage_eClassToCreateLabel);
	label.setLayoutData(new GridData(SWT.LEFT, SWT.CENTER, false, false));

	this.eClassInstanceComboViewer = new ComboViewer(new Combo(parent, SWT.DROP_DOWN \| SWT.READ_ONLY));
	this.eClassInstanceComboViewer.setLabelProvider(new AdapterFactoryLabelProvider(this.composedAdapterFactory) {
	@Override
	public String getText(Object object) {
	String result = super.getText(object);
	if (Util.isBlank(result) && object instanceof EObject) {
	AdapterFactoryLabelProvider labelProvider = new AdapterFactoryLabelProvider(composedAdapterFactory);
	result = labelProvider.getText(((EObject) object).eClass());
	}

	return result;
	}
	});
	this.eClassInstanceComboViewer.setContentProvider(new ArrayContentProvider());
	this.eClassInstanceComboViewer.getCombo().setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false));

	this.eClassInstanceComboViewerListener = new ISelectionChangedListener() {
	@Override
	public void selectionChanged(SelectionChangedEvent event) {
	EEFExtEObjectCreationPage.this.determinePageCompletion();
	}
	};
	this.eClassInstanceComboViewer.addSelectionChangedListener(this.eClassInstanceComboViewerListener);
	}

	/**
	* Determines if the page is complete or not.
	*/
	private void determinePageCompletion() {
	this.setMessage(null);

	boolean isPageComplete = false;
	if (this.eReference.isContainment()) {
	isPageComplete = this.isCompleteViewer(true, this.eClassInstanceComboViewer, Messages.ReferenceCreationWizardPage_missingEClassToCreate);
	} else {
	String message = MessageFormat.format(Messages.ReferenceCreationWizardPage_missingEContainer,
	this.eReference.getEReferenceType().getName());
	isPageComplete = this.isCompleteViewer(true, this.eContainerTreeViewer, message);
	isPageComplete = this.isCompleteViewer(isPageComplete, this.eContainementReferenceComboViewer,
	Messages.ReferenceCreationWizardPage_missingContainmentEReference);
	isPageComplete = this.isCompleteViewer(isPageComplete, this.eClassInstanceComboViewer,
	Messages.ReferenceCreationWizardPage_missingEClassToCreate);
	}
	this.setPageComplete(isPageComplete);
	}

	/**
	* Verifies if the given viewer is complete and if not, set the given error message.
	*
	* @param isCurrentlyComplete
	* The currently completion status
	* @param viewer
	* The viewer
	* @param errorMessage
	* The error message
	* @return <code>true</code> if the wizard is currently complete and the viewer too, <code>false</code> otherwise
	*/
	private boolean isCompleteViewer(boolean isCurrentlyComplete, StructuredViewer viewer, String errorMessage) {
	boolean isComplete = isCurrentlyComplete;
	if (isCurrentlyComplete) {
	boolean isViewerComplete = this.getEObject(viewer) != null;
	isComplete = isComplete && isViewerComplete;

	if (!isViewerComplete) {
	this.setMessage(errorMessage, ERROR);
	}
	}
	return isComplete;
	}

	/**
	* Creates the EObject.
	*
	* @param monitor
	* The {@link IProgressMonitor}
	*/
	public void performFinish(IProgressMonitor monitor) {
	EObject eObject = this.getEObject(this.eClassInstanceComboViewer);
	if (eObject != null) {
	if (this.eReference.isContainment() && this.eReference.isMany()) {
	this.performFinishMultiValuedContainmentReference(eObject);
	} else if (this.eReference.isContainment() && !this.eReference.isMany()) {
	this.performFinistMonoValuedContainmentReference(eObject);
	} else if (!this.eReference.isContainment() && this.eReference.isMany()) {
	this.performFinistMultiValuedNonContainmentReference(eObject);
	} else if (!this.eReference.isContainment() && !this.eReference.isMany()) {
	this.performFinistMonoValuedNonContainmentReference(eObject);
	}
	}
	}

	/**
	* Performs the creation of the object for a multi-valued containment reference. In this case, the operation is
	* quite simple, we will just retrieve the collection containing the values of the reference and add the new
	* element, value, at the end.
	*
	* @param value
	* The element to create
	*/
	private void performFinishMultiValuedContainmentReference(EObject value) {
	this.eContainmentAdd(this.target, this.eReference, value);
	}

	/**
	* Performs the creation of the object for a mono-valued containment reference. In this case, the easiest one, we
	* will just create set the value for the reference.
	*
	* @param value
	* The element to create
	*/
	private void performFinistMonoValuedContainmentReference(EObject value) {
	this.target.eSet(this.eReference, value);
	}

	/**
	* Performs the creation of the object for a multi-valued reference. In this case, we will create the object in a
	* mono or multi-valued containment reference and then add it to the multi-valued reference of our current object.
	*
	* @param value
	* The element to create
	*/
	private void performFinistMultiValuedNonContainmentReference(EObject value) {
	EObject eContainer = this.getEObject(this.eContainerTreeViewer);
	EObject eContainmentReferenceEObject = this.getEObject(this.eContainementReferenceComboViewer);
	if (eContainer != null && eContainmentReferenceEObject instanceof EReference) {
	EReference eContainmentReference = (EReference) eContainmentReferenceEObject;

	if (eContainmentReference.isMany()) {
	this.eContainmentAdd(eContainer, (EReference) eContainmentReferenceEObject, value);
	} else {
	eContainer.eSet(eContainmentReference, value);
	}

	this.eContainmentAdd(this.target, this.eReference, value);
	}
	}

	/**
	* Performs the creation of the object for a mono-valued reference. In this case, we will create the object in a
	* mono or multi-valued containment reference and then add it to the mono-valued reference of our current object.
	*
	* @param value
	* The element to create
	*/
	private void performFinistMonoValuedNonContainmentReference(EObject value) {
	EObject eContainer = this.getEObject(this.eContainerTreeViewer);
	EObject eContainmentReferenceEObject = this.getEObject(this.eContainementReferenceComboViewer);
	if (eContainer != null && eContainmentReferenceEObject instanceof EReference) {
	EReference eContainmentReference = (EReference) eContainmentReferenceEObject;

	if (eContainmentReference.isMany()) {
	this.eContainmentAdd(eContainer, (EReference) eContainmentReferenceEObject, value);
	} else {
	eContainer.eSet(eContainmentReference, value);
	}

	this.target.eSet(this.eReference, value);
	}
	}

	/**
	* Adds the given eObject to the value of the given EReference for the given container EObject.
	*
	* @param eContainer
	* The container
	* @param eContainmentReference
	* The containment EReference
	* @param eObject
	* The EObject
	*/
	private void eContainmentAdd(EObject eContainer, EReference eContainmentReference, EObject eObject) {
	Object value = eContainer.eGet(eContainmentReference);
	if (value instanceof EList<?>) {
	// sbegaudeau: Yes I know, @SuppressWarnings are bad but we really need this one in order to prevent the
	// creation of a new list which would fire, as a side effect, a modification notification for all the
	// siblings of the newly created object. We do not want anyone to believe that those objects have been
	// modified
	@SuppressWarnings("unchecked")
	EList<EObject> objects = (EList<EObject>) value;
	objects.add(eObject);
	}
	}

	/**
	* {@inheritDoc}
	*
	* @see org.eclipse.jface.dialogs.DialogPage#dispose()
	*/
	@Override
	public void dispose() {
	super.dispose();

	this.composedAdapterFactory.dispose();
	this.eClassInstanceComboViewer.removeSelectionChangedListener(this.eClassInstanceComboViewerListener);
	}
	}