bundles/org.eclipse.emfforms.swt.treemasterdetail/src/org/eclipse/emfforms/spi/swt/treemasterdetail/util/CreateChildAction.java

// REUSED CLASS
/**
 * Copyright (c) 2002-2007 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 * IBM - Initial API and implementation
 */
package org.eclipse.emfforms.spi.swt.treemasterdetail.util;

import java.util.Collection;

import org.eclipse.emf.common.command.Command;
import org.eclipse.emf.common.command.UnexecutableCommand;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.EReference;
import org.eclipse.emf.edit.command.AddCommand;
import org.eclipse.emf.edit.command.CommandParameter;
import org.eclipse.emf.edit.command.CreateChildCommand;
import org.eclipse.emf.edit.command.SetCommand;
import org.eclipse.emf.edit.domain.EditingDomain;
import org.eclipse.emf.edit.ui.action.emfforms.StaticSelectionCommandAction;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.Viewer;

/**
 * A child creation action is implemented by creating a {@link CreateChildCommand}.
 */
public class CreateChildAction extends StaticSelectionCommandAction {
	/**
	 * This describes the child to be created.
	 */
	private final CommandParameter descriptor;
	private final EditingDomain editingDomain;
	private final ISelectionProvider selectionProvider;
	private final EObject parent;
	private final CreateElementCallback createElementCallback;

	/**
	 * This constructs an instance of an action that uses the given editing domain to create a child
	 * specified by <code>descriptor</code> for the single object in the <code>selection</code>.
	 *
	 * @since 2.4.0
	 */
	public CreateChildAction(EObject parent, EditingDomain editingDomain, ISelectionProvider selectionProvider,
		CommandParameter descriptor, CreateElementCallback createElementCallback) {
		super(editingDomain);
		this.parent = parent;
		this.descriptor = descriptor;
		this.selectionProvider = selectionProvider;
		configureAction(selectionProvider.getSelection());
		this.editingDomain = editingDomain;
		this.createElementCallback = createElementCallback;
	}

	/**
	 * This creates the command for {@link StaticSelectionCommandAction#createActionCommand}.
	 */
	@Override
	protected Command createActionCommand(EditingDomain editingDomain, Collection<?> collection) {
		if (collection.size() == 1) {
			final Object owner = collection.iterator().next();
			return CreateChildCommand.create(editingDomain, owner,
				descriptor, collection);
		}
		return UnexecutableCommand.INSTANCE;
	}

	@Override
	public void run() {
		final EReference reference = descriptor.getEReference();

		final EObject newObject = descriptor.getEValue();
		// Add the element, so that it is contained in the ResourceSet.

		final Command addCommand;
		if (reference.getUpperBound() == 1) {
			addCommand = SetCommand.create(editingDomain, parent, reference, newObject);
		} else {
			addCommand = AddCommand.create(editingDomain, parent, reference,
				newObject);
		}
		editingDomain.getCommandStack().execute(addCommand);

		boolean callbackResult = true;

		if (createElementCallback != null) {
			/* ask callback after command execution so that callback can navigate to parent */
			callbackResult = createElementCallback.beforeCreateElement(newObject);
		}

		if (callbackResult) {
			// Select the newly added element. It is already added
			if (selectionProvider instanceof Viewer) {
				((Viewer) selectionProvider).refresh();
			}
			selectionProvider.setSelection(new StructuredSelection(newObject));
		} else {
			// If the callback says "cancel" undo the addCommand.
			addCommand.undo();
		}
	}
}