org.eclipse.papyrus.infra.gmfdiag.navigation.CreateDiagramWithNavigationHandler.java Source code

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Here is the source code for org.eclipse.papyrus.infra.gmfdiag.navigation.CreateDiagramWithNavigationHandler.java

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/*****************************************************************************
 * Copyright (c) 2010 Atos Origin.
 *
 *    
 * 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:
 *  Mathieu Velten (Atos Origin) mathieu.velten@atosorigin.com - Initial API and implementation
 *
 *****************************************************************************/
package org.eclipse.papyrus.infra.gmfdiag.navigation;

import java.util.Collections;
import java.util.List;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.gmf.runtime.common.core.command.CompositeCommand;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.papyrus.commands.wrappers.GMFtoEMFCommandWrapper;
import org.eclipse.papyrus.infra.core.extension.commands.ICreationCommand;
import org.eclipse.papyrus.infra.core.extension.commands.ICreationCondition;
import org.eclipse.papyrus.infra.core.utils.BusinessModelResolver;
import org.eclipse.papyrus.infra.core.utils.DiResourceSet;
import org.eclipse.papyrus.infra.core.utils.EditorUtils;
import org.eclipse.papyrus.infra.widgets.toolbox.dialog.InformationDialog;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Display;
import org.eclipse.ui.PlatformUI;

/**
 * This command handler will try to create a diagram on the currently selected
 * element, using navigation if necessary. The action is always available and
 * the check is done in the run to avoid heavy navigation computation on each
 * selection change.
 * 
 * @author mvelten
 * 
 */
public abstract class CreateDiagramWithNavigationHandler extends AbstractHandler {

    private ICreationCondition creationCondition;

    private ICreationCommand creationCommand;

    public CreateDiagramWithNavigationHandler(ICreationCommand creationCommand,
            ICreationCondition creationCondition) {
        super();
        this.creationCommand = creationCommand;
        this.creationCondition = creationCondition;
    }

    @Override
    public boolean isEnabled() {
        return true;
    }

    public Object execute(ExecutionEvent event) throws ExecutionException {
        NavigableElement navElement = getNavigableElementWhereToCreateDiagram();

        if (navElement == null) {
            InformationDialog dialog = new InformationDialog(Display.getCurrent().getActiveShell(),
                    "Impossible diagram creation",
                    "It is not possible to create this diagram on the selected element.", null, null, SWT.OK,
                    MessageDialog.WARNING, new String[] { IDialogConstants.OK_LABEL });
            dialog.open();
        } else {
            createDiagram(navElement);
        }
        return null;
    }

    private NavigableElement getNavigableElementWhereToCreateDiagram() {
        EObject selectedElement = getSelectedElement();

        if (selectedElement != null) {
            // First check if the current element can host the requested diagram
            if (creationCondition.create(selectedElement)) {
                return new ExistingNavigableElement(selectedElement, null);
            } else {
                List<NavigableElement> navElements = NavigationHelper.getInstance()
                        .getAllNavigableElements(selectedElement);
                // this will sort elements by navigation depth
                Collections.sort(navElements);

                for (NavigableElement navElement : navElements) {
                    // ignore existing elements because we want a hierarchy to
                    // be created if it is not on the current element
                    if (navElement instanceof CreatedNavigableElement
                            && creationCondition.create(navElement.getElement())) {
                        return navElement;
                    }
                }
            }
        }
        return null;
    }

    private void createDiagram(NavigableElement navElement) {
        DiResourceSet diResourceSet = EditorUtils.getDiResourceSet();

        if (navElement != null && diResourceSet != null) {
            try {
                CompositeCommand command = NavigationHelper.getLinkCreateAndOpenNavigableDiagramCommand(navElement,
                        creationCommand, null, diResourceSet);
                diResourceSet.getTransactionalEditingDomain().getCommandStack()
                        .execute(new GMFtoEMFCommandWrapper(command));
            } catch (Exception e) {
            }
        }
    }

    private EObject getSelectedElement() {
        ISelection selection = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getSelectionService()
                .getSelection();
        if (selection instanceof IStructuredSelection) {
            Object obj = ((IStructuredSelection) selection).getFirstElement();
            return resolveSemanticObject(obj);
        }
        return null;
    }

    /**
     * Resolve semantic element
     * 
     * @param object
     *        the object to resolve
     * @return <code>null</code> or the semantic element associated to the
     *         specified object
     */
    protected EObject resolveSemanticObject(Object object) {
        if (object instanceof EObject) {
            return (EObject) object;
        }
        Object businessObject = BusinessModelResolver.getInstance().getBusinessModel(object);
        if (businessObject instanceof EObject) {
            return (EObject) businessObject;
        }
        return null;
    }

}