/******************************************************************************
 * Copyright (c) 2002, 2006 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 Corporation - initial API and implementation 
 ****************************************************************************/

package org.eclipse.gmf.runtime.diagram.ui.actions;

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

import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.gmf.runtime.common.core.util.Log;
import org.eclipse.gmf.runtime.common.core.util.Trace;
import org.eclipse.gmf.runtime.diagram.core.util.ViewUtil;
import org.eclipse.gmf.runtime.diagram.ui.actions.internal.DiagramActionsDebugOptions;
import org.eclipse.gmf.runtime.diagram.ui.actions.internal.DiagramActionsPlugin;
import org.eclipse.gmf.runtime.diagram.ui.actions.internal.DiagramActionsStatusCodes;
import org.eclipse.gmf.runtime.emf.ui.action.AbstractModelActionDelegate;
import org.eclipse.gmf.runtime.notation.View;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;

/**
 * Abstract action delegate for diagram actions that work with selected
 * <code>EObject</code> in a model.
 * 
 * @author ldamus
 */
public abstract class AbstractDiagramModelActionDelegate
	extends AbstractModelActionDelegate {

	/**
	 * Returns the elements in the given selection.
	 * 
	 * @return a list of <code>EObject</code>
	 */
	protected List getElements(final ISelection selection) {
        final List result = new ArrayList();

        if (selection instanceof IStructuredSelection) {
            try {

                getEditingDomain().runExclusive(new Runnable() {

                    public void run() {
                        if (selection instanceof IStructuredSelection) {
                            IStructuredSelection structuredSelection = (IStructuredSelection) selection;

                            for (Iterator i = structuredSelection.iterator(); i
                                .hasNext();) {
                                Object next = i.next();

                                View view = (View) ((IAdaptable) next)
                                    .getAdapter(View.class);
                                if (view != null) {
                                    EObject eObject = ViewUtil
                                        .resolveSemanticElement(view);
                                    if (eObject != null) {
                                        result.add(eObject);
                                    } else {
                                        result.add(view);
                                    }
                                }
                            }
                        }
                    }
                });
            } catch (InterruptedException e) {
                Trace.catching(DiagramActionsPlugin.getInstance(),
                    DiagramActionsDebugOptions.EXCEPTIONS_CATCHING, getClass(),
                    "getElements", e); //$NON-NLS-1$

                Log.error(DiagramActionsPlugin.getInstance(),
                    DiagramActionsStatusCodes.IGNORED_EXCEPTION_WARNING, e
                        .getLocalizedMessage(), e);
            }
        }
        return result;
    }

}