<command

            id="org.eclipse.emf.ecp.emfstore.ui.showHistoryView"

            name="showHistoryView">

      </command>

         <command

               commandId="org.eclipse.emf.ecp.emfstore.ui.showHistoryView"

               icon="icons/historyview.png"

               label="Show Historyview"

               style="push"

               tooltip="Shows the HistoryView">

            <visibleWhen

                  checkEnabled="false">

               <and>

                  <count

                        value="1">

                  </count>

                  <iterate>

                     <instanceof

                           value="org.eclipse.emf.ecp.core.ECPProject">

                     </instanceof>

                     <test

                           property="org.eclipse.emf.ecp.core.project.providerName"

                           value="org.eclipse.emf.ecp.emfstore.provider">

                     </test>

                  </iterate>

               </and>

            </visibleWhen>

         </command>

      <handler

            class="org.eclipse.emf.ecp.emfstore.internal.ui.handler.ShowHistoryHandler"

            commandId="org.eclipse.emf.ecp.emfstore.ui.showHistoryView">

         <enabledWhen>

            <with

                  variable="selection">

               <iterate

                     ifEmpty="false"

                     operator="or">

                  <test

                        property="org.eclipse.emf.ecp.emfstore.ui.testers.isShared"

                        value="true">

                  </test>

               </iterate>

            </with>

         </enabledWhen>

      </handler>

package org.eclipse.emf.ecp.emfstore.internal.ui.handler;

import org.eclipse.emf.ecp.emfstore.core.internal.EMFStoreProvider;

import org.eclipse.emf.ecp.spi.core.InternalProject;

import org.eclipse.emf.emfstore.client.model.ProjectSpace;

import org.eclipse.emf.emfstore.client.ui.controller.UIShowHistoryController;

import org.eclipse.core.commands.AbstractHandler;

import org.eclipse.core.commands.ExecutionEvent;

import org.eclipse.core.commands.ExecutionException;

import org.eclipse.jface.viewers.IStructuredSelection;

import org.eclipse.ui.handlers.HandlerUtil;

public class ShowHistoryHandler extends AbstractHandler {

	/*

	 * (non-Javadoc)

	 * @see org.eclipse.core.commands.IHandler#execute(org.eclipse.core.commands.ExecutionEvent)

	 */

	public Object execute(ExecutionEvent event) throws ExecutionException {

		InternalProject project = (InternalProject) ((IStructuredSelection) HandlerUtil.getCurrentSelection(event))

			.getFirstElement();

		if (project == null) {

			return null;

		}

		ProjectSpace projectSpace = EMFStoreProvider.INSTANCE.getProjectSpace(project);

		if (projectSpace != null) {

			new UIShowHistoryController(HandlerUtil.getActiveShell(event), projectSpace).execute();

		}

		return null;

	}

}