/* 
 * Copyright (c) 2008 Stiftung Deutsches Elektronen-Synchrotron, 
 * Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY.
 *
 * THIS SOFTWARE IS PROVIDED UNDER THIS LICENSE ON AN "../AS IS" BASIS. 
 * WITHOUT WARRANTY OF ANY KIND, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED 
 * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE AND 
 * NON-INFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE 
 * FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR 
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. SHOULD THE SOFTWARE PROVE DEFECTIVE 
 * IN ANY RESPECT, THE USER ASSUMES THE COST OF ANY NECESSARY SERVICING, REPAIR OR 
 * CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS LICENSE. 
 * NO USE OF ANY SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER THIS DISCLAIMER.
 * DESY HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, 
 * OR MODIFICATIONS.
 * THE FULL LICENSE SPECIFYING FOR THE SOFTWARE THE REDISTRIBUTION, MODIFICATION, 
 * USAGE AND OTHER RIGHTS AND OBLIGATIONS IS INCLUDED WITH THE DISTRIBUTION OF THIS 
 * PROJECT IN THE FILE LICENSE.HTML. IF THE LICENSE IS NOT INCLUDED YOU MAY FIND A COPY 
 * AT HTTP://WWW.DESY.DE/LEGAL/LICENSE.HTM
 */
package org.csstudio.dal.ui.dnd.rfc;

import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.csstudio.platform.model.pvs.IProcessVariableAddress;
import org.csstudio.platform.model.pvs.IProcessVariableAdressProvider;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.ui.IObjectActionDelegate;
import org.eclipse.ui.IWorkbenchPart;

/**
 * Base class for popup menu actions used in Object contributions for
 * {@link IProcessVariableAdressListProvider}.
 * 
 * @author Sven Wende
 * 
 */
public abstract class ProcessVariablePopupAction implements
		IObjectActionDelegate {

	private List<WeakReference<IProcessVariableAdressProvider>> _pvAdressListProviders;

	public ProcessVariablePopupAction() {
		_pvAdressListProviders = new ArrayList<WeakReference<IProcessVariableAdressProvider>>();
	}

	@Override
	public void setActivePart(IAction action, IWorkbenchPart targetPart) {

	}

	@Override
	public void run(IAction action) {
		Set<IProcessVariableAddress> pvs = new HashSet<IProcessVariableAddress>();

		for (WeakReference<IProcessVariableAdressProvider> ref : _pvAdressListProviders) {
			IProcessVariableAdressProvider provider = ref.get();
			if (provider != null) {
				pvs.addAll(provider.getProcessVariableAdresses());
			}
		}

		handlePvs(pvs);
	}

	@Override
	public void selectionChanged(IAction action, ISelection selection) {
		_pvAdressListProviders.clear();

		if (selection instanceof IStructuredSelection) {
			IStructuredSelection sel = (IStructuredSelection) selection;

			for (Object o : sel.toList()) {
				if (o instanceof IProcessVariableAdressProvider) {
					_pvAdressListProviders
							.add(new WeakReference<IProcessVariableAdressProvider>((IProcessVariableAdressProvider) o));
				}
			}
		}

	}

	protected abstract void handlePvs(Set<IProcessVariableAddress> pvs);

}