LayerService.java

package my.project.sample.design;
 
import java.util.List;
 
import org.eclipse.emf.ecore.EObject;
import org.eclipse.sirius.business.api.componentization.DiagramComponentizationManager;
import org.eclipse.sirius.business.api.session.Session;
import org.eclipse.sirius.business.api.session.SessionManager;
import org.eclipse.sirius.viewpoint.DDiagram;
import org.eclipse.sirius.viewpoint.DDiagramElement;
import org.eclipse.sirius.viewpoint.description.Layer;
 
/**
 * Sample service class.
 */
public class LayerService {
 
	/**	
	 * Sample service able to change the activation of the layer with id equals to "SampleLayer"
	 * for the current diagram, parent of the elementView parameter. 
	 * 
	 * @param context the current context
	 * @param elementView any DDiagramElement
	 * @return the current context
	 */
	public EObject changeSampleLayerActivation(EObject context, EObject elementView) {
		if (elementView instanceof DDiagramElement) {
			DDiagram diagram = ((DDiagramElement) elementView).getParentDiagram();
			Session session = SessionManager.INSTANCE.getSession(((DDiagramElement) elementView).getTarget());
			Layer layer = getLayer(diagram, session, "SampleLayer");
			if (layer != null) {
				if (diagram.getActivatedLayers().contains(layer)) {
					diagram.getActivatedLayers().remove(layer);
				} else {
					diagram.getActivatedLayers().add(layer);
				}
			}
		}
		return context;
	}
 
        /**
         * Method to retrieve the layer with the given id in all available layers for the current diagram.
         */
	private Layer getLayer(DDiagram diagram, Session session, String layerId) {
		List<Layer> allAvailableLayers = new DiagramComponentizationManager()
				.getAllLayers(session.getSelectedViewpoints(false), diagram.getDescription());
		for (Layer layer : allAvailableLayers) {
			if (layerId.equals(layer.getName())) {
				return layer;
			}
		}
		
		return null;
	}
}