ISelectionListener listener = new ISelectionListener() {
      	
		@SuppressWarnings("restriction")
		public void selectionChanged(IWorkbenchPart part, ISelection sel) {
      		if (sel instanceof IStructuredSelection) {
			IStructuredSelection ss = (IStructuredSelection) sel;
			Object o = ss.getFirstElement();
				
	        	if (o instanceof ContainerShapeEditPart) {
	        		ContainerShapeEditPart editPart = (ContainerShapeEditPart) o;
	        		IFeatureProvider fp = editPart.getFeatureProvider();
	        		selection = fp.getBusinessObjectForPictogramElement(editPart.getPictogramElement());
	        		castElement();
	        		createSuggestions();
	        	}
	        	else {
	        		generateErrorInstruction(part, sel);
	        	}
...

public void createPartControl(Composite parent) {

     ...
     getSite().getWorkbenchWindow().getSelectionService().addSelectionListener(listener);
     ...
}

((EObject)selection).eAdapters().add(new AdapterImpl() {
    
    @Override
    public void notifyChanged(Notification msg) {
    // Execute change reaction code.
    }

});