Informs the host application that the plug-in will begin accessing parameters.
- FxPlug 3.1+
The sender is either the custom
NSViewsubclass which implements a custom control, or it is a class implementing the
Fxprotocol which is updating or accessing its own parameters.
It is important to note that plug-ins implementing the
Fx protocol should not invoke the
end methods as the host application is already aware that parameters are likely to change.