[Lazarus] TSimpleIPC documentation

[Graeme Geldenhuys]

Felipe Monteiro de Carvalho wrote:
> I think we should apply the WM_COPYDATA patch.

I don't agree on that.

The messages received by the LCL are for VCL compatebility only. That 
they happen to have the same values as the messages the win32 widgetset 
uses is just a "coincidence"
Like we won't pass all events/signals/messages available for 
carbon/gtk/qt, we won't pass all for win32.
For the simple reason that messages are not cross platform.

I agree that we should think of a way that users can simply hook into 
the main message/event/signal loop it they want to write an app specific 
for one widgetset.
Adding all these messages/evets/signals to the LCL is not the way to do 
this.

Marc