gamedevlists-windows

[GD-Windows] ActiveX Control question

[Brian H. <bri...@gm...>]

I've been reading up on ActiveX control development, and I'm looking
for a good book that covers ActiveX in depth (as opposed to the books
out there that spend 1000 pages on MFC and then devote 50 pages to an
ActiveX clock example written using MFC/ATL).  Any suggestions?

I also have a specific question:  is there a proper way to implement a
control that is completely passive, i.e. accepts no input and just
does something.  Imagine an application that allows you to download an
OCX to perform a bunch of calculations and then upload the results
(kind of like SETI at home, but as an explicit Web page control, not
as an explicit downloadable).

The typical control reacts to events, e.g. with OnXXXX response. 
Should I just setup a timer that periodically calls a callback
function, or is there a better/cleaner weay?

RE: [GD-Windows] ActiveX Control question

[Ivan-Assen I. <as...@ha...>]

> I also have a specific question:  is there a proper way to implement a
> control that is completely passive, i.e. accepts no input and just
> does something.  Imagine an application that allows you to download an
> OCX to perform a bunch of calculations and then upload the results
> (kind of like SETI at home, but as an explicit Web page control, not
> as an explicit downloadable).

Assuming you get the COM threading models right, I believe the "proper" way
would the to launch a separate thread in the OnLoad event. Have you tried that?
The main thread of a "proper" Windows application with a user interface 
(including an ActiveX control) should ideally do nothing but react to events.

Re: [GD-Windows] ActiveX Control question

[Brian H. <bri...@gm...>]

> Assuming you get the COM threading models right, I believe the "proper" way
> would the to launch a separate thread in the OnLoad event. Have you tried that?

No, but I will now =)  The amount of information to digest for COM +
OLE + MFC + ActiveX + the whole ATL distraction thing is just, well,
immense.  Just figuring out where to start has been difficult, most
people who have been doing this stuff have been doing it for 7 years.

Thanks,

Brian

Re: [GD-Windows] ActiveX Control question

[Brian H. <bri...@gm...>]

I looked for references to the OnLoad event -- where is this
documented?  I didn't see it under COleControl.

Re: [GD-Windows] ActiveX Control question

[Ivan-Assen I. <iva...@gm...>]

> I looked for references to the OnLoad event -- where is this
> documented?  I didn't see it under COleControl.

Errrr, sorry to have mislead you... OnLoad is the .NET event. 

COleControl is an MFC class, right? 
Can you do your setup work, including launching a thread, in the constructor?

Re: [GD-Windows] ActiveX Control question

[Brian H. <bri...@gm...>]

> Can you do your setup work, including launching a thread, in the constructor?

That was sort of my original question, stated differently =)  I'm just
not sure where long-term work can be stored, all the examples I see
are basically focused on property exchange, event reaction, and doing
things in OnDraw().

Re: [GD-Windows] ActiveX Control question

[Brian H. <bri...@gm...>]

> That was sort of my original question, stated differently =)  I'm just
> not sure where long-term work can be stored, all the examples I see
> are basically focused on property exchange, event reaction, and doing
> things in OnDraw().

What I ended up doing, and I think this is okay, is having an
OnCreate() for the control which turns around and does a
SendMessage()...then I turn around and have an OnCommand() which calls
"Go()" which spawns the worker thread and goes from there.  Whew. 
Ugly, but it seems to work.