MFC/OLE server in *.EXE only?
Matthias Bohlen -- MATTES@logotec.com
Monday, February 05, 1996
Hello omni-sapient folks,
on the MSDN Library CD January 1996, I have found the following,
startling paragraph in the article "Product Doc, Lang, Vis C++ 4.0,
Programming with MFC, Encyclopedia, DLLs: Programming Tips":
"OLE allows object servers to be completely implemented
inside a DLL. This type of server is called an "in-proc
server". MFC does not completely support in-proc servers for
all the features of visual editing, mainly because OLE does
not provide a way for a server to hook into the container's
main message loop. MFC requires access to the container
application's message loop to handle accelerator keys and
idle-time processing."
Our application "LOGOCAD" consists of a rather small main program
(*.EXE) and about 150 DLL's, one for each group of functions. The
above statement, does it mean that I cannot write an OLE server using
MFC inside one of those 150 DLL's ? What will happen if I ignore the
warning and put the OLE server into a DLL?
To put it into the *.EXE program would be disastrous as it would
spoil our source code structure!
Could anyone comment on this?
TIA...
Matthias Bohlen
-------------------------------------------------------
Matthias Bohlen Logotec Software GmbH
Phone: +49 228 64 80 520 Chateauneufstr. 10
FAX: +49 228 64 80 525 D-53347 Alfter, Germany
E-mail: mattes@logotec.com
-------------------------------------------------------
Randal Parsons -- Randal.Parsons@btal.com.au
Wednesday, February 07, 1996
Matthias Bohlen wrote:
>
> Hello omni-sapient folks,
>
> on the MSDN Library CD January 1996, I have found the following,
> startling paragraph in the article "Product Doc, Lang, Vis C++ 4.0,
> Programming with MFC, Encyclopedia, DLLs: Programming Tips":
>
> "OLE allows object servers to be completely implemented
> inside a DLL. This type of server is called an "in-proc
> server". MFC does not completely support in-proc servers for
> all the features of visual editing, mainly because OLE does
> not provide a way for a server to hook into the container's
> main message loop. MFC requires access to the container
> application's message loop to handle accelerator keys and
> idle-time processing."
>
> Our application "LOGOCAD" consists of a rather small main program
> (*.EXE) and about 150 DLL's, one for each group of functions. The
> above statement, does it mean that I cannot write an OLE server using
> MFC inside one of those 150 DLL's ? What will happen if I ignore the
> warning and put the OLE server into a DLL?
>
Hi.
It sort of depends what part of OLE you want to implement. If you want
to implement OLE Automation, then there is no problem having an in-proc
server at all, and since OCXs (custom controls) are really special DLLs,
you have quite a lot of the visual parts of OLE too. If you want, you
can make an OLE Automation mini-server or full-server (which are EXEs),
but the dispatch interface is much slower (~500 times I think) because
of the marshalling between processes.
I believe that the restriction mentioned is in relation to in-place
activation - where you want to modify the menus displayed in the
container application (and the accelerator keys available). This
requires a window and message loop in the server, which DLLs don't have.
Its the sort of thing you would need to activate an embedded spreadsheet
in a word-processing document, so you could access all the normal
spreadsheet functionality.
My advice - just go ahead and make some OLE in-proc servers.
Regards,
Randal Parsons
Jim Lavin -- ooptech@Onramp.NET
Thursday, February 08, 1996
At 03:07 PM 2/5/96 +0100, you wrote:
>Hello omni-sapient folks,
>
>on the MSDN Library CD January 1996, I have found the following,
>startling paragraph in the article "Product Doc, Lang, Vis C++ 4.0,
>Programming with MFC, Encyclopedia, DLLs: Programming Tips":
>
> "OLE allows object servers to be completely implemented
> inside a DLL. This type of server is called an "in-proc
> server". MFC does not completely support in-proc servers for
> all the features of visual editing, mainly because OLE does
> not provide a way for a server to hook into the container's
> main message loop. MFC requires access to the container
> application's message loop to handle accelerator keys and
> idle-time processing."
>
>Our application "LOGOCAD" consists of a rather small main program
>(*.EXE) and about 150 DLL's, one for each group of functions. The
>above statement, does it mean that I cannot write an OLE server using
>MFC inside one of those 150 DLL's ? What will happen if I ignore the
>warning and put the OLE server into a DLL?
>
>To put it into the *.EXE program would be disastrous as it would
>spoil our source code structure!
>
>Could anyone comment on this?
>
>TIA...
>Matthias Bohlen
>
>-------------------------------------------------------
>Matthias Bohlen Logotec Software GmbH
>Phone: +49 228 64 80 520 Chateauneufstr. 10
>FAX: +49 228 64 80 525 D-53347 Alfter, Germany
>
>E-mail: mattes@logotec.com
>-------------------------------------------------------
>
>
We had the same problem with our current application architecture. We have
a client that displays one of several interface objects based on the type of
view they wish to see. We also needed to provide OLE embedding to each
specific view. We opted to use mini-servers which provided an In-Place
activated object and kept the code seperated. We were not able to find any
examples of In-Place Activated In-Proc Servers that were totaly MFC based
with out resorting to OCXs. OCXs were not an option since we needed the
menus and toolbars that both min and full servers provide. You may need to
do the samething, build a series of mini-servers that provide the In-Place
Activated objects you want but are not runnable except by being embedded or
linked as an object. This keeps the code size down and managable when you
have a-lot of different pieces that specialize in one or two functional areas.
Jim Lavin
OOP Technologies
http://emporium.turnpike.net/~jlavin
http://rampages.onramp.net/~ooptech
I've seen programmers who couldn't be passed by reference or by value!
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