MYVCS - Pete Cervasio's Non-Version Control System.  Version 1.0

A really stupid example of how to interface with the Version Control Manager
in Borland's Delphi.

Copyright 1995, Peter W. Cervasio
All Rights Undeserved.

This is really stupid, but it shows how to use the VCSINTF and TOOLINTF
units.  I don't really have any plans on expanding this into a real version
control system.  Maybe someone out there will do it.  If you do, please
remember where you learned this, and send me a registered copy of it.  I
could really use one.  <grin>

How did I figure this out??  Well, I looked at the demo source code for the
App/Dialog Expert.  That showed me a lot about how the TOOLINTF unit was
used.  I then slowly but surely added more and more functions into this
little DLL until it looked like it showed enough.

This code is released as freely available software.  You may do anything you
wish to with it, including making the the worlds greatest version control
system and selling it for a lot of money.  I don't care, I just wanted to
figure out what I could about the VCS Manager.  The only thing you can't do
is pretend that you wrote this.  Ugh... who would want to admit that,
anyway?  I don't even want to, but my user-id is going to be on the upload
description, so I might as well admit it.  <big grin>

One exception to the preceeding paragraph: Borland International is granted
any rights to this code that they want.  I especially hope that that they
will take this code, do whatever cleanup they feel needs done, and include
it in the next release of Delphi so people will understand what's going on
with the VCSINTF unit a bit.

The real work goes on in MYVCS.PAS.  The code that starts the conversation
between Delphi and MyVCS is in the function MyVCSInit.  Here it is:

    function MyVCSInit (VCSInterface: TIToolServices): TIVCSClient; export;
    begin
        ToolInterface := VCSInterface;
        if ToolInterface <> nil then
        begin
            MyVCSClient := TMyVCSClient.Create;
            WindowHandle := VCSInterface.GetParentHandle;
            result := MyVCSClient;
        end
        else
            result := nil;
    end;

I've declared ToolInterface as a global TIToolServices, and MyVCSClient as a
global TMyVCSClient.  If I receive a valid VCSInterface from Delphi, I
assign it to ToolInterface, and create a TMyVCSClient to pass back.  If not,
I return nil.  When things weren't working so well (the first couple of
tries), I would get a "Could not open communication with the VCS Manager"
type of message from Delphi, but everything else kept working so I guess
this is the right thing to do.

All the rest of the work happens in the TMyVCSClient class.  As a menu title
to add to the Delphi menubar, I'm returning "&Workgroup".  This is what the
PVCS interface uses, so I guess it's a pretty good 'standard' to use.  The
number of menu items is returned by the GetVerbCount method, and the text of
those items is returned by the GetVerb(Index) method.  The state of the menu
items is set with GetVerbState(Index).  Since this is a really stupid
example, I'm just returning vsEnabled for any menu item.  In a *real* VCS
manager, you would enable and disable options as the project state changes.

When the user picks one of those menu items, the ExecuteVerb method is
called with the index of the menu item selected.  This is fairly straight-
forward.  The ToolServices object we were passed on initialization allows us
to open files, close files, get a list of units and forms, and all kinds of
things.  The only things this DLL does: open a file, close the current
project or file (which might be a form or a unit), show a list of units and
forms in the project, and two goofy little dialog boxes that show the number
of files and units.  These last two are leftovers from the very first
incarnation of the DLL.  Oh, there's an about box, too.

I hope this helps people understand how the VCS Interface unit works, and
how you would go about sticking a version control system into Delphi. Again,
it's a really stupid example, but it works.  :-)

If you want to contact me about this code, I can be reached either in the
Delphi forum on Compuserve, or via Fidonet netmail.  I can't promise to
answer your questions, but I'll try.

Peter Cervasio
Compuserve:  73443,1426     Fidonet: 1:130/209