Through the Interface: SDI, the end is nigh

May 2015

Sun Mon Tue Wed Thu Fri Sat
          1 2
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30


« Overruling explode in AutoCAD 2010 using .NET | Main | AutoCAD Exchange, new blogs, webcast recordings posted »

April 17, 2009

SDI, the end is nigh

Sorry if the title is a little abrupt, but it seemed too good an opportunity to show off my now appalling poetry skills. [Something almost no-one knows (well, OK, knew) about me is that, at the age of 8, I was the youngest winner of a poetry competition. I went along to the King’s Lynn Arts Centre (known back then as The Fermoy Centre) to recite my poem, “Words Inside my Pencil”, to a packed – at least it seemed so, at the time – audience of the various winners’ parents. Anyway, as you can see it was all downhill from there, at least in terms of my poetic ambition.]

I’ve talked a little before about SDI and MDI inside AutoCAD (SDI == Single Document Interface, MDI == Multiple Document Interface). I’ve also written a few posts on how best to structure your application to deal with the change to MDI, whether you’re using ObjectARX or you’re using .NET. And there’s a lot of good information on this topic in the ObjectARX Developer’s Guide – be sure to search it for “MDI”.

When we introduced MDI in AutoCAD 2000, we added the capability to force SDI-only execution (i.e. AutoCAD tries to close the existing drawing when you open or create another), whether by an ObjectARX application (one not registering itself as “MDI-aware”) or by setting the SDI system variable to something other than zero (something that loading an MDI-unaware application would also do).

Maintaining this execution mode has added a fair amount of complexity to the development and testing needed for the AutoCAD product, which has inevitably meant that a portion of our engineering resources has focused on maintaining SDI rather than on developing new features. This is a natural trade-off, but we’ve now maintained SDI for 10 releases and the prevailing thinking is that it’s enough: the AutoCAD-based verticals and the majority of independent AutoCAD-based applications have now embraced the brave new world of MDI.

Now there are bound to be stragglers out there, which is one of the reasons I’m writing this post. I want to get a sense for the extent of the problem and determine what my team should do to help.

So, if you know your application currently requires SDI-only execution, please send me an email. Please explain your reasons for not supporting MDI and the potential hurdles you see with doing so. I can’t promise my team will be able to provide personalised assistance – if there are many of you out there then we will have to do something wider-scale – but we will do our best.

If you don’t know whether your application requires SDI-only execution, the chances are it doesn’t, but please do run the application and check it works properly when multiple drawings have been created or loaded in the AutoCAD editor.


TrackBack URL for this entry:

Listed below are links to weblogs that reference SDI, the end is nigh:

blog comments powered by Disqus


10 Random Posts