Path: utzoo!attcan!uunet!cs.utexas.edu!tut.cis.ohio-state.edu!bloom-beacon!SEI.CMU.EDU!rcs
From: rcs@SEI.CMU.EDU (rCs)
Newsgroups: comp.windows.x
Subject: UIDL/ADI Study Group
Message-ID: <8908232256.AA12268@gg.sei.cmu.edu>
Date: 23 Aug 89 22:56:06 GMT
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
Lines: 90


Reference Model

  The  P1201  User  Interface reference model, shown below, is a layered model
which defines the program services and interfaces required for  network-based,
bitmapped  graphic  user interface applications.  For purposes of the UIDL/ADI
Working group Layers 0-3 a in the model could be replaced with a  single  user
interface toolkit, for example the Mac Toolkit or Presentation Manager.

                    Model Layer

          Layer 6   Application
          Layer 5   Dialogue
          Layer 4   Presentation
          Layer 3   Toolkit
          Layer 2   Subroutine Foundation
          Layer 1   Data Stream Interface
          Layer 0   Data Stream Encoding

Domain

   1. Define requirements for the application dialogue interface (between
      layers 5 & 6 in the reference model).

   2. Define requirements for a UIDL (layers  4  &  5  in  the  reference
      model).

   3. Define  the  binding  mechanism for integrating toolkit level API's
      into the presentation layer (between layers 3 & 4 in the  reference
      model).

Assumptions

   1. Any  proposed  solution  should  support  the  toolkit API (between
      layers 3 & 4 in the reference model) being defined by P1201.1.

   2. Any proposed UIDL/API solution should work well on at least  the  X
      Window System and a character based terminal (i.e.  using Curses).

   3. Any proposed solution should work well on low end platforms.

Proposals

   1. Endorse the Seeheim terminology.

   2. The  ADI  will  not  dictate  specific  data  models  for  imaging,
      graphics, and other areas in which existing standards apply.   This
      requires the use of other, existing standards in the development of
      highly portable systems.

   3. Preference will be given for a  minimal  solution  that  meets  the
      requirements.

                                 REQUIREMENTS

ADI

   1. Mixed control model (either/both UI or application control).

   2. Presentation, or media, independent.

   3. Programming language independent (C, Ada, Fortran).

   4. Support dynamic requests for presentation services.

   5. Functional/object interface?

UIDL

   1. Support both presentation and dialogue.

   2. Describe dynamic behavior.

   3. Support dynamic requests for presentation services.

   4. Toolkit independent.

   5. Manipulate toolkit objects.

   6. Support for generic objects.

Toolkit Binding Mechanism

   1. Support multiple window systems (i.e. X, PM, Mac).

   2. Support multiple toolkits (i.e. 1201.1, Motif, OpenLook).

   3. Support character based terminals (i.e. curses on a VT220)

   4. Not wreck existing toolkit interfaces.