STEINER@RUTGERS.ARPA (01/07/85)
From: Steven A. Swernofsky <SASW@MIT-MC>
Date: Monday, 5 November 1984, 16:08-EST
From: <Henry at MIT-OZ>
Subject: Seminar announcement
To: BBoard at MIT-OZ, Bboard at SCRC-STONY-BROOK
There's More to Menu Systems Than Meets the Screen
Henry Lieberman
Thursday, 8 November, 1 PM
AI Playroom, 8th Floor, 545 Tech Sq., Cambridge
Love playing with those fancy menu-and-graphics systems, but afraid
to program one yourself? Are you scared of mice? Feel constrained
by TV:CONSTRAINT-FRAME-WITH-SHARED-IO-BUFFER?
Everyone agrees using these systems is fun, but programming them
isn't as much fun as it should be. Systems like the Lisp Machine
provide powerful graphics primitives and compute power, but the
casual applications designer who desires a simple, straighforward
menu interface is often stymied by the difficulty of mastering the
details of window specification, multiple processes, interpreting
mouse input, etc.
We present a kit for building simple interactive menu-based graphical
applications, called EZWin. Many such applications can be
conveniently described as generalized editors for sets of graphical
objects. An individual application is described simply by creating
an object to represent the application itself, objects to represent
each important kind of graphical object, and an object representing
each command.
The kit provides many common services needed by these systems. A
unique interaction style is established which is insensitive to
whether commands are chosen before or after their arguments.
Interactive type-checking of arguments to commands removes a common
source of frustrating errors. The system handles mouse sensitivity,
managing the selection of commands and arguments with the mouse
according to the current context.
The concepts will be illustrated with a description of how to
implement a simple diagramming system using EZWin.