Lecture Topics in HCI, by Saul Greenberg
Contents for:	All Topics	CPSC 481	SENG 609.05	Industrial Course

Windowing Systems and Toolkits

Computer scientists must not only know about design, but they must also know how to translate their designs into working systems. As in any craft, the tools available to implementers have a profound effect on the end system, both in the style of the interface and the way original designs are translated into working ones.

Overheads

• Windowing systems and toolkits. Under construction.

Handouts

• An overview to the Tcl Scripting Language as well as a source file that you can cut and paste code
• Examples of Tk Widgets, including source, which were illustrated in Lab
• Examples of non-standard widgets, e.g., things you can build and/or use

Topics covered

• The Tcl/Tk language

Readings from Baecker Grudin Buxton and Greenberg

• Chapter 5: Development Tools, p.313-321, gives an introduction to development tools.
• State of the Art in User Interface Software Tools, p.313-321, says why interfaces are hard to build, and then walks through many contemporary methods used by toolkits.
• Optional readings: The remaining papers in Chapter 5, p.344-397, describe particular systems and their philosophies, including Garnet, ITS, and GroupKit.

Getting Tcl/Tk

Tcl/Tk runs on Unix, Macs, and PCs (Windows 95). Programs should run across all platforms, although sometimes things can go funny with the fonts (this is because a font may not be available on your platform, and Tcl tries to find the closest match). As well, Tcl/Tk 8.0 will use native look and feel of all the widgets.

To get the latest versions

• We have a local copy for windows (about 1.7 Mb) or
• get it from Scriptics http://www.scriptics.com/software/8.0.html

Additional Reference material: The Tcl/Tk language

• Unix on-line manual pages, distributed with Tcl/Tk, gives a detailed description of every Tcl/Tk language construct. Very useful.
• Tcl and the Tk Toolkit, John Ousterhout, Addison Wesley gives an overview of the language.
• An incomplete tutorial for writing Ticklets, Tcl/Tk plugins that run within a browser
• A brief page describing Tcl syntax
• An introduction to Tcl/Tk, with examples

Videos

FormsVBT shows an integrated interface builder, text editor, and test interface. Garnet walks through the many sophisticated features of the Garnet toolkit, and is a good example of state of the art toolkit capabilities. GroupKit illustrates a groupware toolkit and the special constructs needed to make real time groupware. All the Widgets shows a variety of widget types. As excerpts were already shown in other topics, I use this only if there is extra time.

• FormsVBT (1990, SGVR Issue 56 ) shows an integrated interface builder, text editor, and test interface.
• The Garnet User Interface Development Environment by Myers (1994, SGVR Issue 97 ) walks through the many sophisticated features of the Garnet toolkit. A good example of state of the art toolkit capabilities.
• GroupKit by Greenberg (1994, SGVR Issue 106) illustrates a groupware toolkit and the special constructs needed to make real time groupware.
• All the Widgets by Myers (1990, SGVR Issue 57) shows a variety of widget types. As excerpts were already shown in other topics, I use this only if there is extra time.

In-class teaching tips

This topic can have a heavy hands-on component through a capstone project. If done, students learn the Tcl/Tk language and apply it to their design. They use it to translate their paper prototypes into a horizontal prototype (often finding out that some of their ideas are not implementable), and then to turn their prototype into a working system.

Of course, other languages could have been used instead of Tcl/Tk. I chose it because it is freely available, has a very rapid learning time (compared to other toolkits), and is reasonably robust. It is cross platform (Unix, Windows, Macs), which means students can install it on their home machines and work at home. I do not let students use other languages, because I want to make sure that I evaluate them on the same base platform. However, other languages could work just as well, and we have had successful experiences with Suit (which is also freely available) and Visual Basic (which is not).

Major sources used to prepare lecture material

• The readings above give a good treatment of toolkits
• John Ousterhaut, the inventor of Tcl/Tk, supplied the overheads and on-line drafts of his book.