The Representer System

20 March 1997

What Is It?

Representer is a system for the creation and implementation of 2-dimensional data visualisations. Its notable features include:

• visual programming of new visualisations
• a basic collection of visualisation resources
• design constraints enforcement and checking

Representer was designed and implemented in Smalltalk 4.1 by Phil Gray while on sabbatical during the academic year 1995-96. Many of its basic ideas come from the earlier Iconographer system developed in the Innovative Iconic Interfaces Project at GUCSD from 1989-1992. Representer is now used as a vehicle for exploring the notion of design constraints. A 3rd year project group is working on adding new representation resources to the system.

System Overview

Representer consists of a number of linked tools, including

• Representer Control Panel
• Source Domain Builder
• Representation Builder
• Representation Workshop

This section describes these tools and their relationships with one another.

The Representer Control Panel

Figure 1. The Representer Control Panel

The Representer Control Panel is the initial entry point into the Representer System. Available source domains and representations are displayed and may be connected. Connected representations can be viewed or configured.

Figure 2. View of representation in figure 1

The Domain Builder

Figure 3. The Source Domain Builder

This tool allows the creation of source domains to be visualised. There are three stages to its use:

• select a potential domain from one of the potential source domains,
• build a source domain based on a selected potential source domain, and
• install the source domain in the Representer Control Panel.

The Representation Builder

The representation builder is the tool which actually creates visualisations from a chosen representation type and a chosen source data domain. It has two parts:

Entity Linker

Figure 4. The Entity Linker

The entity linker allows the entity types in each domain to be linked together. This is equivalent to operations of the sort: "Let boxed labels represent files."

Attribute Linker

Figure 5. The Attribute Linker

Each entity in the source and representation domains has attributes. Typically, one wants the attibutes of a representation to carry information about the attributes of the source domain. This is done by linking the attributes in the attribute linker.

The Representation Workshop

Figure 6. The Representation Workshop

The representation workshop is where the representation domain is selected prior to installation in a representation builder. The basic tool just allows existing representations to be selected for installation. The basic idea is that one chooses one or more representation types and inserts them in a collection. The collection can then installed in the representation builder.

The Style Browser

Figure 7. The Style Browser

The style broswer displays the current set of design styles, each made up of a set of design constraints. Constraints may be added, removed and edited. Styles may also be checked against the currently selected representation in an entity linker or the representation workshop.

Documentation for Representer Developers

• Creating New Primitive Representations