Abstract not found

Almost as long as there have been user interfaces, there have been special software systems and tools to help design and implement the user interface software. Many of these tools have demonstrated significant productivity gains for programmers, and have become important commercial products. Others have proven less successful at supporting the kinds of user interfaces people want to build. This article discusses the different kinds of user interface software tools, and investigates why some approaches have worked and others have not. Many examples of commercial and research systems are included. Finally, current research directions and open issues in the field are discussed.

The data model upon which most of today's commercial database management systems are based has shown to be insufficient for geographic information systems (GISs). The recently promoted object-oriented model provides some useful tools for data abstraction and data structuring, which augment the conventional tools and overcomes some deficiencies inherent to the traditional relational model. In particular, the concepts of complex objects with pertinent operations are more powerful modeling methods than the currently popular structure of relational tables and relational algebra. This survey article presents the concepts of object-oriented modeling applied to geographic data and demonstrates their impact on future GISs.

ing combines and transforms events coming from the presentation techniques into higher level events for higher abstractions. Conversely, concretizing decomposes and transforms high level information into low level information. The lowest level of the dialogue controller is in contact with the presentation techniques provided by the toolkit. This boundary is a rather fuzzy frontier. In general, user interface toolkits such as the X Intrinsics, provide an abstraction mechanism for defining new interaction techniques. However, it is not always possible to build new interaction techniques from the predefined building blocks of the toolkit. For example, in an earlier version of the X intrinsics, interaction techniques would occupy rectangular areas only. In such conditions, the notion of a wall in a floor plan drawing editor, could not be implemented as a diagonal line widget. Instead, a presentation object "wall" would be defined as a new abstraction in the dialogue controller portion. Thi...

... advent of new technologies and user-centred concerns, the user interface portion of interactive systems is becoming increasingly large and complex. In this article, we discuss agent-based architectural styles and show how sound tradeoffs between conflicting requirements and properties can be done using the PAC-Amodeus conceptual model.

This article presents a taxonomy for the user-visible parts of window managers. It is interesting that there are actually very few significant differences, and the differences can be classified in a taxonomy with fairly limited branching. This taxonomy should be useful in evaluating the similarities and differences of various window managers, and it will also serve as a guide for the issues that need to be addressed by designers of future window manager user interfaces. The advantages and disadvantages of the various options are also presented. Since many modern window managers allow the user interface to be customized to a large degree, it is important to study the choices available. A window manager is a software package that helps the user monitor and control different contexts by separating them physically onto different parts of one or more display screens. At its simplest, a window manager provides many separate terminals on the same screen, each with its own connection to a time-sharing computer. At its most advanced, a window manager supports many different activities, each of which uses many windows, and each window, in turn, can contain many different kinds of information including text, graphics, and even video. Window managers are sometimes implemented as part of a computer’s operating system and sometimes as a server that can be used if desired. They September 1988 0272-1;1618810900-0065s0100 198R ltEE 65

The Lapidary interface design tool is a demonstrational system that allows the graphics and run-time behaviors that go inside an application window to be specified pictorially. In particular, Lapidary allows the designer to draw example pictures of application-specific graphical objects that the end user will manipulate (such as boxes and arrows, or elements of a list), the feedback that shows which objects are selected (such as small boxes on the sides and corners of an object), and the dynamic feedback objects (such as hair-line boxes to show where an object is being dragged). The run-time behavior of all these objects can be specified in a straightforward way using constraints, demonstration, and dialog boxes that allow the designer to provide abstract descriptions of the interactive response to the input devices. Lapidary generalizes from these specific example pictures and behaviors to create prototype objects and behaviors from which instances can be made at run-time. A novel fea...

Abstract not found

If an object oriented program is a collection of communicating objects, then the objects' protocols define the languages the program speaks. Unfortunately, protocols are difficult to design in isolation, so many programs' protocols are not as well designed as they could be. This paper presents six patterns which describe how objects protocols can be designed or redesigned. By using these patterns, programs and designs can be made more simple, more general, and more easy to change. Introduction Object's protocols, also know as interfaces, are very important in object oriented design. An object's protocol is the face the object presents to other objects surrounding it. Using an object's protocol, other objects in the program can use the object as a server, thus accessing the behaviour the object provides. Similarly, an object can act as a client to other objects, in turn using their protocols to access their services. This paper presents six patterns for designing object oriented protoc...

Memento is a novel client/server infrastructure that includes a "collaboration framework" to support the collaborative creation and manipulation of digital artifacts within arbitrary semantic domains. Memento's novelty lies in its representation and maintenance of semantic constraints on information that are represented explicitly in a formalized data model within the Memento server; for this reason, we say that Memento is meaning independent and object independent. Memento accomplishes these independencies by means of a self-describing and extensible type system. Because the structure of Memento objects facilitates their distribution across computer networks and enables real-time notification of updates, Memento provides support for many kinds of collaborative applications.