Miguel Antunes

Forms2Net – migrating oracle forms to microsoft .NET

Forms2Net is an ATX Software commercial reengineering tool that automatically converts Oracle Forms applications to the equivalent .NET (C#) ones, with approximately 75% rate of automatic conversion. From the reengineering and transformation theoretical viewpoint, Forms2Net falls in the general category of language-platform conversion tools. As theory and practice indicate, for such tools to be effective, there are two major issues that must be handled: (a) the resolution of the semantic gap between the pair of source-target languages and (b) the resolution of the dependencies (e.g., API dependencies) on functionalities provided by default by the source platform or on programming idiosyncrasies of the source platform (in this case Oracle Forms). This paper presents the important practical aspects of Forms2Net and the underlying technology. We discuss the semantic gap between Oracle Forms and .NET forms and the design principles and solution strategies used to bridge this gap.

Naming: design pattern and framework

Naming is an important, but frequently overlooked, aspect of software systems. Naming is usually combined with other issues, e.g. distributed communication technology. The paper treats naming in isolation. It presents a naming design pattern which abstracts several naming policies and an object-oriented framework that can be customized to support naming policies. An applications designer can choose the correct naming properties (relative, absolute, universal identifiers, etc.) to refer to specific objects.

Using separation and composition of concerns to build multiuser virtual environments

Developing multiuser virtual environments (MUVE) is a very complex task since it involves several engineering domain aspects such as virtual reality, cooperative work and distributed systems. Furthermore, existing technologies like graphics capabilities, processing power and network bandwidth, are permanently evolving. For MUVE systems to be successfully developed, they must not only deal with all the different aspects that are inherent to these systems but also have the ability to deal with the continuous technology and requirements evolution. To cope with these problems, a software engineering separation of concerns approach is proposed. Concerns are identified for each of the different aspects of MUVEs. To obtain the necessary flexibility, each one of the concerns should abstract its possible variations in order to support the future system evolution. Moreover it is shown how concerns composition has the necessary expressive power to build multiuser virtual environments.

An abstraction for awareness management in collaborative virtual environments

This paper describes an object-oriented abstraction for the problem of awareness management in Collaborative Virtual Environments (CVEs). The described abstraction allows for different types of awareness information and awareness management policies to be used. It is also described how the defined abstraction was used to support the awareness management policies of two demo CVEs application.

Separating replication from distributed communication: problems and solutions

Replication and distributed communication are usually tightly coupled. This code tangling forbids their independent reuse and adaptation. In this position paper, the problems resulting from coupling replication with distributed communication are discussed. In addition, a solution based on separation of concerns is proposed. The abstractions for each concern are presented, as well as their composition.

Distributed Proxy: A Design Pattern for the Incremental Development of Distributed Applications

Developing a distributed application is hard due to the complexity inherent to distributed communication. Moreover, distributed object communication technology is always changing, todays edge technology will become tomorrows legacy technology. This paper proposes an incremental approach to allow a divide and conquer strategy that copes with these problems. It presents a design pattern for distributed object communication. The proposed solution decouples distributed object communication from object specific functionalities. It further decouples logical communication from physical communication. The solution enforces an incremental development process and encapsulates the underlying distribution mechanisms. The paper uses a stage-based design description which allow design description at a different level of abstraction than code.

Multi-user Object-Oriented Environments

Network-based computer environments emulating selected aspects of the physical world and allowing interaction among their human users first appeared in the late 1970s. These environments implemented a networked version of a role-playing fantasy game known as Dungeons and Dragons, hence their acronym MUD (Multi-user Dungeons). When it became obvious that many MUD users use the environment mainly to meet virtually with other users rather than to play games, new forms of MUDs and other types of emulated universes were developed and the term Virtual Environment (VE) was introduced to refer to all of them.