The persistent difficulty to develop and maintain interactive software has unveiled the inadequacy of traditional imperative programming languages. In the recent years, several solutions have been proposed to enrich the existing languages with constructs dedicated to interaction. In this paper, we propose a different approach that takes interaction as the primary concern to build a new programming language. We present Djnn, a conceptual framework based on the concepts of process and process activation, then we introduce Smala a programming language derived from this framework. We propose a solution for the unification of the concepts of event and data-flow, and for the derivation of complex control structures from a small set of basic ones. We detail the syntax and the semantics of Smala. Finally, we illustrate through a real-size application how it enables building all parts of an interactive software. Djnn and Smala may offer designers and programmers usable means to think of interactions and translate them into running code.

Collaboration is key to safety and efficiency in Air Traffic Control. Legacy paper-based systems enable seamless and non-verbal collaboration, but trends in new software and hardware for ATC tend to separate controllers more and more, which hinders collaboration. This paper presents a new interactive system designed to support collaboration in ATC. We ran a series of interviews and workshops to identify collaborative situations in ATC. From this analysis, we derived a set of requirements to support collaboration: support mutual awareness, communication and coordination, dynamic task allocation and simultaneous use with more than two people. We designed a set of new interactive tools to fulfill the requirements, by using a multi-user tabletop surface, appropriate feedthrough, and reified and partially-accomplishable actions. Preliminary evaluation shows that feedthrough is important, users benefit from a number of tools to communicate and coordinate their actions, and the tabletop is actually usable by three people both in tightly coupled tasks and parallel, individual activities. At a higher level, we also found that co-location is not enough to generate mutual awareness if users are not engaged in meaningful collaboration.

When involved in the visual design of graphical user interfaces, graphic designers can do more than providing static graphics for programmers to incorporate into applications. We describe a technique that allows them to provide examples of graphical objects at various key sizes using their usual drawing tool, then let the system interpolate their resizing behavior. We relate this technique to current practices of graphic designers, provide examples of its use and describe the underlying inference algorithm. We show how the mathematical properties of the algorithm allows the system to be predictable and explain how it can be combined with more traditional layout mechanisms.

Involving graphic designers in the large-scale development of user interfaces requires tools that provide more graphical flexibility and support efficient software processes. These requirements were analysed and used in the design of the TkZ-inc graphical library and the IntuiKit interface design environment. More flexibility is obtained through a wider palette of visual techniques and support for iterative construction of images, composition and parametric displays. More efficient processes are obtained with the use of the SVG standard to import graphics, support for linking graphics and behaviour, and a unifying model-driven architecture. We describe the corresponding features of our tools, and show their use in the development of an application for airports. Benefits include a wider access to high quality visual interfaces for specialised applications, and shorter prototyping and development cycles for multidisciplinary teams.

Modernizing workstations for air traffic controllers is a challenge: designers must increase efficiency without affecting safety in any way. Air traffic control is a time-intensive and safety-critical activity, and thus interaction efficiency and low error rates are crucial. Classical interaction techniques have been used in prototype workstations, but the resulting efficiency is not always satisfactory. This leads designers to consider more advanced interaction techniques. This paper reports on the design and a preliminary evaluation of the first prototype of project IMAGINE, which represents the second generation of graphical interfaces for air traffic control. This prototype, GRIGRI, uses a high resolution touch screen and provides mark based input through the screen. The use of gestures, as well as the use of multi-modal techniques, make interaction faster, and closer to the controllers' habits. Keywords Air traffic control, gesture recognition, mark-based input, pen computing, t...

Multimodal interaction combines input from multiple sensors such as pointing devices or speech recognition systems, in order to achieve more fluid and natural interaction. Two-handed interaction has been used recently to enrich graphical interaction. Building applications that use such combined interaction requires new software techniques and frameworks. Using additional devices means that user interface toolkits must be more flexible with regard to input devices and event types. The possibility of parallel interactions must also be taken into account, with consequences on the structure of toolkits. Finally, frameworks must be provided for the combination of events and status of several devices. This paper reports on the extensions we made to the direct manipulation interface toolkit Whizz in order to experiment two-handed interaction. These extensions range from structural adaptations of the toolkit to new techniques for specifying the time-dependent fusion of events.