

This paper presents motivation, design, and algorithms for using and implementing translucent, non-rectangular patches as a substitute for rectangular opaque windows. The underlying metaphor is closer to a mix between the architects yellow paper and the usage of white boards, than to rectangular opaque paper in piles and folders on a desktop.
Translucent patches lead to a unified view of windows, sub-windows and selections, and provide a base from which the tight connection between windows, their content, and applications can be dissolved. It forms one aspect of on-going work to support design activities that involve “marking” media, like paper and white boards, with computers. The central idea of that research is to allow the user to associate structure and meaning dynamically and smoothly to marks on a display surface.

Making effective use of the available display space has long been a fundamental issue in user interface design. We live in a time of rapid advances in available CPU power and memory. However, the common sizes of our computational display spaces have only minimally increased or in some cases, such as hand held devices, actually decreased. In addition, the size and scope of the information spaces we wish to explore are also expanding. Representing vast amounts of information on our relatively small screens has become increasingly problematic and has been associated with problems in navigation, interpretation and recognition. User interface research has proposed several differing presentation approaches to address these problems. These methods create displays that vary considerably, visually and algorithmically. We present a unified framework that provides a way of relating seemingly distinct methods, facilitating the inclusion of more than one presentation method in a single interface. Furthermore, it supports extrapolation between the presentation methods it describes. Of particular interest are the presentation possibilities that exist in the ranges between various distortion presentations, magnified insets and detail-in-context presentations, and between detail-in-context presentations and a full-zooming environment. This unified framework offers a geometric presentation library in which presentation variations are available independently of the mode of graphic representation. The intention is to promote the ease of exploration and experimentation into the use of varied presentation combinations.

Despite novel interaction techniques proposed for virtual desktops, common yet challenging tasks remain to be investigated. Dragging and dropping between overlapping windows is one of them. The fold-and-drop technique presented here offers a natural and efficient way of performing those tasks. We show how this technique successfully builds upon several interaction paradigms previously described, while shedding new light on them.

Conventional scrolling methods for small sized display in PDAs or mobile phones are difficult to use when frequent switching of scrolling and editing operations are required, for example, browsing and operating large sized WWW pages.In this paper, we propose a new user-interface method to provide seamless switching between scrolling and other operations such as editing, based on "Paperweight Metaphor". A sheet of paper that has been placed on a slippery table is difficult to draw on. Therefore, in order to write or draw something on the sheet of paper, a person must secure the paper with his/her palm to avoid the paper from moving. This will be a good metaphor to design switching operation of scroll and editing modes.We have made prototype systems by placing a touch sensor under each PDA display where user's palm will be hit. Three application programs - map browser, WWW browser, and photograph browser - that switch between scrolling and other operation modes depending on sensor output have been developed. We have carried out user tests on this mode switching method and have received favorable feedback on the same.