Elastic Windows' origin goes back as far as Nassi-Shneiderman
diagrams [68] (Figure 
).
Nassi-Shneiderman diagrams depict the program structure in flow charts
by appropriate tilings of rectangular boxes. Each programming
construct such as if, while, for, etc. has a
corresponding box representation. A program sequence is represented by
vertically stacked boxes for each program segment. Following on this
idea, the treemap concept was developed by
Shneiderman [69] and implemented by
Johnson [12] (Figure ). Treemaps are novel
visualization methods that map hierarchically structured data to
nested boxes in a space-filling manner, where users can interactively
specify presentation attributes of both structure and content of the
data. Application of the space-filling tiling of the screen space to
present personal information originates from the work by Plaisant and
Shneiderman [9] (Figure ). The Elastic Windows
approach extends this work by providing arbitrarily deep nested
hierarchical windows, where users can operate on windows at any level
of the hierarchy. The Elastic Windows approach also facilitates
multi-window operations by applying window operations on group of
windows at any level of the hierarchy. The elastic sheet metaphor is
exploited for dynamics of the layout, where windows stretch and shrink
like an elastic material allowing more information to be presented in
a smaller screen space.
