think-cell technical report TC2003/01 A GUI-based Interaction ...

3.3 State of the Art – Résumé STATE OF THE ART
The smart grid is a hybrid of the regular grid and the popular guideline tool,
which were both discussed in section 3.1.2. The basic idea is to implicitly generate
guidelines when needed and use them subsequently to align shapes. In contrast
to the guidelines generally found in drawing applications and notably in Microsoft
PowerPoint, which are static except for explicit modifications by the user, the smart
grid is dynamically updated. In this regard, the smart grid resembles a web page
that is laid out using HTML tables: Objects are arranged in an irregular grid,
that is stretched and bent as required to accommodate the (preferred) sizes of the
contained objects as well as the available real estate on a page or screen.
The smart grid integrates guidelines with constraints. This approach exhibits
some resemblance to augmented snapping [Gle92]: Drawing objects snap to align-
ment objects, generating constraints that are enforced during later editing opera-
tions. While maintaining the basic idea, in my approach the variety of alignment
objects is restricted to horizontal and vertical lines. This appears to satisfy most
alignment requirements that arise in the context of business slides and makes the
necessary computation for constraint solving a lot easier.
It is important to note another fundamental difference: While in augmented
snapping, any two objects on a page may or may not be related by some constraint,
in the approach presented in this work all objects on a slide are always related
through the smart grid.
3.3 State of the Art – Résumé
The review of literature shows that a lot of research has been done in the fields of
menu based user interfaces, as well as layout automation. Nonetheless, Microsoft
PowerPoint does not employ any of the techniques suggested by research, neither
constraint-based layout support nor any of the menu techniques that have shown
to be more efficient than standard linear menus. On the other hand, none of the
discussed research systems is designed for business slide creation, and obviously
there is also no standard software available that is better suited to this task than
PowerPoint. (If there was, one can assume that professionals would use it, but
everybody uses PowerPoint.)
The smart grid approach and the user interface concept that are presented in
the remainder of this work have the goal to remedy this situation: I developed a
working prototype that implements a new and particularly efficient user interface for
constraint specification. Based on the think-cell software, my prototype is designed
as an add-in to extend PowerPoint with constraint-based layout capability.
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