Early computer terminals allowed only textual I/O. Because the user read and wrote vectors of character strings, this mode of I/O (character-based user interface, or “CUI”) could be thought of as one-dimensional, 1D. As terminal technology improved, users could manipulate graphical objects (via a graphical user interface, or “GUI”) in 2D. Although the I/O was no longer unidimensional, it was still limited to the planar dimensionality of a CRT or tablet. Now there exist 3D spatial pointers and 3D graphics devices; this latest phase of I/O devices (Blattner, 1992; Blattner and Dannenberg, 1992; Robinett, 1992) approaches the way that people deal with “the real world.” 3D audio (in which the sound has a spatial attribute, originating, virtually or actually, from an arbitrary point with respect to the listener) and more exotic spatial I/O modalities are under development. The evolution of I/O devices can be roughly grouped into generations that also correspond to the number of dimensions. Representative instances of each technology are shown in Table 8-1. This chapter focuses on the italicized entries in the third-generation aural sector. Audio alarms and signals of various types have been with us since long before there were computers, but even though music and visual arts are considered sibling muses, a disparity exists between the exploitation of sound and graphics in interfaces. (Most people think that it would be easier to be hearing- than sight-impaired, even though the incidence of disability-related cultural isolation is higher among the deaf than the blind.) For whatever reasons, the development of user interfaces has historically been focused more on visual modes than aural. This imbalance is especially striking in view of the increasing availability of sound in current technology platforms. Sound is frequently included and utilized to the limits of its availability or affordability in personal computers. However, computer-aided exploitation of audio bandwidth is only beginning to rival that of graphics. General sound capability is slowly being woven into the fabric of applications. Indeed, some of these programs are inherently dependent on sound—voicemail, or voice annotation to electronic mail, teleconferencing, audio archiving—while other applications use sound to complement their underlying functionality.
Adaptive Graphical User Interface for Web Applications Using Aspect Oriented Component Engineering
