Graphics permit entry of data specially formatted to show spatial, temporal,
or other relations among data sets.
When
graphic data entry involves frequent pointing on a display surface, design the
user interface so that actions for display control and sequence control are also accomplished by pointing, in order to minimize shifts from one entry device to another.
Example: In drawing a flow chart,
a user should be able to link predecessor and successor elements directly by
pointing at them, or by drawing lines between them, rather than by separately
keyed entries.
Exception:
Alphabetic entry for titles, labels, and other annotation of graphic displays
will be accomplished more quickly by conventional keyboard input than by
pointing.
Comment: This recommendation implies extensive use
of menus in the margins of a graphic display to permit direct selection of data
attributes and control options by pointing. If screen capacity is too limited to
permit simultaneous display of both graphic data and menus, then the designer
might provide temporary superposition of menu windows on displayed data, or
might provide some separate display device to show current options for control
entry. Control entry via keyboard and/or function keys will be less
satisfactory.
Comment: If pointing is performed on some separate input device, such
as a stylus on a digitizing tablet, then associated control actions should
also be implemented via that device.
Comment: For graphics software, a pointing action by a user can accomplish
several different logical functions: specifying a displayed element ("pick"
function); selecting a system-defined object, attribute or action ("button"
or "choice" function); or indicating a location in the conceptual drawing
space ("locator" function). A designer must
distinguish among these functions, although most users will not.
See also:
Indicate the current cursor position by displaying some distinctive cursor
symbol at that point.
Comment: The cursor may take various forms
on a graphics display. Many designers recommend a plus-sign for this purpose,
representing abbreviated cross-hairs whose intersection can mark a position
with reasonable precision.
In some applications it may help to extend those cross-hairs the full
height and width of the display. In some applications it may help to display
a cursor incorporating the current values of various attributes (color,
size, etc.) that can be selected by a user.
See also:
Pointing
