programming-for-dummies

294
Elements of a User Interface
The simplest way to display a command to the user is through a button.
Because buttons can take up so much space on-screen, buttons are most
useful for displaying a limited number of commands to the user, such as two
or three possible choices, as shown in Figure 10-4.
Figure 10-4:
Buttons
can display
the entire
command
name .
The problem with buttons is that they take up screen space, so using more
than a handful of buttons can crowd the screen and confuse the user. So
rather than bombard users with screens full of buttons, programs generally
use buttons to offer choices that users need to make immediately.
For example, when quitting a program, the program may ask the user if she
wants to save her file before quitting. So the limited number of choices are
only: Don’t Save, Save, and Cancel.
Buttons are useful for limiting the user’s choices to a handful of options.
However, buttons are impractical for displaying a large number of commands.
The most popular way for displaying multiple commands to the user is
through pull-down menus. Pull-down menus organize commands into categories,
such as File, Edit, Window, and Help.
Unfortunately, pull-down menus aren’t easy to use when a program has hundreds
of possible commands. As a result, commands often get buried within
multiple pull-down menus.
To solve this problem, many programs group related commands within
submenus, but now you have the problem of trying to find a command
buried within a submenu, which is buried in a pull-down menu, as shown
in Figure 10-5.
Because pull-down menus can get overloaded with so many commands, user
interface designers started displaying commands as icons and grouping
icons together in toolbars that usually appear directly underneath pull-down
menus, as shown in Figure 10-6.