Windows.XP.in.a.Nutshell.1002005.2Ed [Electronic resources] نسخه متنی

Chapter 3. The User Interface

One of the responsibilities of a
graphical operating system like Windows XP is to provide a common set
of interface controls not only for itself, but for all the
applications that run on it. This chapter provides an alphabetical
reference to the elements of the Windows XP user interface, how
they're used, and what tricks can be performed with
them. Also included are some of the building blocks of the Windows XP
shell (commonly known as Explorer),
such as the Desktop and the various toolbars. Chapter 4 provides a similar alphabetical reference
to the individual programs and utilities that make up Windows,
whether they are accessible through the graphical user interface or
the command line. The alphabetical reference entries in this chapter
are as follows:.

In addition to imposing a certain level of user interface
consistency, these common elements allow programmers to quickly piece
together the interfaces for their applications with a
"toolbox" of parts. While these
interface elements are available to all applications, some
application designers choose instead to implement their own custom
controls and interface paradigms. Sometimes this can lead to an
innovative and clever design, but more often than not, it just
results in a mess. A poor result typically comes not so much from the
choice not to use Windows common controls, but from a failure to
follow the rules of good user interface design.

The following are a few guidelines that apply to all elements
of the Windows interface, which should provide some understanding of
why certain elements are designed the way they are in Windows XP.

Visual clues (perceived affordances)

One of the most basic advantages of a graphical operating system is
that the elements of the interface contain
visual clues on how
they're used. For example, buttons have a 3D look,
implying that you're supposed to push them in.
Folder icons look like actual yellow folders
you'd see in a file cabinet, reinforcing the notion
that they are containers that hold your documents. They also light up
when you're dragging items over them, signalling
that they can accept dropped objects. Even the mouse pointer provides
visual feedback, changing to a resize arrow when
it's over the edge of the window, or changing to a
circle with a line though it when you're dragging
over an object that can't accept the object
you're holding. (Don Norman, author of

The Design of
Everyday Things [Doubleday], calls these

visual clues , which are intended to recall the
way the physical world affords opportunities to interact with
objects, "perceived affordances.")
These clues are present in nearly every aspect of the Windows
interface; learn to recognize them, and you quickly find even the
most unfamiliar interface more intuitive and easier to use.

Constraints

Many controls have limits, or

constraints
, that permit only certain values to be
entered. Scrollbars have a maximum and minimum limit, for instance,
so you can't scroll past the end of a document.

Grayed-out (inactive) controls

Any control that appears
"
grayed
out" is disabled because the underlying operation is
not currently available. For example, in the dialog box shown in
Figure 3-1, you need to click the
"Single-click to open an item"
checkbox before you can choose the Underline button.

Figure 3-1. Some options are disabled (grayed out) when unavailable or not applicable

Gray items typically
don't respond at all when clicked, and sometimes
it's not obvious what action must be taken in order
to "un-gray" a menu item. If
you're stuck, try to imagine in what context the
menu item is used, and then try to put the application in the correct
state for that menu item to be appropriate. For example, some menu
items in your word processor will be grayed out when graphics are
selected, or if the spelling checker is open.

Ellipses (...)

You'll commonly see ellipses on menu items and
command buttons, and occasionally on other interface elements. This
notation implies that a new window will appear when the control is
activated.

Focus

The
focus
(explained in greater detail in Chapter 2) is
the visual highlighting of a single control, identifying which
element will receive input from the keyboard. Since
there's only one keyboard, only one control can have
the focus at a time, and since only one window can be active at a
time, you should always be able to determine what will happen when
you press keys on the keyboard by simply looking for the focus. For
example, if a button has the focus, a dotted line will
appear around its inner parameter (classic style only); if an
input field has the focus, a


blinking cursor will
appear where text is to be typed (this is known as the
"insertion point"). You
can usually click an item to give it
focus, or use the Tab key to move the focus from one control
to another.

Style

A new concept in Windows XP is the user-selectable

style of all your windows and interface
elements. The cheerful, brightly colored style that is the default
when Windows XP is first installed is known as
"Windows XP style." As shown in
Figure 3-2, you can choose another style, such as
"Windows Classic style," by going
to Control Panel Display
Properties Appearance.
Windows XP only ships with these two styles, but additional styles
can be added with third-party utilities (available at http://www.annoyances.org/exec/show/article02-001).
Using these tools, you can choose the look and feel of all of the
controls documented in this chapter, including titlebars, buttons,
scrollbars, and even the Start button and Taskbar.

Figure 3-2. The Display Properties dialog allows you to choose between the two visual styles available in Windows XP

Don't confuse

styles with themes. A theme is a
collection of settings. Once you've chosen the
style, specified colors, and selected a screensaver, go to Control
Panel Display Properties
Themes tab to
"save" your settings under a single
theme name. See "Display Properties" in
Chapter 4 for more information on these
settings.