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Motif and CDE 2.1 Style Guide Reference
Warning Signal
Reference
Description
A warning signal is a transient cue that alerts the user about a minor,
nonfatal error or problem with interaction. A warning signal may be an audible
signal (such as a beep) or a visible signal (such as a flashing screen) or
both. A warning signal may also be other transient, sensory signals that the
operating environment supports. The warning signal should use as many modes as
needed to supplement other on-screen cues. For example, if the user is in a
low-light environment, an audible signal can be a useful supplement to other
visible on-screen messages and graphical cues.
When to Use
RequiredProvide a warning signal when the user types a character that is not
supported as input for a text-entry field that has focus. For example, if a
text-entry field supports only numeric characters, provide a warning signal
when the user types a letter.
RequiredProvide a warning signal when the user types a character that cannot be
used as a mnemonic at the active cursor position or the control on which the
cursor is positioned does not accept text input. For example, if mnemonics are
supported but no choice has L assigned as the mnemonic, provide a warning
signal when the user presses the L key.
RequiredUse a warning signal to supplement a message. Note that in degraded
environments, a message may occur in sensory modalities other than the
standard visual on-screen mode. See Chapter
12 for more information.
RecommendedProvide a warning signal when a user attempts to activate a choice or
interact with a control that is displayed with unavailable emphasis.
RecommendedProvide a warning signal to supplement a persistent cue that might
otherwise be ignored by the user, or if the cue is intended to alert the user,
or if the situation is urgent.
Guidelines
RequiredIf the user has turned off a warning signal option for the operating
environment and a situation arises in which the system would normally generate
that warning signal, do not generate a warning signal. For example, if the
user has turned off audible signals for the operating environment, do not
generate an audible signal when an action message is displayed.
RecommendedAllow the user to take advantage of various capabilities of hardware and
software. For example, if the operating environment supports the generation of
a variety of sounds, allow the user to specify different sounds for a warning
message, an action message, and for an attempt to activate a choice currently
displayed with unavailable emphasis.
RecommendedEven if the operating environment allows an unlimited range of warning
signals in any sensory modality, assign meaning to only a limited number of
signals. Generally, your application should support no more than seven
different audible signals and about five different visible signals.
RecommendedIf a warning signal is the only indication of a condition and the
environment is degraded such that a warning signal cannot be used effectively,
use a warning message instead.
Essential Related Topics
For more information, see Chapter
4 and the Action Message, Message, and Persistent Cue reference pages.
Supplemental Related Topics
For more information, see the Information and Message Areas (Area) and
Mnemonic reference pages.
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