_DblClick, _IncSeek
These system variables
control two aspects of the user interface. _DBLCLICK determines
how long the user can pause between mouse clicks and still have
it considered a double-click. _INCSEEK determines the speed for
incremental search in list and combo boxes.
Usage
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_DBLCLICK = nSeconds
_INCSEEK = nSeconds
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nSeconds can range from .05 (1/20th of a second—we don't
know anybody who can double-click that fast) to 5.5 (handy for
someone with a physical disability that makes double-clicking or
typing quickly difficult). Because the ability to double-click
varies widely from one person to the next, you'll make your users
really happy if you let them set _DBLCLICK through your
application.Of course, we and our users would be even happier if
this setting were controlled by the similar setting in the
Windows Control Panel. Happily, as of VFP 7, it is: _DBLCLICK
gets its initial value from the setting chosen by the user in the
Mouse applet. Prior to VFP 7, _DBLCLICK had a second use:
controlling the speed of typing for incremental search. We're
delighted that Microsoft decided to follow our advice and create
a new system variable for this item. _INCSEEK (which also draws
its initial value from the double-click setting in the Mouse
applet!) determines how much time can pass between keystrokes and
still take advantage of the incremental search feature of combos
and lists.Since users' ability to type may be quite different
from their clicking ability, you may want to uncouple _INCSEEK
from _DBLCLICK and provide a facility for the user to adjust this
value in your applications.
Example
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_DBLCLICK = 1 && 1-second delay
_INCSEEK = ThisForm.spnIncSeek.Value
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Copyright © 2002-2018 by Tamar E. Granor,
Ted Roche, Doug Hennig, and Della Martin. Click for license
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