XChangePointerControl(XS) 6 January 1993 XChangePointerControl(XS)
X Version 11 (Release 5)
Name
XChangePointerControl - control pointer
Syntax
XChangePointerControl(display, do_accel, do_threshold, accel_numerator,
accel_denominator, threshold)
Display *display;
Bool do_accel, do_threshold;
int accel_numerator, accel_denominator;
int threshold;
XGetPointerControl(display, accel_numerator_return,
accel_denominator_return, threshold_return)
Display *display;
int *accel_numerator_return, *accel_denominator_return;
int *threshold_return;
Arguments
acceldenominator
Specifies the denominator for the acceleration multiplier.
acceldenominatorreturn
Returns the denominator for the acceleration multiplier.
accelnumerator
Specifies the numerator for the acceleration multiplier.
accelnumeratorreturn
Returns the numerator for the acceleration multiplier.
display Specifies the connection to the X server.
doaccel Specifies a Boolean value that controls whether the values
for the accelnumerator or acceldenominator are used.
dothreshold Specifies a Boolean value that controls whether the value
for the threshold is used.
threshold Specifies the acceleration threshold.
thresholdreturn
Returns the acceleration threshold.
Description
The XChangePointerControl function defines how the pointing device moves.
The acceleration, expressed as a fraction, is a multiplier for movement.
For example, specifying 3/1 means the pointer moves three times as fast
as normal. The fraction may be rounded arbitrarily by the X server.
Acceleration only takes effect if the pointer moves more than threshold
pixels at once and only applies to the amount beyond the value in the
threshold argument. Setting a value to -1 restores the default. The
values of the doaccel and dothreshold arguments must be True for the
pointer values to be set, or the parameters are unchanged. Negative
values (other than -1) generate a ``BadValue'' error, as does a zero
value for the acceldenominator argument.
XChangePointerControl can generate a ``BadValue'' error.
The XGetPointerControl function returns the pointer's current accelera-
tion multiplier and acceleration threshold.
Diagnostics
``BadValue'' Some numeric value falls outside the range of values
accepted by the request. Unless a specific range is
specified for an argument, the full range defined by the
argument's type is accepted. Any argument defined as a
set of alternatives can generate this error.
See also
Xlib - C Language X Interface