X Version 11 (Release 6.1)

XChangePointerControl(X3xlib)

XChangePointerControl -- control pointer

Synopsis

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

accel_denominator: Specifies the denominator for the acceleration multiplier.
accel_denominator_return: Returns the denominator for the acceleration multiplier.
accel_numerator: Specifies the numerator for the acceleration multiplier.
accel_numerator_return: Returns the numerator for the acceleration multiplier.
display: Specifies the connection to the X server.
do_accel: Specifies a Boolean value that controls whether the values for the accel_numerator or accel_denominator are used.
do_threshold: Specifies a Boolean value that controls whether the value for the threshold is used.
threshold: Specifies the acceleration threshold.
threshold_return: 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 do_accel and do_threshold 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 accel_denominator argument.

XChangePointerControl can generate a ``BadValue'' error.

The XGetPointerControl function returns the pointer's current acceleration 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.

References

Xlib - C Language X Interface