XChangePointerControl(3X11) — MIT X11R4

Name

XChangePointerControl, XGetPointerControl − 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

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.

displaySpecifies the connection to the X server.

do_accelSpecifies a Boolean value that controls whether the values for the accel_numerator or accel_denominator are used.

do_thresholdSpecifies a Boolean value that controls whether the value for the threshold is used.

thresholdSpecifies 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.