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.\"     Title: xgetdevicecontrol
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.77.1 <http://docbook.sf.net/>
.\"      Date: 03/09/2013
.\"    Manual: \ \&
.\"    Source: \ \&
.\"  Language: English
.\"
.TH "XGETDEVICECONTROL" "3" "03/09/2013" "\ \&" "\ \&"
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.SH "NAME"
XGetDeviceControl, XChangeDeviceControl \- query and change input device controls
.SH "SYNOPSIS"
.sp
.nf
#include <X11/extensions/XInput\&.h>
.fi
.sp
.nf
XDeviceControl *XGetDeviceControl( Display *display,
                                   XDevice *device,
                                   int *controlType);
.fi
.sp
.nf
int XChangeDeviceControl( Display *display,
                          XDevice *device,
                          int controlType,
                          XDeviceControl *control);
.fi
.sp
.nf
display
       Specifies the connection to the X server\&.
.fi
.sp
.nf
device
       Specifies the device whose control is to be interrogated
       or modified\&.
.fi
.sp
.nf
controlType
       Specifies the type of control to be interrogated or
       changed\&.
.fi
.sp
.nf
control
       Specifies the address of an XDeviceControl structure
       that contains the new values for the Device\&.
.fi
.SH "DESCRIPTION"
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These requests are provided to manipulate those input devices
that support device control\&. A BadMatch error will be generated
if the requested device does not support any device controls\&.
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.RE
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.RS 4
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.nf
Valid device control types that can be used with these requests
include the following:
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DEVICE_RESOLUTION: Queries or changes the resolution of
valuators on input devices\&.
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.RE
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.nf
The XGetDeviceControl request returns a pointer to an
XDeviceControl structure\&.
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.RE
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XGetDeviceControl can generate a BadDevice or BadMatch error\&.
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.RE
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.RS 4
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.nf
The XChangeDeviceControl request modifies the values of one
control on the specified device\&. The control is identified by
the id field of the XDeviceControl structure that is passed
with the request\&.
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.RE
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XChangeDeviceControl can generate a BadDevice, BadMatch, or
BadValue error\&.
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.RE
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.SH "STRUCTURES"
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Each control is described by a structure specific to that control\&.
These structures are defined in the file XInput\&.h\&.
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XDeviceControl is a generic structure that contains two fields
that are at the beginning of each class of control:
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typedef struct {
    XID class;
    int length;
} XDeviceControl;
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The XDeviceResolutionState structure defines the information
that is returned for device resolution for devices with
valuators\&.
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typedef struct {
    XID control;
    int length;
    int num_valuators;
    int* resolutions;
    int* min_resolutions;
    int* max_resolutions;
} XDeviceResolutionState;
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The XDeviceResolutionControl structure defines the attributes
that can be controlled for keyboard Devices\&.
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typedef struct {
    XID control;
    int length;
    int first_valuator;
    int num_valuators;
    int* resolutions;
} XDeviceResolutionControl;
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.SH "DIAGNOSTICS"
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BadDevice
       An invalid device was specified\&. The specified device
       does not exist or has not been opened by this client via
       XOpenInputDevice\&. This error may also occur if some
       other client has caused the specified device to become
       the X keyboard or X pointer device via the
       XChangeKeyboardDevice or XChangePointerDevice requests\&.
.fi
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.RE
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BadMatch
       This error may occur if an XGetDeviceControl request was
       made specifying a device that has no controls or an
       XChangeDeviceControl request was made with an
       XDeviceControl structure that contains an invalid Device
       type\&. It may also occur if an invalid combination of
       mask bits is specified ( DvKey but no DvAutoRepeatMode
       for keyboard Devices), or if an invalid KeySym is
       specified for a string Device\&.
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.RE
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BadValue
       Some numeric value falls outside the range of values
       accepted by the XChangeDeviceControl request\&. Unless a
       specific range is specified for an argument, the full
       range defined by the argument\*(Aqs type is accepted\&. Any
       argument defined as a set of alternatives can generate
       this error\&.
.fi
.if n \{\
.RE
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