XQUERYDEVICESTATE(libmansuffix)
===============================

NAME
----

   XQueryDeviceState - query the state of an extension input
   device.

SYNOPSIS
--------

   #include <X11/extensions/XInput.h>

   int XQueryDeviceState( Display *display,
                          XDevice *device);
   
   display
          Specifies the connection to the X server.

   device
          Specifies the device whose state is to be queried.

DESCRIPTION
-----------

   The XQueryDeviceState request queries the state of an input
   device. The current state of keys and buttons (up or down), and
   valuators (current value) on the device is reported by this
   request. Each key or button is represented by a bit in the
   XDeviceState structure that is returned. Valuators on the
   device report 0 if they are reporting relative information, and
   the current value if they are reporting absolute information.

   XQueryDeviceState can generate a BadDevice error.

Structures

   The XDeviceState structure contains:

                typedef struct {
                    XID device_id;
                    int num_classes;
                    XInputClass *data;
                } XDeviceState;

   The XValuatorState structure contains:

                typedef struct {
                    unsigned char class;
                    unsigned char length;
                    unsigned char num_valuators;
                    unsigned char mode;
                    int *valuators;
                } XValuatorState;

   The XKeyState structure contains:

                typedef struct {
                    unsigned char class;
                    unsigned char length;
                    short     num_keys;
                    char keys[32];
                } XKeyState;

   The XButtonState structure contains:

                typedef struct {
                    unsigned char class;
                    unsigned char length;
                    short     num_buttons;
                    char buttons[32];
                } XButtonState;

DIAGNOSTICS
-----------

   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.