Man page 3 : XkbGetDeviceInfo

XkbGetDeviceInfo - Determine whether the X server allows Xkb access to particular capabilities of input devices other than the core X keyboard, or to determine the status of indicator maps, indicator names or button actions on a non-KeyClass extension device

XkbDeviceInfoPtr XkbGetDeviceInfo (Display * dpy , unsigned int which , unsigned int device_spec , unsigned int ind_class , unsigned int ind_id );

• - dpy
      connection to X server
• - which
      mask indicating information to return
• - device_spec
      device ID, or XkbUseCoreKbd
• - ind_class
      feedback class for indicator requests
• - ind_id
      feedback ID for indicator requests

To determine whether the X server allows Xkb access to particular capabilities of input devices other than the core X keyboard, or to determine the status of indicator maps, indicator names or button actions on a non-KeyClass extension device, use XkbGetDeviceInfo. XkbGetDeviceInforeturns information about the input device specified by device_spec.Unlike the device_specparameter of most Xkb functions, device_specdoes not need to be a keyboard device. It must, however, indicate either the core keyboard or a valid X Input Extension device. The whichparameter is a mask specifying optional information to be returned. It is an inclusive OR of one or more of the values from Table 1 and causes the returned XkbDeviceInfoRec to contain values for the corresponding fields specified in the table.

                        Table 1 XkbDeviceInfoRec Mask Bits
____________________________________________________________________________________
Name                         XkbDeviceInfoRec Value     Capability If Set
                             Fields Effected
____________________________________________________________________________________
XkbXI_KeyboardsMask                           (1L <<0) Clients can use all
                                                       Xkb requests and events
                                                       with KeyClass devices
                                                       supported by the input
                                                       device extension.
XkbXI_ButtonActionsMask       num_btns        (1L <<1) Clients can assign key
                              btn_acts                 actions to buttons
                                                       non-KeyClass input
                                                       extension devices.
XkbXI_IndicatorNamesMask      leds->names     (1L <<2) Clients can assign
                                                       names to indicators on
                                                       non-KeyClass input
                                                       extension devices.
XkbXI_IndicatorMapsMask       leds->maps      (1L <<3) Clients can assign
                                                       indicator maps to
                                                       indicators on
                                                       non-KeyClass input
                                                       extension devices.
XkbXI_IndicatorStateMask      leds->state     (1L <<4) Clients can request
                                                       the status of indicators
                                                       on non-KeyClass input
                                                       extension devices.
XkbXI_IndicatorsMask          sz_leds         (0x1c)   XkbXI_IndicatorNamesMask |
                              num_leds                 XkbXI_IndicatorMapsMask |
                              leds->*                  XkbXI_IndicatorStateMask
XkbXI_UnsupportedFeaturesMask unsupported     (1L <<15)
XkbXI_AllDeviceFeaturesMask   Those selected  (0x1e)   XkbXI_IndicatorsMask |
                              by Value Column          XkbSI_ButtonActionsMask
                              masks
XkbXI_AllFeaturesMask         Those selected  (0x1f)   XkbSI_AllDeviceFeaturesMask |
                              by Value Column          XkbSI_KeyboardsMask
                              masks
XkbXI_AllDetailsMask          Those selected  (0x801f) XkbXI_AllFeaturesMask |
                              by Value column          XkbXI_UnsupportedFeaturesMask
                              masks

The XkbDeviceInfoRec returned by XkbGetDeviceInfoalways has values for name(may be a null string, ""), type, supported, unsupported, has_own_state, dflt_kbd_fd,and dflt_kbd_fb.Other fields are filled in as specified by which. Upon return, the supportedfield will be set to the inclusive OR of zero or more bits from Table 1; each bit set indicates an optional Xkb extension device feature supported by the server implementation, and a client may modify the associated behavior. If the XkbButtonActionsMask bit is set in which,the XkbDeviceInfoRec returned will have the button actions (btn_actsfield) filled in for all buttons. If whichincludes one of the bits in XkbXI_IndicatorsMask, the feedback class of the indicators must be specified in ind_class,and the feedback ID of the indicators must be specified in ind_id.If the request does not include any of the bits in XkbXI_IndicatorsMask, the ind_classand ind_idparameters are ignored. The class and ID can be obtained via the input device extension XListInputDevicesrequest. If any of the XkbXI_IndicatorsMask bits are set in which,the XkbDeviceInfoRec returned will have filled in the portions of the ledsstructure corresponding to the indicator feedback identified by ind_classand ind_id.The ledsvector of the XkbDeviceInfoRec is allocated if necessary and sz_ledsand num_ledsfilled in. The led_class, led_idand phys_indicatorsfields of the ledsentry corresponding to ind_classand ind_idare always filled in. If whichcontains XkbXI_IndicatorNamesMask, the names_presentand namesfields of the ledsstructure corresponding to ind_classand ind_idare returned. If whichcontains XkbXI_IndicatorStateMask, the corresponding statefield is updated. If whichcontains XkbXI_IndicatorMapsMask, the maps_presentand mapsfields are updated. Xkb provides convenience functions to request subsets of the information available via XkbGetDeviceInfo.These convenience functions mirror some of the mask bits. The functions all take an XkbDeviceInfoPtr as an input argument and operate on the X Input Extension device specified by the device_specfield of the structure. Only the parts of the structure indicated in the function description are updated. The XkbDeviceInfoRec structure used in the function call can be obtained by calling XkbGetDeviceInfoor can be allocated by calling XkbAllocDeviceInfo.

Information about X Input Extension devices is transferred between a client program and the Xkb extension in an XkbDeviceInfoRec structure:

typedef struct {
    char *               name;          /(** name for device */
    Atom                 type;          /(** name for class of devices */
    unsigned short       device_spec;   /(** device of interest */
    Bool                 has_own_state; /(** True=>this device has its own state */
    unsigned short       supported;     /(** bits indicating supported capabilities */
    unsigned short       unsupported;   /(** bits indicating unsupported capabilities */
    unsigned short       num_btns;      /(** number of entries in btn_acts */
    XkbAction *          btn_acts;      /(** button actions */
    unsigned short       sz_leds;       /(** total number of entries in LEDs vector */
    unsigned short       num_leds;      /(** number of valid entries in LEDs vector */
    unsigned short       dflt_kbd_fb;   /(** input extension ID of default (core kbd) indicator */
    unsigned short       dflt_led_fb;   /(** input extension ID of default indicator feedback */
    XkbDeviceLedInfoPtr  leds;          /(** LED descriptions */
} XkbDeviceInfoRec, *XkbDeviceInfoPtr;

R XkbAllocDeviceInfo (3),

R XListInputDevices (3)