XkbGetDeviceInfo - Man Page

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.

XkbGetDeviceInfo returns information about the input device specified by device_spec. Unlike the device_spec parameter of most Xkb functions, device_spec does not need to be a keyboard device. It must, however, indicate either the core keyboard or a valid X Input Extension  device.

The which parameter 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 XkbGetDeviceInfo always 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 supported field 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_acts field) filled in for all buttons.

If which includes 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_class and ind_id parameters are ignored. The class and ID can be obtained via the input device extension XListInputDevices request.

If any of the XkbXI_IndicatorsMask bits are set in which, the XkbDeviceInfoRec returned will have filled in the portions of the leds structure corresponding to the indicator feedback identified by ind_class and ind_id. The leds vector of the XkbDeviceInfoRec is allocated if necessary and sz_leds and num_leds filled in. The led_class, led_id and phys_indicators fields of the leds entry corresponding to ind_class and ind_id are always filled in. If which contains XkbXI_IndicatorNamesMask, the names_present and names fields of the leds structure corresponding to ind_class and ind_id are returned. If which contains XkbXI_IndicatorStateMask, the corresponding state field is updated. If which contains XkbXI_IndicatorMapsMask, the maps_present and maps fields 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_spec field 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 XkbGetDeviceInfo or 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;

XkbAllocDeviceInfo(3), XListInputDevices(3)

XkbGetDeviceInfoChanges(3), XkbSetDeviceInfo(3).