XkbAddDeviceLedInfo - Initialize an XkbDeviceLedInfoRec structure


   XkbDeviceLedInfoPtr  XkbAddDeviceLedInfo (XkbDeviceInfoPtr device_info,
          unsigned int led_class, unsigned int led_id);


   - device_info
          structure in which to add LED info

   - led_class
          input extension class for LED device of interest

   - led_id
          input extension ID for LED device of interest


   XkbAddDeviceLedInfo first checks  to  see  whether  an  entry  matching
   led_class  and led_id already exists in the device_info->leds array. If
   it finds a  matching  entry,  it  returns  a  pointer  to  that  entry.
   Otherwise,  it  checks  to be sure there is at least one empty entry in
   device_info->leds and extends it if there is not enough room.  It  then
   increments  device_info->num_leds and fills in the next available entry
   in device_info->leds with led_class and led_id.

   If  successful,  XkbAddDeviceLedInfo   returns   a   pointer   to   the
   XkbDeviceLedInfoRec  structure  that  was  initialized.  If  unable  to
   allocate sufficient storage, or if device_info  points  to  an  invalid
   XkbDeviceInfoRec   structure,   or   if   led_class   or   led_id   are
   inappropriate, XkbAddDeviceLedInfo returns NULL.

   To allocate additional space for button actions in an  XkbDeviceInfoRec
   structure, use XkbResizeDeviceButtonActions.


   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;

       typedef struct {
           unsigned short      led_class;        / class for this LED device*/
           unsigned short      led_id;           / ID for this LED device */
           unsigned int        phys_indicators;  / bits for which LEDs physically present */
           unsigned int        maps_present;     / bits for which LEDs have maps in maps */
           unsigned int        names_present;    / bits for which LEDs are in names */
           unsigned int        state;            / 1 bit => corresponding LED is on */
           Atom                names[XkbNumIndicators];   / names for LEDs */
           XkbIndicatorMapRec  maps;             / indicator maps for each LED */
       } XkbDeviceLedInfoRec, *XkbDeviceLedInfoPtr;




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