---
name: "XkbAddDeviceLedInfo"
section: "3"
platform: "linux"
package: "libx11"
version: "1.8.14-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/XkbAddDeviceLedInfo"
---

# XkbAddDeviceLedInfo(3)

Initialize an XkbDeviceLedInfoRec structure

## NAME

XkbAddDeviceLedInfo - Initialize an XkbDeviceLedInfoRec structure

## SYNOPSIS

**XkbDeviceLedInfoPtr XkbAddDeviceLedInfo** **(XkbDeviceInfoPtr** *device\_info***,** **unsigned int** *led\_class***,** **unsigned int** *led\_id***);**

## ARGUMENTS

- *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

## DESCRIPTION

*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.*

## STRUCTURES

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;
```

## SEE ALSO

[**XkbResizeDeviceButtonActions**(3)](/XkbResizeDeviceButtonActions/3.md)