Ubuntu: How to get the name of the active keyboard using C++ gtk or xkb

To access the name of the active keyboard layout using C++ with GDK or XKB, you can use the following approaches:

Using GDK:

1. Get the current GdkSeat: Use the gdk_display_get_default_seat() function to retrieve the default GdkSeat associated with the display.

2. Get the active GdkKeyboard: Use the gdk_seat_get_keyboard() function to obtain the active GdkKeyboard for the seat.

3. Get the GdkKeymap: Use the gdk_keyboard_get_keymap() function to retrieve the GdkKeymap associated with the GdkKeyboard.

4. Get the active layout name: Use the gdk_keymap_get_layout_name() function to obtain the name of the active keyboard layout.

Here’s an example code snippet that demonstrates this approach:

#include <gdk/gdk.h>

int main() {
    // Initialize GDK
    gdk_init(nullptr, nullptr);

    // Get the default GdkDisplay
    GdkDisplay* display = gdk_display_get_default();

    // Get the default GdkSeat
    GdkSeat* seat = gdk_display_get_default_seat(display);

    // Get the active GdkKeyboard
    GdkKeyboard* keyboard = gdk_seat_get_keyboard(seat);

    // Get the GdkKeymap
    GdkKeymap* keymap = gdk_keyboard_get_keymap(keyboard);

    // Get the active layout name
    const gchar* layoutName = gdk_keymap_get_layout_name(keymap);

    // Print the active layout name
    g_print("Active keyboard layout: %sn", layoutName);

    return 0;
}

Using XKB:

1. Open the connection to the X server: Use the XOpenDisplay() function to open a connection to the X server.

2. Get the active XkbStateRec: Use the XkbGetState() function to retrieve the current XkbStateRec structure.

3. Get the XkbDescPtr: Use the XkbGetKeyboard() function to obtain the XkbDescPtr structure.

4. Get the active layout name: Access the names field of the XkbDescRec structure to retrieve the name of the active keyboard layout.

Here’s an example code snippet that demonstrates this approach:

#include <X11/Xlib.h>
#include <X11/XKBlib.h>

int main() {
    // Open the connection to the X server
    Display* display = XOpenDisplay(nullptr);

    // Get the current XkbStateRec
    XkbStateRec state;
    XkbGetState(display, XkbUseCoreKbd, &state);

    // Get the XkbDescPtr
    XkbDescPtr desc = XkbGetKeyboard(display, XkbAllComponentsMask, XkbUseCoreKbd);

    // Get the active layout name
    Atom atom = desc->names->groups[state.group].name;
    char* layoutName = XGetAtomName(display, atom);

    // Print the active layout name
    printf("Active keyboard layout: %sn", layoutName);

    // Free resources
    XFree(layoutName);
    XkbFreeKeyboard(desc, XkbAllComponentsMask, True);

    // Close the connection to the X server
    XCloseDisplay(display);

    return 0;
}

Make sure to link against the appropriate GDK or XKB libraries when compiling your code.

Note: The GDK approach relies on the GDK library, which is a higher-level abstraction that sits on top of XKB. The XKB approach directly interacts with the XKB extension. Both approaches should give you the desired result, but you may choose the one that best fits your needs and existing codebase.