xkb: implementation of keyboard layout switched

This patch provides functions to get/set current keyboard layout.

Current implementation doesn't support any configuration of layout,
it's a merely a layout indicator and switcher, however layout
configuration can be set by tools like setxkbmap or by any third-party
tools.

CMakeLists.txt

@@ -56,6 +56,7 @@ set(AWE_SRCS
     ${SOURCE_DIR}/strut.c
     ${SOURCE_DIR}/systray.c
     ${SOURCE_DIR}/xwindow.c
+    ${SOURCE_DIR}/xkb.c
     ${SOURCE_DIR}/common/atoms.c
     ${SOURCE_DIR}/common/backtrace.c
     ${SOURCE_DIR}/common/buffer.c

awesome.c

@@ -26,6 +26,7 @@
 #include "common/backtrace.h"
 #include "common/version.h"
 #include "common/xutil.h"
+#include "xkb.h"
 #include "dbus.h"
 #include "event.h"
 #include "ewmh.h"
@@ -499,6 +500,9 @@ main(int argc, char **argv)
     /* init spawn (sn) */
     spawn_init();
 
+    /* init xkb */
+    xkb_init();
+
     /* The default GC is just a newly created associated with a window with
      * depth globalconf.default_depth */
     xcb_window_t tmp_win = xcb_generate_id(globalconf.connection);

awesomeConfig.cmake

@@ -140,6 +140,7 @@ pkg_check_modules(AWESOME_REQUIRED REQUIRED
     xcb-util>=0.3.8
     xcb-keysyms>=0.3.4
     xcb-icccm>=0.3.8
+    xcb-xkb>=1.11
     cairo-xcb
     libstartup-notification-1.0>=0.10
     xproto>=7.0.15

docs/capi/awesome.lua.in

@@ -75,3 +75,16 @@
 -- @param name A string with the event name.
 -- @param ... Signal arguments.
 -- @function emit_signal
+
+--- Switch keyboard layout group.
+-- @param num keyboard layout number, integer from 0 to 3
+-- @function xkb_set_layout_group
+
+--- Get current keyboard layout group.
+-- @return current keyboard layout number
+-- @function xkb_get_layout_group
+
+
+--- Get description of configured layouts
+-- @return String with description of configured layouts
+-- @function xkb_get_group_names

event.c

@@ -32,6 +32,7 @@
 #include "mousegrabber.h"
 #include "luaa.h"
 #include "systray.h"
+#include "xkb.h"
 #include "objects/screen.h"
 #include "common/atoms.h"
 #include "common/xutil.h"
@@ -42,6 +43,7 @@
 #include <xcb/xcb_atom.h>
 #include <xcb/xcb_icccm.h>
 #include <xcb/xcb_event.h>
+#include <xcb/xkb.h>
 
 #define DO_EVENT_HOOK_CALLBACK(type, xcbtype, xcbeventprefix, arraytype, match) \
     static void \
@@ -880,6 +882,7 @@ void event_handle(xcb_generic_event_t *event)
 
     static uint8_t randr_screen_change_notify = 0;
     static uint8_t shape_notify = 0;
+    static uint8_t xkb_notify = 0;
 
     if(randr_screen_change_notify == 0)
     {
@@ -898,10 +901,21 @@ void event_handle(xcb_generic_event_t *event)
             shape_notify = shape_query->first_event + XCB_SHAPE_NOTIFY;
     }
 
+    if(xkb_notify == 0)
+    {
+        /* check for xkb extension */
+        const xcb_query_extension_reply_t *xkb_query;
+        xkb_query = xcb_get_extension_data(globalconf.connection, &xcb_xkb_id);
+        if(xkb_query->present)
+            xkb_notify = xkb_query->first_event;
+    }
+
     if (response_type == randr_screen_change_notify)
         event_handle_randr_screen_change_notify((void *) event);
     if (response_type == shape_notify)
         event_handle_shape_notify((void *) event);
+    if (response_type == xkb_notify)
+        event_handle_xkb_notify((void *) event);
 }
 
 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80

luaa.c

@@ -37,6 +37,7 @@
 #include "selection.h"
 #include "spawn.h"
 #include "systray.h"
+#include "xkb.h"
 
 #include <lua.h>
 #include <lauxlib.h>
@@ -359,6 +360,9 @@ luaA_init(xdgHandle* xdg)
         { "get_xproperty", luaA_get_xproperty },
         { "__index", luaA_awesome_index },
         { "__newindex", luaA_default_newindex },
+        { "xkb_set_layout_group", luaA_xkb_set_layout_group},
+        { "xkb_get_layout_group", luaA_xkb_get_layout_group},
+        { "xkb_get_group_names", luaA_xkb_get_group_names},
         { NULL, NULL }
     };
 
@@ -473,6 +477,8 @@ luaA_init(xdgHandle* xdg)
     signal_add(&global_signals, "debug::newindex::miss");
     signal_add(&global_signals, "systray::update");
     signal_add(&global_signals, "wallpaper_changed");
+    signal_add(&global_signals, "xkb::map_changed");
+    signal_add(&global_signals, "xkb::group_changed");
     signal_add(&global_signals, "refresh");
     signal_add(&global_signals, "startup");
     signal_add(&global_signals, "exit");

xkb.c

@@ -0,0 +1,185 @@
+/*
+ * xkb.c - keyboard layout control functions
+ *
+ * Copyright © 2015 Aleksey Fedotov <lexa@cfotr.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include "xkb.h"
+#include "globalconf.h"
+#include <xcb/xkb.h>
+
+
+/* \brief switch keyboard layout
+ * \param L The Lua VM state.
+ * \return The number of elements pushed on stack.
+ * \luastack
+ * \lparam layout number, integer from 0 to 3
+ */
+int
+luaA_xkb_set_layout_group(lua_State *L)
+{
+    unsigned group = luaL_checkinteger(L, 1);
+    xcb_xkb_latch_lock_state (globalconf.connection, XCB_XKB_ID_USE_CORE_KBD,
+                              0, 0, true, group, 0, 0, 0);
+    return 0;
+}
+
+/* \brief get current layout number
+ * \param L The Lua VM state.
+ * \return The number of elements pushed on stack.
+ * \luastack
+ * \lreturn current layout number, integer from 0 to 3
+ */
+int
+luaA_xkb_get_layout_group(lua_State *L)
+{
+    xcb_xkb_get_state_cookie_t state_c;
+    state_c = xcb_xkb_get_state_unchecked (globalconf.connection,
+                                           XCB_XKB_ID_USE_CORE_KBD);
+    xcb_xkb_get_state_reply_t* state_r;
+    state_r = xcb_xkb_get_state_reply (globalconf.connection,
+                                       state_c, NULL);
+    if (!state_r)
+    {
+        free(state_r);
+        return 0;
+    }
+    lua_pushinteger(L, state_r->group);
+    free(state_r);
+    return 1;
+}
+
+/* \brief get layout short names
+ * \param L The Lua VM state.
+ * \return The number of elements pushed on stack.
+ * \luastack
+ * \lreturn string describing current layout settings, \
+ * example: 'pc+us+de:2+inet(evdev)+group(alt_shift_toggle)+ctrl(nocaps)'
+ */
+int
+luaA_xkb_get_group_names(lua_State *L)
+{
+    xcb_xkb_get_names_cookie_t name_c;
+    name_c = xcb_xkb_get_names_unchecked (globalconf.connection,
+                                          XCB_XKB_ID_USE_CORE_KBD,
+                                          XCB_XKB_NAME_DETAIL_SYMBOLS);
+    xcb_xkb_get_names_reply_t* name_r;
+    name_r = xcb_xkb_get_names_reply (globalconf.connection, name_c, NULL);
+
+    if (!name_r)
+    {
+        luaA_warn(L, "Failed to get xkb symbols name");
+        return 0;
+    }
+
+    xcb_xkb_get_names_value_list_t name_list;
+    void *buffer = xcb_xkb_get_names_value_list(name_r);
+    xcb_xkb_get_names_value_list_unpack (
+        buffer, name_r->nTypes, name_r->indicators,
+        name_r->virtualMods, name_r->groupNames, name_r->nKeys,
+        name_r->nKeyAliases, name_r->nRadioGroups, name_r->which,
+        &name_list);
+
+    xcb_get_atom_name_cookie_t atom_name_c;
+    atom_name_c = xcb_get_atom_name_unchecked(globalconf.connection, name_list.symbolsName);
+    xcb_get_atom_name_reply_t *atom_name_r;
+    atom_name_r = xcb_get_atom_name_reply(globalconf.connection, atom_name_c, NULL);
+    if (!atom_name_r) {
+        luaA_warn(L, "Failed to get atom symbols name");
+        free(name_r);
+        return 0;
+    }
+
+    const char *name = xcb_get_atom_name_name(atom_name_r);
+    size_t name_len = xcb_get_atom_name_name_length(atom_name_r);
+    lua_pushlstring(L, name, name_len);
+
+    free(atom_name_r);
+    free(name_r);
+    return 1;
+}
+
+/** The xkb notify event handler.
+ * \param event The event.
+ */
+void event_handle_xkb_notify(xcb_generic_event_t* event)
+{
+    lua_State *L = globalconf_get_lua_State();
+    /* The pad0 field of xcb_generic_event_t contains the event sub-type,
+     * unfortunately xkb doesn't provide a usable struct for getting this in a
+     * nicer way*/
+    switch (event->pad0)
+    {
+      case XCB_XKB_NEW_KEYBOARD_NOTIFY:
+        {
+          xcb_xkb_new_keyboard_notify_event_t *new_keyboard_event = (void*)event;
+          if (new_keyboard_event->changed & XCB_XKB_NKN_DETAIL_KEYCODES)
+          {
+              signal_object_emit(L, &global_signals, "xkb::map_changed", 0);
+          }
+          break;
+        }
+      case XCB_XKB_NAMES_NOTIFY:
+        {
+          signal_object_emit(L, &global_signals, "xkb::map_changed", 0);
+          break;
+        }
+      case XCB_XKB_STATE_NOTIFY:
+        {
+          xcb_xkb_state_notify_event_t *state_notify_event = (void*)event;
+          if (state_notify_event->changed & XCB_XKB_STATE_PART_GROUP_STATE)
+          {
+              lua_pushnumber(L, state_notify_event->group);
+              signal_object_emit(L, &global_signals, "xkb::group_changed", 1);
+          }
+          break;
+        }
+    }
+}
+
+/** Initialize XKB support
+ */
+
+void xkb_init(void)
+{
+    /* check that XKB extension present in this X server */
+    const xcb_query_extension_reply_t *xkb_r;
+    xkb_r = xcb_get_extension_data(globalconf.connection, &xcb_xkb_id);
+    if (!xkb_r || !xkb_r->present)
+    {
+        fatal("Xkb extension not present");
+    }
+
+    /* check xkb version */
+    xcb_xkb_use_extension_cookie_t ext_cookie = xcb_xkb_use_extension(globalconf.connection, 1, 0);
+    xcb_xkb_use_extension_reply_t *ext_reply = xcb_xkb_use_extension_reply (globalconf.connection, ext_cookie, NULL);
+    if (!ext_reply || !ext_reply->supported)
+    {
+        fatal("Required xkb extension is not supported");
+    }
+    unsigned int map = XCB_XKB_EVENT_TYPE_STATE_NOTIFY | XCB_XKB_EVENT_TYPE_MAP_NOTIFY | XCB_XKB_EVENT_TYPE_NEW_KEYBOARD_NOTIFY;
+    xcb_xkb_select_events_checked(globalconf.connection,
+                                  XCB_XKB_ID_USE_CORE_KBD,
+                                  map,
+                                  0,
+                                  map,
+                                  0,
+                                  0,
+                                  0);
+
+}

xkb.h

@@ -0,0 +1,36 @@
+/*
+ * xkb.h - Keyboard layout manager header
+ *
+ * Copyright © 2015 Aleksey Fedotov <lexa@cfotr.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#ifndef AWESOME_XKB_H
+#define AWESOME_XKB_H
+
+#include <xcb/xcb.h>
+#include <lua.h>
+
+void event_handle_xkb_notify(xcb_generic_event_t* event);
+void xkb_init(void);
+
+int luaA_xkb_set_layout_group(lua_State *L);
+int luaA_xkb_get_layout_group(lua_State *L);
+int luaA_xkb_get_group_names(lua_State *L);
+
+
+#endif