Add input command xkb_current_layout

include/sway/commands.h

@@ -236,6 +236,7 @@ sway_cmd input_cmd_scroll_method;
 sway_cmd input_cmd_tap;
 sway_cmd input_cmd_tap_button_map;
 sway_cmd input_cmd_xkb_capslock;
+sway_cmd input_cmd_xkb_current_layout;
 sway_cmd input_cmd_xkb_layout;
 sway_cmd input_cmd_xkb_model;
 sway_cmd input_cmd_xkb_numlock;

sway/commands/input.c

@@ -38,6 +38,11 @@ static struct cmd_handler input_config_handlers[] = {
 	{ "xkb_numlock", input_cmd_xkb_numlock },
 };
 
+// must be in order for the bsearch
+static struct cmd_handler input_runtime_handlers[] = {
+	{ "xkb_current_layout", input_cmd_xkb_current_layout },
+};
+
 struct cmd_results *cmd_input(int argc, char **argv) {
 	struct cmd_results *error = NULL;
 	if ((error = checkarg(argc, "input", EXPECTED_AT_LEAST, 2))) {
@@ -51,6 +56,7 @@ struct cmd_results *cmd_input(int argc, char **argv) {
 		return cmd_results_new(CMD_FAILURE, NULL, "Couldn't allocate config");
 	}
 
+	bool apply_config = true;
 	struct cmd_results *res;
 
 	if (find_handler(argv[1], input_config_handlers,
@@ -62,12 +68,22 @@ struct cmd_results *cmd_input(int argc, char **argv) {
 			res = cmd_results_new(CMD_FAILURE, "input",
 				"Can only be used in config file.");
 		}
+    } else if (find_handler(argv[1], input_runtime_handlers,
+			sizeof(input_runtime_handlers))) {
+		apply_config = false;
+		if (!config->reading) {
+			res = config_subcommand(argv + 1, argc - 1,
+				input_runtime_handlers, sizeof(input_runtime_handlers));
+		} else {
+			res = cmd_results_new(CMD_FAILURE, "input",
+				"Can only be used while sway is running.");
+		}
 	} else {
 		res = config_subcommand(argv + 1, argc - 1,
 			input_handlers, sizeof(input_handlers));
 	}
 
-	if (!res || res->status == CMD_SUCCESS) {
+	if (apply_config && (!res || res->status == CMD_SUCCESS)) {
 		struct input_config *ic =
 			store_input_config(config->handler_context.input_config);
 

sway/commands/input/xkb_current_layout.c

@@ -0,0 +1,47 @@
+#define _XOPEN_SOURCE 700
+#include "sway/config.h"
+#include "sway/commands.h"
+#include "sway/input/keyboard.h"
+#include "log.h"
+
+static void switch_xkb_layout(struct xkb_state *xkb_state,
+		xkb_layout_index_t layout_index) {
+	xkb_mod_mask_t depressed = xkb_state_serialize_mods(xkb_state, XKB_STATE_MODS_DEPRESSED);
+	xkb_mod_mask_t latched = xkb_state_serialize_mods(xkb_state, XKB_STATE_MODS_LATCHED);
+	xkb_mod_mask_t locked = xkb_state_serialize_mods(xkb_state, XKB_STATE_MODS_LOCKED);
+	xkb_state_update_mask(xkb_state, depressed, latched, locked, 0, 0, layout_index);
+}
+
+struct cmd_results *input_cmd_xkb_current_layout(int argc, char **argv) {
+	struct cmd_results *error = NULL;
+	if ((error = checkarg(argc, "xkb_current_layout", EXPECTED_EQUAL_TO, 1))) {
+		return error;
+	}
+	struct input_config *ic = config->handler_context.input_config;
+	if (!ic) {
+		return cmd_results_new(CMD_FAILURE, "xkb_current_layout",
+				"No input device defined.");
+	}
+
+	int layout_index = atoi(argv[0]);
+	if (layout_index < 0) {
+		return cmd_results_new(CMD_INVALID, "xkb_current_layout",
+			"Layout index cannot be negative");
+	}
+
+	struct sway_input_device *input_device = NULL;
+	bool wildcard = strcmp(ic->identifier, "*") == 0;
+	wl_list_for_each(input_device, &server.input->devices, link) {
+		if (strcmp(input_device->identifier, ic->identifier) == 0
+				|| wildcard) {
+			if (input_device->wlr_device->type == WLR_INPUT_DEVICE_KEYBOARD) {
+				switch_xkb_layout(input_device->wlr_device->keyboard->xkb_state,
+						layout_index);
+				wlr_log(WLR_DEBUG, "switch-xkb-layout '%s' -> %i",
+						input_device->identifier,  layout_index);
+			}
+		}
+	}
+
+	return cmd_results_new(CMD_SUCCESS, NULL, NULL);
+}

sway/meson.build

@@ -139,6 +139,7 @@ sway_sources = files(
 	'commands/input/tap.c',
 	'commands/input/tap_button_map.c',
 	'commands/input/xkb_capslock.c',
+	'commands/input/xkb_current_layout.c',
 	'commands/input/xkb_layout.c',
 	'commands/input/xkb_model.c',
 	'commands/input/xkb_numlock.c',

sway/sway-input.5.scd

@@ -46,6 +46,11 @@ The following commands may only be used in the configuration file.
 *input* <identifier> xkb\_numlock enabled|disabled
 	Initially enables or disables NumLock on startup, the default is disabled.
 
+The following commands may only be used while sway is running.
+
+*input* <identifier> xkb\_current\_layout <layout\_index>
+	Switches the current layout of the keyboard.
+
 ## MAPPING CONFIGURATION
 
 *input* <identifier> map\_to\_output <identifier>