add an option to manage when keyboard layout is changed

This patch adds an option, but the actual functional for it to control
being added in next one.

To keep keyboard layout per window add in sway config:

    seat * keep_keyboard_layout per_window

To keep keyboard layout globally either do not add anything (it's the
default), or to explicitly enable it use the following:

    seat * keep_keyboard_layout global

Signed-off-by: Konstantin Kharlamov <Hi-Angel@yandex.ru>

include/sway/commands.h

@@ -277,6 +277,7 @@ sway_cmd seat_cmd_attach;
 sway_cmd seat_cmd_cursor;
 sway_cmd seat_cmd_fallback;
 sway_cmd seat_cmd_hide_cursor;
+sway_cmd seat_cmd_keep_keyboard_layout;
 sway_cmd seat_cmd_pointer_constraint;
 
 sway_cmd cmd_ipc_cmd;

include/sway/config.h

@@ -41,6 +41,12 @@ enum binding_flags {
 	BINDING_CODE=32,     // keyboard only; convert keysyms into keycodes
 };
 
+enum sway_keep_keyboard_layout {
+	KEYBOARD_LAYOUT_UNDEFINED = 0,
+	KEYBOARD_LAYOUT_GLOBAL,
+	KEYBOARD_LAYOUT_PER_WINDOW
+};
+
 /**
  * A key binding and an associated command.
  */
@@ -165,6 +171,7 @@ struct seat_config {
 	list_t *attachments; // list of seat_attachment configs
 	int hide_cursor_timeout;
 	enum seat_config_allow_constrain allow_constrain;
+	enum sway_keep_keyboard_layout keep_keyboard_layout;
 };
 
 enum config_dpms {

sway/commands/seat.c

@@ -12,6 +12,7 @@ static struct cmd_handler seat_handlers[] = {
 	{ "cursor", seat_cmd_cursor },
 	{ "fallback", seat_cmd_fallback },
 	{ "hide_cursor", seat_cmd_hide_cursor },
+	{ "keep_keyboard_layout", seat_cmd_keep_keyboard_layout },
 	{ "pointer_constraint", seat_cmd_pointer_constraint },
 };
 

sway/commands/seat/keep_keyboard_layout.c

@@ -0,0 +1,29 @@
+#include "log.h"
+#include "sway/commands.h"
+#include "sway/config.h"
+#include "sway/input/input-manager.h"
+
+struct cmd_results *seat_cmd_keep_keyboard_layout(int argc, char **argv) {
+	const char *STR_LAYOUT_GLOBAL = "global",
+		*STR_LAYOUT_PER_WINDOW = "per_window";
+	struct cmd_results *error = NULL;
+	if ((error = checkarg(argc, "keep_keyboard_layout", EXPECTED_EQUAL_TO, 1))) {
+		return error;
+	}
+	if (!config->handler_context.seat_config) {
+		return cmd_results_new(CMD_FAILURE, "No seat defined");
+	}
+
+	if (!strcmp(argv[0], STR_LAYOUT_GLOBAL)) {
+		config->handler_context.seat_config->keep_keyboard_layout
+			= KEYBOARD_LAYOUT_GLOBAL;
+		return cmd_results_new(CMD_SUCCESS, NULL, NULL);
+	} else if (!strcmp(argv[0], STR_LAYOUT_PER_WINDOW)) {
+		config->handler_context.seat_config->keep_keyboard_layout
+			= KEYBOARD_LAYOUT_PER_WINDOW;
+		return cmd_results_new(CMD_SUCCESS, NULL, NULL);
+	} else {
+		return cmd_results_new(CMD_FAILURE, "keep_keyboard_layout",
+				"Expected 'keep_keyboard_layout global|per_window");
+	}
+}

sway/meson.build

@@ -88,6 +88,7 @@ sway_sources = files(
 	'commands/seat/cursor.c',
 	'commands/seat/fallback.c',
 	'commands/seat/hide_cursor.c',
+	'commands/seat/keep_keyboard_layout.c',
 	'commands/seat/pointer_constraint.c',
 	'commands/set.c',
 	'commands/show_marks.c',

sway/sway-input.5.scd

@@ -201,6 +201,9 @@ correct seat.
 	disables hiding the cursor. The minimal timeout is 100 and any value less
 	than that (aside from 0), will be increased to 100.
 
+*seat* <name> keep_keyboard_layout global|per_window
+	Controls whether to keep keyboard layout per window. Default is _global_.
+
 *seat* <name> pointer_constraint enable|disable|escape
 	Enables or disables the ability for clients to capture the cursor (enabled
 	by default) for the seat. This is primarily useful for video games. The