Display xkb layout while typing

Displays the current keyboard layout below the unlock indicator if more
than one xkb layout is configured or the show-keyboard-layout option is
given. The text is displayed with a background box.

Adds commandline options for text color, background color and border
color of the box as well.

include/swaylock.h

@@ -34,6 +34,9 @@ struct swaylock_colors {
 	uint32_t caps_lock_bs_highlight;
 	uint32_t caps_lock_key_highlight;
 	uint32_t separator;
+	uint32_t layout_background;
+	uint32_t layout_border;
+	uint32_t layout_text;
 	struct swaylock_colorset inside;
 	struct swaylock_colorset line;
 	struct swaylock_colorset ring;
@@ -50,6 +53,7 @@ struct swaylock_args {
 	bool show_indicator;
 	bool show_caps_lock_text;
 	bool show_caps_lock_indicator;
+	bool show_keyboard_layout;
 	bool show_failed_attempts;
 	bool daemonize;
 };

main.c

@@ -423,6 +423,9 @@ static void set_default_colors(struct swaylock_colors *colors) {
 	colors->caps_lock_bs_highlight = 0xDB3300FF;
 	colors->caps_lock_key_highlight = 0x33DB00FF;
 	colors->separator = 0x000000FF;
+	colors->layout_background = 0x000000C0;
+	colors->layout_border = 0x00000000;
+	colors->layout_text = 0xFFFFFFFF;
 	colors->inside = (struct swaylock_colorset){
 		.input = 0x000000C0,
 		.cleared = 0xE5A445C0,
@@ -474,6 +477,9 @@ static int parse_options(int argc, char **argv, struct swaylock_state *state,
 		LO_INSIDE_VER_COLOR,
 		LO_INSIDE_WRONG_COLOR,
 		LO_KEY_HL_COLOR,
+		LO_LAYOUT_TXT_COLOR,
+		LO_LAYOUT_BG_COLOR,
+		LO_LAYOUT_BORDER_COLOR,
 		LO_LINE_COLOR,
 		LO_LINE_CLEAR_COLOR,
 		LO_LINE_CAPS_LOCK_COLOR,
@@ -508,6 +514,7 @@ static int parse_options(int argc, char **argv, struct swaylock_state *state,
 		{"scaling", required_argument, NULL, 's'},
 		{"tiling", no_argument, NULL, 't'},
 		{"no-unlock-indicator", no_argument, NULL, 'u'},
+		{"show-keyboard-layout", no_argument, NULL, 'k'},
 		{"show-failed-attempts", no_argument, NULL, 'F'},
 		{"version", no_argument, NULL, 'v'},
 		{"bs-hl-color", required_argument, NULL, LO_BS_HL_COLOR},
@@ -522,6 +529,9 @@ static int parse_options(int argc, char **argv, struct swaylock_state *state,
 		{"inside-ver-color", required_argument, NULL, LO_INSIDE_VER_COLOR},
 		{"inside-wrong-color", required_argument, NULL, LO_INSIDE_WRONG_COLOR},
 		{"key-hl-color", required_argument, NULL, LO_KEY_HL_COLOR},
+		{"layout-bg-color", required_argument, NULL, LO_LAYOUT_BG_COLOR},
+		{"layout-border-color", required_argument, NULL, LO_LAYOUT_BORDER_COLOR},
+		{"layout-text-color", required_argument, NULL, LO_LAYOUT_TXT_COLOR},
 		{"line-color", required_argument, NULL, LO_LINE_COLOR},
 		{"line-clear-color", required_argument, NULL, LO_LINE_CLEAR_COLOR},
 		{"line-caps-lock-color", required_argument, NULL, LO_LINE_CAPS_LOCK_COLOR},
@@ -552,12 +562,16 @@ static int parse_options(int argc, char **argv, struct swaylock_state *state,
 			"Enable debugging output.\n"
 		"  -e, --ignore-empty-password      "
 			"When an empty password is provided, do not validate it.\n"
+		"  -F, --show-failed-attempts       "
+			"Show current count of failed authentication attempts.\n"
 		"  -f, --daemonize                  "
 			"Detach from the controlling terminal after locking.\n"
 		"  -h, --help                       "
 			"Show help message and quit.\n"
 		"  -i, --image [[<output>]:]<path>  "
 			"Display the given image.\n"
+		"  -k, --show-keyboard-layout       "
+			"Display the current xkb layout while typing.\n"
 		"  -L, --disable-caps-lock-text     "
 			"Disable the Caps Lock text.\n"
 		"  -l, --indicator-caps-lock        "
@@ -568,8 +582,6 @@ static int parse_options(int argc, char **argv, struct swaylock_state *state,
 			"Same as --scaling=tile.\n"
 		"  -u, --no-unlock-indicator        "
 			"Disable the unlock indicator.\n"
-		"  -F, --show-failed-attempts       "
-			"Show current count of failed authentication attempts.\n"
 		"  -v, --version                    "
 			"Show the version number and quit.\n"
 		"  --bs-hl-color <color>            "
@@ -599,6 +611,12 @@ static int parse_options(int argc, char **argv, struct swaylock_state *state,
 			"Sets the color of the inside of the indicator when invalid.\n"
 		"  --key-hl-color <color>           "
 			"Sets the color of the key press highlight segments.\n"
+		"  --layout-bg-color <color>        "
+			"Sets the background color of the box containing the layout text.\n"
+		"  --layout-border-color <color>    "
+			"Sets the color of the border of the box containing the layout text.\n"
+		"  --layout-text-color <color>      "
+			"Sets the color of the layout text.\n"
 		"  --line-color <color>             "
 			"Sets the color of the line between the inside and ring.\n"
 		"  --line-clear-color <color>       "
@@ -647,7 +665,7 @@ static int parse_options(int argc, char **argv, struct swaylock_state *state,
 	optind = 1;
 	while (1) {
 		int opt_idx = 0;
-		c = getopt_long(argc, argv, "c:deFfhi:Llnrs:tuvC:", long_options,
+		c = getopt_long(argc, argv, "c:deFfhi:kLlnrs:tuvC:", long_options,
 				&opt_idx);
 		if (c == -1) {
 			break;
@@ -671,6 +689,11 @@ static int parse_options(int argc, char **argv, struct swaylock_state *state,
 				state->args.ignore_empty = true;
 			}
 			break;
+		case 'F':
+			if (state) {
+				state->args.show_failed_attempts = true;
+			}
+			break;
 		case 'f':
 			if (state) {
 				state->args.daemonize = true;
@@ -681,6 +704,11 @@ static int parse_options(int argc, char **argv, struct swaylock_state *state,
 				load_image(optarg, state);
 			}
 			break;
+		case 'k':
+			if (state) {
+				state->args.show_keyboard_layout = true;
+			}
+			break;
 		case 'L':
 			if (state) {
 				state->args.show_caps_lock_text = false;
@@ -719,11 +747,6 @@ static int parse_options(int argc, char **argv, struct swaylock_state *state,
 				state->args.show_indicator = false;
 			}
 			break;
-		case 'F':
-			if (state) {
-				state->args.show_failed_attempts = true;
-			}
-			break;
 		case 'v':
 			fprintf(stdout, "swaylock version " SWAYLOCK_VERSION "\n");
 			exit(EXIT_SUCCESS);
@@ -789,6 +812,21 @@ static int parse_options(int argc, char **argv, struct swaylock_state *state,
 				state->args.colors.key_highlight = parse_color(optarg);
 			}
 			break;
+		case LO_LAYOUT_BG_COLOR:
+			if (state) {
+				state->args.colors.layout_background = parse_color(optarg);
+			}
+			break;
+		case LO_LAYOUT_BORDER_COLOR:
+			if (state) {
+				state->args.colors.layout_border = parse_color(optarg);
+			}
+			break;
+		case LO_LAYOUT_TXT_COLOR:
+			if (state) {
+				state->args.colors.layout_text = parse_color(optarg);
+			}
+			break;
 		case LO_LINE_COLOR:
 			if (state) {
 				state->args.colors.line.input = parse_color(optarg);
@@ -989,6 +1027,7 @@ int main(int argc, char **argv) {
 		.show_indicator = true,
 		.show_caps_lock_indicator = false,
 		.show_caps_lock_text = true,
+		.show_keyboard_layout = false,
 		.show_failed_attempts = false
 	};
 	wl_list_init(&state.images);

render.c

@@ -86,6 +86,7 @@ void render_frame(struct swaylock_surface *surface) {
 
 		// Draw a message
 		char *text = NULL;
+		const char *layout_text = NULL;
 		char attempts[4]; // like i3lock: count no more than 999
 		set_color_for_state(cairo, state, &state->args.colors.text);
 		cairo_select_font_face(cairo, state->args.font,
@@ -116,6 +117,20 @@ void render_frame(struct swaylock_surface *surface) {
 					text = attempts;
 				}
 			}
+
+			xkb_layout_index_t num_layout = xkb_keymap_num_layouts(state->xkb.keymap);
+			if (state->args.show_keyboard_layout || num_layout > 1) {
+				xkb_layout_index_t curr_layout = 0;
+
+				// advance to the first active layout (if any)
+				while (curr_layout < num_layout &&
+					xkb_state_layout_index_is_active(state->xkb.state,
+						curr_layout, XKB_STATE_LAYOUT_EFFECTIVE) != 1) {
+					++curr_layout;
+				}
+				// will handle invalid index if none are active
+				layout_text = xkb_keymap_layout_get_name(state->xkb.keymap, curr_layout);
+			}
 			break;
 		default:
 			break;
@@ -185,6 +200,39 @@ void render_frame(struct swaylock_surface *surface) {
 		cairo_arc(cairo, buffer_width / 2, buffer_height / 2,
 				arc_radius + arc_thickness / 2, 0, 2 * M_PI);
 		cairo_stroke(cairo);
+
+		// display layout text seperately
+		if (layout_text) {
+			cairo_text_extents_t extents;
+			cairo_font_extents_t fe;
+			double x, y;
+			double box_padding = 4.0 * surface->scale;
+			cairo_text_extents(cairo, layout_text, &extents);
+			cairo_font_extents(cairo, &fe);
+			// upper left coordinates for box
+			x = (buffer_width / 2) - (extents.width / 2) - box_padding;
+			y = (buffer_height / 2) + arc_radius + arc_thickness/2 +
+				box_padding; // use box_padding also as gap to indicator
+
+			// background box
+			cairo_rectangle(cairo, x, y,
+				extents.width + 2.0 * box_padding,
+				fe.height + 2.0 * box_padding);
+			cairo_set_source_u32(cairo, state->args.colors.layout_background);
+			cairo_fill_preserve(cairo);
+			// border
+			cairo_set_source_u32(cairo, state->args.colors.layout_border);
+			cairo_stroke(cairo);
+			cairo_new_sub_path(cairo);
+
+			// take font extents and padding into account
+			cairo_move_to(cairo,
+				x - extents.x_bearing + box_padding,
+				y + (fe.height - fe.descent) + box_padding);
+			cairo_set_source_u32(cairo, state->args.colors.layout_text);
+			cairo_show_text(cairo, layout_text);
+			cairo_new_sub_path(cairo);
+		}
 	}
 
 	wl_surface_set_buffer_scale(surface->surface, surface->scale);

swaylock.1.scd

@@ -27,6 +27,9 @@ Locks your Wayland session.
 *-e, --ignore-empty-password*
 	When an empty password is provided by the user, do not validate it.
 
+*-F, --show-failed-attempts*
+	Show the number of failed authentication attempts on the indicator.
+
 *-f, --daemonize*
 	Detach from the controlling terminal after locking.
 
@@ -48,15 +51,16 @@ Locks your Wayland session.
 	a background color. If the path potentially contains a ':', prefix it with another
 	':' to prevent interpreting part of it as <output>.
 
+*-k, --show-keyboard-layout*
+	Force displaying the current xkb layout while typing, even if only one layout
+	is configured.
+
 *-L, --disable-caps-lock-text*
 	Disable the Caps Lock Text.
 
 *-l, --indicator-caps-lock*
 	Show the current Caps Lock state also on the indicator.
 
-*-F, --show-failed-attempts*
-	Show the number of failed authentication attempts on the indicator.
-
 *-s, --scaling*
 	Scaling mode for images: _stretch_, _fill_, _fit_, _center_, or _tile_. Use
 	the additional mode _solid\_color_ to display only the background color, even
@@ -107,6 +111,15 @@ Locks your Wayland session.
 *--key-hl-color* <rrggbb[aa]>
 	Sets the color of key press highlight segments.
 
+*--layout-bg-color* <rrggbb[aa]>
+	Sets the background color of the box containing the layout text.
+
+*--layout-border-color* <rrggbb[aa]>
+	Sets the color of the border of the box containing the layout text.
+
+*--layout-text-color* <rrggbb[aa]>
+	Sets the color of the layout text.
+
 *--line-color* <rrggbb[aa]>
 	Sets the color of the lines that separate the inside and outside of the
 	indicator when typing or idle.