Window switcher, allow to use percent of monitor width.

OSD will size per monitor. With this the width stays relative sized on
my 4k as well as my 1080p monitor

example from my theme
osd.window-switcher.width: 60%

docs/labwc-theme.5.scd

@@ -164,6 +164,8 @@ elements are not listed here, but are supported.
 
 *osd.window-switcher.width*
 	Width of window switcher in pixels. Default is 600.
+	Width can also be percent of the width of the monitor.
+	% is mandatory as last character, max 100%
 
 *osd.window-switcher.padding*
 	Padding of window switcher in pixels. This is the space between the

docs/themerc

@@ -60,7 +60,10 @@ osd.border.color: #000000
 osd.border.width: 1
 osd.label.text.color: #000000
 
+# width can be set as percent (of screen width)
+# example 50% or 75% instead of 600, max 100%
 osd.window-switcher.width: 600
+
 osd.window-switcher.padding: 4
 osd.window-switcher.item.padding.x: 10
 osd.window-switcher.item.padding.y: 1

include/theme.h

@@ -112,6 +112,7 @@ struct theme {
 
 	/* not set in rc.xml/themerc, but derived from font & padding_height */
 	int osd_window_switcher_item_height;
+	bool osd_width_should_parse_as_percentage;
 };
 
 /**

src/osd.c

@@ -321,7 +321,7 @@ render_osd(struct server *server, cairo_t *cairo, int w, int h,
 	if (show_workspace) {
 		/* Center workspace indicator on the x axis */
 		int x = font_width(&rc.font_osd, workspace_name);
-		x = (theme->osd_window_switcher_width - x) / 2;
+		x = (w - x) / 2;
 		cairo_move_to(cairo, x, y + theme->osd_window_switcher_item_active_border_width);
 		PangoWeight weight = pango_font_description_get_weight(desc);
 		pango_font_description_set_weight(desc, PANGO_WEIGHT_BOLD);
@@ -432,7 +432,7 @@ render_osd(struct server *server, cairo_t *cairo, int w, int h,
 			struct wlr_fbox fbox = {
 				.x = theme->osd_border_width + theme->osd_window_switcher_padding,
 				.y = y,
-				.width = theme->osd_window_switcher_width
+				.width = w
 					- 2 * theme->osd_border_width
 					- 2 * theme->osd_window_switcher_padding,
 				.height = theme->osd_window_switcher_item_height,
@@ -460,6 +460,9 @@ display_osd(struct output *output, struct wl_array *views)
 
 	float scale = output->wlr_output->scale;
 	int w = theme->osd_window_switcher_width;
+	if (theme->osd_width_should_parse_as_percentage) {
+		w = output->wlr_output->width * theme->osd_window_switcher_width / 100;
+	}
 	int h = wl_array_len(views) * rc.theme->osd_window_switcher_item_height
 		+ 2 * rc.theme->osd_border_width
 		+ 2 * rc.theme->osd_window_switcher_padding;

src/theme.c

@@ -670,6 +670,12 @@ entry(struct theme *theme, const char *key, const char *value)
 		parse_hexstr(value, theme->osd_border_color);
 	}
 	if (match_glob(key, "osd.window-switcher.width")) {
+		theme->osd_width_should_parse_as_percentage = false;
+		char *p = strrchr(value, '%');
+		if (p) {
+			*p = '\0';
+			theme->osd_width_should_parse_as_percentage = true;
+		}
 		theme->osd_window_switcher_width = atoi(value);
 	}
 	if (match_glob(key, "osd.window-switcher.padding")) {