Introduce a config directive 'binding_mode' in the 'bar' config, pass it through the IPC and parse it in i3bar.

i3bar/include/xcb.h

@@ -40,6 +40,9 @@ struct xcb_color_strings_t {
     char *urgent_ws_bg;
     char *urgent_ws_fg;
     char *urgent_ws_border;
+    char *binding_mode_bg;
+    char *binding_mode_fg;
+    char *binding_mode_border;
 };
 
 typedef struct xcb_colors_t xcb_colors_t;

i3bar/src/config.c

@@ -191,6 +191,9 @@ static int config_string_cb(void *params_, const unsigned char *val, size_t _len
     COLOR(urgent_workspace_border, urgent_ws_border);
     COLOR(urgent_workspace_bg, urgent_ws_bg);
     COLOR(urgent_workspace_text, urgent_ws_fg);
+    COLOR(binding_mode_border, binding_mode_border);
+    COLOR(binding_mode_bg, binding_mode_bg);
+    COLOR(binding_mode_text, binding_mode_fg);
 
     printf("got unexpected string %.*s for cur_key = %s\n", len, val, cur_key);
 
@@ -286,5 +289,8 @@ void free_colors(struct xcb_color_strings_t *colors) {
     FREE_COLOR(focus_ws_fg);
     FREE_COLOR(focus_ws_bg);
     FREE_COLOR(focus_ws_border);
+    FREE_COLOR(binding_mode_fg);
+    FREE_COLOR(binding_mode_bg);
+    FREE_COLOR(binding_mode_border);
 #undef FREE_COLOR
 }

i3bar/src/xcb.c

@@ -106,6 +106,9 @@ struct xcb_colors_t {
     uint32_t focus_ws_bg;
     uint32_t focus_ws_fg;
     uint32_t focus_ws_border;
+    uint32_t binding_mode_bg;
+    uint32_t binding_mode_fg;
+    uint32_t binding_mode_border;
 };
 struct xcb_colors_t colors;
 
@@ -374,6 +377,18 @@ void init_colors(const struct xcb_color_strings_t *new_colors) {
     PARSE_COLOR(focus_ws_border, "#4c7899");
 #undef PARSE_COLOR
 
+#define PARSE_COLOR_FALLBACK(name, fallback)                                                 \
+    do {                                                                                     \
+        colors.name = new_colors->name ? get_colorpixel(new_colors->name) : colors.fallback; \
+    } while (0)
+
+    /* For the binding mode indicator colors, we don't hardcode a default.
+     * Instead, we fall back to urgent_ws_* colors. */
+    PARSE_COLOR_FALLBACK(binding_mode_fg, urgent_ws_fg);
+    PARSE_COLOR_FALLBACK(binding_mode_bg, urgent_ws_bg);
+    PARSE_COLOR_FALLBACK(binding_mode_border, urgent_ws_border);
+#undef PARSE_COLOR_FALLBACK
+
     init_tray_colors();
     xcb_flush(xcb_connection);
 }

include/config.h

@@ -344,6 +344,10 @@ struct Barconfig {
         char *urgent_workspace_border;
         char *urgent_workspace_bg;
         char *urgent_workspace_text;
+
+        char *binding_mode_border;
+        char *binding_mode_bg;
+        char *binding_mode_text;
     } colors;
 
     TAILQ_ENTRY(Barconfig) configs;

parser-specs/config.spec

@@ -511,7 +511,7 @@ state BAR_COLORS:
   'set' -> BAR_COLORS_IGNORE_LINE
   colorclass = 'background', 'statusline', 'separator'
       -> BAR_COLORS_SINGLE
-  colorclass = 'focused_workspace', 'active_workspace', 'inactive_workspace', 'urgent_workspace'
+  colorclass = 'focused_workspace', 'active_workspace', 'inactive_workspace', 'urgent_workspace', 'binding_mode'
       -> BAR_COLORS_BORDER
   '}'
       -> BAR

src/config.c

@@ -130,6 +130,9 @@ void load_configuration(xcb_connection_t *conn, const char *override_configpath,
             FREE(barconfig->colors.urgent_workspace_border);
             FREE(barconfig->colors.urgent_workspace_bg);
             FREE(barconfig->colors.urgent_workspace_text);
+            FREE(barconfig->colors.binding_mode_border);
+            FREE(barconfig->colors.binding_mode_bg);
+            FREE(barconfig->colors.binding_mode_text);
             TAILQ_REMOVE(&barconfigs, barconfig, configs);
             FREE(barconfig);
         }

src/config_directives.c

@@ -570,6 +570,7 @@ CFGFUN(bar_color, const char *colorclass, const char *border, const char *backgr
     APPLY_COLORS(active_workspace);
     APPLY_COLORS(inactive_workspace);
     APPLY_COLORS(urgent_workspace);
+    APPLY_COLORS(binding_mode);
 
 #undef APPLY_COLORS
 }

src/ipc.c

@@ -611,6 +611,9 @@ static void dump_bar_config(yajl_gen gen, Barconfig *config) {
     YSTR_IF_SET(urgent_workspace_border);
     YSTR_IF_SET(urgent_workspace_bg);
     YSTR_IF_SET(urgent_workspace_text);
+    YSTR_IF_SET(binding_mode_border);
+    YSTR_IF_SET(binding_mode_bg);
+    YSTR_IF_SET(binding_mode_text);
     y(map_close);
 
     y(map_close);

testcases/t/177-bar-config.t

@@ -112,6 +112,7 @@ bar {
         active_workspace    #333333 #222222 #888888
         inactive_workspace  #333333 #222222 #888888
         urgent_workspace    #2f343a #900000 #ffffff
+        binding_mode        #abc123 #123abc #ababab
     }
 }
 EOT
@@ -151,6 +152,9 @@ is_deeply($bar_config->{colors},
         urgent_workspace_border => '#2f343a',
         urgent_workspace_text => '#ffffff',
         urgent_workspace_bg => '#900000',
+        binding_mode_border => '#abc123',
+        binding_mode_text => '#ababab',
+        binding_mode_bg => '#123abc',
     }, 'colors ok');
 
 exit_gracefully($pid);