csi: implement ‘CSI ? 1042 h/l’ - enable/disable bell-is-urgent

CHANGELOG.md

@@ -23,8 +23,10 @@
   (https://codeberg.org/dnkl/foot/issues/150).
 * **bell** option to `foot.ini`. Can be set to `set-urgency` to make
   foot render the margins in red when receiving `BEL` while **not**
-  having keyboard focus. Note that Wayland does **not** implement an
+  having keyboard focus. Applications can dynamically enable/disable
-  _urgency_ hint like X11, but that there is a
+  this with the `CSI ? 1042 h` and `CSI ? 1042 l` escape
+  sequences. Note that Wayland does **not** implement an _urgency_
+  hint like X11, but that there is a
   [proposal](https://gitlab.freedesktop.org/wayland/wayland-protocols/-/merge_requests/9)
   to add support for this. The value `set-urgency` was chosen for
   forward-compatibility, in the hopes that this proposal eventualizes

config.c

@@ -519,14 +519,14 @@ parse_section_main(const char *key, const char *value, struct config *conf,
 
     else if (strcmp(key, "bell") == 0) {
         if (strcmp(value, "set-urgency") == 0)
-            conf->bell_set_urgency = true;
+            conf->bell_is_urgent = true;
         else if (strcmp(value, "none") == 0)
-            conf->bell_set_urgency = false;
+            conf->bell_is_urgent = false;
         else {
             LOG_AND_NOTIFY_ERR(
                 "%s:%d: [default]: bell: "
                 "expected either 'set-urgency' or 'none'", path, lineno);
-            conf->bell_set_urgency = false;
+            conf->bell_is_urgent = false;
             return false;
         }
     }
@@ -1902,7 +1902,7 @@ config_load(struct config *conf, const char *conf_path,
         },
         .pad_x = 2,
         .pad_y = 2,
-        .bell_set_urgency = false,
+        .bell_is_urgent = false,
         .startup_mode = STARTUP_WINDOWED,
         .fonts = tll_init(),
         .scrollback = {

config.h

@@ -73,7 +73,7 @@ struct config {
     unsigned pad_x;
     unsigned pad_y;
 
-    bool bell_set_urgency;
+    bool bell_is_urgent;
 
     enum { STARTUP_WINDOWED, STARTUP_MAXIMIZED, STARTUP_FULLSCREEN } startup_mode;
 

csi.c

@@ -476,11 +476,11 @@ decset_decrst(struct terminal *term, unsigned param, bool enable)
         term->meta.esc_prefix = enable;
         break;
 
-#if 0
     case 1042:
-        LOG_WARN("unimplemented: 'urgency' window manager hint on ctrl-g");
+        term->bell_is_urgent = enable;
         break;
 
+#if 0
     case 1043:
         LOG_WARN("unimplemented: raise window on ctrl-g");
         break;
@@ -593,6 +593,7 @@ xtsave(struct terminal *term, unsigned param)
     case 1015: term->xtsave.mouse_urxvt = term->mouse_reporting == MOUSE_URXVT; break;
     case 1034: term->xtsave.meta_eight_bit = term->meta.eight_bit; break;
     case 1036: term->xtsave.meta_esc_prefix = term->meta.esc_prefix; break;
+    case 1042: term->xtsave.bell_is_urgent = term->bell_is_urgent; break;
     case 1049: term->xtsave.alt_screen = term->grid == &term->alt; break;
     case 2004: term->xtsave.bracketed_paste = term->bracketed_paste; break;
     }
@@ -624,6 +625,7 @@ xtrestore(struct terminal *term, unsigned param)
     case 1015: enable = term->xtsave.mouse_urxvt; break;
     case 1034: enable = term->xtsave.meta_eight_bit; break;
     case 1036: enable = term->xtsave.meta_esc_prefix; break;
+    case 1042: enable = term->xtsave.bell_is_urgent; break;
     case 1049: enable = term->xtsave.alt_screen; break;
     case 2004: enable = term->xtsave.bracketed_paste; break;
 

doc/foot.ini.5.scd

@@ -103,6 +103,9 @@ in this order:
 	protocol is added in the future (in which case foot will use that
 	instead of painting its margins red).
 	
+	Applications can enable/disable this feature programatically with
+	the *CSI ? 1042 h* and *CSI ? 1042 l* escape sequences.
+	
 	_Note_: expect this feature to be *replaced* with proper
 	compositor urgency support once/if that gets implemented.
 	

terminal.c

@@ -996,6 +996,7 @@ term_init(const struct config *conf, struct fdm *fdm, struct reaper *reaper,
             .esc_prefix = true,
             .eight_bit = true,
         },
+        .bell_is_urgent = conf->bell_is_urgent,
         .tab_stops = tll_init(),
         .wl = wayl,
         .render = {
@@ -2374,7 +2375,7 @@ term_flash(struct terminal *term, unsigned duration_ms)
 void
 term_bell(struct terminal *term)
 {
-    if (term->kbd_focus || !term->conf->bell_set_urgency)
+    if (term->kbd_focus || !term->bell_is_urgent)
         return;
 
     /* There's no 'urgency' hint in Wayland - we just paint the margins red */

terminal.h

@@ -251,6 +251,8 @@ struct terminal {
         bool eight_bit;
     } meta;
 
+    bool bell_is_urgent;
+
     /* Saved DECSET modes - we save the SET state */
     struct {
         uint32_t origin:1;
@@ -272,6 +274,7 @@ struct terminal {
         uint32_t mouse_urxvt:1;
         uint32_t meta_eight_bit:1;
         uint32_t meta_esc_prefix:1;
+        uint32_t bell_is_urgent:1;
         uint32_t alt_screen:1;
     } xtsave;