From d9675a714016553264ae3b77fee785c6c49d2b6d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Mon, 9 Jun 2025 07:38:26 +0200
Subject: [PATCH] main: do a theme toggle upon receiving SIGUSR1

Caveat: in server mode, *all* instances toggle their themes.
---
 CHANGELOG.md |  2 ++
 main.c       | 17 +++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b048bda3..82b4238b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -73,6 +73,8 @@
   `key-bindings.color-theme-toggle` key bindings. These can be used to
   switch between the primary and alternative color themes. They are
   not bound by default.
+* Sending `SIGUSR1` to the foot process now triggers a theme switch
+  (in server mode, **all** instances toggles their themes).
 * Support for private mode 2031 - [_Dark and Light Mode
   Detection_](https://contour-terminal.org/vt-extensions/color-palette-update-notifications/)
   ([#2025][2025])
diff --git a/main.c b/main.c
index b9404503..37bbb6a7 100644
--- a/main.c
+++ b/main.c
@@ -45,6 +45,19 @@ fdm_sigint(struct fdm *fdm, int signo, void *data)
     return true;
 }
 
+static bool
+fdm_sigusr1(struct fdm *fdm, int signo, void *data)
+{
+    struct wayland *wayl = data;
+
+    tll_foreach(wayl->terms, it) {
+        struct terminal *term = it->item;
+        term_theme_toggle(term);
+    }
+
+    return true;
+}
+
 static void
 print_usage(const char *prog_name)
 {
@@ -608,6 +621,9 @@ main(int argc, char *const *argv)
         goto out;
     }
 
+    if (!fdm_signal_add(fdm, SIGUSR1, &fdm_sigusr1, wayl))
+        goto out;
+
     struct sigaction sig_ign = {.sa_handler = SIG_IGN};
     sigemptyset(&sig_ign.sa_mask);
     if (sigaction(SIGHUP, &sig_ign, NULL) < 0 ||
@@ -643,6 +659,7 @@ out:
     wayl_destroy(wayl);
     key_binding_manager_destroy(key_binding_manager);
     reaper_destroy(reaper);
+    fdm_signal_del(fdm, SIGUSR1);
     fdm_signal_del(fdm, SIGTERM);
     fdm_signal_del(fdm, SIGINT);
     fdm_destroy(fdm);