Preload DWM plugins (dialer, calllog, xdrawer) with resident X11/Pango state and FIFO IPC

src/sxmo-dwm/dwm.c

@@ -1572,19 +1572,56 @@ host_spawn_command(const char *const *argv)
 	spawn(&a);
 }
 
+static int
+is_plugin_daemon_alive(const char *plugin_name)
+{
+	char pidpath[128], buf[32];
+	snprintf(pidpath, sizeof(pidpath), "/tmp/dwm_plugin_%s.pid", plugin_name);
+	read_sysfs_str(pidpath, buf, sizeof(buf));
+	int pid = atoi(buf);
+	return (pid > 0 && kill(pid, 0) == 0);
+}
+
 static void
 host_spawn_plugin(const char *plugin_name, const char *arg)
 {
 	if (!plugin_name || !plugin_name[0])
 		return;
+	if (arg && strcmp(arg, "--preload") == 0) {
+		if (is_plugin_daemon_alive(plugin_name))
+			return;
+		const char *cmd[4] = { "dwm-plugin", plugin_name, "--preload", NULL };
+		Arg a = { .v = cmd };
+		spawn(&a);
+		return;
+	}
+	XUngrabKeyboard(dpy, CurrentTime);
+	XFlush(dpy);
+	if (is_plugin_daemon_alive(plugin_name)) {
+		char fifopath[128], msg[128];
+		snprintf(fifopath, sizeof(fifopath), "/tmp/dwm_plugin_%s.fifo", plugin_name);
+		int fd = open(fifopath, O_WRONLY | O_NONBLOCK | O_CLOEXEC);
+		if (fd >= 0) {
+			int len;
+			if (strcmp(plugin_name, "xdrawer") == 0)
+				len = snprintf(msg, sizeof(msg), "TOGGLE\n");
+			else if (arg && arg[0])
+				len = snprintf(msg, sizeof(msg), "OPEN %s\n", arg);
+			else
+				len = snprintf(msg, sizeof(msg), "OPEN\n");
+			if (write(fd, msg, len) == len) {
+				close(fd);
+				return;
+			}
+			close(fd);
+		}
+	}
 	const char *cmd[4];
 	cmd[0] = "dwm-plugin";
 	cmd[1] = plugin_name;
 	cmd[2] = (arg && arg[0]) ? arg : NULL;
 	cmd[3] = NULL;
 	Arg a = { .v = cmd };
-	XUngrabKeyboard(dpy, CurrentTime);
-	XFlush(dpy);
 	spawn(&a);
 }
 
@@ -2849,7 +2886,7 @@ unmapnotify(XEvent *e)
 			setclientstate(c, WithdrawnState);
 		else
 			unmanage(c, 0);
-	} else if (selmon && !selmon->sel) {
+	} else {
 		focus(NULL);
 	}
 }