time: Tick per sec if strftime has seconds spec

It's possible to have a discrepancy between strftime and the
show_seconds setting. If show_seconds is disabled but a user's strftime
formatter has a seconds specifier, then the time applet won't update
seconds because it's internally ticking per minute.

The fix is to ensure that the time applet updates per second regardless
of the user's setting if strftime has a seconds specifier. This is an
internal flag and shouldn't affect the user's show_seconds setting.

Author: joshuamegnauth54

cosmic-applet-time/src/window.rs

@@ -43,6 +43,11 @@ use icu::{
 
 static AUTOSIZE_MAIN_ID: LazyLock<Id> = LazyLock::new(|| Id::new("autosize-main"));
 
+// Specifiers for strftime that indicate seconds. Subsecond precision isn't supported by the applet
+// so those specifiers aren't listed here. This list is non-exhaustive, and it's possible that %X
+// and other specifiers have to be added depending on locales.
+const STRFTIME_SECONDS: &[char] = &['S', 'T', '+', 's'];
+
 fn get_system_locale() -> Locale {
     for var in ["LC_TIME", "LC_ALL", "LANG"] {
         if let Ok(locale_str) = std::env::var(var) {
@@ -604,7 +609,17 @@ impl cosmic::Application for Window {
             Message::ConfigChanged(c) => {
                 // Don't interrupt the tick subscription unless necessary
                 self.show_seconds_tx.send_if_modified(|show_seconds| {
-                    if *show_seconds == c.show_seconds {
+                    if c.format_strftime
+                        .split('%')
+                        .any(|s| STRFTIME_SECONDS.contains(&s.chars().next().unwrap_or_default()))
+                        && !*show_seconds
+                    {
+                        // The strftime formatter contains a seconds specifier. Force enable
+                        // ticking per seconds internally regardless of the user setting.
+                        // This does not change the user's setting. It's invisible to the user.
+                        *show_seconds = true;
+                        true
+                    } else if *show_seconds == c.show_seconds {
                         false
                     } else {
                         *show_seconds = c.show_seconds;