settings: add future tracking and fix empty string in map

src/settings/setting/base.py

@@ -43,6 +43,7 @@ class BaseSetting:
         self._executor = get_executor()
         self._timer_id = None
         self._destroyed = False
+        self._pending_futures = []
 
         self.search_target = setting_data.get("search_target", None)
 
@@ -140,9 +141,10 @@ class BaseSetting:
         if "choice" in self.type or "list_dual" in self.type:
             map_data = {}
             for var in range_value:
-                key = var
-                display_name = var[0].upper() + var[1:] if var else ""
-                map_data[key] = display_name
+                if not var:
+                    continue
+                display_name = var[0].upper() + var[1:]
+                map_data[var] = display_name
             return map_data
 
         if self.type == "number":
@@ -202,7 +204,7 @@ class BaseSetting:
             self._map_loading = False
             self._set_busy(False)
 
-        self._executor.submit(_load, on_success=_on_success, on_error=_on_error, on_done=_on_done)
+        self._submit_task(_load, on_success=_on_success, on_error=_on_error, on_done=_on_done)
 
     def _notify_map_updated(self):
         if self.widget and self._widget_ready:
@@ -242,7 +244,7 @@ class BaseSetting:
             self._value_loading = False
             self._set_busy(False)
 
-        self._executor.submit(_load, on_success=_on_success, on_error=_on_error, on_done=_on_done)
+        self._submit_task(_load, on_success=_on_success, on_error=_on_error, on_done=_on_done)
 
     def _get_backend_value(self, force=False):
         if self._current_value is None or force:
@@ -270,7 +272,7 @@ class BaseSetting:
                 return
             self._set_busy(False)
 
-        self._executor.submit(_save, on_error=_on_error, on_done=_on_done)
+        self._submit_task(_save, on_error=_on_error, on_done=_on_done)
 
     def _get_backend_range(self):
         if not self._map_ready:
@@ -291,11 +293,25 @@ class BaseSetting:
 
         self._timer_id = GLib.timeout_add(int(interval * 1000), _poll)
 
+    def _submit_task(self, func, on_success=None, on_error=None, on_done=None):
+        def _wrapped_done():
+            if future in self._pending_futures:
+                self._pending_futures.remove(future)
+            if on_done:
+                on_done()
+
+        future = self._executor.submit(func, on_success=on_success, on_error=on_error, on_done=_wrapped_done)
+        self._pending_futures.append(future)
+        return future
+
     def destroy(self):
         self._destroyed = True
         if self._timer_id is not None:
             GLib.source_remove(self._timer_id)
             self._timer_id = None
+        for future in self._pending_futures:
+            future.cancel()
+        self._pending_futures.clear()
 
     def _update_widget(self):
         if self.widget and self._widget_ready: