app: debounce channel tree and cache render width

src/tuimble/app.py

@@ -25,6 +25,7 @@ VOLUME_STEPS = (0.0, 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 2.0)
 RECONNECT_INITIAL = 2    # seconds before first retry
 RECONNECT_MAX = 30       # maximum backoff delay
 RECONNECT_RETRIES = 10   # attempts before giving up
+TREE_DEBOUNCE = 0.1      # seconds to coalesce state changes
 
 
 def _next_volume(current: float) -> float:
@@ -186,8 +187,7 @@ class ChannelTree(Static):
         for child in children:
             self._collect_order(child.channel_id, order)
 
-    @property
-    def _available_width(self) -> int:
+    def _get_width(self) -> int:
         """Usable character width (content area, excludes padding/border)."""
         w = self.content_size.width
         if w <= 0:
@@ -218,9 +218,10 @@ class ChannelTree(Static):
         if not self._channels:
             return " Channels\n [dim]\u2514\u2500 (not connected)[/]"
 
+        w = self._get_width()
         lines = [" [bold]Channels[/]"]
         root_id = self._find_root()
-        self._render_tree(root_id, lines, indent=1, is_last=True)
+        self._render_tree(root_id, lines, indent=1, is_last=True, w=w)
         return "\n".join(lines)
 
     def _find_root(self) -> int:
@@ -235,12 +236,11 @@ class ChannelTree(Static):
         lines: list[str],
         indent: int,
         is_last: bool,
+        w: int,
     ) -> None:
         ch = self._channels.get(channel_id)
         if ch is None:
             return
-
-        w = self._available_width
         prefix = " " * indent
         branch = "\u2514\u2500" if is_last else "\u251c\u2500"
 
@@ -294,6 +294,7 @@ class ChannelTree(Static):
                 lines,
                 indent + 2,
                 is_last=i == len(children) - 1,
+                w=w,
             )
 
     def on_key(self, event: events.Key) -> None:
@@ -412,6 +413,7 @@ class TuimbleApp(App):
         self._audio.input_gain = acfg.input_gain
         self._audio.output_gain = acfg.output_gain
         self._pending_reload: Config | None = None
+        self._tree_refresh_timer = None
         self._reconnecting: bool = False
         self._reconnect_attempt: int = 0
         self._intentional_disconnect: bool = False
@@ -620,7 +622,11 @@ class TuimbleApp(App):
         chatlog.write(f"[#7aa2f7]{msg.sender}[/] {clean}")
 
     def on_server_state_changed(self, _msg: ServerStateChanged) -> None:
-        self._refresh_channel_tree()
+        if self._tree_refresh_timer is not None:
+            self._tree_refresh_timer.stop()
+        self._tree_refresh_timer = self.set_timer(
+            TREE_DEBOUNCE, self._refresh_channel_tree,
+        )
 
     def on_channel_selected(self, msg: ChannelSelected) -> None:
         if not self._client.connected: