resize on idle

src/textual/app.py

@@ -786,6 +786,9 @@ def __init__(
 
         self._hover_effects_timer: Timer | None = None
 
+        self._resize_event: events.Resize | None = None
+        """A pending resize event, sent on idle."""
+
         if self.ENABLE_COMMAND_PALETTE:
             for _key, binding in self._bindings:
                 if binding.action in {"command_palette", "app.command_palette"}:
@@ -3826,9 +3829,7 @@ async def _on_key(self, event: events.Key) -> None:
 
     async def _on_resize(self, event: events.Resize) -> None:
         event.stop()
-        self.screen.post_message(event)
-        for screen in self._background_screens:
-            screen.post_message(event)
+        self._resize_event = event
 
     async def _on_app_focus(self, event: events.AppFocus) -> None:
         """App has focus."""
@@ -4467,3 +4468,11 @@ def _on_terminal_supports_in_band_window_resize(
         we will just log it.
         """
         self.log.debug(message)
+
+    def _on_idle(self) -> None:
+        event = self._resize_event
+        if event is not None:
+            self._resize_event = None
+            self.screen.post_message(event)
+            for screen in self._background_screens:
+                screen.post_message(event)

src/textual/drivers/linux_driver.py

@@ -20,6 +20,7 @@
 from textual.driver import Driver
 from textual.drivers._writer_thread import WriterThread
 from textual.geometry import Size
+from textual.message import Message
 from textual.messages import TerminalSupportInBandWindowResize
 
 if TYPE_CHECKING:
@@ -443,18 +444,21 @@ def process_selector_events(
             except ParseError:
                 pass
 
-    def process_message(self, event: events.Event) -> None:
-        if isinstance(event, TerminalSupportInBandWindowResize):
-            if event.supported and not event.enabled:
+    def process_message(self, message: Message) -> None:
+        # intercept in-band window resize
+        if isinstance(message, TerminalSupportInBandWindowResize):
+            # If it is supported, enabled it
+            if message.supported and not message.enabled:
                 self._enable_in_band_window_resize()
-                self._in_band_window_resize = event.supported
-            elif event.enabled:
-                self._in_band_window_resize = event.supported
+                self._in_band_window_resize = message.supported
+            elif message.enabled:
+                self._in_band_window_resize = message.supported
+            # Send up-to-date message
             super().process_message(
                 TerminalSupportInBandWindowResize(
-                    event.supported, self._in_band_window_resize
+                    message.supported, self._in_band_window_resize
                 )
             )
             return
 
-        super().process_message(event)
+        super().process_message(message)