Fix frame rate limiter (#2318)

* simplify

* fix for frame rate limiter

* fix update

* fix update

* update comment

* No need for lock

* remove comment

* fix for glitched test

* force update

* implement dim fix

* docstrings

* foreground fix

* cached filters

* cache default

* fix for filter tests

* docstring

* optimization

* Update src/textual/filter.py

Co-authored-by: Rodrigo Girão Serrão <5621605+rodrigogiraoserrao@users.noreply.github.com>

* Update src/textual/constants.py

Co-authored-by: Rodrigo Girão Serrão <5621605+rodrigogiraoserrao@users.noreply.github.com>

* fix cache

* remove comment [skip ci]

---------

Co-authored-by: Rodrigo Girão Serrão <5621605+rodrigogiraoserrao@users.noreply.github.com>

src/textual/_compositor.py

@@ -245,19 +245,15 @@ class ChopsUpdate(CompositorUpdate):
                     append(strip.render(console))
                     continue
 
-                if x < x1:
+                strip = strip.crop(0, min(end, x2) - x)
-                    strip = strip.crop(x1 - x, x2 - x)
+                append(move_to(x, y).segment.text)
-                    append(move_to(x1, y).segment.text)
-                else:
-                    strip = strip.crop(0, x2 - x)
-                    append(move_to(x, y).segment.text)
-
                 append(strip.render(console))
 
             if y != last_y:
                 append("\n")
 
-        return "".join(sequences)
+        terminal_sequences = "".join(sequences)
+        return terminal_sequences
 
     def __rich_repr__(self) -> rich.repr.Result:
         yield from ()

src/textual/filter.py

@@ -117,12 +117,8 @@ def dim_style(style: Style, background: Color, factor: float) -> Style:
         style
         + Style.from_color(
             dim_color(
-                (
+                (background.rich_color if style.bgcolor.is_default else style.bgcolor),
-                    background.rich_color
+                style.color,
-                    if style.bgcolor.is_default
-                    else (style.bgcolor or DEFAULT_COLOR)
-                ),
-                style.color or DEFAULT_COLOR,
                 factor,
             ),
             None,

src/textual/pilot.py

@@ -141,6 +141,7 @@ class Pilot(Generic[ReturnType]):
             delay: Seconds to pause, or None to wait for cpu idle.
         """
         # These sleep zeros, are to force asyncio to give up a time-slice,
+        self.app.screen._on_timer_update()  # Force one last repaint
         if delay is None:
             await wait_for_idle(0)
         else:

src/textual/screen.py

@@ -42,8 +42,8 @@ from .widget import Widget
 if TYPE_CHECKING:
     from typing_extensions import Final
 
-# Screen updates will be batched so that they don't happen more often than 120 times per second:
+# Screen updates will be batched so that they don't happen more often than 60 times per second:
-UPDATE_PERIOD: Final[float] = 1 / 120
+UPDATE_PERIOD: Final[float] = 1 / 60
 
 ScreenResultType = TypeVar("ScreenResultType")
 """The result type of a screen."""
@@ -437,42 +437,49 @@ class Screen(Generic[ScreenResultType], Widget):
         event.prevent_default()
 
         if not self.app._batch_count and self.is_current:
-            async with self.app._dom_lock:
+            if (
-                if self.is_current:
+                self._layout_required
-                    if self._layout_required:
+                or self._scroll_required
-                        self._refresh_layout()
+                or self._repaint_required
-                        self._layout_required = False
+                or self._dirty_widgets
-                        self._scroll_required = False
+            ):
-                        self._dirty_widgets.clear()
+                self._update_timer.resume()
-                    elif self._scroll_required:
-                        self._refresh_layout(scroll=True)
-                        self._scroll_required = False
-
-                    if self._repaint_required:
-                        self._dirty_widgets.clear()
-                        self._dirty_widgets.add(self)
-                        self._repaint_required = False
-
-                    if self._dirty_widgets:
-                        self._update_timer.resume()
 
         # The Screen is idle - a good opportunity to invoke the scheduled callbacks
-        await self._invoke_and_clear_callbacks()
+
+        if self._callbacks:
+            self._on_timer_update()
 
     def _on_timer_update(self) -> None:
         """Called by the _update_timer."""
-        # Render widgets together
-        if self._dirty_widgets and self.is_current:
-            self._compositor.update_widgets(self._dirty_widgets)
-            update = self._compositor.render_update(
-                screen_stack=self.app._background_screens
-            )
-            self.app._display(self, update)
-            self._dirty_widgets.clear()
-        if self._callbacks:
-            self.post_message(events.InvokeCallbacks())
 
         self._update_timer.pause()
+        if self.is_current:
+            if self._layout_required:
+                self._refresh_layout()
+                self._layout_required = False
+                self._scroll_required = False
+                self._dirty_widgets.clear()
+            elif self._scroll_required:
+                self._refresh_layout(scroll=True)
+                self._scroll_required = False
+
+            if self._repaint_required:
+                self._update_timer.resume()
+                self._dirty_widgets.clear()
+                self._dirty_widgets.add(self)
+                self._repaint_required = False
+
+            if self._dirty_widgets and self.is_current:
+                self._compositor.update_widgets(self._dirty_widgets)
+                update = self._compositor.render_update(
+                    screen_stack=self.app._background_screens
+                )
+                self.app._display(self, update)
+                self._dirty_widgets.clear()
+
+        if self._callbacks:
+            self.post_message(events.InvokeCallbacks())
 
     async def _on_invoke_callbacks(self, event: events.InvokeCallbacks) -> None:
         """Handle PostScreenUpdate events, which are sent after the screen is updated"""

src/textual/strip.py

@@ -282,6 +282,7 @@ class Strip:
             cached_strip = Strip(
                 filter.apply(self._segments, background), self._cell_length
             )
+            self._filter_cache[(filter, background)] = cached_strip
         return cached_strip
 
     def style_links(self, link_id: str, link_style: Style) -> Strip:
@@ -312,7 +313,7 @@ class Strip:
         ]
         return Strip(segments, self._cell_length)
 
-    def crop(self, start: int, end: int) -> Strip:
+    def crop(self, start: int, end: int | None = None) -> Strip:
         """Crop a strip between two cell positions.
 
         Args:
@@ -323,7 +324,7 @@ class Strip:
             A new Strip.
         """
         start = max(0, start)
-        end = min(self.cell_length, end)
+        end = self.cell_length if end is None else min(self.cell_length, end)
         if start == 0 and end == self.cell_length:
             return self
         cache_key = (start, end)