optimize layout

Author: willmcgugan

src/textual/_profile.py

@@ -10,10 +10,17 @@
 
 
 @contextlib.contextmanager
-def timer(subject: str = "time") -> Generator[None, None, None]:
-    """print the elapsed time. (only used in debugging)"""
+def timer(subject: str = "time", threshold: float = 0) -> Generator[None, None, None]:
+    """print the elapsed time. (only used in debugging).
+
+    Args:
+        subject: Text shown in log.
+        threshold: Time in second after which the log is written.
+
+    """
     start = perf_counter()
     yield
     elapsed = perf_counter() - start
-    elapsed_ms = elapsed * 1000
-    log(f"{subject} elapsed {elapsed_ms:.4f}ms")
+    if elapsed >= threshold:
+        elapsed_ms = elapsed * 1000
+        log(f"{subject} elapsed {elapsed_ms:.4f}ms")

src/textual/layout.py

@@ -226,6 +226,7 @@ def arrange(
             An iterable of widget location
         """
 
+    # @timer("get_content_width")
     def get_content_width(self, widget: Widget, container: Size, viewport: Size) -> int:
         """Get the optimal content width by arranging children.
 
@@ -247,6 +248,7 @@ def get_content_width(self, widget: Widget, container: Size, viewport: Size) ->
             width = arrangement.total_region.right
         return width
 
+    # @timer("get_content_height")
     def get_content_height(
         self, widget: Widget, container: Size, viewport: Size, width: int
     ) -> int:

src/textual/layouts/stream.py

@@ -10,6 +10,9 @@
     from textual.widget import Widget
 
 
+from textual._profile import timer
+
+
 class StreamLayout(Layout):
     """A cut down version of the vertical layout.
 
@@ -31,9 +34,11 @@ class StreamLayout(Layout):
 
     name = "stream"
 
+    @timer("arrange STREAM")
     def arrange(
         self, parent: Widget, children: list[Widget], size: Size, greedy: bool = True
     ) -> ArrangeResult:
+        print(parent)
         parent.pre_layout(self)
         if not children:
             return []
@@ -81,3 +86,39 @@ def arrange(
             y += height
 
         return placements
+
+    @timer("STREAM.get_content_width")
+    def get_content_width(self, widget: Widget, container: Size, viewport: Size) -> int:
+        """Get the optimal content width by arranging children.
+
+        Args:
+            widget: The container widget.
+            container: The container size.
+            viewport: The viewport size.
+
+        Returns:
+            Width of the content.
+        """
+        return widget.scrollable_content_region.width
+
+    @timer("STREAM.get_content_height")
+    def get_content_height(
+        self, widget: Widget, container: Size, viewport: Size, width: int
+    ) -> int:
+        """Get the content height.
+
+        Args:
+            widget: The container widget.
+            container: The container size.
+            viewport: The viewport.
+            width: The content width.
+
+        Returns:
+            Content height (in lines).
+        """
+        if widget._nodes:
+            arrangement = widget._arrange(Size(width, 0))
+            height = arrangement.total_region.height
+        else:
+            height = 0
+        return height

src/textual/layouts/vertical.py

@@ -11,12 +11,15 @@
     from textual.geometry import Spacing
     from textual.widget import Widget
 
+from textual._profile import timer
+
 
 class VerticalLayout(Layout):
     """Used to layout Widgets vertically on screen, from top to bottom."""
 
     name = "vertical"
 
+    @timer("arrange VERTICAL")
     def arrange(
         self, parent: Widget, children: list[Widget], size: Size, greedy: bool = True
     ) -> ArrangeResult:

src/textual/widget.py

@@ -717,10 +717,10 @@ def _cover(self, widget: Widget) -> None:
         self._uncover()
         self._cover_widget = widget
         widget._parent = self
+        widget._start_messages()
         widget._post_register(self.app)
         self.app.stylesheet.apply(widget)
         self.refresh(layout=True)
-        widget._start_messages()
 
     def _uncover(self) -> None:
         """Remove any widget, previously set via [`_cover`][textual.widget.Widget._cover]."""