Factor out 'Bar' widget.

src/textual/widgets/_bar.py

@@ -0,0 +1,50 @@
+"""
+Auxiliary widget that renders a bar, used in other widgets like tabs and progress bar.
+"""
+from __future__ import annotations
+
+from rich.style import Style
+
+from ..app import RenderResult
+from ..reactive import reactive
+from ..renderables.bar import RenderableBar
+from ..widget import Widget
+
+
+class Bar(Widget):
+    """A widget that renders a highlighted bar."""
+
+    DEFAULT_CSS = """
+    Bar {
+        width: 1fr;
+        height: 1;
+    }
+    Bar > .bar--bar {
+        background: $foreground 10%;
+    """
+
+    COMPONENT_CLASSES = {"bar--bar"}
+    """
+    | Class | Description |
+    | :- | :- |
+    | `bar--bar` | Style of the bar (may be used to change the color). |
+    """
+
+    highlight_start = reactive(0)
+    """First cell in highlight."""
+    highlight_end = reactive(0)
+    """Last cell (inclusive) in highlight."""
+
+    @property
+    def _highlight_range(self) -> tuple[int, int]:
+        """Highlighted range for the bar."""
+        return (self.highlight_start, self.highlight_end)
+
+    def render(self) -> RenderResult:
+        """Render the bar."""
+        bar_style = self.get_component_rich_style("bar--bar")
+        return RenderableBar(
+            highlight_range=self._highlight_range,
+            highlight_style=Style.from_color(bar_style.color),
+            background_style=Style.from_color(bar_style.bgcolor),
+        )

src/textual/widgets/_tabs.py

@@ -3,53 +3,34 @@
 from typing import TYPE_CHECKING, ClassVar
 
 import rich.repr
-from rich.style import Style
 from rich.text import Text, TextType
 
 from .. import events
-from ..app import ComposeResult, RenderResult
+from ..app import ComposeResult
 from ..binding import Binding, BindingType
 from ..containers import Container, Horizontal, Vertical
 from ..css.query import NoMatches
 from ..events import Mount
 from ..geometry import Offset
 from ..message import Message
 from ..reactive import reactive
-from ..renderables.bar import RenderableBar
 from ..widget import Widget
 from ..widgets import Static
+from ._bar import Bar
 
 if TYPE_CHECKING:
     from typing_extensions import Self
 
 
-class Underline(Widget):
+class Underline(Bar):
     """The animated underline beneath tabs."""
 
     DEFAULT_CSS = """
-    Underline {
-        width: 1fr;
-        height: 1;
-    }
-    Underline > .underline--bar {
-        background: $foreground 10%;
+    Underline > .bar--bar {
         color: $accent;
     }
     """
 
-    COMPONENT_CLASSES = {"underline--bar"}
-    """
-    | Class | Description |
-    | :- | :- |
-    | `underline-bar` | Style of the bar (may be used to change the color). |
-
-    """
-
-    highlight_start = reactive(0)
-    """First cell in highlight."""
-    highlight_end = reactive(0)
-    """Last cell (inclusive) in highlight."""
-
     class Clicked(Message):
         """Inform ancestors the underline was clicked."""
 
@@ -60,20 +41,6 @@ def __init__(self, offset: Offset) -> None:
             self.offset = offset
             super().__init__()
 
-    @property
-    def _highlight_range(self) -> tuple[int, int]:
-        """Highlighted range for underline bar."""
-        return (self.highlight_start, self.highlight_end)
-
-    def render(self) -> RenderResult:
-        """Render the bar."""
-        bar_style = self.get_component_rich_style("underline--bar")
-        return RenderableBar(
-            highlight_range=self._highlight_range,
-            highlight_style=Style.from_color(bar_style.color),
-            background_style=Style.from_color(bar_style.bgcolor),
-        )
-
     def _on_click(self, event: events.Click):
         """Catch clicks, so that the underline can activate the tabs."""
         event.stop()
@@ -160,7 +127,7 @@ class Tabs(Widget, can_focus=True):
         min-width: 100%;
         overflow: hidden hidden;
     }
-    Tabs:focus .underline--bar {
+    Tabs:focus .bar--bar {
         background: $foreground 20%;
     }
     """