allow component classes in content

src/textual/content.py

@@ -33,7 +33,7 @@
 from textual.selection import Selection
 from textual.strip import Strip
 from textual.style import Style
-from textual.visual import RulesMap, Visual
+from textual.visual import RenderOptions, RulesMap, Visual
 
 __all__ = ["ContentType", "Content", "Span"]
 
@@ -502,6 +502,7 @@ def _wrap_and_format(
         selection: Selection | None = None,
         selection_style: Style | None = None,
         post_style: Style | None = None,
+        get_style: Callable[[str | Style], Style] = Style.parse,
     ) -> list[_FormattedLine]:
         """Wraps the text and applies formatting.
 
@@ -543,15 +544,17 @@ def get_span(y: int) -> tuple[int, int] | None:
                 if overflow == "fold":
                     cuts = list(range(0, line.cell_length, width))[1:]
                     new_lines = [
-                        _FormattedLine(line, width, y=y, align=align)
+                        _FormattedLine(get_style, line, width, y=y, align=align)
                         for line in line.divide(cuts)
                     ]
                 else:
                     line = line.truncate(width, ellipsis=overflow == "ellipsis")
-                    content_line = _FormattedLine(line, width, y=y, align=align)
+                    content_line = _FormattedLine(
+                        get_style, line, width, y=y, align=align
+                    )
                     new_lines = [content_line]
             else:
-                content_line = _FormattedLine(line, width, y=y, align=align)
+                content_line = _FormattedLine(get_style, line, width, y=y, align=align)
                 offsets = divide_line(
                     line.plain, width - line_pad * 2, fold=overflow == "fold"
                 )
@@ -568,6 +571,7 @@ def get_span(y: int) -> tuple[int, int] | None:
 
                 new_lines = [
                     _FormattedLine(
+                        get_style,
                         content.rstrip_end(width).pad(line_pad, line_pad),
                         width,
                         offset,
@@ -583,25 +587,15 @@ def get_span(y: int) -> tuple[int, int] | None:
         return output_lines
 
     def render_strips(
-        self,
-        rules: RulesMap,
-        width: int,
-        height: int | None,
-        style: Style,
-        selection: Selection | None = None,
-        selection_style: Style | None = None,
-        post_style: Style | None = None,
+        self, width: int, height: int | None, style: Style, options: RenderOptions
     ) -> list[Strip]:
-        """Render the visual into an iterable of strips. Part of the Visual protocol.
+        """Render the Visual into an iterable of strips. Part of the Visual protocol.
 
         Args:
-            rules: A mapping of style rules, such as the Widgets `styles` object.
             width: Width of desired render.
             height: Height of desired render or `None` for any height.
             style: The base style to render on top of.
-            selection: Selection information, if applicable, otherwise `None`.
-            selection_style: Selection style if `selection` is not `None`.
-            post_style: Style | None = None,
+            options: Additional render options.
 
         Returns:
             An list of Strips.
@@ -610,17 +604,18 @@ def render_strips(
         if not width:
             return []
 
-        get_rule = rules.get
+        get_rule = options.rules.get
         lines = self._wrap_and_format(
             width,
             align=get_rule("text_align", "left"),
             overflow=get_rule("text_overflow", "fold"),
             no_wrap=get_rule("text_wrap", "wrap") == "nowrap",
             line_pad=get_rule("line_pad", 0),
             tab_size=8,
-            selection=selection,
-            selection_style=selection_style,
-            post_style=post_style,
+            selection=options.selection,
+            selection_style=options.selection_style,
+            post_style=options.post_style,
+            get_style=options.get_style,
         )
 
         if height is not None:
@@ -1478,6 +1473,7 @@ class _FormattedLine:
 
     def __init__(
         self,
+        get_style: Callable[[str | Style], Style],
         content: Content,
         width: int,
         x: int = 0,
@@ -1486,6 +1482,7 @@ def __init__(
         line_end: bool = False,
         link_style: Style | None = None,
     ) -> None:
+        self.get_style = get_style
         self.content = content
         self.width = width
         self.x = x
@@ -1506,6 +1503,7 @@ def to_strip(self, style: Style) -> tuple[list[Segment], int]:
         content = self.content
         x = self.x
         y = self.y
+        get_style = self.get_style
 
         if align in ("start", "left") or (align == "justify" and self.line_end):
             pass
@@ -1534,7 +1532,9 @@ def to_strip(self, style: Style) -> tuple[list[Segment], int]:
             add_segment = segments.append
             x = self.x
             for index, word in enumerate(words):
-                for text, text_style in word.render(style, end=""):
+                for text, text_style in word.render(
+                    style, end="", parse_style=get_style
+                ):
                     add_segment(
                         _Segment(
                             text, (style + text_style).rich_style_with_offset(x, y)
@@ -1552,7 +1552,7 @@ def to_strip(self, style: Style) -> tuple[list[Segment], int]:
             else []
         )
         add_segment = segments.append
-        for text, text_style in content.render(style, end=""):
+        for text, text_style in content.render(style, end="", parse_style=get_style):
             add_segment(
                 _Segment(text, (style + text_style).rich_style_with_offset(x, y))
             )

src/textual/renderables/blank.py

@@ -5,9 +5,8 @@
 from textual.color import Color
 from textual.content import Style
 from textual.css.styles import RulesMap
-from textual.selection import Selection
 from textual.strip import Strip
-from textual.visual import Visual
+from textual.visual import RenderOptions, Visual
 
 
 class Blank(Visual):
@@ -26,14 +25,18 @@ def get_height(self, rules: RulesMap, width: int) -> int:
         return 1
 
     def render_strips(
-        self,
-        rules: RulesMap,
-        width: int,
-        height: int | None,
-        style: Style,
-        selection: Selection | None = None,
-        selection_style: Style | None = None,
-        post_style: Style | None = None,
+        self, width: int, height: int | None, style: Style, options: RenderOptions
     ) -> list[Strip]:
+        """Render the Visual into an iterable of strips. Part of the Visual protocol.
+
+        Args:
+            width: Width of desired render.
+            height: Height of desired render or `None` for any height.
+            style: The base style to render on top of.
+            options: Additional render options.
+
+        Returns:
+            An list of Strips.
+        """
         line_count = 1 if height is None else height
         return [Strip.blank(width, self._rich_style)] * line_count

src/textual/visual.py

@@ -1,8 +1,9 @@
 from __future__ import annotations
 
 from abc import ABC, abstractmethod
+from dataclasses import dataclass
 from itertools import islice
-from typing import TYPE_CHECKING, Protocol
+from typing import TYPE_CHECKING, Callable, Protocol
 
 import rich.repr
 from rich.console import Console, ConsoleOptions, RenderableType
@@ -31,6 +32,22 @@ def is_visual(obj: object) -> bool:
     return isinstance(obj, Visual) or hasattr(obj, "textualize")
 
 
+@dataclass(frozen=True)
+class RenderOptions:
+    """Additional options passed to `Visual.render_strips`."""
+
+    get_style: Callable[[str | Style], Style]
+    """Callable to get a style."""
+    rules: RulesMap
+    """Mapping of style rules."""
+    selection: Selection | None = None
+    """Text selection information."""
+    selection_style: Style | None = None
+    """Style of text selection."""
+    post_style: Style | None = None
+    """Optional style to apply post render."""
+
+
 # Note: not runtime checkable currently, as I've found that to be slow
 class SupportsVisual(Protocol):
     """An object that supports the textualize protocol."""
@@ -112,25 +129,15 @@ class Visual(ABC):
 
     @abstractmethod
     def render_strips(
-        self,
-        rules: RulesMap,
-        width: int,
-        height: int | None,
-        style: Style,
-        selection: Selection | None = None,
-        selection_style: Style | None = None,
-        post_style: Style | None = None,
+        self, width: int, height: int | None, style: Style, options: RenderOptions
     ) -> list[Strip]:
         """Render the Visual into an iterable of strips.
 
         Args:
-            rules: A mapping of style rules, such as the Widgets `styles` object.
             width: Width of desired render.
             height: Height of desired render or `None` for any height.
             style: The base style to render on top of.
-            selection: Selection information, if applicable, otherwise `None`.
-            selection_style: Selection style if `selection` is not `None`.
-            post_style: Optional style to apply post render.
+            options: Additional render options.
 
         Returns:
             An list of Strips.
@@ -216,12 +223,15 @@ def to_strips(
             selection_style = None
 
         strips = visual.render_strips(
-            widget.styles,
             width,
             height,
             style,
-            selection,
-            selection_style,
+            RenderOptions(
+                widget._get_style,
+                widget.styles,
+                selection,
+                selection_style,
+            ),
         )
         strips = [strip._apply_link_style(widget.link_style) for strip in strips]
 
@@ -303,24 +313,28 @@ def get_height(self, rules: RulesMap, width: int) -> int:
         return height
 
     def render_strips(
-        self,
-        rules: RulesMap,
-        width: int,
-        height: int | None,
-        style: Style,
-        selection: Selection | None = None,
-        selection_style: Style | None = None,
-        post_style: Style | None = None,
+        self, width: int, height: int | None, style: Style, options: RenderOptions
     ) -> list[Strip]:
+        """Render the Visual into an iterable of strips. Part of the Visual protocol.
+
+        Args:
+            width: Width of desired render.
+            height: Height of desired render or `None` for any height.
+            style: The base style to render on top of.
+            options: Additional render options.
+
+        Returns:
+            An list of Strips.
+        """
         console = active_app.get().console
-        options = console.options.update(
+        console_options = console.options.update(
             highlight=False,
             width=width,
             height=height,
         )
         rich_style = style.rich_style
         renderable = self._widget.post_render(self._renderable, rich_style)
-        segments = console.render(renderable, options.update_width(width))
+        segments = console.render(renderable, console_options.update_width(width))
         strips = [
             Strip(line)
             for line in islice(
@@ -365,28 +379,30 @@ def get_height(self, rules: RulesMap, width: int) -> int:
         )
 
     def render_strips(
-        self,
-        rules: RulesMap,
-        width: int,
-        height: int | None,
-        style: Style,
-        selection: Selection | None = None,
-        selection_style: Style | None = None,
-        post_style: Style | None = None,
+        self, width: int, height: int | None, style: Style, options: RenderOptions
     ) -> list[Strip]:
+        """Render the Visual into an iterable of strips. Part of the Visual protocol.
+
+        Args:
+            width: Width of desired render.
+            height: Height of desired render or `None` for any height.
+            style: The base style to render on top of.
+            options: Additional render options.
+
+        Returns:
+            An list of Strips.
+        """
         padding = self._spacing
         top, right, bottom, left = self._spacing
         render_width = width - (left + right)
         if render_width <= 0:
             return []
 
         strips = self._visual.render_strips(
-            rules,
             render_width,
             None if height is None else height - padding.height,
             style,
-            selection,
-            selection_style,
+            options,
         )
 
         if padding:

src/textual/widget.py

@@ -1140,9 +1140,15 @@ def iter_styles() -> Iterable[StylesBase]:
                     text_background = background + styles.background.tint(
                         styles.background_tint
                     )
-                    background += (
-                        styles.background.tint(styles.background_tint)
-                    ).multiply_alpha(opacity)
+                    if partial:
+                        background_tint = styles.background.tint(styles.background_tint)
+                        background = background.blend(
+                            background_tint, 1 - background_tint.a
+                        ).multiply_alpha(opacity)
+                    else:
+                        background += (
+                            styles.background.tint(styles.background_tint)
+                        ).multiply_alpha(opacity)
                 else:
                     text_background = background
                 if has_rule("color"):
@@ -1164,7 +1170,7 @@ def iter_styles() -> Iterable[StylesBase]:
 
         return visual_style
 
-    def _get_style(self, style: str) -> VisualStyle | None:
+    def _get_style(self, style: VisualStyle | str) -> VisualStyle:
         """A get_style method for use in Content.
 
         Args:
@@ -1173,9 +1179,25 @@ def _get_style(self, style: str) -> VisualStyle | None:
         Returns:
             A visual style if one is fund, otherwise `None`.
         """
+        if isinstance(style, VisualStyle):
+            return style
         if style.startswith("."):
-            return self.get_visual_style(style[1:])
-        return None
+            for node in self.ancestors_with_self:
+                if not isinstance(node, Widget):
+                    break
+                try:
+                    visual_style = node.get_visual_style(style[1:], partial=True)
+                    break
+                except KeyError:
+                    continue
+            else:
+                raise KeyError(f"No matching component class found for '{style}'")
+            return visual_style
+        try:
+            visual_style = VisualStyle.parse(style)
+        except Exception:
+            visual_style = VisualStyle.null()
+        return visual_style
 
     @overload
     def render_str(self, text_content: str) -> Content: ...