docs

src/textual/color.py

@@ -241,7 +241,8 @@ class Color(NamedTuple):
         """Parse a string containing a CSS-style color.
 
         Args:
-            color_text (str): Text with a valid color format.
+            color_text (str | Color): Text with a valid color format. Color objects will
+                be returned unmodified.
 
         Raises:
             ColorParseError: If the color is not encoded correctly.

src/textual/css/_styles_builder.py

@@ -460,6 +460,7 @@ class StylesBuilder:
                     )
 
     def process_color(self, name: str, tokens: list[Token], important: bool) -> None:
+        """Processes a simple color declaration."""
         name = name.replace("-", "_")
         for token in tokens:
             if token.name in ("color", "token"):
@@ -474,40 +475,13 @@ class StylesBuilder:
                     name, token, f"unexpected token {token.value!r} in declaration"
                 )
 
-    def process_background(
+    process_background = process_color
-        self, name: str, tokens: list[Token], important: bool
+    process_scrollbar_color = process_color
-    ) -> None:
+    process_scrollbar_color_hover = process_color
-        self.process_color(name, tokens, important)
+    process_scrollbar_color_active = process_color
-
+    process_scrollbar_background = process_color
-    def process_scrollbar_color(
+    process_scrollbar_background_hover = process_color
-        self, name: str, tokens: list[Token], important: bool
+    process_scrollbar_background_active = process_color
-    ) -> None:
-        self.process_color(name, tokens, important)
-
-    def process_scrollbar_color_hover(
-        self, name: str, tokens: list[Token], important: bool
-    ) -> None:
-        self.process_color(name, tokens, important)
-
-    def process_scrollbar_color_active(
-        self, name: str, tokens: list[Token], important: bool
-    ) -> None:
-        self.process_color(name, tokens, important)
-
-    def process_scrollbar_background(
-        self, name: str, tokens: list[Token], important: bool
-    ) -> None:
-        self.process_color(name, tokens, important)
-
-    def process_scrollbar_background_hover(
-        self, name: str, tokens: list[Token], important: bool
-    ) -> None:
-        self.process_color(name, tokens, important)
-
-    def process_scrollbar_background_active(
-        self, name: str, tokens: list[Token], important: bool
-    ) -> None:
-        self.process_color(name, tokens, important)
 
     def process_text_style(
         self, name: str, tokens: list[Token], important: bool

tests/test_color.py

@@ -108,6 +108,12 @@ def test_color_parse(text, expected):
     assert Color.parse(text) == expected
 
 
+def test_color_parse_color():
+    # as a convenience, if Color.parse is passed a color object, it will return it
+    color = Color(20, 30, 40, 0.5)
+    assert Color.parse(color) is color
+
+
 def test_color_add():
     assert Color(50, 100, 200) + Color(10, 20, 30, 0.9) == Color(14, 28, 47)