Merge pull request #5553 from TomJGooding/fix-border-fix-flipped-title-colors-in-panel-border

fix(border): fix flipped title colors in panel border

Author: willmcgugan

CHANGELOG.md

@@ -13,8 +13,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Fixed height of auto container which contains auto height children https://github.com/Textualize/textual/pull/5552
 - Fixed `Content.from_markup` not stripping control codes https://github.com/Textualize/textual/pull/5557
 - Fixed `delta_x` and `delta_y` in mouse events when smooth scrolling is enabled https://github.com/Textualize/textual/pull/5556
+- Fixed flipped title colors in panel border https://github.com/Textualize/textual/issues/5548
 - Fixed detection of smooth scrolling https://github.com/Textualize/textual/pull/5558
 
+
 ### Added
 
 - Added `pointer_x`, `pointer_y`, `pointer_screen_x`, and `pointer_screen_y` attributes to mouse events https://github.com/Textualize/textual/pull/5556

src/textual/_border.py

@@ -385,7 +385,10 @@ def render_border_label(
         assert False
 
     if (flip_top and is_title) or (flip_bottom and not is_title):
-        base_style = base_style.without_color + Style(reverse=True)
+        base_style = base_style.without_color + Style(
+            background=base_style.foreground,
+            foreground=base_style.background,
+        )
 
     segments = text_label.render_segments(base_style)
     yield from segments

src/textual/_styles_cache.py

@@ -379,7 +379,11 @@ def post(segments: Iterable[Segment]) -> Iterable[Segment]:
                         if label_background.a
                         else TRANSPARENT
                     ),
-                    (base_label_background + border_color + label_color),
+                    (
+                        (base_label_background + label_color)
+                        if label_color.a
+                        else TRANSPARENT
+                    ),
                 )
                 render_label = (label, style)
 

tests/snapshot_tests/__snapshots__/test_snapshots/test_border_tab.svg

@@ -3720,3 +3720,50 @@ def on_mount(self) -> None:
             table.add_rows(rows[1:])
 
     assert snap_compare(MyApp())
+
+
+def test_panel_border_title_colors(snap_compare):
+    """Regression test for https://github.com/Textualize/textual/issues/5548
+
+    You should see four labels with panel type borders. The border title colors
+    should match the description in the label."""
+
+    class BorderTitleApp(App):
+        CSS = """
+        Label {
+            border: panel red;
+            width: 40;
+            margin: 1;
+        }
+
+        .with-border-title-color {
+            border-title-color: yellow;
+        }
+
+        .with-border-title-background {
+            border-title-background: green;
+        }
+        """
+
+        def compose(self) -> ComposeResult:
+            yield Label(
+                "with default",
+            )
+            yield Label(
+                "with yellow color",
+                classes="with-border-title-color",
+            )
+            yield Label(
+                "with green background",
+                classes="with-border-title-background",
+            )
+            yield Label(
+                "with yellow color and green background",
+                classes="with-border-title-background with-border-title-color",
+            )
+
+        def on_mount(self) -> None:
+            for label in self.query(Label):
+                label.border_title = "Border title"
+
+    assert snap_compare(BorderTitleApp())