fix(footer): enable spacing between key and description

CHANGELOG.md

@@ -16,6 +16,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - "Discover" hits in the command palette are no longer sorted alphabetically https://github.com/Textualize/textual/pull/4720
 
+### Added
+
+- Added `Footer` component style handling of padding for the key/description https://github.com/Textualize/textual/pull/4651
+
 ## [0.72.0] - 2024-07-09
 
 ### Changed
@@ -42,7 +46,6 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Fixed link inside markdown table not posting a `Markdown.LinkClicked` message https://github.com/Textualize/textual/issues/4683
 - Fixed issue with mouse movements on non-active screen https://github.com/Textualize/textual/pull/4688
 
-
 ## [0.70.0] - 2024-06-19
 
 ### Fixed

src/textual/widgets/_footer.py

@@ -33,6 +33,11 @@ class FooterKey(Widget):
             color: $secondary;
             background: $panel;
             text-style: bold;
+            padding: 0 1;
+        }
+
+        .footer-key--description {
+            padding: 0 1 0 0;
         }
 
         &:light .footer-key--key {
@@ -57,6 +62,14 @@ class FooterKey(Widget):
             }
         }
 
+        &.-compact {
+            .footer-key--key {
+                padding: 0;
+            }
+            .footer-key--description {
+                padding: 0 0 0 1;
+            }
+        }
     }
     """
 
@@ -83,19 +96,27 @@ def render(self) -> Text:
         key_style = self.get_component_rich_style("footer-key--key")
         description_style = self.get_component_rich_style("footer-key--description")
         key_display = self.key_display
+        key_padding = self.get_component_styles("footer-key--key").padding
+        description_padding = self.get_component_styles(
+            "footer-key--description"
+        ).padding
         if self.upper_case_keys:
             key_display = key_display.upper()
         if self.ctrl_to_caret and key_display.lower().startswith("ctrl+"):
             key_display = "^" + key_display.split("+", 1)[1]
         description = self.description
-        if self.compact:
-            label_text = Text.assemble(
-                (key_display, key_style), " ", (description, description_style)
-            )
-        else:
-            label_text = Text.assemble(
-                (f" {key_display} ", key_style), (description, description_style), " "
-            )
+        label_text = Text.assemble(
+            (
+                " " * key_padding.left + key_display + " " * key_padding.right,
+                key_style,
+            ),
+            (
+                " " * description_padding.left
+                + description
+                + " " * description_padding.right,
+                description_style,
+            ),
+        )
         label_text.stylize_before(self.rich_style)
         return label_text
 

tests/snapshot_tests/snapshot_apps/footer_classic_styling.py

@@ -0,0 +1,50 @@
+from textual.app import App, ComposeResult
+from textual.widgets import Footer
+
+
+class ClassicFooterStylingApp(App):
+    """
+    This app attempts to replicate the styling of the classic footer in
+    Textual before v0.63.0, in particular the distinct background color
+    for the binding keys and spacing between the key and binding description.
+
+    Regression test for https://github.com/Textualize/textual/issues/4557
+    """
+
+    CSS = """
+    Footer {
+        background: $accent;
+
+        FooterKey {
+            background: $accent;
+            color: $text;
+
+            .footer-key--key {
+                background: $accent-darken-2;
+                color: $text;
+            }
+
+            .footer-key--description {
+                padding: 0 1;
+            }
+        }
+    }
+    """
+
+    BINDINGS = [
+        ("ctrl+t", "app.toggle_dark", "Toggle Dark mode"),
+        ("ctrl+q", "quit", "Quit"),
+    ]
+
+    def compose(self) -> ComposeResult:
+        yield Footer()
+
+    def on_mount(self) -> None:
+        footer = self.query_one(Footer)
+        footer.upper_case_keys = True
+        footer.ctrl_to_caret = False
+
+
+if __name__ == "__main__":
+    app = ClassicFooterStylingApp()
+    app.run()

tests/snapshot_tests/snapshot_apps/footer_toggle_compact.py

@@ -0,0 +1,34 @@
+from textual.app import App, ComposeResult
+from textual.widgets import Footer, Label
+
+
+class ToggleCompactFooterApp(App):
+    CSS = """
+    Screen {
+        align: center middle;
+    }
+    """
+
+    BINDINGS = [
+        ("ctrl+t", "toggle_compact_footer", "Toggle Compact Footer"),
+        ("ctrl+q", "quit", "Quit"),
+    ]
+
+    def compose(self) -> ComposeResult:
+        yield Label("Compact Footer")
+        yield Footer()
+
+    def on_mount(self) -> None:
+        footer = self.query_one(Footer)
+        footer.compact = True
+
+    def action_toggle_compact_footer(self) -> None:
+        footer = self.query_one(Footer)
+        footer.compact = not footer.compact
+        footer_type = "Compact" if footer.compact else "Standard"
+        self.query_one(Label).update(f"{footer_type} Footer")
+
+
+if __name__ == "__main__":
+    app = ToggleCompactFooterApp()
+    app.run()

tests/snapshot_tests/test_snapshots.py

@@ -1296,6 +1296,46 @@ def test_grid_auto(snap_compare):
     assert snap_compare(SNAPSHOT_APPS_DIR / "grid_auto.py")
 
 
+def test_footer_compact(snap_compare):
+    """Test Footer in the compact style"""
+    assert snap_compare(SNAPSHOT_APPS_DIR / "footer_toggle_compact.py")
+
+
+def test_footer_compact_with_hover(snap_compare):
+    """Test Footer in the compact style when the mouse is hovering over a keybinding"""
+
+    async def run_before(pilot) -> None:
+        await pilot.hover("Footer", offset=(0, 0))
+
+    assert snap_compare(
+        SNAPSHOT_APPS_DIR / "footer_toggle_compact.py", run_before=run_before
+    )
+
+
+def test_footer_standard_after_reactive_change(snap_compare):
+    """Test Footer in the standard style after `compact` reactive change"""
+    assert snap_compare(
+        SNAPSHOT_APPS_DIR / "footer_toggle_compact.py", press=["ctrl+t"]
+    )
+
+
+def test_footer_standard_with_hover(snap_compare):
+    """Test Footer in the standard style when the mouse is hovering over a keybinding"""
+
+    async def run_before(pilot) -> None:
+        await pilot.press("ctrl+t")
+        await pilot.hover("Footer", offset=(0, 0))
+
+    assert snap_compare(
+        SNAPSHOT_APPS_DIR / "footer_toggle_compact.py", run_before=run_before
+    )
+
+
+def test_footer_classic_styling(snap_compare):
+    """Regression test for https://github.com/Textualize/textual/issues/4557"""
+    assert snap_compare(SNAPSHOT_APPS_DIR / "footer_classic_styling.py")
+
+
 def test_option_list_scrolling_with_multiline_options(snap_compare):
     # https://github.com/Textualize/textual/issues/4705
     assert snap_compare(WIDGET_EXAMPLES_DIR / "option_list_tables.py", press=["up"])