fix command palette key

CHANGELOG.md

@@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Fix crash when `validate_on` value isn't a set https://github.com/Textualize/textual/pull/4868
 - Fix `Input.cursor_blink` having no effect on the blink cycle after mounting https://github.com/Textualize/textual/pull/4869
+- Fix command palette key override https://github.com/Textualize/textual/pull/4890
 
 ## [0.76.0]
 

src/textual/app.py

@@ -367,18 +367,13 @@ class MyApp(App[None]):
     """
 
     COMMAND_PALETTE_BINDING: ClassVar[str] = "ctrl+p"
-    """The key that launches the command palette (if enabled)."""
+    """The key that launches the command palette (if enabled by [`App.ENABLE_COMMAND_PALETTE`][textual.app.App.ENABLE_COMMAND_PALETTE])."""
+
+    COMMAND_PALETTE_DISPLAY: ClassVar[str | None] = None
+    """How the command palette key should be displayed in the footer (or `None` for default)."""
 
     BINDINGS: ClassVar[list[BindingType]] = [
-        Binding("ctrl+c", "quit", "Quit", show=False, priority=True),
-        Binding(
-            COMMAND_PALETTE_BINDING,
-            "command_palette",
-            "palette",
-            show=False,
-            priority=True,
-            tooltip="Open command palette",
-        ),
+        Binding("ctrl+c", "quit", "Quit", show=False, priority=True)
     ]
     """The default key bindings."""
 
@@ -650,6 +645,23 @@ def __init__(
         # Size of previous inline update
         self._previous_inline_height: int | None = None
 
+        if self.ENABLE_COMMAND_PALETTE:
+            for _key, binding in self._bindings:
+                if binding.action in {"command_palette", "app.command_palette"}:
+                    break
+            else:
+                self._bindings._add_binding(
+                    Binding(
+                        self.COMMAND_PALETTE_BINDING,
+                        "command_palette",
+                        "palette",
+                        show=False,
+                        key_display=self.COMMAND_PALETTE_DISPLAY,
+                        priority=True,
+                        tooltip="Open command palette",
+                    )
+                )
+
     def validate_title(self, title: Any) -> str:
         """Make sure the title is set to a string."""
         return str(title)

src/textual/binding.py

@@ -123,6 +123,14 @@ def make_bindings(bindings: Iterable[BindingType]) -> Iterable[Binding]:
         for binding in make_bindings(bindings or {}):
             self.key_to_bindings.setdefault(binding.key, []).append(binding)
 
+    def _add_binding(self, binding: Binding) -> None:
+        """Add a new binding.
+
+        Args:
+            binding: New Binding to add.
+        """
+        self.key_to_bindings.setdefault(binding.key, []).append(binding)
+
     def __iter__(self) -> Iterator[tuple[str, Binding]]:
         """Iterating produces a sequence of (KEY, BINDING) tuples."""
         return iter(

tests/snapshot_tests/snapshot_apps/command_palette_key.py

@@ -0,0 +1,15 @@
+from textual.app import App, ComposeResult
+from textual.widgets import Footer
+
+
+class NewPaletteBindingApp(App):
+    COMMAND_PALETTE_BINDING = "ctrl+backslash"
+    COMMAND_PALETTE_DISPLAY = "ctrl+\\"
+
+    def compose(self) -> ComposeResult:
+        yield Footer()
+
+
+if __name__ == "__main__":
+    app = NewPaletteBindingApp()
+    app.run()

tests/snapshot_tests/test_snapshots.py

@@ -1438,3 +1438,8 @@ async def run_before(pilot: Pilot):
     assert snap_compare(
         SNAPSHOT_APPS_DIR / "command_palette_dismiss.py", run_before=run_before
     )
+
+
+def test_command_palette_key_change(snap_compare):
+    """Regression test for https://github.com/Textualize/textual/issues/4887"""
+    assert snap_compare(SNAPSHOT_APPS_DIR / "command_palette_key.py")