Fix allow_focus method

CHANGELOG.md

@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Fixed footer / key panel not updating when keymaps are applied https://github.com/Textualize/textual/pull/5724
 - Fixed alignment not being applied when there are min and max limits on dimensions https://github.com/Textualize/textual/pull/5732
 - Fixed issues with OptionList scrollbar not updating https://github.com/Textualize/textual/pull/5736
+- Fixed allow_focus method not overriding `can_focus()` https://github.com/Textualize/textual/pull/5737
 
 ### Changed
 

examples/theme_sandbox.py

@@ -303,7 +303,7 @@ def action_widget_search(self) -> None:
                     widget.__class__.__name__,
                     (
                         partial(self.set_focus, widget)
-                        if widget.can_focus
+                        if widget.allow_focus()
                         else lambda: None
                     ),
                     f"Focus on {widget.__class__.__name__}",

src/textual/widget.py

@@ -378,7 +378,7 @@ class Widget(DOMNode):
         "hover": lambda widget: widget.mouse_hover,
         "focus": lambda widget: widget.has_focus,
         "blur": lambda widget: not widget.has_focus,
-        "can-focus": lambda widget: widget.can_focus,
+        "can-focus": lambda widget: widget.allow_focus(),
         "disabled": lambda widget: widget.is_disabled,
         "enabled": lambda widget: not widget.is_disabled,
         "dark": lambda widget: widget.app.current_theme.dark,
@@ -2111,7 +2111,7 @@ def focusable(self) -> bool:
         """Can this widget currently be focused?"""
         return (
             not self.loading
-            and self.can_focus
+            and self.allow_focus()
             and self.visible
             and not self._self_or_ancestors_disabled
         )

tests/snapshot_tests/test_snapshots.py

@@ -3894,6 +3894,7 @@ def on_mount(self) -> None:
 
     assert snap_compare(ToastApp())
 
+
 def test_option_list_size_when_options_removed(snap_compare):
     """Regression test for https://github.com/Textualize/textual/issues/5728
 
@@ -3935,6 +3936,7 @@ def action_clear_options(self) -> None:
 
     assert snap_compare(OptionListApp(), press=["x"])
 
+
 def test_alignment_with_auto_and_min_height(snap_compare):
     """Regression test for https://github.com/Textualize/textual/issues/5608
     You should see a blue label that is centered both horizontally and vertically
@@ -3962,3 +3964,41 @@ def compose(self) -> ComposeResult:
                 yield Label("centered")
 
     assert snap_compare(AlignmentApp())
+
+
+def test_allow_focus(snap_compare):
+    """Regression test for https://github.com/Textualize/textual/issues/5609
+
+    You should see two placeholders split vertically.
+    The top should have the label "FOCUSABLE", and have a heavy red border.
+    The bottom should have the label "NON FOCUSABLE" and have the default border.
+    """
+
+    class Focusable(Placeholder, can_focus=False):
+        """Override can_focus from False to True"""
+
+        def allow_focus(self) -> bool:
+            return True
+
+    class NonFocusable(Placeholder, can_focus=True):
+        """Override can_focus from True to False"""
+
+        def allow_focus(self) -> bool:
+            return False
+
+    class FocusApp(App):
+        CSS = """
+        Placeholder {
+            height: 1fr;
+        }
+        *:can-focus {
+            border: heavy red;
+        }
+
+        """
+
+        def compose(self) -> ComposeResult:
+            yield Focusable("FOCUSABLE")
+            yield NonFocusable("NON FOCUSABLE")
+
+    assert snap_compare(FocusApp())

tests/test_focus.py

@@ -2,6 +2,7 @@
 from textual.containers import Container, ScrollableContainer
 from textual.widget import Widget
 from textual.widgets import Button, Label
+from textual.widgets._placeholder import Placeholder
 
 
 class Focusable(Widget, can_focus=True):
@@ -464,3 +465,45 @@ def compose(self) -> ComposeResult:
         await pilot.click("#egg")
         # Confirm nothing focused
         assert app.screen.focused is None
+
+
+async def test_allow_focus_override():
+    """Test that allow_focus() method override can_focus."""
+
+    class Focusable(Placeholder, can_focus=False):
+        """Override can_focus from False to True"""
+
+        def allow_focus(self) -> bool:
+            return True
+
+    class NonFocusable(Placeholder, can_focus=True):
+        """Override can_focus from True to False"""
+
+        def allow_focus(self) -> bool:
+            return False
+
+    class FocusApp(App):
+        CSS = """
+        Placeholder {
+            height: 1fr;
+        }
+        *:can-focus {
+            border: heavy red;
+        }
+
+        """
+
+        def compose(self) -> ComposeResult:
+            yield Focusable("FOCUSABLE")
+            yield NonFocusable("NON FOCUSABLE")
+
+    app = FocusApp()
+    async with app.run_test():
+        # Default should be focused
+        assert isinstance(app.focused, Focusable)
+        # Attempt to focus non focusable
+        app.query(NonFocusable).focus()
+        # Unable to focus NonFocusable
+        assert isinstance(app.focused, Focusable)
+        # Check focus chain
+        assert app.screen.focus_chain == [app.query_one(Focusable)]