Support focusable containers (#1130)

* Fix containers not being focusable

* Fix tests to allow for focusable containers

* Add test for non-focusable container with focusable children

* Fix a typo in a test

Author: darrenburns

src/textual/screen.py

@@ -169,9 +169,8 @@ def focus_chain(self) -> list[Widget]:
             else:
                 if node.is_container and node.can_focus_children:
                     push(iter(node.focusable_children))
-                else:
-                    if node.can_focus:
-                        add_widget(node)
+                if node.can_focus:
+                    add_widget(node)
 
         return widgets
 

tests/test_focus.py

@@ -10,8 +10,11 @@ class Focusable(Widget, can_focus=True):
 class NonFocusable(Widget, can_focus=False, can_focus_children=False):
     pass
 
+class ChildrenFocusableOnly(Widget, can_focus=False, can_focus_children=True):
+    pass
+
 
-async def test_focus_chain():
+def test_focus_chain():
     app = App()
     app._set_active()
     app.push_screen(Screen())
@@ -27,13 +30,14 @@ async def test_focus_chain():
         Focusable(Focusable(id="Paul"), id="container1"),
         NonFocusable(Focusable(id="Jessica"), id="container2"),
         Focusable(id="baz"),
+        ChildrenFocusableOnly(Focusable(id="child")),
     )
 
-    focused = [widget.id for widget in screen.focus_chain]
-    assert focused == ["foo", "Paul", "baz"]
+    focus_chain = [widget.id for widget in screen.focus_chain]
+    assert focus_chain == ["foo", "container1", "Paul", "baz", "child"]
 
 
-async def test_focus_next_and_previous():
+def test_focus_next_and_previous():
     app = App()
     app._set_active()
     app.push_screen(Screen())
@@ -46,11 +50,16 @@ async def test_focus_next_and_previous():
         Focusable(Focusable(id="Paul"), id="container1"),
         NonFocusable(Focusable(id="Jessica"), id="container2"),
         Focusable(id="baz"),
+        ChildrenFocusableOnly(Focusable(id="child")),
     )
 
     assert screen.focus_next().id == "foo"
+    assert screen.focus_next().id == "container1"
     assert screen.focus_next().id == "Paul"
     assert screen.focus_next().id == "baz"
+    assert screen.focus_next().id == "child"
 
+    assert screen.focus_previous().id == "baz"
     assert screen.focus_previous().id == "Paul"
+    assert screen.focus_previous().id == "container1"
     assert screen.focus_previous().id == "foo"