Merge pull request #1873 from Textualize/screen-children-fix

fix walk children

CHANGELOG.md

@@ -31,6 +31,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Numbers in a descendant-combined selector no longer cause an error https://github.com/Textualize/textual/issues/1836
 - Fixed superfluous scrolling when focusing a docked widget https://github.com/Textualize/textual/issues/1816
+- Fixes walk_children which was returning more than one screen https://github.com/Textualize/textual/issues/1846
+- Fixed issue with watchers fired for detached nodes https://github.com/Textualize/textual/issues/1846
 
 ## [0.11.1] - 2023-02-17
 

src/textual/app.py

@@ -2153,6 +2153,9 @@ class App(Generic[ReturnType], DOMNode):
             if widget.parent is not None:
                 widget.parent._nodes._remove(widget)
 
+        for node in pruned_remove:
+            node._detach()
+
         # Return the list of widgets that should end up being sent off in a
         # prune event.
         return pruned_remove

src/textual/reactive.py

@@ -343,7 +343,6 @@ def _watch(
         callback: A callable to call when the attribute changes.
         init: True to call watcher initialization. Defaults to True.
     """
-
     if not hasattr(obj, "__watchers"):
         setattr(obj, "__watchers", {})
     watchers: dict[str, list[tuple[Reactable, Callable]]] = getattr(obj, "__watchers")

src/textual/walk.py

@@ -53,7 +53,7 @@ def walk_depth_first(
     """
     from textual.dom import DOMNode
 
-    stack: list[Iterator[DOMNode]] = [iter(root._nodes)]
+    stack: list[Iterator[DOMNode]] = [iter(root.children)]
     pop = stack.pop
     push = stack.append
     check_type = filter_type or DOMNode

tests/test_screens.py

@@ -11,6 +11,22 @@ skip_py310 = pytest.mark.skipif(
 )
 
 
+async def test_screen_walk_children():
+    """Test query only reports active screen."""
+
+    class ScreensApp(App):
+        pass
+
+    app = ScreensApp()
+    async with app.run_test() as pilot:
+        screen1 = Screen()
+        screen2 = Screen()
+        pilot.app.push_screen(screen1)
+        assert list(pilot.app.query("*")) == [screen1]
+        pilot.app.push_screen(screen2)
+        assert list(pilot.app.query("*")) == [screen2]
+
+
 async def test_installed_screens():
     class ScreensApp(App):
         SCREENS = {