From 4b596352d9fcea990747c06abed0da1832f110b0 Mon Sep 17 00:00:00 2001
From: Will McGugan <willmcgugan@gmail.com>
Date: Wed, 17 Aug 2022 09:33:46 +0100
Subject: [PATCH] removed cruft

---
 src/textual/app.py          | 11 +++++++++--
 src/textual/dom.py          |  5 -----
 src/textual/message_pump.py |  4 ----
 tests/test_screens.py       | 10 ++++++++++
 4 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/src/textual/app.py b/src/textual/app.py
index fe288a2a5..d60aecde1 100644
--- a/src/textual/app.py
+++ b/src/textual/app.py
@@ -733,10 +733,17 @@ class App(Generic[ReturnType], DOMNode):
             str | None: The name of the screen that was uninstalled, or None if no screen was uninstalled.
         """
         if isinstance(screen, str):
-            uninstalled_screen = self._installed_screens.pop(screen)
-            self.log(f"{uninstalled_screen} UNINSTALLED name={screen!r}")
+            if screen not in self._installed_screens:
+                return None
+            uninstall_screen = self._installed_screens[screen]
+            if uninstall_screen in self._screen_stack:
+                raise ScreenStackError("Can't uninstall screen in screen stack")
+            del self._installed_screens[screen]
+            self.log(f"{uninstall_screen} UNINSTALLED name={screen!r}")
             return screen
         else:
+            if screen in self._screen_stack:
+                raise ScreenStackError("Can't uninstall screen in screen stack")
             for name, installed_screen in self._installed_screens.items():
                 if installed_screen is screen:
                     self._installed_screens.pop(name)
diff --git a/src/textual/dom.py b/src/textual/dom.py
index a5d2ac4f5..f1a0fc59f 100644
--- a/src/textual/dom.py
+++ b/src/textual/dom.py
@@ -445,11 +445,6 @@ class DOMNode(MessagePump):
         """The children which don't have display: none set."""
         return [child for child in self.children if child.display]
 
-    def detach(self) -> None:
-        if self._parent and isinstance(self._parent, DOMNode):
-            self._parent.children._remove(self)
-            self._detach()
-
     def get_pseudo_classes(self) -> Iterable[str]:
         """Get any pseudo classes applicable to this Node, e.g. hover, focus.
 
diff --git a/src/textual/message_pump.py b/src/textual/message_pump.py
index b263fea83..02583de9b 100644
--- a/src/textual/message_pump.py
+++ b/src/textual/message_pump.py
@@ -130,10 +130,6 @@ class MessagePump(metaclass=MessagePumpMeta):
         """
         self._parent = parent
 
-    def _detach(self) -> None:
-        """Unset the parent, removing it from the tree."""
-        self._parent = None
-
     def check_message_enabled(self, message: Message) -> bool:
         return type(message) not in self._disabled_messages
 
diff --git a/tests/test_screens.py b/tests/test_screens.py
index 7ab342ad4..73ee7f1e4 100644
--- a/tests/test_screens.py
+++ b/tests/test_screens.py
@@ -64,6 +64,16 @@ async def test_screens():
     assert app.screen is screen2
     assert app.screen_stack == [screen2]
 
+    # Uninstall screens
+    app.uninstall_screen(screen1)
+    assert not app.is_screen_installed(screen1)
+    app.uninstall_screen("screen3")
+    assert not app.is_screen_installed(screen1)
+
+    # Check we can't uninstall a screen on the stack
+    with pytest.raises(ScreenStackError):
+        app.uninstall_screen(screen2)
+
     # Check we can't pop last screen
     with pytest.raises(ScreenStackError):
         app.pop_screen()