remove functionality

src/textual/_node_list.py

@@ -45,6 +45,12 @@ class NodeList:
             self._nodes_set.add(widget)
             self._updates += 1
 
+    def _remove(self, widget: Widget) -> None:
+        if widget in self._nodes_set:
+            del self._nodes[self._nodes.index(widget)]
+            self._nodes_set.remove(widget)
+            self._updates += 1
+
     def _clear(self) -> None:
         if self._nodes:
             self._nodes.clear()

src/textual/app.py

@@ -884,6 +884,16 @@ class App(Generic[ReturnType], DOMNode):
         for _widget_id, widget in name_widgets:
             widget.post_message_no_wait(events.Mount(sender=parent))
 
+    def unregister(self, widget: Widget) -> None:
+        """Unregister a widget.
+
+        Args:
+            widget (Widget): _description_
+        """
+        if isinstance(widget._parent, Widget):
+            widget._parent.children._remove(widget)
+        self.registry.discard(widget)
+
     async def _disconnect_devtools(self):
         await self.devtools.disconnect()
 
@@ -906,9 +916,6 @@ class App(Generic[ReturnType], DOMNode):
             child = self.registry.pop()
             await child.close_messages()
 
-    async def remove(self, child: MessagePump) -> None:
-        self.registry.remove(child)
-
     async def shutdown(self):
         await self._disconnect_devtools()
         driver = self._driver

src/textual/css/query.py

@@ -24,6 +24,7 @@ from .parse import parse_selectors
 
 if TYPE_CHECKING:
     from ..dom import DOMNode
+    from ..widget import Widget
 
 
 class NoMatchingNodesError(Exception):
@@ -36,14 +37,16 @@ class DOMQuery:
         self,
         node: DOMNode | None = None,
         selector: str | None = None,
-        nodes: list[DOMNode] | None = None,
+        nodes: list[Widget] | None = None,
     ) -> None:
+        from ..widget import Widget
+
         self._selector = selector
-        self._nodes: list[DOMNode] = []
+        self._nodes: list[Widget] = []
         if nodes is not None:
             self._nodes = nodes
         elif node is not None:
-            self._nodes = list(node.walk_children())
+            self._nodes = [node for node in node.walk_children()]
         else:
             self._nodes = []
 
@@ -58,9 +61,12 @@ class DOMQuery:
         """True if non-empty, otherwise False."""
         return bool(self._nodes)
 
-    def __iter__(self) -> Iterator[DOMNode]:
+    def __iter__(self) -> Iterator[Widget]:
         return iter(self._nodes)
 
+    def __getitem__(self, index: int) -> DOMNode:
+        return self._nodes[index]
+
     def __rich_repr__(self) -> rich.repr.Result:
         yield self._nodes
 
@@ -73,6 +79,7 @@ class DOMQuery:
         Returns:
             DOMQuery: New DOM Query.
         """
+
         selector_set = parse_selectors(selector)
         query = DOMQuery(
             nodes=[_node for _node in self._nodes if match(selector_set, _node)]
@@ -94,7 +101,7 @@ class DOMQuery:
         )
         return query
 
-    def first(self) -> DOMNode:
+    def first(self) -> Widget:
         """Get the first matched node.
 
         Returns:
@@ -107,6 +114,19 @@ class DOMQuery:
                 f"No nodes match the selector {self._selector!r}"
             )
 
+    def last(self) -> Widget:
+        """Get the last matched node.
+
+        Returns:
+            DOMNode: A DOM Node.
+        """
+        if self._nodes:
+            return self._nodes[-1]
+        else:
+            raise NoMatchingNodesError(
+                f"No nodes match the selector {self._selector!r}"
+            )
+
     def add_class(self, *class_names: str) -> DOMQuery:
         """Add the given class name(s) to nodes."""
         for node in self._nodes:
@@ -125,6 +145,12 @@ class DOMQuery:
             node.toggle_class(*class_names)
         return self
 
+    def remove(self) -> DOMQuery:
+        """Remove matched nodes from the DOM"""
+        for node in self._nodes:
+            node.remove()
+        return self
+
     def set_styles(self, css: str | None = None, **styles: str) -> DOMQuery:
         """Set styles on matched nodes.
 

src/textual/dom.py

@@ -254,7 +254,7 @@ class DOMNode(MessagePump):
         """
         Returns: ``True`` if this DOMNode is displayed (``display != "none"``), ``False`` otherwise.
         """
-        return self.styles.display != "none"
+        return self.styles.display != "none" and not (self._closing or self._closed)
 
     @display.setter
     def display(self, new_val: bool | str) -> None:

src/textual/events.py

@@ -130,6 +130,10 @@ class Unmount(Event, bubble=False):
     """Sent when a widget is unmounted, and may no longer receive messages."""
 
 
+class Remove(Event, bubble=False):
+    """Sent to a widget to ask it to remove itself from the DOM."""
+
+
 class Show(Event, bubble=False):
     """Sent when a widget has become visible."""
 

src/textual/message_pump.py

@@ -214,16 +214,19 @@ class MessagePump:
 
     async def close_messages(self) -> None:
         """Close message queue, and optionally wait for queue to finish processing."""
-        if self._closed:
+        if self._closed or self._closing:
             return
-
+        print(self, "close_messages")
         self._closing = True
         await self._message_queue.put(MessagePriority(None))
-        for task in self._child_tasks:
+        self.app.unregister(self)
+        cancel_tasks = list(self._child_tasks)
+        for task in cancel_tasks:
             task.cancel()
+        for task in cancel_tasks:
             await task
         self._child_tasks.clear()
-        if self._task is not None:
+        if self._task is not None and asyncio.current_task() != self._task:
             # Ensure everything is closed before returning
             await self._task
 

src/textual/widget.py

@@ -181,6 +181,16 @@ class Widget(DOMNode):
             self.scroll_to(0, 0, animate=False)
 
     def mount(self, *anon_widgets: Widget, **widgets: Widget) -> None:
+        """Mount child widgets (making this widget a container).
+
+        Widgets may be passed as positional arguments or keyword arguments. If keyword arguments,
+        the keys will be set as the Widget's id.
+
+        Example:
+            self.mount(Static("hello"), header=Header())
+
+
+        """
         self.app.register(self, *anon_widgets, **widgets)
         self.screen.refresh()
 
@@ -815,6 +825,17 @@ class Widget(DOMNode):
             )
         return delta
 
+    def scroll_visible(self) -> bool:
+        """Scroll the container to make this widget visible.
+
+        Returns:
+            bool: True if the parent was scrolled.
+        """
+        parent = self.parent
+        if isinstance(parent, Widget):
+            return parent.scroll_to_widget(self)
+        return False
+
     def __init_subclass__(
         cls,
         can_focus: bool = False,
@@ -1051,6 +1072,10 @@ class Widget(DOMNode):
 
         self.check_idle()
 
+    def remove(self) -> None:
+        """Remove the Widget from the DOM (effectively deleting it)"""
+        self.post_message_no_wait(events.Remove(self))
+
     def render(self) -> RenderableType:
         """Get renderable for widget.
 
@@ -1122,6 +1147,10 @@ class Widget(DOMNode):
     async def on_key(self, event: events.Key) -> None:
         await self.dispatch_key(event)
 
+    async def on_remove(self, event: events.Remove) -> None:
+        await self.close_messages()
+        self.parent.refresh(layout=True)
+
     def on_mount(self, event: events.Mount) -> None:
         widgets = list(self.compose())
         if widgets: