Merge branch 'main' into package-docs

CHANGELOG.md

@@ -19,11 +19,13 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Added Shift+scroll wheel and ctrl+scroll wheel to scroll horizontally
 - Added `Tree.action_toggle_node` to toggle a node without selecting, and bound it to <kbd>Space</kbd> https://github.com/Textualize/textual/issues/1433
 - Added `Tree.reset` to fully reset a `Tree` https://github.com/Textualize/textual/issues/1437
+- Added DOMNode.watch and DOMNode.is_attached methods  https://github.com/Textualize/textual/pull/1750
 
 ### Changed
 
 - Breaking change: `TreeNode` can no longer be imported from `textual.widgets`; it is now available via `from textual.widgets.tree import TreeNode`. https://github.com/Textualize/textual/pull/1637
 - `Tree` now shows a (subdued) cursor for a highlighted node when focus has moved elsewhere https://github.com/Textualize/textual/issues/1471
+- Breaking change: renamed `Checkbox` to `Switch`.
 
 ### Fixed
 
@@ -42,6 +44,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Removed
 
 - Methods `MessagePump.emit` and `MessagePump.emit_no_wait` https://github.com/Textualize/textual/pull/1738
+- Removed `reactive.watch` in favor of DOMNode.watch.
 
 ## [0.10.1] - 2023-01-20
 

docs/api/checkbox.md

@@ -1 +0,0 @@
-::: textual.widgets.Checkbox

docs/api/switch.md

@@ -0,0 +1 @@
+::: textual.widgets.Switch

docs/blog/posts/on-dog-food-the-original-metaverse-and-not-being-bored.md

@@ -288,7 +288,7 @@ So, thanks to this bit of code in my `Activity` widget...
             parent.move_child(
                 self, before=parent.children.index( self ) - 1
             )
-            self.post_message_no_wait( self.Moved( self ) )
+            self.emit_no_wait( self.Moved( self ) )
             self.scroll_visible( top=True )
 ```
 

docs/examples/widgets/switch.css

@@ -7,7 +7,7 @@ Screen {
     width: auto;
 }
 
-Checkbox {
+Switch {
     height: auto;
     width: auto;
 }
@@ -22,7 +22,7 @@ Checkbox {
     background: darkslategrey;
 }
 
-#custom-design > .checkbox--switch {
+#custom-design > .switch--switch {
     color: dodgerblue;
     background: darkslateblue;
 }

docs/examples/widgets/switch.py

@@ -1,35 +1,35 @@
 from textual.app import App, ComposeResult
 from textual.containers import Horizontal
-from textual.widgets import Checkbox, Static
+from textual.widgets import Switch, Static
 
 
-class CheckboxApp(App):
+class SwitchApp(App):
     def compose(self) -> ComposeResult:
-        yield Static("[b]Example checkboxes\n", classes="label")
+        yield Static("[b]Example switches\n", classes="label")
         yield Horizontal(
             Static("off:     ", classes="label"),
-            Checkbox(animate=False),
+            Switch(animate=False),
             classes="container",
         )
         yield Horizontal(
             Static("on:      ", classes="label"),
-            Checkbox(value=True),
+            Switch(value=True),
             classes="container",
         )
 
-        focused_checkbox = Checkbox()
+        focused_switch = Switch()
-        focused_checkbox.focus()
+        focused_switch.focus()
         yield Horizontal(
-            Static("focused: ", classes="label"), focused_checkbox, classes="container"
+            Static("focused: ", classes="label"), focused_switch, classes="container"
         )
 
         yield Horizontal(
             Static("custom:  ", classes="label"),
-            Checkbox(id="custom-design"),
+            Switch(id="custom-design"),
             classes="container",
         )
 
 
-app = CheckboxApp(css_path="checkbox.css")
+app = SwitchApp(css_path="switch.css")
 if __name__ == "__main__":
     app.run()

docs/roadmap.md

@@ -40,7 +40,7 @@ Widgets are key to making user-friendly interfaces. The builtin widgets should c
 - [x] Buttons
     * [x] Error / warning variants
 - [ ] Color picker
-- [x] Checkbox
+- [ ] Checkbox
 - [ ] Content switcher
 - [x] DataTable
     * [x] Cell select
@@ -70,6 +70,7 @@ Widgets are key to making user-friendly interfaces. The builtin widgets should c
     * [ ] Style variants (solid, thin etc)
 - [ ] Radio boxes
 - [ ] Spark-lines
+- [X] Switch
 - [ ] Tabs
 - [ ] TextArea (multi-line input)
     * [ ] Basic controls

docs/widgets/checkbox.md

@@ -1,63 +0,0 @@
-# Checkbox
-
-A simple checkbox widget which stores a boolean value.
-
-- [x] Focusable
-- [ ] Container
-
-## Example
-
-The example below shows checkboxes in various states.
-
-=== "Output"
-
-    ```{.textual path="docs/examples/widgets/checkbox.py"}
-    ```
-
-=== "checkbox.py"
-
-    ```python
-    --8<-- "docs/examples/widgets/checkbox.py"
-    ```
-
-=== "checkbox.css"
-
-    ```sass
-    --8<-- "docs/examples/widgets/checkbox.css"
-    ```
-
-## Reactive Attributes
-
-| Name    | Type   | Default | Description                        |
-| ------- | ------ | ------- | ---------------------------------- |
-| `value` | `bool` | `False` | The default value of the checkbox. |
-
-## Bindings
-
-The checkbox widget defines directly the following bindings:
-
-::: textual.widgets.Checkbox.BINDINGS
-    options:
-      show_root_heading: false
-      show_root_toc_entry: false
-
-## Component Classes
-
-The checkbox widget provides the following component classes:
-
-::: textual.widgets.Checkbox.COMPONENT_CLASSES
-    options:
-      show_root_heading: false
-      show_root_toc_entry: false
-
-## Messages
-
-### ::: textual.widgets.Checkbox.Changed
-
-## Additional Notes
-
-- To remove the spacing around a checkbox, set `border: none;` and `padding: 0;`.
-
-## See Also
-
-- [Checkbox](../api/checkbox.md) code reference

docs/widgets/switch.md

@@ -0,0 +1,63 @@
+# Switch
+
+A simple switch widget which stores a boolean value.
+
+- [x] Focusable
+- [ ] Container
+
+## Example
+
+The example below shows switches in various states.
+
+=== "Output"
+
+    ```{.textual path="docs/examples/widgets/switch.py"}
+    ```
+
+=== "switch.py"
+
+    ```python
+    --8<-- "docs/examples/widgets/switch.py"
+    ```
+
+=== "switch.css"
+
+    ```sass
+    --8<-- "docs/examples/widgets/switch.css"
+    ```
+
+## Reactive Attributes
+
+| Name    | Type   | Default | Description                      |
+|---------|--------|---------|----------------------------------|
+| `value` | `bool` | `False` | The default value of the switch. |
+
+## Bindings
+
+The switch widget defines directly the following bindings:
+
+::: textual.widgets.Switch.BINDINGS
+    options:
+      show_root_heading: false
+      show_root_toc_entry: false
+
+## Component Classes
+
+The switch widget provides the following component classes:
+
+::: textual.widgets.Switch.COMPONENT_CLASSES
+    options:
+      show_root_heading: false
+      show_root_toc_entry: false
+
+## Messages
+
+### ::: textual.widgets.Switch.Changed
+
+## Additional Notes
+
+- To remove the spacing around a `Switch`, set `border: none;` and `padding: 0;`.
+
+## See Also
+
+- [Switch](../api/switch.md) code reference

mkdocs-nav.yml

@@ -121,7 +121,6 @@ nav:
       - "styles/width.md"
     - Widgets:
       - "widgets/button.md"
-      - "widgets/checkbox.md"
       - "widgets/data_table.md"
       - "widgets/directory_tree.md"
       - "widgets/footer.md"
@@ -133,6 +132,7 @@ nav:
       - "widgets/list_view.md"
       - "widgets/placeholder.md"
       - "widgets/static.md"
+      - "widgets/switch.md"
       - "widgets/text_log.md"
       - "widgets/tree.md"
   - API:
@@ -140,7 +140,6 @@ nav:
     - "api/app.md"
     - "api/binding.md"
     - "api/button.md"
-    - "api/checkbox.md"
     - "api/color.md"
     - "api/containers.md"
     - "api/coordinate.md"
@@ -165,6 +164,7 @@ nav:
     - "api/scroll_view.md"
     - "api/static.md"
     - "api/strip.md"
+    - "api/switch.md"
     - "api/text_log.md"
     - "api/timer.md"
     - "api/tree.md"

src/textual/cli/previews/easing.py

@@ -5,7 +5,7 @@ from textual._easing import EASING
 from textual.app import App, ComposeResult
 from textual.cli.previews.borders import TEXT
 from textual.containers import Container, Horizontal, Vertical
-from textual.reactive import Reactive
+from textual.reactive import reactive, var
 from textual.scrollbar import ScrollBarRender
 from textual.widget import Widget
 from textual.widgets import Button, Footer, Label, Input
@@ -23,8 +23,8 @@ class EasingButtons(Widget):
 
 
 class Bar(Widget):
-    position = Reactive.init(START_POSITION)
+    position = reactive(START_POSITION)
-    animation_running = Reactive(False)
+    animation_running = reactive(False)
 
     DEFAULT_CSS = """
 
@@ -53,8 +53,8 @@ class Bar(Widget):
 
 
 class EasingApp(App):
-    position = Reactive.init(START_POSITION)
+    position = reactive(START_POSITION)
-    duration = Reactive.var(1.0)
+    duration = var(1.0)
 
     def on_load(self):
         self.bind(

src/textual/demo.css

@@ -119,7 +119,7 @@ DarkSwitch .label {
     color: $text-muted;
 }
 
-DarkSwitch Checkbox {
+DarkSwitch Switch {
     background: $boost;
     dock: left;
 }

src/textual/demo.py

@@ -15,15 +15,15 @@ from rich.text import Text
 from textual.app import App, ComposeResult
 from textual.binding import Binding
 from textual.containers import Container, Horizontal
-from textual.reactive import reactive, watch
+from textual.reactive import reactive
 from textual.widgets import (
     Button,
-    Checkbox,
     DataTable,
     Footer,
     Header,
     Input,
     Static,
+    Switch,
     TextLog,
 )
 
@@ -138,7 +138,7 @@ Build your own or use the builtin widgets.
 
 - **Input** Text / Password input.
 - **Button** Clickable button with a number of styles.
-- **Checkbox** A checkbox to toggle between states.
+- **Switch** A switch to toggle between states.
 - **DataTable** A spreadsheet-like widget for navigating data. Cells may contain text or Rich renderables.
 - **Tree** An generic tree with expandable nodes.
 - **DirectoryTree** A tree of file and folders.
@@ -199,16 +199,16 @@ class Title(Static):
 
 class DarkSwitch(Horizontal):
     def compose(self) -> ComposeResult:
-        yield Checkbox(value=self.app.dark)
+        yield Switch(value=self.app.dark)
         yield Static("Dark mode toggle", classes="label")
 
     def on_mount(self) -> None:
-        watch(self.app, "dark", self.on_dark_change, init=False)
+        self.watch(self.app, "dark", self.on_dark_change, init=False)
 
     def on_dark_change(self, dark: bool) -> None:
-        self.query_one(Checkbox).value = self.app.dark
+        self.query_one(Switch).value = self.app.dark
 
-    def on_checkbox_changed(self, event: Checkbox.Changed) -> None:
+    def on_switch_changed(self, event: Switch.Changed) -> None:
         self.app.dark = event.value
 
 

src/textual/dom.py

@@ -22,6 +22,7 @@ from rich.tree import Tree
 
 from ._context import NoActiveAppError
 from ._node_list import NodeList
+from ._types import CallbackType
 from .binding import Bindings, BindingType
 from .color import BLACK, WHITE, Color
 from .css._error_tools import friendly_list
@@ -31,7 +32,7 @@ from .css.parse import parse_declarations
 from .css.styles import RenderStyles, Styles
 from .css.tokenize import IDENTIFIER
 from .message_pump import MessagePump
-from .reactive import Reactive
+from .reactive import Reactive, _watch
 from .timer import Timer
 from .walk import walk_breadth_first, walk_depth_first
 
@@ -210,6 +211,10 @@ class DOMNode(MessagePump):
         styles = self._component_styles[name]
         return styles
 
+    def _post_mount(self):
+        """Called after the object has been mounted."""
+        Reactive._initialize_object(self)
+
     @property
     def _node_bases(self) -> Iterator[Type[DOMNode]]:
         """Iterator[Type[DOMNode]]: The DOMNode bases classes (including self.__class__)"""
@@ -643,6 +648,23 @@ class DOMNode(MessagePump):
         """
         return [child for child in self.children if child.display]
 
+    def watch(
+        self,
+        obj: DOMNode,
+        attribute_name: str,
+        callback: CallbackType,
+        init: bool = True,
+    ) -> None:
+        """Watches for modifications to reactive attributes on another object.
+
+        Args:
+            obj: Object containing attribute to watch.
+            attribute_name: Attribute to watch.
+            callback: A callback to run when attribute changes.
+            init: Check watchers on first call.
+        """
+        _watch(self, obj, attribute_name, callback, init=init)
+
     def get_pseudo_classes(self) -> Iterable[str]:
         """Get any pseudo classes applicable to this Node, e.g. hover, focus.
 

src/textual/message_pump.py

@@ -123,6 +123,19 @@ class MessagePump(metaclass=MessagePumpMeta):
         """
         return self.app._logger
 
+    @property
+    def is_attached(self) -> bool:
+        """Is the node is attached to the app via the DOM."""
+        from .app import App
+
+        node = self
+
+        while not isinstance(node, App):
+            if node._parent is None:
+                return False
+            node = node._parent
+        return True
+
     def _attach(self, parent: MessagePump) -> None:
         """Set the parent, and therefore attach this node to the tree.
 
@@ -358,7 +371,10 @@ class MessagePump(metaclass=MessagePumpMeta):
         finally:
             # This is critical, mount may be waiting
             self._mounted_event.set()
-        Reactive._initialize_object(self)
+        self._post_mount()
+
+    def _post_mount(self):
+        """Called after the object has been mounted."""
 
     async def _process_messages_loop(self) -> None:
         """Process messages until the queue is closed."""

src/textual/pilot.py

@@ -53,6 +53,7 @@ class Pilot(Generic[ReturnType]):
     async def wait_for_scheduled_animations(self) -> None:
         """Wait for any current and scheduled animations to complete."""
         await self._app.animator.wait_until_complete()
+        await wait_for_idle(0)
 
     async def exit(self, result: ReturnType) -> None:
         """Exit the app with the given result.

src/textual/reactive.py

@@ -7,36 +7,26 @@ from typing import (
     Any,
     Awaitable,
     Callable,
+    ClassVar,
     Generic,
     Type,
     TypeVar,
-    Union,
 )
 
 import rich.repr
 
 from . import events
-from ._callback import count_parameters, invoke
+from ._callback import count_parameters
-from ._types import MessageTarget
+from ._types import MessageTarget, CallbackType
 
 if TYPE_CHECKING:
-    from .app import App
+    from .dom import DOMNode
-    from .widget import Widget
 
-    Reactable = Union[Widget, App]
+    Reactable = DOMNode
 
 ReactiveType = TypeVar("ReactiveType")
 
 
-class _NotSet:
-    pass
-
-
-_NOT_SET = _NotSet()
-
-T = TypeVar("T")
-
-
 @rich.repr.auto
 class Reactive(Generic[ReactiveType]):
     """Reactive descriptor.
@@ -50,7 +40,7 @@ class Reactive(Generic[ReactiveType]):
         compute: Run compute methods when attribute is changed. Defaults to True.
     """
 
-    _reactives: TypeVar[dict[str, object]] = {}
+    _reactives: ClassVar[dict[str, object]] = {}
 
     def __init__(
         self,
@@ -77,37 +67,6 @@ class Reactive(Generic[ReactiveType]):
         yield "always_update", self._always_update
         yield "compute", self._run_compute
 
-    @classmethod
-    def init(
-        cls,
-        default: ReactiveType | Callable[[], ReactiveType],
-        *,
-        layout: bool = False,
-        repaint: bool = True,
-        always_update: bool = False,
-        compute: bool = True,
-    ) -> Reactive:
-        """A reactive variable that calls watchers and compute on initialize (post mount).
-
-        Args:
-            default: A default value or callable that returns a default.
-            layout: Perform a layout on change. Defaults to False.
-            repaint: Perform a repaint on change. Defaults to True.
-            always_update: Call watchers even when the new value equals the old value. Defaults to False.
-            compute: Run compute methods when attribute is changed. Defaults to True.
-
-        Returns:
-            A Reactive instance which calls watchers or initialize.
-        """
-        return cls(
-            default,
-            layout=layout,
-            repaint=repaint,
-            init=True,
-            always_update=always_update,
-            compute=compute,
-        )
-
     @classmethod
     def var(
         cls,
@@ -254,7 +213,7 @@ class Reactive(Generic[ReactiveType]):
 
         def invoke_watcher(
             watch_function: Callable, old_value: object, value: object
-        ) -> bool:
+        ) -> None:
             """Invoke a watch function.
 
             Args:
@@ -262,8 +221,6 @@ class Reactive(Generic[ReactiveType]):
                 old_value: The old value of the attribute.
                 value: The new value of the attribute.
 
-            Returns:
-                True if the watcher was run, or False if it was posted.
             """
             _rich_traceback_omit = True
             param_count = count_parameters(watch_function)
@@ -280,17 +237,23 @@ class Reactive(Generic[ReactiveType]):
                         sender=obj, callback=partial(await_watcher, watch_result)
                     )
                 )
-                return False
-            else:
-                return True
 
         watch_function = getattr(obj, f"watch_{name}", None)
         if callable(watch_function):
             invoke_watcher(watch_function, old_value, value)
 
-        watchers: list[Callable] = getattr(obj, "__watchers", {}).get(name, [])
+        # Process "global" watchers
-        for watcher in watchers:
+        watchers: list[tuple[Reactable, Callable]]
-            invoke_watcher(watcher, old_value, value)
+        watchers = getattr(obj, "__watchers", {}).get(name, [])
+        # Remove any watchers for reactables that have since closed
+        if watchers:
+            watchers[:] = [
+                (reactable, callback)
+                for reactable, callback in watchers
+                if reactable.is_attached and not reactable._closing
+            ]
+            for _, callback in watchers:
+                invoke_watcher(callback, old_value, value)
 
     @classmethod
     def _compute(cls, obj: Reactable) -> None:
@@ -362,10 +325,12 @@ class var(Reactive[ReactiveType]):
         )
 
 
-def watch(
+def _watch(
+    node: DOMNode,
     obj: Reactable,
     attribute_name: str,
-    callback: Callable[[Any], object],
+    callback: CallbackType,
+    *,
     init: bool = True,
 ) -> None:
     """Watch a reactive variable on an object.
@@ -379,11 +344,11 @@ def watch(
 
     if not hasattr(obj, "__watchers"):
         setattr(obj, "__watchers", {})
-    watchers: dict[str, list[Callable]] = getattr(obj, "__watchers")
+    watchers: dict[str, list[tuple[Reactable, Callable]]] = getattr(obj, "__watchers")
     watcher_list = watchers.setdefault(attribute_name, [])
     if callback in watcher_list:
         return
-    watcher_list.append(callback)
+    watcher_list.append((node, callback))
     if init:
         current_value = getattr(obj, attribute_name, None)
         Reactive._check_watchers(obj, attribute_name, current_value)

src/textual/widgets/__init__.py

@@ -9,7 +9,6 @@ from ..case import camel_to_snake
 # be able to "see" them.
 if typing.TYPE_CHECKING:
     from ._button import Button
-    from ._checkbox import Checkbox
     from ._data_table import DataTable
     from ._directory_tree import DirectoryTree
     from ._footer import Footer
@@ -21,6 +20,7 @@ if typing.TYPE_CHECKING:
     from ._placeholder import Placeholder
     from ._pretty import Pretty
     from ._static import Static
+    from ._switch import Switch
     from ._text_log import TextLog
     from ._tree import Tree
     from ._welcome import Welcome
@@ -29,7 +29,7 @@ if typing.TYPE_CHECKING:
 
 __all__ = [
     "Button",
-    "Checkbox",
+    "Switch",
     "DataTable",
     "DirectoryTree",
     "Footer",

src/textual/widgets/__init__.pyi

@@ -1,18 +1,17 @@
 # This stub file must re-export every classes exposed in the __init__.py's `__all__` list:
 from ._button import Button as Button
 from ._data_table import DataTable as DataTable
-from ._checkbox import Checkbox as Checkbox
 from ._directory_tree import DirectoryTree as DirectoryTree
 from ._footer import Footer as Footer
 from ._header import Header as Header
+from ._input import Input as Input
 from ._label import Label as Label
 from ._list_view import ListView as ListView
 from ._list_item import ListItem as ListItem
 from ._placeholder import Placeholder as Placeholder
 from ._pretty import Pretty as Pretty
 from ._static import Static as Static
-from ._input import Input as Input
+from ._switch import Switch as Switch
 from ._text_log import TextLog as TextLog
 from ._tree import Tree as Tree
-from ._tree_node import TreeNode as TreeNode
 from ._welcome import Welcome as Welcome

src/textual/widgets/_button.py

@@ -11,7 +11,7 @@ from rich.text import Text, TextType
 from .. import events
 from ..css._error_tools import friendly_list
 from ..message import Message
-from ..reactive import Reactive
+from ..reactive import reactive
 from ..widgets import Static
 
 
@@ -151,13 +151,13 @@ class Button(Static, can_focus=True):
     ACTIVE_EFFECT_DURATION = 0.3
     """When buttons are clicked they get the `-active` class for this duration (in seconds)"""
 
-    label: Reactive[RenderableType] = Reactive("")
+    label: reactive[RenderableType] = reactive("")
     """The text label that appears within the button."""
 
-    variant = Reactive.init("default")
+    variant = reactive("default")
     """The variant name for the button."""
 
-    disabled = Reactive(False)
+    disabled = reactive(False)
     """The disabled state of the button; `True` if disabled, `False` if not."""
 
     class Pressed(Message, bubble=True):

src/textual/widgets/_data_table.py

@@ -1042,7 +1042,7 @@ class DataTable(ScrollView, Generic[CellType], can_focus=True):
         self._set_hover_cursor(True)
         if self.show_cursor and self.cursor_type != "none":
             # Only post selection events if there is a visible row/col/cell cursor.
-            self._post_message_selected_message()
+            self._post_selected_message()
             meta = self.get_style_at(event.x, event.y).meta
             if meta:
                 self.cursor_cell = Coordinate(meta["row"], meta["column"])

src/textual/widgets/_footer.py

@@ -8,7 +8,7 @@ from rich.console import RenderableType
 from rich.text import Text
 
 from .. import events
-from ..reactive import Reactive, watch
+from ..reactive import Reactive
 from ..widget import Widget
 
 
@@ -66,7 +66,7 @@ class Footer(Widget):
         self.refresh()
 
     def on_mount(self) -> None:
-        watch(self.screen, "focused", self._focus_changed)
+        self.watch(self.screen, "focused", self._focus_changed)
 
     def _focus_changed(self, focused: Widget | None) -> None:
         self._key_text = None

src/textual/widgets/_header.py

@@ -5,7 +5,7 @@ from datetime import datetime
 from rich.text import Text
 
 from ..widget import Widget
-from ..reactive import Reactive, watch
+from ..reactive import Reactive
 
 
 class HeaderIcon(Widget):
@@ -133,5 +133,5 @@ class Header(Widget):
         def set_sub_title(sub_title: str) -> None:
             self.query_one(HeaderTitle).sub_text = sub_title
 
-        watch(self.app, "title", set_title)
+        self.watch(self.app, "title", set_title)
-        watch(self.app, "sub_title", set_sub_title)
+        self.watch(self.app, "sub_title", set_sub_title)

src/textual/widgets/_switch.py

@@ -12,12 +12,12 @@ from ..widget import Widget
 from ..scrollbar import ScrollBarRender
 
 
-class Checkbox(Widget, can_focus=True):
+class Switch(Widget, can_focus=True):
-    """A checkbox widget that represents a boolean value.
+    """A switch widget that represents a boolean value.
 
-    Can be toggled by clicking on it or through its [bindings][textual.widgets.Checkbox.BINDINGS].
+    Can be toggled by clicking on it or through its [bindings][textual.widgets.Switch.BINDINGS].
 
-    The checkbox widget also contains [component classes][textual.widgets.Checkbox.COMPONENT_CLASSES]
+    The switch widget also contains [component classes][textual.widgets.Switch.COMPONENT_CLASSES]
     that enable more customization.
     """
 
@@ -27,20 +27,20 @@ class Checkbox(Widget, can_focus=True):
     """
     | Key(s) | Description |
     | :- | :- |
-    | enter,space | Toggle the checkbox status. |
+    | enter,space | Toggle the switch state. |
     """
 
     COMPONENT_CLASSES: ClassVar[set[str]] = {
-        "checkbox--switch",
+        "switch--switch",
     }
     """
     | Class | Description |
     | :- | :- |
-    | `checkbox--switch` | Targets the switch of the checkbox. |
+    | `switch--switch` | Targets the switch of the switch. |
     """
 
     DEFAULT_CSS = """
-    Checkbox {
+    Switch {
         border: tall transparent;
         background: $panel;
         height: auto;
@@ -48,49 +48,49 @@ class Checkbox(Widget, can_focus=True):
         padding: 0 2;
     }
 
-    Checkbox > .checkbox--switch {
+    Switch > .switch--switch {
         background: $panel-darken-2;
         color: $panel-lighten-2;
     }
 
-    Checkbox:hover {
+    Switch:hover {
         border: tall $background;
     }
 
-    Checkbox:focus {
+    Switch:focus {
         border: tall $accent;
     }
 
-    Checkbox.-on {
+    Switch.-on {
 
     }
 
-    Checkbox.-on > .checkbox--switch {
+    Switch.-on > .switch--switch {
         color: $success;
     }
     """
 
     value = reactive(False, init=False)
-    """The value of the checkbox; `True` for on and `False` for off."""
+    """The value of the switch; `True` for on and `False` for off."""
 
     slider_pos = reactive(0.0)
     """The position of the slider."""
 
     class Changed(Message, bubble=True):
-        """Posted when the status of the checkbox changes.
+        """Posted when the status of the switch changes.
 
-        Can be handled using `on_checkbox_changed` in a subclass of `Checkbox`
+        Can be handled using `on_switch_changed` in a subclass of `Switch`
         or in a parent widget in the DOM.
 
         Attributes:
-            value: The value that the checkbox was changed to.
+            value: The value that the switch was changed to.
-            input: The `Checkbox` widget that was changed.
+            input: The `Switch` widget that was changed.
         """
 
-        def __init__(self, sender: Checkbox, value: bool) -> None:
+        def __init__(self, sender: Switch, value: bool) -> None:
             super().__init__(sender)
             self.value: bool = value
-            self.input: Checkbox = sender
+            self.input: Switch = sender
 
     def __init__(
         self,
@@ -101,14 +101,14 @@ class Checkbox(Widget, can_focus=True):
         id: str | None = None,
         classes: str | None = None,
     ):
-        """Initialise the checkbox.
+        """Initialise the switch.
 
         Args:
-            value: The initial value of the checkbox. Defaults to False.
+            value: The initial value of the switch. Defaults to False.
-            animate: True if the checkbox should animate when toggled. Defaults to True.
+            animate: True if the switch should animate when toggled. Defaults to True.
-            name: The name of the checkbox.
+            name: The name of the switch.
-            id: The ID of the checkbox in the DOM.
+            id: The ID of the switch in the DOM.
-            classes: The CSS classes of the checkbox.
+            classes: The CSS classes of the switch.
         """
         super().__init__(name=name, id=id, classes=classes)
         if value:
@@ -128,7 +128,7 @@ class Checkbox(Widget, can_focus=True):
         self.set_class(slider_pos == 1, "-on")
 
     def render(self) -> RenderableType:
-        style = self.get_component_rich_style("checkbox--switch")
+        style = self.get_component_rich_style("switch--switch")
         return ScrollBarRender(
             virtual_size=100,
             window_size=50,
@@ -150,6 +150,6 @@ class Checkbox(Widget, can_focus=True):
         self.toggle()
 
     def toggle(self) -> None:
-        """Toggle the checkbox value. As a result of the value changing,
+        """Toggle the switch value. As a result of the value changing,
-        a Checkbox.Changed message will be posted."""
+        a Switch.Changed message will be posted."""
         self.value = not self.value

tests/snapshot_tests/snapshot_apps/screen_switch.py

@@ -0,0 +1,38 @@
+from textual.app import App, ComposeResult
+from textual.screen import Screen
+from textual.widgets import Static, Header, Footer
+
+
+class ScreenA(Screen):
+    BINDINGS = [("b", "switch_to_b", "Switch to screen B")]
+
+    def compose(self) -> ComposeResult:
+        yield Header()
+        yield Static("A")
+        yield Footer()
+
+    def action_switch_to_b(self):
+        self.app.switch_screen(ScreenB())
+
+
+class ScreenB(Screen):
+    def compose(self) -> ComposeResult:
+        yield Header()
+        yield Static("B")
+        yield Footer()
+
+
+class ModalApp(App):
+    BINDINGS = [("a", "push_a", "Push screen A")]
+
+    def compose(self) -> ComposeResult:
+        yield Header()
+        yield Footer()
+
+    def action_push_a(self) -> None:
+        self.push_screen(ScreenA())
+
+
+if __name__ == "__main__":
+    app = ModalApp()
+    app.run()

tests/snapshot_tests/test_snapshots.py

@@ -52,8 +52,8 @@ def test_dock_layout_sidebar(snap_compare):
 # from these examples which test rendering and simple interactions with it.
 
 
-def test_checkboxes(snap_compare):
+def test_switches(snap_compare):
-    """Tests checkboxes but also acts a regression test for using
+    """Tests switches but also acts a regression test for using
     width: auto in a Horizontal layout context."""
     press = [
         "shift+tab",
@@ -63,7 +63,7 @@ def test_checkboxes(snap_compare):
         "enter",  # toggle on
         "wait:20",
     ]
-    assert snap_compare(WIDGET_EXAMPLES_DIR / "checkbox.py", press=press)
+    assert snap_compare(WIDGET_EXAMPLES_DIR / "switch.py", press=press)
 
 
 def test_input_and_focus(snap_compare):
@@ -214,3 +214,7 @@ def test_auto_width_input(snap_compare):
     assert snap_compare(
         SNAPSHOT_APPS_DIR / "auto_width_input.py", press=["tab", *"Hello"]
     )
+
+
+def test_screen_switch(snap_compare):
+    assert snap_compare(SNAPSHOT_APPS_DIR / "screen_switch.py", press=["a", "b"])

tests/test_focus.py

@@ -152,21 +152,21 @@ def test_focus_next_and_previous_with_type_selector_without_self():
     screen = app.screen
 
     from textual.containers import Horizontal, Vertical
-    from textual.widgets import Button, Checkbox, Input
+    from textual.widgets import Button, Input, Switch
 
     screen._add_children(
         Vertical(
             Horizontal(
                 Input(id="w3"),
-                Checkbox(id="w4"),
+                Switch(id="w4"),
                 Input(id="w5"),
                 Button(id="w6"),
-                Checkbox(id="w7"),
+                Switch(id="w7"),
                 id="w2",
             ),
             Horizontal(
                 Button(id="w9"),
-                Checkbox(id="w10"),
+                Switch(id="w10"),
                 Button(id="w11"),
                 Input(id="w12"),
                 Input(id="w13"),
@@ -180,11 +180,11 @@ def test_focus_next_and_previous_with_type_selector_without_self():
     assert screen.focused.id == "w3"
 
     assert screen.focus_next(Button).id == "w6"
-    assert screen.focus_next(Checkbox).id == "w7"
+    assert screen.focus_next(Switch).id == "w7"
     assert screen.focus_next(Input).id == "w12"
 
     assert screen.focus_previous(Button).id == "w11"
-    assert screen.focus_previous(Checkbox).id == "w10"
+    assert screen.focus_previous(Switch).id == "w10"
     assert screen.focus_previous(Button).id == "w9"
     assert screen.focus_previous(Input).id == "w5"
 

tests/test_widget_removing.py

@@ -8,9 +8,13 @@ from textual.containers import Container
 async def test_remove_single_widget():
     """It should be possible to the only widget on a screen."""
     async with App().run_test() as pilot:
-        await pilot.app.mount(Static())
+        widget = Static()
+        assert not widget.is_attached
+        await pilot.app.mount(widget)
+        assert widget.is_attached
         assert len(pilot.app.screen.children) == 1
         await pilot.app.query_one(Static).remove()
+        assert not widget.is_attached
         assert len(pilot.app.screen.children) == 0