refactor of compositor

docs/examples/timers/clock.py

@@ -17,7 +17,7 @@ class Clock(Widget):
 
 class ClockApp(App):
     async def on_mount(self):
-        await self.view.dock(Clock())
+        await self.screen.dock(Clock())
 
 
 ClockApp.run()

docs/examples/widgets/custom.py

@@ -26,7 +26,7 @@ class HoverApp(App):
         """Build layout here."""
 
         hovers = (Hover() for _ in range(10))
-        await self.view.dock(*hovers, edge="top")
+        await self.screen.dock(*hovers, edge="top")
 
 
 HoverApp.run(log="textual.log")

docs/examples/widgets/placeholders.py

@@ -8,8 +8,8 @@ class SimpleApp(App):
     async def on_mount(self) -> None:
         """Build layout here."""
 
-        await self.view.dock(Placeholder(), edge="left", size=40)
+        await self.screen.dock(Placeholder(), edge="left", size=40)
-        await self.view.dock(Placeholder(), Placeholder(), edge="top")
+        await self.screen.dock(Placeholder(), Placeholder(), edge="top")
 
 
 SimpleApp.run(log="textual.log")

examples/animation.py

@@ -26,9 +26,9 @@ class SmoothApp(App):
         footer = Footer()
         self.bar = Placeholder(name="left")
 
-        await self.view.dock(footer, edge="bottom")
+        await self.screen.dock(footer, edge="bottom")
-        await self.view.dock(Placeholder(), Placeholder(), edge="top")
+        await self.screen.dock(Placeholder(), Placeholder(), edge="top")
-        await self.view.dock(self.bar, edge="left", size=40, z=1)
+        await self.screen.dock(self.bar, edge="left", size=40, z=1)
 
         self.bar.layout_offset_x = -40
 

examples/basic.css

@@ -2,7 +2,7 @@
 
 $primary: #20639b;
 
-App > View {
+App > Screen {
   layout: dock;
   docks: side=left/1;
   text: on $primary;
@@ -13,6 +13,7 @@ App > View {
   dock: side;
   width: 30;
   offset-x: -100%;
+
   transition: offset 500ms in_out_cubic;
   border-right: outer #09312e;
 }

examples/big_table.py

@@ -15,7 +15,7 @@ class MyApp(App):
 
         self.body = body = ScrollView(auto_width=True)
 
-        await self.view.dock(body)
+        await self.screen.dock(body)
 
         async def add_content():
             table = Table(title="Demo")

examples/calculator.py

@@ -209,7 +209,7 @@ class CalculatorApp(App):
 
     async def on_mount(self) -> None:
         """Mount the calculator widget."""
-        await self.view.dock(Calculator())
+        await self.screen.dock(Calculator())
 
 
 CalculatorApp.run(title="Calculator Test", log="textual.log")

examples/code_viewer.py

@@ -36,14 +36,14 @@ class MyApp(App):
         self.directory = DirectoryTree(self.path, "Code")
 
         # Dock our widgets
-        await self.view.dock(Header(), edge="top")
+        await self.screen.dock(Header(), edge="top")
-        await self.view.dock(Footer(), edge="bottom")
+        await self.screen.dock(Footer(), edge="bottom")
 
         # Note the directory is also in a scroll view
-        await self.view.dock(
+        await self.screen.dock(
             ScrollView(self.directory), edge="left", size=48, name="sidebar"
         )
-        await self.view.dock(self.body, edge="top")
+        await self.screen.dock(self.body, edge="top")
 
     async def handle_file_click(self, message: FileClick) -> None:
         """A message sent by the directory tree when a file is clicked."""

examples/easing.py

@@ -32,8 +32,8 @@ class EasingApp(App):
             await tree.add(tree.root.id, easing_key, {"easing": easing_key})
         await tree.root.expand()
 
-        await self.view.dock(ScrollView(tree), edge="left", size=32)
+        await self.screen.dock(ScrollView(tree), edge="left", size=32)
-        await self.view.dock(self.easing_view)
+        await self.screen.dock(self.easing_view)
         await self.easing_view.dock(self.placeholder, edge="left", size=32)
 
     async def handle_tree_click(self, message: TreeClick[dict]) -> None:

examples/grid.py

@@ -6,7 +6,7 @@ class GridTest(App):
     async def on_mount(self) -> None:
         """Make a simple grid arrangement."""
 
-        grid = await self.view.dock_grid(edge="left", name="left")
+        grid = await self.screen.dock_grid(edge="left", name="left")
 
         grid.add_column(fraction=1, name="left", min_size=20)
         grid.add_column(size=30, name="center")

examples/grid_auto.py

@@ -7,7 +7,7 @@ class GridTest(App):
     async def on_mount(self, event: events.Mount) -> None:
         """Create a grid with auto-arranging cells."""
 
-        grid = await self.view.dock_grid()
+        grid = await self.screen.dock_grid()
 
         grid.add_column("col", fraction=1, max_size=20)
         grid.add_row("row", fraction=1, max_size=10)

examples/simple.py

@@ -33,7 +33,7 @@ class MyApp(App):
         """Create and dock the widgets."""
 
         body = ScrollView()
-        await self.view.mount(
+        await self.screen.mount(
             Header(),
             Footer(),
             body=body,

sandbox/dev_sandbox.py

@@ -19,6 +19,7 @@ class BasicApp(App):
         self.bind("a", "toggle_class('#header', '-visible')")
         self.bind("c", "toggle_class('#content', '-content-visible')")
         self.bind("d", "toggle_class('#footer', 'dim')")
+        self.bind("x", "dump")
 
     def on_mount(self):
         """Build layout here."""
@@ -29,5 +30,8 @@ class BasicApp(App):
             sidebar=Widget(),
         )
 
+    def action_dump(self):
+        self.panic(self.tree)
+
 
 BasicApp.run(css_file="dev_sandbox.scss", watch_css=True, log="textual.log")

sandbox/dev_sandbox.scss

@@ -2,7 +2,7 @@
 
 $text: #f0f0f0;
 $primary: #021720;
-$secondary:#95d52a;
+$secondary: #95d52a;
 $background: #262626;
 
 $primary-style: $text on $background;

sandbox/uber.css

@@ -1,4 +1,24 @@
 #uber {
-  border: heavy green;
+  /* border: heavy green; */
-  margin: 5;
+  margin: 2;
+  layout: dock;
+  docks: panels=top;
+}
+
+#child1 {
+  dock: panels;
+}
+
+#child2 {
+  dock: panels;
+}
+
+#child3 {
+  dock: panels;
+}
+
+#uber2 {
+  margin: 3;
+  layout: dock;
+  docks: _default=left;
 }

sandbox/uber.py

@@ -1,3 +1,4 @@
+from tkinter import Place
 from textual.app import App
 from textual import events
 from textual.widgets import Placeholder
@@ -9,7 +10,22 @@ class BasicApp(App):
 
     def on_mount(self):
         """Build layout here."""
-        self.mount(uber=Placeholder())
+
+        uber2 = Widget()
+        uber2.add_children(
+            Placeholder(id="uber2-child1"),
+            Placeholder(id="uber2-child2"),
+        )
+
+        self.mount(
+            uber=Widget(
+                Placeholder(id="child1"),
+                Placeholder(id="child2"),
+                Placeholder(id="child3"),
+            ),
+            uber2=uber2,
+        )
+        # self.panic(self.tree)
 
     async def on_key(self, event: events.Key) -> None:
         await self.dispatch_key(event)

src/textual/_animator.py

@@ -110,6 +110,8 @@ class BoundAnimator:
 
 
 class Animator:
+    """An object to manage updates to a given attributed over a period of time."""
+
     def __init__(self, target: MessageTarget, frames_per_second: int = 60) -> None:
         self._animations: dict[tuple[object, str], Animation] = {}
         self.target = target
@@ -225,4 +227,6 @@ class Animator:
 
     def on_animation_frame(self) -> None:
         # TODO: We should be able to do animation without refreshing everything
-        self.target.view.refresh(True, True)
+
+        self.target.screen.refresh(layout=True)
+        # self.target.screen.app.refresh()

src/textual/_compositor.py

@@ -11,10 +11,9 @@ from rich.control import Control
 from rich.segment import Segment, SegmentLines
 from rich.style import Style
 
-from . import log
+from . import errors, log
 from .geometry import Region, Offset, Size
 
-from .layout import WidgetPlacement
 from ._loop import loop_last
 from ._types import Lines
 from .widget import Widget
@@ -26,13 +25,10 @@ else:  # pragma: no cover
 
 
 if TYPE_CHECKING:
+    from .screen import Screen
     from .widget import Widget
 
 
-class NoWidget(Exception):
-    """Raised when there is no widget at the requested coordinate."""
-
-
 class ReflowResult(NamedTuple):
     """The result of a reflow operation. Describes the chances to widgets."""
 
@@ -137,8 +133,8 @@ class Compositor:
         self.width = size.width
         self.height = size.height
 
-        map, virtual_size = self._arrange_root(parent)
+        map, virtual_size, widgets = self._arrange_root(parent)
-        log(map)
+
         self._require_update = False
 
         old_widgets = set(self.map.keys())
@@ -165,12 +161,13 @@ class Compositor:
         }
 
         parent.virtual_size = virtual_size
-
+        self.widgets.clear()
+        self.widgets.update(widgets)
         return ReflowResult(
             hidden=hidden_widgets, shown=shown_widgets, resized=resized_widgets
         )
 
-    def _arrange_root(self, root: Widget) -> tuple[RenderRegionMap, Size]:
+    def _arrange_root(self, root: Widget) -> tuple[RenderRegionMap, Size, set[Widget]]:
         """Arrange a widgets children based on its layout attribute.
 
         Args:
@@ -192,7 +189,7 @@ class Compositor:
             order: tuple[int, ...],
             clip: Region,
         ):
-            widgets: set[Widget] = set()
+            widgets.add(widget)
             styles_offset = widget.styles.offset
             total_region = region
             layout_offset = (
@@ -200,7 +197,6 @@ class Compositor:
                 if styles_offset
                 else ORIGIN
             )
-
             map[widget] = RenderRegion(region + layout_offset, order, clip)
 
             if widget.layout is not None:
@@ -227,12 +223,10 @@ class Compositor:
             return total_region.size
 
         virtual_size = add_widget(root, size.region, (), size.region)
-        self.widgets.clear()
+        return map, virtual_size, widgets
-        self.widgets.update(widgets)
-        return map, virtual_size
 
-    async def mount_all(self, view: "View") -> None:
+    async def mount_all(self, screen: Screen) -> None:
-        view.mount(*self.widgets)
+        screen.app.mount(*self.widgets)
 
     def __iter__(self) -> Iterator[tuple[Widget, Region, Region]]:
         layers = sorted(self.map.items(), key=lambda item: item[1].order, reverse=True)
@@ -244,14 +238,14 @@ class Compositor:
         try:
             return self.map[widget].region.origin
         except KeyError:
-            raise NoWidget("Widget is not in layout")
+            raise errors.NoWidget("Widget is not in layout")
 
     def get_widget_at(self, x: int, y: int) -> tuple[Widget, Region]:
         """Get the widget under the given point or None."""
         for widget, cropped_region, region in self:
-            if widget.is_visual and cropped_region.contains(x, y):
+            if cropped_region.contains(x, y):
                 return widget, region
-        raise NoWidget(f"No widget under screen coordinate ({x}, {y})")
+        raise errors.NoWidget(f"No widget under screen coordinate ({x}, {y})")
 
     def get_style_at(self, x: int, y: int) -> Style:
         """Get the Style at the given cell or Style.null()
@@ -265,13 +259,15 @@ class Compositor:
         """
         try:
             widget, region = self.get_widget_at(x, y)
-        except NoWidget:
+        except errors.NoWidget:
             return Style.null()
         if widget not in self.regions:
             return Style.null()
         lines = widget._get_lines()
         x -= region.x
         y -= region.y
+        if y > len(lines):
+            return Style.null()
         line = lines[y]
         end = 0
         for segment in line:
@@ -296,7 +292,7 @@ class Compositor:
         try:
             region, *_ = self.map[widget]
         except KeyError:
-            raise NoWidget("Widget is not in layout")
+            raise errors.NoWidget("Widget is not in layout")
         else:
             return region
 
@@ -344,7 +340,7 @@ class Compositor:
 
         for widget, region, _order, clip in widget_regions:
 
-            if not (widget.is_visual and widget.visible):
+            if not (widget.visible and widget.is_visual):
                 continue
 
             lines = widget._get_lines()
@@ -465,5 +461,4 @@ class Compositor:
         update_region = region.intersection(clip)
         update_lines = self.render(console, crop=update_region).lines
         update = LayoutUpdate(update_lines, update_region)
-        log(update)
         return update

src/textual/_node_list.py

@@ -22,6 +22,13 @@ class NodeList:
         self._node_refs: list[ref[DOMNode]] = []
         self.__nodes: list[DOMNode] | None = []
 
+    def __bool__(self) -> bool:
+        self._prune()
+        return bool(self._node_refs)
+
+    def __length_hint__(self) -> int:
+        return len(self._node_refs)
+
     def __rich_repr__(self) -> rich.repr.Result:
         yield self._widgets
 

src/textual/_timer.py

@@ -35,7 +35,7 @@ class Timer:
         *,
         name: str | None = None,
         callback: TimerCallback | None = None,
-        repeat: int = None,
+        repeat: int | None = None,
         skip: bool = False,
         pause: bool = False,
     ) -> None:

src/textual/_types.py

@@ -9,11 +9,9 @@ else:
 
 
 if TYPE_CHECKING:
-    from .events import Event
     from .message import Message
 
 Callback = Callable[[], None]
-# IntervalID = int
 
 
 class MessageTarget(Protocol):

src/textual/app.py

@@ -12,7 +12,7 @@ import rich.repr
 from rich.console import Console, RenderableType
 from rich.control import Control
 from rich.measure import Measurement
-from rich.screen import Screen
+from rich.screen import Screen as ScreenRenderable
 from rich.traceback import Traceback
 
 from . import actions
@@ -34,10 +34,9 @@ from .layouts.dock import Dock
 from .message_pump import MessagePump
 from .reactive import Reactive
 from .renderables.gradient import VerticalGradient
-from .view import View
+from .screen import Screen
 from .widget import Widget
 
-from .css.query import NoMatchingNodesError
 
 if TYPE_CHECKING:
     from .css.query import DOMQuery
@@ -50,8 +49,6 @@ warnings.simplefilter("always", ResourceWarning)
 
 LayoutDefinition = "dict[str, Any]"
 
-ViewType = TypeVar("ViewType", bound=View)
-
 
 class AppError(Exception):
     pass
@@ -86,12 +83,12 @@ class App(DOMNode):
             driver_class (Type[Driver], optional): Driver class, or None to use default. Defaults to None.
             title (str, optional): Title of the application. Defaults to "Textual Application".
         """
-        self.console = Console()
+        self.console = Console(markup=False)
-        self.error_console = Console(stderr=True)
+        self.error_console = Console(markup=False, stderr=True)
         self._screen = screen
         self.driver_class = driver_class or self.get_driver_class()
         self._title = title
-        self._view_stack: list[View] = []
+        self._screen_stack: list[Screen] = []
 
         self.focused: Widget | None = None
         self.mouse_over: Widget | None = None
@@ -100,7 +97,7 @@ class App(DOMNode):
         self._exit_renderables: list[RenderableType] = []
 
         self._docks: list[Dock] = []
-        self._action_targets = {"app", "view"}
+        self._action_targets = {"app", "screen"}
         self._animator = Animator(self)
         self.animate = self._animator.bind(self)
         self.mouse_position = Offset(0, 0)
@@ -158,8 +155,8 @@ class App(DOMNode):
         return self._animator
 
     @property
-    def view(self) -> View:
+    def screen(self) -> Screen:
-        return self._view_stack[-1]
+        return self._screen_stack[-1]
 
     @property
     def css_type(self) -> str:
@@ -262,10 +259,10 @@ class App(DOMNode):
                 self.reset_styles()
                 self.stylesheet = stylesheet
                 self.stylesheet.update(self)
-                self.view.refresh(layout=True)
+                self.screen.refresh(layout=True)
 
     def query(self, selector: str | None = None) -> DOMQuery:
-        """Get a DOM query in the current view.
+        """Get a DOM query in the current screen.
 
         Args:
             selector (str, optional): A CSS selector or `None` for all nodes. Defaults to None.
@@ -275,10 +272,10 @@ class App(DOMNode):
         """
         from .css.query import DOMQuery
 
-        return DOMQuery(self.view, selector)
+        return DOMQuery(self.screen, selector)
 
     def get_child(self, id: str) -> DOMNode:
-        """Shorthand for self.view.get_child(id: str)
+        """Shorthand for self.screen.get_child(id: str)
         Returns the first child (immediate descendent) of this DOMNode
         with the given ID.
 
@@ -288,7 +285,7 @@ class App(DOMNode):
         Returns:
             DOMNode: The first child of this node with the specified ID.
         """
-        return self.view.get_child(id)
+        return self.screen.get_child(id)
 
     def render_background(self) -> RenderableType:
         gradient = VerticalGradient("red", "blue")
@@ -303,12 +300,12 @@ class App(DOMNode):
         self.post_message_no_wait(messages.StylesUpdated(self))
 
     def mount(self, *anon_widgets: Widget, **widgets: Widget) -> None:
-        self.register(self.view, *anon_widgets, **widgets)
+        self.register(self.screen, *anon_widgets, **widgets)
-        self.view.refresh()
+        self.screen.refresh()
 
-    async def push_view(self, view: ViewType) -> ViewType:
+    async def push_screen(self, screen: Screen) -> Screen:
-        self._view_stack.append(view)
+        self._screen_stack.append(screen)
-        return view
+        return screen
 
     async def set_focus(self, widget: Widget | None) -> None:
         """Focus (or unfocus) a widget. A focused widget will receive key events first.
@@ -450,7 +447,7 @@ class App(DOMNode):
 
     def _register_child(self, parent: DOMNode, child: DOMNode) -> bool:
         if child not in self.registry:
-            parent.children._append(child)
+            parent.node_list._append(child)
             self.registry.add(child)
             child.set_parent(parent)
             child.start_messages()
@@ -473,6 +470,11 @@ class App(DOMNode):
         name_widgets = [*((None, widget) for widget in anon_widgets), *widgets.items()]
         apply_stylesheet = self.stylesheet.apply
 
+        # Register children
+        for _widget_id, widget in name_widgets:
+            if widget.node_list:
+                self.register(widget, *widget.children)
+
         for widget_id, widget in name_widgets:
             if widget not in self.registry:
                 if widget_id is not None:
@@ -500,7 +502,9 @@ class App(DOMNode):
         driver.disable_input()
         await self.close_messages()
 
-    def refresh(self) -> None:
+    def refresh(self, *, repaint: bool = True, layout: bool = False) -> None:
+        if not self._running:
+            return
         sync_available = (
             os.environ.get("TERM_PROGRAM", "") != "Apple_Terminal" and not WINDOWS
         )
@@ -509,9 +513,7 @@ class App(DOMNode):
             try:
                 if sync_available:
                     console.file.write("\x1bP=1s\x1b\\")
-                console.print(
+                console.print(ScreenRenderable(Control.home(), self.screen.render()))
-                    Screen(Control.home(), self.view.render_styled(), Control.home())
-                )
                 if sync_available:
                     console.file.write("\x1bP=2s\x1b\\")
                 console.file.flush()
@@ -519,6 +521,8 @@ class App(DOMNode):
                 self.panic()
 
     def display(self, renderable: RenderableType) -> None:
+        if not self._running:
+            return
         if not self._closed:
             console = self.console
             try:
@@ -551,7 +555,7 @@ class App(DOMNode):
         Returns:
             tuple[Widget, Region]: The widget and the widget's screen region.
         """
-        return self.view.get_widget_at(x, y)
+        return self.screen.get_widget_at(x, y)
 
     def bell(self) -> None:
         """Play the console 'bell'."""
@@ -578,9 +582,9 @@ class App(DOMNode):
         # Handle input events that haven't been forwarded
         # If the event has been forwarded it may have bubbled up back to the App
         if isinstance(event, events.Mount):
-            view = View()
+            screen = Screen()
-            self.register(self, view)
+            self.register(self, screen)
-            await self.push_view(view)
+            await self.push_screen(screen)
             await super().on_event(event)
 
         elif isinstance(event, events.InputEvent) and not event.is_forwarded:
@@ -596,7 +600,7 @@ class App(DOMNode):
                     await super().on_event(event)
             else:
                 # Forward the event to the view
-                await self.view.forward_event(event)
+                await self.screen.forward_event(event)
         else:
             await super().on_event(event)
 
@@ -636,6 +640,16 @@ class App(DOMNode):
     async def broker_event(
         self, event_name: str, event: events.Event, default_namespace: object | None
     ) -> bool:
+        """Allow the app an opportunity to dispatch events to action system.
+
+        Args:
+            event_name (str): _description_
+            event (events.Event): An event object.
+            default_namespace (object | None): _description_
+
+        Returns:
+            bool: _description_
+        """
         event.stop()
         try:
             style = getattr(event, "style")
@@ -661,7 +675,7 @@ class App(DOMNode):
 
     async def handle_layout(self, message: messages.Layout) -> None:
         message.stop()
-        # await self.view.refresh_layout()
+        # await self.screen.refresh_layout()
         self.app.refresh()
 
     async def on_key(self, event: events.Key) -> None:
@@ -672,7 +686,7 @@ class App(DOMNode):
         await self.close_messages()
 
     async def on_resize(self, event: events.Resize) -> None:
-        await self.view.post_message(event)
+        await self.screen.post_message(event)
 
     async def action_press(self, key: str) -> None:
         await self.press(key)
@@ -687,13 +701,13 @@ class App(DOMNode):
         self.bell()
 
     async def action_add_class_(self, selector: str, class_name: str) -> None:
-        self.view.query(selector).add_class(class_name)
+        self.screen.query(selector).add_class(class_name)
 
     async def action_remove_class_(self, selector: str, class_name: str) -> None:
-        self.view.query(selector).remove_class(class_name)
+        self.screen.query(selector).remove_class(class_name)
 
     async def action_toggle_class(self, selector: str, class_name: str) -> None:
-        self.view.query(selector).toggle_class(class_name)
+        self.screen.query(selector).toggle_class(class_name)
 
     async def handle_styles_updated(self, message: messages.StylesUpdated) -> None:
         self.stylesheet.update(self)

src/textual/css/_style_properties.py

@@ -15,6 +15,7 @@ import rich.repr
 from rich.color import Color
 from rich.style import Style
 
+from .. import log
 from ._error_tools import friendly_list
 from .constants import NULL_SPACING
 from .errors import StyleTypeError, StyleValueError
@@ -537,7 +538,6 @@ class OffsetProperty:
             ScalarParseError: If any of the string values supplied in the 2-tuple cannot
                 be parsed into a Scalar. For example, if you specify an non-existent unit.
         """
-
         if offset is None:
             if obj.clear_rule(self.name):
                 obj.refresh(layout=True)
@@ -557,6 +557,7 @@ class OffsetProperty:
                 else Scalar(float(y), Unit.CELLS, Unit.HEIGHT)
             )
             _offset = ScalarOffset(scalar_x, scalar_y)
+
             if obj.set_rule(self.name, _offset):
                 obj.refresh(layout=True)
 

src/textual/css/query.py

@@ -135,7 +135,7 @@ class DOMQuery:
             node.set_styles(css, **styles)
         return self
 
-    def refresh(self, repaint: bool = True, layout: bool = False) -> DOMQuery:
+    def refresh(self, *, repaint: bool = True, layout: bool = False) -> DOMQuery:
         """Refresh matched nodes.
 
         Args:

src/textual/css/scalar_animation.py

@@ -2,7 +2,7 @@ from __future__ import annotations
 
 from typing import TYPE_CHECKING
 
-from .. import events
+from .. import events, log
 from ..geometry import Offset
 from .._animator import Animation
 from .scalar import ScalarOffset

src/textual/css/styles.py

@@ -11,6 +11,7 @@ import rich.repr
 from rich.color import Color
 from rich.style import Style
 
+from .. import log
 from .._animator import Animation, EasingFunction
 from ..geometry import Spacing
 from ._style_properties import (
@@ -361,6 +362,7 @@ class Styles(StylesBase):
         return self._rules.get(rule, default)
 
     def refresh(self, *, layout: bool = False) -> None:
+        return
         self._repaint_required = True
         self._layout_required = self._layout_required or layout
 

src/textual/dom.py

@@ -6,6 +6,7 @@ import rich.repr
 from rich.highlighter import ReprHighlighter
 from rich.pretty import Pretty
 from rich.style import Style
+from rich.text import Text
 from rich.tree import Tree
 
 from ._node_list import NodeList
@@ -19,7 +20,7 @@ from .message_pump import MessagePump
 
 if TYPE_CHECKING:
     from .css.query import DOMQuery
-    from .view import View
+    from .screen import Screen
 
 
 class NoParent(Exception):
@@ -37,11 +38,16 @@ class DOMNode(MessagePump):
     DEFAULT_STYLES = ""
     INLINE_STYLES = ""
 
-    def __init__(self, name: str | None = None, id: str | None = None) -> None:
+    def __init__(
+        self,
+        name: str | None = None,
+        id: str | None = None,
+        classes: Iterable[str] | None = None,
+    ) -> None:
         self._name = name
         self._id = id
-        self._classes: set[str] = set()
+        self._classes: set[str] = set(classes) if classes else set()
-        self.children = NodeList()
+        self.node_list = NodeList()
         self._css_styles: Styles = Styles(self)
         self._inline_styles: Styles = Styles.parse(
             self.INLINE_STYLES, repr(self), node=self
@@ -73,18 +79,23 @@ class DOMNode(MessagePump):
         return self._parent
 
     @property
-    def view(self) -> "View":
+    def screen(self) -> "Screen":
-        """Get the current view."""
+        """Get the current screen."""
         # Get the node by looking up a chain of parents
-        # Note that self.view may not be the same as self.app.view
+        # Note that self.screen may not be the same as self.app.screen
-        from .view import View
+        from .screen import Screen
 
         node = self
-        while node and not isinstance(node, View):
+        while node and not isinstance(node, Screen):
             node = node._parent
-        assert isinstance(node, View)
+        assert isinstance(node, Screen)
         return node
 
+    @property
+    def is_visual(self) -> bool:
+        """Check if the widget is visual (i.e. draws something on Screen)."""
+        return True
+
     @property
     def id(self) -> str | None:
         """The ID of this node, or None if the node has no ID.
@@ -116,6 +127,22 @@ class DOMNode(MessagePump):
     def name(self) -> str | None:
         return self._name
 
+    @property
+    def css_identifier(self) -> str:
+        tokens = [self.__class__.__name__]
+        if self.id is not None:
+            tokens.append(f"#{self.id}")
+        return "".join(tokens)
+
+    @property
+    def css_identifier_styled(self) -> Text:
+        tokens = Text(self.__class__.__name__)
+        if self.id is not None:
+            tokens.append(f"#{self.id}", style="bold")
+        if self.name:
+            tokens.append(f"[name={self.name}]", style="underline")
+        return tokens
+
     @property
     def classes(self) -> frozenset[str]:
         return frozenset(self._classes)
@@ -237,12 +264,25 @@ class DOMNode(MessagePump):
         Returns:
             Tree: A Rich object which may be printed.
         """
+        from rich.columns import Columns
+        from rich.panel import Panel
+
         highlighter = ReprHighlighter()
         tree = Tree(highlighter(repr(self)))
 
         def add_children(tree, node):
-            for child in node.children:
+            for child in node.node_list:
-                branch = tree.add(Pretty(child))
+                branch = tree.add(
+                    Columns(
+                        [
+                            Pretty(child),
+                            Text(
+                                f"{child.size.width} X {child.size.height}", style="dim"
+                            ),
+                            Panel(Text(child.styles.css), border_style="dim"),
+                        ]
+                    )
+                )
                 if tree.children:
                     add_children(branch, child)
 
@@ -276,12 +316,20 @@ class DOMNode(MessagePump):
         Args:
             node (DOMNode): A DOM node.
         """
-        self.children._append(node)
+        self.node_list._append(node)
         node.set_parent(self)
 
+    def add_children(self, *nodes: DOMNode, **named_nodes: DOMNode) -> None:
+        _append = self.node_list._append
+        for node in nodes:
+            _append(node)
+        for node_id, node in named_nodes.items():
+            _append(node)
+            node.id = node_id
+
     def walk_children(self, with_self: bool = True) -> Iterable[DOMNode]:
 
-        stack: list[Iterator[DOMNode]] = [iter(self.children)]
+        stack: list[Iterator[DOMNode]] = [iter(self.node_list)]
         pop = stack.pop
         push = stack.append
 
@@ -294,8 +342,8 @@ class DOMNode(MessagePump):
                 pop()
             else:
                 yield node
-                if node.children:
+                if node.node_list:
-                    push(iter(node.children))
+                    push(iter(node.node_list))
 
     def get_child(self, id: str) -> DOMNode:
         """Return the first child (immediate descendent) of this node with the given ID.
@@ -306,7 +354,7 @@ class DOMNode(MessagePump):
         Returns:
             DOMNode: The first child of this node with the ID.
         """
-        for child in self.children:
+        for child in self.node_list:
             if child.id == id:
                 return child
         raise NoMatchingNodesError(f"No child found with id={id!r}")
@@ -379,5 +427,5 @@ class DOMNode(MessagePump):
         has_pseudo_classes = self.pseudo_classes.issuperset(class_names)
         return has_pseudo_classes
 
-    def refresh(self, repaint: bool = True, layout: bool = False) -> None:
+    def refresh(self, *, repaint: bool = True, layout: bool = False) -> None:
         raise NotImplementedError()

src/textual/errors.py

@@ -1,2 +1,9 @@
-class MissingWidget(Exception):
+from __future__ import annotations
+
+
+class TextualError(Exception):
+    pass
+
+
+class NoWidget(TextualError):
     pass

src/textual/events.py

@@ -5,6 +5,7 @@ from typing import Awaitable, Callable, Type, TYPE_CHECKING, TypeVar
 import rich.repr
 from rich.style import Style
 
+from . import log
 from .geometry import Offset, Size
 from .message import Message
 from ._types import MessageTarget
@@ -389,8 +390,3 @@ class Focus(Event, bubble=False):
 
 class Blur(Event, bubble=False):
     pass
-
-
-# class Update(Event, bubble=False):
-#     def can_replace(self, event: Message) -> bool:
-#         return isinstance(event, Update) and event.sender == self.sender

src/textual/layout.py

@@ -1,15 +1,16 @@
 from __future__ import annotations
 
 from abc import ABC, abstractmethod
-from typing import ClassVar, Generator, Iterable, NamedTuple, Sequence, TYPE_CHECKING
+from typing import ClassVar, Iterable, NamedTuple, TYPE_CHECKING
 
 
 from .geometry import Region, Offset, Size
 
 
 if TYPE_CHECKING:
+    from .dom import DOMNode
     from .widget import Widget
-    from .view import View
+    from .screen import Screen
 
 
 class WidgetPlacement(NamedTuple):
@@ -47,8 +48,8 @@ class Layout(ABC):
 
     @abstractmethod
     def arrange(
-        self, parent: View, size: Size, scroll: Offset
+        self, parent: Screen, size: Size, scroll: Offset
-    ) -> tuple[list[WidgetPlacement], set[Widget]]:
+    ) -> tuple[Iterable[WidgetPlacement], set[Widget]]:
         """Generate a layout map that defines where on the screen the widgets will be drawn.
 
         Args:

src/textual/layout_map.py

@@ -1,86 +0,0 @@
-"""
-
-Planned for deprecation
-
-"""
-
-from __future__ import annotations
-
-
-from typing import ItemsView, KeysView, ValuesView, NamedTuple
-
-from . import log
-from .geometry import Offset, Region, Size
-from operator import attrgetter
-from .widget import Widget
-
-
-class RenderRegion(NamedTuple):
-    """Defines the absolute location of a Widget."""
-
-    region: Region
-    order: tuple[int, ...]
-    clip: Region
-
-
-class LayoutMap:
-    """A container that maps widgets on to their absolute location."""
-
-    def __init__(self, size: Size) -> None:
-        self.size = size
-        self.widgets: dict[Widget, RenderRegion] = {}
-
-    def __getitem__(self, widget: Widget) -> RenderRegion:
-        return self.widgets[widget]
-
-    def items(self) -> ItemsView[Widget, RenderRegion]:
-        return self.widgets.items()
-
-    def keys(self) -> KeysView[Widget]:
-        return self.widgets.keys()
-
-    def values(self) -> ValuesView[RenderRegion]:
-        return self.widgets.values()
-
-    def clear(self) -> None:
-        self.widgets.clear()
-
-    def add_widget(
-        self,
-        widget: Widget,
-        region: Region,
-        order: tuple[int, ...],
-        clip: Region,
-    ) -> None:
-        from .view import View
-
-        if widget in self.widgets:
-            return
-
-        layout_offset = Offset(0, 0)
-        if any(widget.styles.offset):
-            layout_offset = widget.styles.offset.resolve(region.size, clip.size)
-
-        self.widgets[widget] = RenderRegion(region + layout_offset, order, clip)
-
-        # TODO: replace with widget.layout
-
-        if isinstance(widget, View):
-            view: View = widget
-            scroll = view.scroll
-            total_region = region.size.region
-            sub_clip = clip.intersection(region)
-
-            arrangement = sorted(
-                view.get_arrangement(region.size, scroll), key=attrgetter("order")
-            )
-            for sub_region, sub_widget, z in arrangement:
-                total_region = total_region.union(sub_region)
-                if sub_widget is not None:
-                    self.add_widget(
-                        sub_widget,
-                        sub_region + region.origin - scroll,
-                        sub_widget.z + (z,),
-                        sub_clip,
-                    )
-            view.virtual_size = total_region.size

src/textual/layouts/dock.py

@@ -3,7 +3,7 @@ from __future__ import annotations
 import sys
 from collections import defaultdict
 from dataclasses import dataclass
-from typing import TYPE_CHECKING, NamedTuple, Sequence
+from typing import Iterable, TYPE_CHECKING, NamedTuple, Sequence
 
 from .._layout_resolve import layout_resolve
 from ..css.types import Edge
@@ -17,7 +17,7 @@ else:
     from typing_extensions import Literal
 
 if TYPE_CHECKING:
-    from ..view import View
+    from ..screen import Screen
 
 DockEdge = Literal["top", "right", "bottom", "left"]
 
@@ -61,7 +61,7 @@ class DockLayout(Layout):
 
     def arrange(
         self, parent: Widget, size: Size, scroll: Offset
-    ) -> tuple[list[WidgetPlacement], set[Widget]]:
+    ) -> tuple[Iterable[WidgetPlacement], set[Widget]]:
 
         width, height = size
         layout_region = Region(0, 0, width, height)
@@ -69,7 +69,7 @@ class DockLayout(Layout):
 
         docks = self.get_docks(parent)
 
-        def make_dock_options(widget, edge: Edge) -> DockOptions:
+        def make_dock_options(widget: Widget, edge: Edge) -> DockOptions:
             styles = widget.styles
             has_rule = styles.has_rule
 

src/textual/layouts/grid.py

@@ -14,7 +14,7 @@ from ..layout import Layout, WidgetPlacement
 
 if TYPE_CHECKING:
     from ..widget import Widget
-    from ..view import View
+    from ..screen import Screen
 
 
 if sys.version_info >= (3, 8):
@@ -266,7 +266,7 @@ class GridLayout(Layout):
         return self.widgets.keys()
 
     def arrange(
-        self, view: View, size: Size, scroll: Offset
+        self, view: Screen, size: Size, scroll: Offset
     ) -> Iterable[WidgetPlacement]:
         """Generate a map that associates widgets with their location on screen.
 

src/textual/layouts/horizontal.py

@@ -6,7 +6,7 @@ from textual._loop import loop_last
 from textual.css.styles import Styles
 from textual.geometry import Size, Offset, Region
 from textual.layout import Layout, WidgetPlacement
-from textual.view import View
+from textual.screen import Screen
 from textual.widget import Widget
 
 
@@ -15,26 +15,29 @@ class HorizontalLayout(Layout):
     fill the space of their parent container, all widgets used in a horizontal layout should have a specified.
     """
 
-    def get_widgets(self, view: View) -> Iterable[Widget]:
-        return view.children
-
     def arrange(
-        self, view: View, size: Size, scroll: Offset
+        self, parent: Widget, size: Size, scroll: Offset
-    ) -> Iterable[WidgetPlacement]:
+    ) -> tuple[list[WidgetPlacement], set[Widget]]:
+
+        placements: list[WidgetPlacement] = []
+        add_placement = placements.append
+
         parent_width, parent_height = size
-        x, y = 0, 0
+        x = y = 0
-        for last, widget in loop_last(view.children):
+        app = parent.app
-            styles: Styles = widget.styles
+        for widget in parent.children:
+            styles = widget.styles
+
             if styles.height:
-                render_height = int(
+                render_height = int(styles.height.resolve_dimension(size, app.size))
-                    styles.height.resolve_dimension(size, view.app.size)
-                )
             else:
                 render_height = parent_height
             if styles.width:
-                render_width = int(styles.width.resolve_dimension(size, view.app.size))
+                render_width = int(styles.width.resolve_dimension(size, app.size))
             else:
                 render_width = parent_width
             region = Region(x, y, render_width, render_height)
-            yield WidgetPlacement(region, widget, order=0)
+            add_placement(WidgetPlacement(region, widget, order=0))
             x += render_width
+
+        return placements, set(parent.children)

src/textual/layouts/vertical.py

@@ -8,34 +8,35 @@ from ..layout import Layout, WidgetPlacement
 
 if TYPE_CHECKING:
     from ..widget import Widget
-    from ..view import View
+    from ..screen import Screen
 
 
 class VerticalLayout(Layout):
-    def get_widgets(self, view: View) -> Iterable[Widget]:
-        return view.children
-
     def arrange(
-        self, view: View, size: Size, scroll: Offset
+        self, parent: Widget, size: Size, scroll: Offset
-    ) -> Iterable[WidgetPlacement]:
+    ) -> tuple[list[WidgetPlacement], set[Widget]]:
-        parent_width, parent_height = size
-        x, y = 0, 0
 
-        for widget in view.children:
+        placements: list[WidgetPlacement] = []
-            styles: Styles = widget.styles
+        add_placement = placements.append
+
+        parent_width, parent_height = size
+        x = y = 0
+        app = parent.app
+        for widget in parent.children:
+            styles = widget.styles
 
             if styles.height:
-                render_height = int(
+                render_height = int(styles.height.resolve_dimension(size, app.size))
-                    styles.height.resolve_dimension(size, view.app.size)
-                )
             else:
                 render_height = size.height
 
             if styles.width:
-                render_width = int(styles.width.resolve_dimension(size, view.app.size))
+                render_width = int(styles.width.resolve_dimension(size, app.size))
             else:
                 render_width = parent_width
 
             region = Region(x, y, render_width, render_height)
-            yield WidgetPlacement(region, widget, 0)
+            add_placement(WidgetPlacement(region, widget, 0))
             y += render_height
+
+        return placements, set(parent.children)

src/textual/message.py

@@ -24,8 +24,11 @@ class Message:
     ]
 
     sender: MessageTarget
-    bubble: ClassVar[bool] = True
+    bubble: ClassVar[bool] = True  # Message will bubble to parent
-    verbosity: ClassVar[int] = 1
+    verbosity: ClassVar[int] = 1  # Verbosity (higher the more verbose)
+    system: ClassVar[
+        bool
+    ] = False  # Message is system related and may not be handled by client code
 
     def __init__(self, sender: MessageTarget) -> None:
         """
@@ -45,10 +48,13 @@ class Message:
     def __rich_repr__(self) -> rich.repr.Result:
         yield self.sender
 
-    def __init_subclass__(cls, bubble: bool = True, verbosity: int = 1) -> None:
+    def __init_subclass__(
+        cls, bubble: bool = True, verbosity: int = 1, system: bool = False
+    ) -> None:
         super().__init_subclass__()
         cls.bubble = bubble
         cls.verbosity = verbosity
+        cls.system = system
 
     @property
     def is_forwarded(self) -> bool:

src/textual/message_pump.py

@@ -13,10 +13,11 @@ from ._timer import Timer, TimerCallback
 from ._callback import invoke
 from ._context import active_app
 from .message import Message
+from . import messages
 
 if TYPE_CHECKING:
     from .app import App
-    from .view import View
+    from .screen import Screen
 
 
 class NoParent(Exception):
@@ -215,7 +216,7 @@ class MessagePump:
                 self.app.panic()
                 break
             finally:
-                if isinstance(message, events.Event) and self._message_queue.empty():
+                if self._message_queue.empty():
                     if not self._closed:
                         event = events.Idle(self)
                         for method in self._get_dispatch_methods("on_idle", event):
@@ -225,6 +226,8 @@ class MessagePump:
 
     async def dispatch_message(self, message: Message) -> bool | None:
         _rich_traceback_guard = True
+        if message.system:
+            return False
         if isinstance(message, events.Event):
             if not isinstance(message, events.Null):
                 await self.on_event(message)
@@ -271,13 +274,10 @@ class MessagePump:
             if not self._parent._closed and not self._parent._closing:
                 await self._parent.post_message(message)
 
-    def post_message_no_wait(self, message: Message) -> bool:
+    def check_idle(self):
-        if self._closing or self._closed:
+        """Prompt the message pump to call idle if the queue is empty."""
-            return False
+        if self._message_queue.empty():
-        if not self.check_message_enabled(message):
+            self.post_message_no_wait(messages.Prompt(sender=self))
-            return True
-        self._message_queue.put_nowait(message)
-        return True
 
     async def post_message(self, message: Message) -> bool:
         if self._closing or self._closed:
@@ -287,16 +287,24 @@ class MessagePump:
         await self._message_queue.put(message)
         return True
 
-    def post_message_from_child_no_wait(self, message: Message) -> bool:
+    def post_message_no_wait(self, message: Message) -> bool:
         if self._closing or self._closed:
             return False
-        return self.post_message_no_wait(message)
+        if not self.check_message_enabled(message):
+            return True
+        self._message_queue.put_nowait(message)
+        return True
 
     async def post_message_from_child(self, message: Message) -> bool:
         if self._closing or self._closed:
             return False
         return await self.post_message(message)
 
+    def post_message_from_child_no_wait(self, message: Message) -> bool:
+        if self._closing or self._closed:
+            return False
+        return self.post_message_no_wait(message)
+
     async def on_callback(self, event: events.Callback) -> None:
         await event.callback()
 

src/textual/messages.py

@@ -11,6 +11,12 @@ if TYPE_CHECKING:
     from .widget import Widget
 
 
+@rich.repr.auto
+class Refresh(Message):
+    def can_replace(self, message: Message) -> bool:
+        return isinstance(message, Refresh)
+
+
 @rich.repr.auto
 class Update(Message, verbosity=3):
     def __init__(self, sender: MessagePump, widget: Widget):
@@ -50,3 +56,10 @@ class StylesUpdated(Message):
 
     def can_replace(self, message: Message) -> bool:
         return isinstance(message, StylesUpdated)
+
+
+class Prompt(Message, system=True):
+    """Used to 'wake up' an event loop."""
+
+    def can_replace(self, message: Message) -> bool:
+        return isinstance(message, StylesUpdated)

src/textual/screen.py

@@ -5,7 +5,7 @@ import rich.repr
 from rich.style import Style
 
 
-from . import events, messages
+from . import events, messages, errors
 
 from .geometry import Offset, Region
 from ._compositor import Compositor
@@ -14,7 +14,7 @@ from .renderables.gradient import VerticalGradient
 
 
 @rich.repr.auto
-class View(Widget):
+class Screen(Widget):
     """A widget for the root of the app."""
 
     DEFAULT_STYLES = """
@@ -33,7 +33,7 @@ class View(Widget):
         return False
 
     def render(self) -> RenderableType:
-        return VerticalGradient("#11998e", "#38ef7d")
+        return self._compositor
 
     def get_offset(self, widget: Widget) -> Offset:
         """Get the absolute offset of a given Widget.
@@ -58,7 +58,7 @@ class View(Widget):
         """
         return self._compositor.get_widget_at(x, y)
 
-    def get_style_add(self, x: int, y: int) -> Style:
+    def get_style_at(self, x: int, y: int) -> Style:
         """Get the style under a given coordinate.
 
         Args:
@@ -96,8 +96,7 @@ class View(Widget):
             for widget in shown:
                 widget.post_message_no_wait(events.Show(self))
 
-            send_resize = shown
+            send_resize = shown | resized
-            send_resize.update(resized)
 
             for widget, region, unclipped_region in self._compositor:
                 widget._update_size(unclipped_region.size)
@@ -123,12 +122,11 @@ class View(Widget):
     async def handle_layout(self, message: messages.Layout) -> None:
         message.stop()
         await self.refresh_layout()
-        self.app.refresh()
 
     async def on_resize(self, event: events.Resize) -> None:
-        event.stop()
         self._update_size(event.size)
         await self.refresh_layout()
+        event.stop()
 
     async def on_idle(self, event: events.Idle) -> None:
         if self._compositor.check_update():
@@ -143,23 +141,61 @@ class View(Widget):
                 region = self.get_widget_region(widget)
             else:
                 widget, region = self.get_widget_at(event.x, event.y)
-        except NoWidget:
+        except errors.NoWidget:
             await self.app.set_mouse_over(None)
         else:
             await self.app.set_mouse_over(widget)
-            await widget.forward_event(
+            mouse_event = events.MouseMove(
-                events.MouseMove(
+                self,
-                    self,
+                event.x - region.x,
-                    event.x - region.x,
+                event.y - region.y,
-                    event.y - region.y,
+                event.delta_x,
-                    event.delta_x,
+                event.delta_y,
-                    event.delta_y,
+                event.button,
-                    event.button,
+                event.shift,
-                    event.shift,
+                event.meta,
-                    event.meta,
+                event.ctrl,
-                    event.ctrl,
+                screen_x=event.screen_x,
-                    screen_x=event.screen_x,
+                screen_y=event.screen_y,
-                    screen_y=event.screen_y,
+                style=event.style,
-                    style=event.style,
-                )
             )
+            mouse_event.set_forwarded()
+            await widget.forward_event(mouse_event)
+
+    async def forward_event(self, event: events.Event) -> None:
+        if event.is_forwarded:
+            return
+        event.set_forwarded()
+        if isinstance(event, (events.Enter, events.Leave)):
+            await self.post_message(event)
+
+        elif isinstance(event, events.MouseMove):
+            event.style = self.get_style_at(event.screen_x, event.screen_y)
+            await self._on_mouse_move(event)
+
+        elif isinstance(event, events.MouseEvent):
+            try:
+                if self.app.mouse_captured:
+                    widget = self.app.mouse_captured
+                    region = self.get_widget_region(widget)
+                else:
+                    widget, region = self.get_widget_at(event.x, event.y)
+            except errors.NoWidget:
+                await self.app.set_focus(None)
+            else:
+                if isinstance(event, events.MouseDown) and widget.can_focus:
+                    await self.app.set_focus(widget)
+                event.style = self.get_style_at(event.screen_x, event.screen_y)
+                await widget.forward_event(event.offset(-region.x, -region.y))
+
+        elif isinstance(event, (events.MouseScrollDown, events.MouseScrollUp)):
+            try:
+                widget, _region = self.get_widget_at(event.x, event.y)
+            except errors.NoWidget:
+                return
+            scroll_widget = widget
+            if scroll_widget is not None:
+                await scroll_widget.forward_event(event)
+        else:
+            self.log("view.forwarded", event)
+            await self.post_message(event)

src/textual/viewX.py

@@ -127,7 +127,7 @@ class View(Widget):
         try:
             await self.layout.mount_all(self)
             if not self.is_root_view:
-                await self.app.view.refresh_layout()
+                await self.app.screen.refresh_layout()
                 return
 
             if not self.size:
@@ -247,7 +247,7 @@ class View(Widget):
             self.log("view.forwarded", event)
             await self.post_message(event)
 
-    async def action_toggle(self, name: str) -> None:
+    # async def action_toggle(self, name: str) -> None:
-        widget = self[name]
+    #     widget = self[name]
-        widget.visible = not widget.display
+    #     widget.visible = not widget.display
-        await self.post_message(messages.Layout(self))
+    #     await self.post_message(messages.Layout(self))

src/textual/views/_dock_view.py

@@ -3,7 +3,7 @@ from typing import cast, Optional
 
 from ..layouts.dock import DockLayout, Dock, DockEdge
 from ..layouts.grid import GridLayout, GridAlign
-from ..view import View
+from ..screen import Screen
 from ..widget import Widget
 
 
@@ -14,7 +14,7 @@ class DoNotSet:
 do_not_set = DoNotSet()
 
 
-class DockView(View):
+class DockView(Screen):
     def __init__(self, name: str | None = None) -> None:
         super().__init__(layout=DockLayout(), name=name)
 
@@ -58,7 +58,7 @@ class DockView(View):
     ) -> GridLayout:
 
         grid = GridLayout(gap=gap, gutter=gutter, align=align)
-        view = View(layout=grid, id=id, name=name)
+        view = Screen(layout=grid, id=id, name=name)
         dock = Dock(edge, (view,), z)
         assert isinstance(self.layout, DockLayout)
         self.layout.docks.append(dock)

src/textual/views/_document_view.py

@@ -1,3 +1,3 @@
 from __future__ import annotations
 
-from ..view import View
+from ..screen import Screen

src/textual/views/_grid_view.py

@@ -1,8 +1,8 @@
-from ..view import View
+from ..screen import Screen
 from ..layouts.grid import GridLayout
 
 
-class GridView(View, layout=GridLayout):
+class GridView(Screen, layout=GridLayout):
     @property
     def grid(self) -> GridLayout:
         assert isinstance(self.layout, GridLayout)

src/textual/views/_window_view.py

@@ -5,7 +5,7 @@ from rich.console import RenderableType
 from .. import events
 from ..geometry import Size, SpacingDimensions
 from ..layouts.vertical import VerticalLayout
-from ..view import View
+from ..screen import Screen
 from ..message import Message
 from .. import messages
 from ..widget import Widget
@@ -17,7 +17,7 @@ class WindowChange(Message):
         return isinstance(message, WindowChange)
 
 
-class WindowView(View, layout=VerticalLayout):
+class WindowView(Screen, layout=VerticalLayout):
     def __init__(
         self,
         widget: RenderableType | Widget,

src/textual/widget.py

@@ -37,7 +37,7 @@ from .reactive import Reactive, watch
 from .renderables.opacity import Opacity
 
 if TYPE_CHECKING:
-    from .view import View
+    from .screen import Screen
 
 
 class RenderCache(NamedTuple):
@@ -55,20 +55,20 @@ class RenderCache(NamedTuple):
 
 @rich.repr.auto
 class Widget(DOMNode):
-    _counts: ClassVar[dict[str, int]] = {}
+
     can_focus: bool = False
 
     DEFAULT_STYLES = """
         dock: _default
     """
 
-    def __init__(self, name: str | None = None, id: str | None = None) -> None:
+    def __init__(
-        if name is None:
+        self,
-            class_name = self.__class__.__name__
+        *children: Widget,
-            Widget._counts.setdefault(class_name, 0)
+        name: str | None = None,
-            Widget._counts[class_name] += 1
+        id: str | None = None,
-            _count = self._counts[class_name]
+        classes: Iterable[str] | None = None,
-            name = f"{class_name}{_count}"
+    ) -> None:
 
         self._size = Size(0, 0)
         self._repaint_required = False
@@ -79,8 +79,11 @@ class Widget(DOMNode):
         self.render_cache: RenderCache | None = None
         self.highlight_style: Style | None = None
 
-        super().__init__(name=name, id=id)
+        super().__init__(name=name, id=id, classes=classes)
+        self.add_children(*children)
 
+    has_focus = Reactive(False)
+    mouse_over = Reactive(False)
     scroll_x = Reactive(0)
     scroll_y = Reactive(0)
     virtual_size = Reactive(Size(0, 0))
@@ -103,6 +106,8 @@ class Widget(DOMNode):
         """Pseudo classes for a widget"""
         if self._mouse_over:
             yield "hover"
+        if self.has_focus:
+            yield "focus"
         # TODO: focus
 
     def watch(self, attribute_name, callback: Callable[[Any], Awaitable[None]]) -> None:
@@ -148,6 +153,10 @@ class Widget(DOMNode):
 
         return renderable
 
+    @property
+    def children(self) -> list[Widget]:
+        return list(self.node_list)
+
     @property
     def size(self) -> Size:
         return self._size
@@ -165,11 +174,6 @@ class Widget(DOMNode):
         """Get the current console."""
         return active_app.get().console
 
-    @property
-    def root_view(self) -> "View":
-        """Return the top-most view."""
-        return active_app.get().view
-
     @property
     def animate(self) -> BoundAnimator:
         if self._animate is None:
@@ -181,6 +185,14 @@ class Widget(DOMNode):
     def layout(self) -> Layout | None:
         return self.styles.layout
 
+    def watch_mouse_over(self, value: bool) -> None:
+        """Update from CSS if mouse over state changes."""
+        self.app.update_styles()
+
+    def watch_has_focus(self, value: bool) -> None:
+        """Update from CSS if has focus state changes."""
+        self.app.update_styles()
+
     def on_style_change(self) -> None:
         self.clear_render_cache()
 
@@ -218,8 +230,8 @@ class Widget(DOMNode):
         self._layout_required = False
 
     def get_style_at(self, x: int, y: int) -> Style:
-        offset_x, offset_y = self.root_view.get_offset(self)
+        offset_x, offset_y = self.screen.get_offset(self)
-        return self.root_view.get_style_at(x + offset_x, y + offset_y)
+        return self.screen.get_style_at(x + offset_x, y + offset_y)
 
     async def call_later(self, callback: Callable, *args, **kwargs) -> None:
         await self.app.call_later(callback, *args, **kwargs)
@@ -228,7 +240,7 @@ class Widget(DOMNode):
         event.set_forwarded()
         await self.post_message(event)
 
-    def refresh(self, repaint: bool = True, layout: bool = False) -> None:
+    def refresh(self, *, repaint: bool = True, layout: bool = False) -> None:
         """Initiate a refresh of the widget.
 
         This method sets an internal flag to perform a refresh, which will be done on the
@@ -244,7 +256,7 @@ class Widget(DOMNode):
         elif repaint:
             self.clear_render_cache()
             self._repaint_required = True
-        self.post_message_no_wait(events.Null(self))
+        self.check_idle()
 
     def render(self) -> RenderableType:
         """Get renderable for widget.
@@ -254,9 +266,8 @@ class Widget(DOMNode):
         """
 
         # Default displays a pretty repr in the center of the screen
-        return Align.center(
+
-            Pretty(self, no_wrap=True, overflow="ellipsis"), vertical="middle"
+        return Align.center(self.css_identifier_styled, vertical="middle")
-        )
 
     async def action(self, action: str, *params) -> None:
         await self.app.action(action, self)
@@ -269,6 +280,7 @@ class Widget(DOMNode):
         return await super().post_message(message)
 
     async def on_resize(self, event: events.Resize) -> None:
+        self._update_size(event.size)
         self.refresh()
 
     async def on_idle(self, event: events.Idle) -> None:
@@ -277,13 +289,14 @@ class Widget(DOMNode):
             # self.render_cache = None
             self.reset_check_repaint()
             self.reset_check_layout()
-            await self.emit(messages.Layout(self))
+            await self.screen.post_message(messages.Layout(self))
         elif repaint or self.check_repaint():
             # self.render_cache = None
             self.reset_check_repaint()
             await self.emit(messages.Update(self, self))
 
     async def focus(self) -> None:
+        """Give input focus to this widget."""
         await self.app.set_focus(self)
 
     async def capture_mouse(self, capture: bool = True) -> None:
@@ -315,14 +328,6 @@ class Widget(DOMNode):
     async def on_click(self, event: events.Click) -> None:
         await self.broker_event("click", event)
 
-    async def on_enter(self, event: events.Enter) -> None:
-        self._mouse_over = True
-        self.app.update_styles()
-
-    async def on_leave(self, event: events.Leave) -> None:
-        self._mouse_over = False
-        self.app.update_styles()
-
     async def on_key(self, event: events.Key) -> None:
         if await self.dispatch_key(event):
             event.prevent_default()

src/textual/widgets/_directory_tree.py

@@ -130,6 +130,6 @@ if __name__ == "__main__":
 
     class TreeApp(App):
         async def on_mount(self, event: events.Mount) -> None:
-            await self.view.dock(DirectoryTree("/Users/willmcgugan/projects"))
+            await self.screen.dock(DirectoryTree("/Users/willmcgugan/projects"))
 
     TreeApp.run(log="textual.log")

src/textual/widgets/_placeholder.py

@@ -24,9 +24,9 @@ class Placeholder(Widget, can_focus=True):
     style: Reactive[str] = Reactive("")
     height: Reactive[int | None] = Reactive(None)
 
-    def __init__(self, *, name: str | None = None, height: int | None = None) -> None:
+    # def __init__(self, *, name: str | None = None, height: int | None = None) -> None:
-        super().__init__(name=name)
+    #     super().__init__(name=name)
-        self.height = height
+    #     self.height = height
 
     def __rich_repr__(self) -> rich.repr.Result:
         yield from super().__rich_repr__()

src/textual/widgets/_scroll_view.py

@@ -11,14 +11,14 @@ from ..message import Message
 from ..messages import CursorMove
 from ..scrollbar import ScrollTo, ScrollBar
 from ..geometry import clamp
-from ..view import View
+from ..screen import Screen
 
 from ..widget import Widget
 
 from ..reactive import Reactive
 
 
-class ScrollView(View):
+class ScrollView(Screen):
     def __init__(
         self,
         contents: RenderableType | Widget | None = None,

src/textual/widgets/_tree_control.py

@@ -317,7 +317,7 @@ if __name__ == "__main__":
 
     class TreeApp(App):
         async def on_mount(self, event: events.Mount) -> None:
-            await self.view.dock(TreeControl("Tree Root", data="foo"))
+            await self.screen.dock(TreeControl("Tree Root", data="foo"))
 
         async def handle_tree_click(self, message: TreeClick) -> None:
             if message.node.empty:

tests/test_view.py

@@ -4,17 +4,4 @@ from textual.layouts.dock import DockLayout
 from textual.layouts.grid import GridLayout
 from textual.layouts.horizontal import HorizontalLayout
 from textual.layouts.vertical import VerticalLayout
-from textual.view import View
+from textual.screen import Screen
-
-
-@pytest.mark.parametrize("layout_name, layout_type", [
-    ["dock", DockLayout],
-    ["grid", GridLayout],
-    ["vertical", VerticalLayout],
-    ["horizontal", HorizontalLayout],
-])
-def test_view_layout_get_and_set(layout_name, layout_type):
-    view = View()
-    view.layout = layout_name
-    assert type(view.layout) is layout_type
-    assert view.styles.layout is view.layout