focus level bindings

examples/code_browser.css

@@ -1,14 +1,14 @@
 #tree-view {
     display: none;
     scrollbar-gutter: stable;
+    width: auto;
 }
 
 CodeBrowser.-show-tree #tree-view {
     display: block;
     dock: left;
-    height: 100%;    
+    height: 100%;            
-    width: auto;
+    max-width: 50%;
-    max-width:50%;
     background: $surface;     
 }
 

examples/code_browser.py

@@ -2,6 +2,7 @@ import sys
 
 from rich.syntax import Syntax
 from rich.traceback import Traceback
+
 from textual.app import App, ComposeResult
 from textual.layout import Container, Vertical
 from textual.reactive import Reactive
@@ -9,17 +10,21 @@ from textual.widgets import DirectoryTree, Footer, Header, Static
 
 
 class CodeBrowser(App):
+    """Textual code browser app."""
+
+    BINDINGS = [
+        ("t", "toggle_tree", "Toggle Tree"),
+        ("q", "quit", "Quit"),
+    ]
 
     show_tree = Reactive.init(True)
 
     def watch_show_tree(self, show_tree: bool) -> None:
+        """Called when show_tree is modified."""
         self.set_class(show_tree, "-show-tree")
 
-    def on_load(self) -> None:
-        self.bind("t", "toggle_tree", description="Toggle Tree")
-        self.bind("q", "quit", description="Quit")
-
     def compose(self) -> ComposeResult:
+        """Compose our UI."""
         path = "./" if len(sys.argv) < 2 else sys.argv[1]
         yield Header()
         yield Container(
@@ -29,6 +34,7 @@ class CodeBrowser(App):
         yield Footer()
 
     def on_directory_tree_file_click(self, event: DirectoryTree.FileClick) -> None:
+        """Called when the user click a file in the directory tree."""
         code_view = self.query_one("#code", Static)
         try:
             syntax = Syntax.from_path(

src/textual/_styles_cache.py

@@ -95,15 +95,15 @@ class StylesCache:
             Lines: Rendered lines.
         """
         base_background, background = widget.background_colors
-        padding = widget.styles.padding + widget.scrollbar_gutter
+        styles = widget.styles
         lines = self.render(
-            widget.styles,
+            styles,
             widget.region.size,
             base_background,
             background,
             widget.render_line,
             content_size=widget.content_region.size,
-            padding=padding,
+            padding=styles.padding,
             crop=crop,
         )
         return lines

src/textual/app.py

@@ -191,7 +191,6 @@ class App(Generic[ReturnType], DOMNode):
         self._animator = Animator(self)
         self.animate = self._animator.bind(self)
         self.mouse_position = Offset(0, 0)
-        self.bindings = Bindings()
         if title is None:
             self._title = f"{self.__class__.__name__}"
         else:
@@ -199,7 +198,7 @@ class App(Generic[ReturnType], DOMNode):
 
         self._logger = Logger()
 
-        self.bindings.bind("ctrl+c", "quit", show=False, allow_forward=False)
+        self._bindings.bind("ctrl+c", "quit", show=False, allow_forward=False)
         self._refresh_required = False
 
         self.design = DEFAULT_COLORS
@@ -319,6 +318,13 @@ class App(Generic[ReturnType], DOMNode):
 
         return widgets
 
+    @property
+    def bindings(self) -> Bindings:
+        if self.focused is None:
+            return self._bindings
+        else:
+            return Bindings.merge(node._bindings for node in self.focused.ancestors)
+
     def _set_active(self) -> None:
         """Set this app to be the currently active app."""
         active_app.set(self)
@@ -595,7 +601,7 @@ class App(Generic[ReturnType], DOMNode):
             show (bool, optional): Show key in UI. Defaults to True.
             key_display (str, optional): Replacement text for key, or None to use default. Defaults to None.
         """
-        self.bindings.bind(
+        self._bindings.bind(
             keys, action, description, show=show, key_display=key_display
         )
 
@@ -1318,7 +1324,7 @@ class App(Generic[ReturnType], DOMNode):
             bool: True if the key was handled by a binding, otherwise False
         """
         try:
-            binding = self.bindings.get_key(key)
+            binding = self._bindings.get_key(key)
         except NoBinding:
             return False
         else:
@@ -1355,15 +1361,14 @@ class App(Generic[ReturnType], DOMNode):
             await super().on_event(event)
 
     async def action(
-        self,
+        self, action: str, default_namespace: object | None = None
-        action: str,
-        default_namespace: object | None = None,
-        modifiers: set[str] | None = None,
     ) -> None:
         """Perform an action.
 
         Args:
             action (str): Action encoded in a string.
+            default_namespace (object | None): Namespace to use if not provided in the action,
+                or None to use app. Defaults to None.
         """
         target, params = actions.parse(action)
         if "." in target:
@@ -1412,15 +1417,13 @@ class App(Generic[ReturnType], DOMNode):
         except AttributeError:
             return False
         try:
-            modifiers, action = extract_handler_actions(event_name, style.meta)
+            _modifiers, action = extract_handler_actions(event_name, style.meta)
         except NoHandler:
             return False
         else:
             event.stop()
         if isinstance(action, str):
-            await self.action(
+            await self.action(action, default_namespace=default_namespace)
-                action, default_namespace=default_namespace, modifiers=modifiers
-            )
         elif callable(action):
             await action()
         else:

src/textual/binding.py

@@ -1,5 +1,18 @@
 from __future__ import annotations
+
+import sys
+import rich.repr
+
 from dataclasses import dataclass
+from typing import Iterable, MutableMapping
+
+if sys.version_info >= (3, 10):
+    from typing import TypeAlias
+else:  # pragma: no cover
+    from typing_extensions import TypeAlias
+
+
+BindingType: TypeAlias = "Binding | tuple[str, str] | tuple[str, str, str]"
 
 
 class NoBinding(Exception):
@@ -11,16 +24,46 @@ class Binding:
     key: str
     action: str
     description: str
-    show: bool = False
+    show: bool = True
     key_display: str | None = None
     allow_forward: bool = True
 
 
+@rich.repr.auto
 class Bindings:
     """Manage a set of bindings."""
 
-    def __init__(self) -> None:
+    def __init__(self, bindings: Iterable[BindingType] | None = None) -> None:
-        self.keys: dict[str, Binding] = {}
+        def make_bindings(bindings: Iterable[BindingType]) -> Iterable[Binding]:
+            for binding in bindings:
+                if isinstance(binding, Binding):
+                    yield binding
+                else:
+                    yield Binding(*binding)
+
+        self.keys: MutableMapping[str, Binding] = (
+            {binding.key: binding for binding in make_bindings(bindings)}
+            if bindings
+            else {}
+        )
+
+    def __rich_repr__(self) -> rich.repr.Result:
+        yield self.keys
+
+    @classmethod
+    def merge(cls, bindings: Iterable[Bindings]) -> Bindings:
+        """Merge a bindings. Subsequence bound keys override initial keys.
+
+        Args:
+            bindings (Iterable[Bindings]): A number of bindings.
+
+        Returns:
+            Bindings: New bindings.
+        """
+        keys: dict[str, Binding] = {}
+        for _bindings in bindings:
+            keys |= _bindings.keys
+        return Bindings(keys.values())
 
     @property
     def shown_keys(self) -> list[Binding]:
@@ -58,23 +101,3 @@ class Bindings:
         if binding is None:
             return True
         return binding.allow_forward
-
-
-class BindingStack:
-    """Manage a stack of bindings."""
-
-    def __init__(self, *bindings: Bindings) -> None:
-        self._stack: list[Bindings] = list(bindings)
-
-    def push(self, bindings: Bindings) -> None:
-        self._stack.append(bindings)
-
-    def pop(self) -> Bindings:
-        return self._stack.pop()
-
-    def get_key(self, key: str) -> Binding:
-        for bindings in reversed(self._stack):
-            binding = bindings.keys.get(key, None)
-            if binding is not None:
-                return binding
-        raise NoBinding(f"No binding for {key}") from None

src/textual/cli/previews/easing.css

@@ -27,7 +27,7 @@ Bar {
 
 #other {
     width: 1fr;
-    background: #555555;
+    background: $panel;
     padding: 1;
     height: 100%;
     border-left: vkey $background;
@@ -35,6 +35,7 @@ Bar {
 
 #opacity-widget {
     padding: 1;
-    background: $panel;
+    background: $warning;
-    border: wide #969696;
+    color: $text-warning;
+    border: wide $background;
 }

src/textual/cli/previews/easing.py

@@ -29,12 +29,30 @@ class Bar(Widget):
     position = Reactive.init(START_POSITION)
     animation_running = Reactive(False)
 
+    DEFAULT_CSS = """
+    
+    Bar {
+        background: $surface;
+        color: $error;
+    }
+
+    Bar.-active {
+        background: $surface;
+        color: $success;
+    }
+    
+    """
+
+    def watch_animation_running(self, running: bool) -> None:
+        self.set_class(running, "-active")
+
     def render(self) -> RenderableType:
+
         return ScrollBarRender(
             virtual_size=VIRTUAL_SIZE,
             window_size=WINDOW_SIZE,
             position=self.position,
-            style="green" if self.animation_running else "red",
+            style=self.rich_style,
         )
 
 

src/textual/dom.py

@@ -22,6 +22,7 @@ from rich.tree import Tree
 
 from ._context import NoActiveAppError
 from ._node_list import NodeList
+from .binding import Bindings, BindingType
 from .color import Color, WHITE, BLACK
 from .css._error_tools import friendly_list
 from .css.constants import VALID_DISPLAY, VALID_VISIBILITY
@@ -91,6 +92,9 @@ class DOMNode(MessagePump):
     # Virtual DOM nodes
     COMPONENT_CLASSES: ClassVar[set[str]] = set()
 
+    # Mapping of key bindings
+    BINDINGS: ClassVar[list[BindingType]] = []
+
     # True if this node inherits the CSS from the base class.
     _inherit_css: ClassVar[bool] = True
     # List of names of base class (lower cased) that inherit CSS
@@ -123,6 +127,7 @@ class DOMNode(MessagePump):
         self._auto_refresh: float | None = None
         self._auto_refresh_timer: Timer | None = None
         self._css_types = {cls.__name__ for cls in self._css_bases(self.__class__)}
+        self._bindings = Bindings(self.BINDINGS)
 
         super().__init__()
 
@@ -475,21 +480,25 @@ class DOMNode(MessagePump):
         Returns:
             Style: Rich Style object.
         """
-
+        return Style.combine(
-        # TODO: Feels like there may be opportunity for caching here.
+            node.styles.text_style for node in reversed(self.ancestors)
-
+        )
-        style = Style()
-        for node in reversed(self.ancestors):
-            style += node.styles.text_style
-        return style
 
     @property
     def rich_style(self) -> Style:
         """Get a Rich Style object for this DOMNode."""
-        _, _, background, color = self.colors
+        background = WHITE
-        style = (
+        color = BLACK
-            Style.from_color((background + color).rich_color, background.rich_color)
+        style = Style()
-            + self.text_style
+        for node in reversed(self.ancestors):
+            styles = node.styles
+            if styles.has_rule("background"):
+                background += styles.background
+            if styles.has_rule("color"):
+                color = styles.color
+            style += styles.text_style
+        style += Style.from_color(
+            (background + color).rich_color, background.rich_color
         )
         return style
 
@@ -501,9 +510,7 @@ class DOMNode(MessagePump):
             tuple[Color, Color]: Tuple of (base background, background)
 
         """
-
         base_background = background = BLACK
-
         for node in reversed(self.ancestors):
             styles = node.styles
             if styles.has_rule("background"):
@@ -533,15 +540,13 @@ class DOMNode(MessagePump):
     @property
     def ancestors(self) -> list[DOMNode]:
         """Get a list of Nodes by tracing ancestors all the way back to App."""
-        nodes: list[DOMNode] = [self]
+        nodes: list[MessagePump | None] = []
         add_node = nodes.append
-        node: DOMNode = self
+        node: MessagePump | None = self
-        while True:
+        while node is not None:
-            node = node._parent
-            if node is None:
-                break
             add_node(node)
-        return nodes
+            node = node._parent
+        return cast(list[DOMNode], nodes)
 
     @property
     def displayed_children(self) -> list[Widget]:

src/textual/widget.py

@@ -7,13 +7,8 @@ from operator import attrgetter
 from typing import TYPE_CHECKING, ClassVar, Collection, Iterable, NamedTuple
 
 import rich.repr
-from rich.console import (
+from rich.console import Console, ConsoleRenderable, JustifyMethod, RenderableType
-    Console,
+from rich.measure import Measurement
-    ConsoleRenderable,
-    Measurement,
-    JustifyMethod,
-    RenderableType,
-)
 from rich.segment import Segment
 from rich.style import Style
 from rich.styled import Styled
@@ -27,6 +22,7 @@ from ._layout import Layout
 from ._segment_tools import align_lines
 from ._styles_cache import StylesCache
 from ._types import Lines
+from .binding import NoBinding
 from .box_model import BoxModel, get_box_model
 from .css.constants import VALID_TEXT_ALIGN
 from .dom import DOMNode, NoScreen
@@ -522,7 +518,7 @@ class Widget(DOMNode):
         """Get the height used by the *horizontal* scrollbar."""
         styles = self.styles
         if styles.scrollbar_gutter == "stable" and styles.overflow_x == "auto":
-            return self.styles.scrollbar_size_horizontal
+            return styles.scrollbar_size_horizontal
         return styles.scrollbar_size_horizontal if self.show_horizontal_scrollbar else 0
 
     @property
@@ -1474,7 +1470,12 @@ class Widget(DOMNode):
         await self.broker_event("click", event)
 
     async def _on_key(self, event: events.Key) -> None:
-        await self.dispatch_key(event)
+        try:
+            binding = self._bindings.get_key(event.key)
+        except NoBinding:
+            await self.dispatch_key(event)
+        else:
+            await self.action(binding.action)
 
     def _on_mount(self, event: events.Mount) -> None:
         widgets = self.compose()