Merge pull request #1785 from davep/promote-disabled

Promote disabled to `Widget` level

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## Unreleased
 
+### Added
+
+- Added `Widget.disabled` https://github.com/Textualize/textual/pull/1785
+
 ### Fixed
 
 - Numbers in a descendant-combined selector no longer cause an error https://github.com/Textualize/textual/issues/1836

docs/guide/CSS.md

@@ -315,6 +315,8 @@ The `background: green` is only applied to the Button underneath the mouse curso
 
 Here are some other pseudo classes:
 
+- `:disabled` Matches widgets which are in a disabled state.
+- `:enabled` Matches widgets which are in an enabled state.
 - `:focus` Matches widgets which have input focus.
 - `:focus-within` Matches widgets with a focused a child widget.
 

examples/five_by_five.py

@@ -1,7 +1,7 @@
-from __future__ import annotations
-
 """Simple version of 5x5, developed for/with Textual."""
 
+from __future__ import annotations
+
 from pathlib import Path
 from typing import TYPE_CHECKING, cast
 
@@ -192,8 +192,7 @@ class Game(Screen):
         Args:
             playable (bool): Should the game currently be playable?
         """
-        for cell in self.query(GameCell):
+        self.query_one(GameGrid).disabled = not playable
-            cell.disabled = not playable
 
     def cell(self, row: int, col: int) -> GameCell:
         """Get the cell at a given location.

src/textual/app.py

@@ -241,6 +241,11 @@ class App(Generic[ReturnType], DOMNode):
         background: $background;
         color: $text;
     }
+
+    *:disabled {
+        opacity: 0.6;
+        text-opacity: 0.8;
+    }
     """
 
     SCREENS: dict[str, Screen | Callable[[], Screen]] = {}

src/textual/dom.py

@@ -872,6 +872,16 @@ class DOMNode(MessagePump):
         else:
             self.remove_class(*class_names)
 
+    def _update_styles(self) -> None:
+        """Request an update of this node's styles.
+
+        Should be called whenever CSS classes / pseudo classes change.
+        """
+        try:
+            self.app.update_styles(self)
+        except NoActiveAppError:
+            pass
+
     def add_class(self, *class_names: str) -> None:
         """Add class names to this Node.
 
@@ -884,10 +894,7 @@ class DOMNode(MessagePump):
         self._classes.update(class_names)
         if old_classes == self._classes:
             return
-        try:
+        self._update_styles()
-            self.app.update_styles(self)
-        except NoActiveAppError:
-            pass
 
     def remove_class(self, *class_names: str) -> None:
         """Remove class names from this Node.
@@ -900,10 +907,7 @@ class DOMNode(MessagePump):
         self._classes.difference_update(class_names)
         if old_classes == self._classes:
             return
-        try:
+        self._update_styles()
-            self.app.update_styles(self)
-        except NoActiveAppError:
-            pass
 
     def toggle_class(self, *class_names: str) -> None:
         """Toggle class names on this Node.
@@ -916,10 +920,7 @@ class DOMNode(MessagePump):
         self._classes.symmetric_difference_update(class_names)
         if old_classes == self._classes:
             return
-        try:
+        self._update_styles()
-            self.app.update_styles(self)
-        except NoActiveAppError:
-            pass
 
     def has_pseudo_class(self, *class_names: str) -> bool:
         """Check for pseudo classes (such as hover, focus etc)

src/textual/screen.py

@@ -159,11 +159,7 @@ class Screen(Widget):
 
     @property
     def focus_chain(self) -> list[Widget]:
-        """Get widgets that may receive focus, in focus order.
+        """A list of widgets that may receive focus, in focus order."""
-
-        Returns:
-            List of Widgets in focus order.
-        """
         widgets: list[Widget] = []
         add_widget = widgets.append
         stack: list[Iterator[Widget]] = [iter(self.focusable_children)]
@@ -177,7 +173,7 @@ class Screen(Widget):
             else:
                 if node.is_container and node.can_focus_children:
                     push(iter(node.focusable_children))
-                if node.can_focus:
+                if node.focusable:
                     add_widget(node)
 
         return widgets
@@ -314,7 +310,7 @@ class Screen(Widget):
             # It may have been made invisible
             # Move to a sibling if possible
             for sibling in widget.visible_siblings:
-                if sibling not in avoiding and sibling.can_focus:
+                if sibling not in avoiding and sibling.focusable:
                     self.set_focus(sibling)
                     break
             else:
@@ -351,7 +347,7 @@ class Screen(Widget):
                 self.focused.post_message_no_wait(events.Blur(self))
                 self.focused = None
             self.log.debug("focus was removed")
-        elif widget.can_focus:
+        elif widget.focusable:
             if self.focused != widget:
                 if self.focused is not None:
                     # Blur currently focused widget
@@ -547,7 +543,7 @@ class Screen(Widget):
             except errors.NoWidget:
                 self.set_focus(None)
             else:
-                if isinstance(event, events.MouseUp) and widget.can_focus:
+                if isinstance(event, events.MouseUp) and widget.focusable:
                     if self.focused is not widget:
                         self.set_focus(widget)
                         event.stop()

src/textual/widget.py

@@ -225,6 +225,8 @@ class Widget(DOMNode):
     """Rich renderable may shrink."""
     auto_links = Reactive(True)
     """Widget will highlight links automatically."""
+    disabled = Reactive(False)
+    """The disabled state of the widget. `True` if disabled, `False` if not."""
 
     hover_style: Reactive[Style] = Reactive(Style, repaint=False)
     highlight_link_id: Reactive[str] = Reactive("")
@@ -235,6 +237,7 @@ class Widget(DOMNode):
         name: str | None = None,
         id: str | None = None,
         classes: str | None = None,
+        disabled: bool = False,
     ) -> None:
         self._size = Size(0, 0)
         self._container_size = Size(0, 0)
@@ -277,6 +280,7 @@ class Widget(DOMNode):
             raise WidgetError("A widget can't be its own parent")
 
         self._add_children(*children)
+        self.disabled = disabled
 
     virtual_size = Reactive(Size(0, 0), layout=True)
     auto_width = Reactive(True)
@@ -1173,6 +1177,20 @@ class Widget(DOMNode):
         """
         return self.virtual_region.grow(self.styles.margin)
 
+    @property
+    def _self_or_ancestors_disabled(self) -> bool:
+        """Is this widget or any of its ancestors disabled?"""
+        return any(
+            node.disabled
+            for node in self.ancestors_with_self
+            if isinstance(node, Widget)
+        )
+
+    @property
+    def focusable(self) -> bool:
+        """Can this widget currently receive focus?"""
+        return self.can_focus and not self._self_or_ancestors_disabled
+
     @property
     def focusable_children(self) -> list[Widget]:
         """Get the children which may be focused.
@@ -2080,6 +2098,14 @@ class Widget(DOMNode):
             Names of the pseudo classes.
 
         """
+        node = self
+        while isinstance(node, Widget):
+            if node.disabled:
+                yield "disabled"
+                break
+            node = node._parent
+        else:
+            yield "enabled"
         if self.mouse_over:
             yield "hover"
         if self.has_focus:
@@ -2127,11 +2153,15 @@ class Widget(DOMNode):
     def watch_mouse_over(self, value: bool) -> None:
         """Update from CSS if mouse over state changes."""
         if self._has_hover_style:
-            self.app.update_styles(self)
+            self._update_styles()
 
     def watch_has_focus(self, value: bool) -> None:
         """Update from CSS if has focus state changes."""
-        self.app.update_styles(self)
+        self._update_styles()
+
+    def watch_disabled(self) -> None:
+        """Update the styles of the widget and its children when disabled is toggled."""
+        self._update_styles()
 
     def _size_updated(
         self, size: Size, virtual_size: Size, container_size: Size
@@ -2421,6 +2451,18 @@ class Widget(DOMNode):
         """
         self.app.capture_mouse(None)
 
+    def check_message_enabled(self, message: Message) -> bool:
+        # Do the normal checking and get out if that fails.
+        if not super().check_message_enabled(message):
+            return False
+        # Otherwise, if this is a mouse event, the widget receiving the
+        # event must not be disabled at this moment.
+        return (
+            not self._self_or_ancestors_disabled
+            if isinstance(message, (events.MouseEvent, events.Enter, events.Leave))
+            else True
+        )
+
     async def broker_event(self, event_name: str, event: events.Event) -> bool:
         return await self.app._broker_event(event_name, event, default_namespace=self)
 
@@ -2479,11 +2521,11 @@ class Widget(DOMNode):
 
     def _on_descendant_blur(self, event: events.DescendantBlur) -> None:
         if self._has_focus_within:
-            self.app.update_styles(self)
+            self._update_styles()
 
     def _on_descendant_focus(self, event: events.DescendantBlur) -> None:
         if self._has_focus_within:
-            self.app.update_styles(self)
+            self._update_styles()
 
     def _on_mouse_scroll_down(self, event: events.MouseScrollDown) -> None:
         if event.ctrl or event.shift:

src/textual/widgets/_button.py

@@ -39,11 +39,6 @@ class Button(Static, can_focus=True):
         text-style: bold;
     }
 
-    Button.-disabled {
-        opacity: 0.4;
-        text-opacity: 0.7;
-    }
-
     Button:focus {
         text-style: bold reverse;
     }
@@ -156,9 +151,6 @@ class Button(Static, can_focus=True):
     variant = reactive("default")
     """The variant name for the button."""
 
-    disabled = reactive(False)
-    """The disabled state of the button; `True` if disabled, `False` if not."""
-
     class Pressed(Message, bubble=True):
         """Event sent when a `Button` is pressed.
 
@@ -176,45 +168,35 @@ class Button(Static, can_focus=True):
     def __init__(
         self,
         label: TextType | None = None,
-        disabled: bool = False,
         variant: ButtonVariant = "default",
         *,
         name: str | None = None,
         id: str | None = None,
         classes: str | None = None,
+        disabled: bool = False,
     ):
         """Create a Button widget.
 
         Args:
             label: The text that appears within the button.
-            disabled: Whether the button is disabled or not.
             variant: The variant of the button.
             name: The name of the button.
             id: The ID of the button in the DOM.
             classes: The CSS classes of the button.
+            disabled: Whether the button is disabled or not.
         """
-        super().__init__(name=name, id=id, classes=classes)
+        super().__init__(name=name, id=id, classes=classes, disabled=disabled)
 
         if label is None:
             label = self.css_identifier_styled
 
         self.label = self.validate_label(label)
 
-        self.disabled = disabled
-        if disabled:
-            self.add_class("-disabled")
-
         self.variant = self.validate_variant(variant)
 
     def __rich_repr__(self) -> rich.repr.Result:
         yield from super().__rich_repr__()
         yield "variant", self.variant, "default"
-        yield "disabled", self.disabled, False
-
-    def watch_mouse_over(self, value: bool) -> None:
-        """Update from CSS if mouse over state changes."""
-        if self._has_hover_style and not self.disabled:
-            self.app.update_styles(self)
 
     def validate_variant(self, variant: str) -> str:
         if variant not in _VALID_BUTTON_VARIANTS:
@@ -227,10 +209,6 @@ class Button(Static, can_focus=True):
         self.remove_class(f"-{old_variant}")
         self.add_class(f"-{variant}")
 
-    def watch_disabled(self, disabled: bool) -> None:
-        self.set_class(disabled, "-disabled")
-        self.can_focus = not disabled
-
     def validate_label(self, label: RenderableType) -> RenderableType:
         """Parse markup for self.label"""
         if isinstance(label, str):
@@ -272,11 +250,11 @@ class Button(Static, can_focus=True):
     def success(
         cls,
         label: TextType | None = None,
-        disabled: bool = False,
         *,
         name: str | None = None,
         id: str | None = None,
         classes: str | None = None,
+        disabled: bool = False,
     ) -> Button:
         """Utility constructor for creating a success Button variant.
 
@@ -292,22 +270,22 @@ class Button(Static, can_focus=True):
         """
         return Button(
             label=label,
-            disabled=disabled,
             variant="success",
             name=name,
             id=id,
             classes=classes,
+            disabled=disabled,
         )
 
     @classmethod
     def warning(
         cls,
         label: TextType | None = None,
-        disabled: bool = False,
         *,
         name: str | None = None,
         id: str | None = None,
         classes: str | None = None,
+        disabled: bool = False,
     ) -> Button:
         """Utility constructor for creating a warning Button variant.
 
@@ -323,22 +301,22 @@ class Button(Static, can_focus=True):
         """
         return Button(
             label=label,
-            disabled=disabled,
             variant="warning",
             name=name,
             id=id,
             classes=classes,
+            disabled=disabled,
         )
 
     @classmethod
     def error(
         cls,
         label: TextType | None = None,
-        disabled: bool = False,
         *,
         name: str | None = None,
         id: str | None = None,
         classes: str | None = None,
+        disabled: bool = False,
     ) -> Button:
         """Utility constructor for creating an error Button variant.
 
@@ -354,9 +332,9 @@ class Button(Static, can_focus=True):
         """
         return Button(
             label=label,
-            disabled=disabled,
             variant="error",
             name=name,
             id=id,
             classes=classes,
+            disabled=disabled,
         )

src/textual/widgets/_data_table.py

@@ -473,8 +473,9 @@ class DataTable(ScrollView, Generic[CellType], can_focus=True):
         name: str | None = None,
         id: str | None = None,
         classes: str | None = None,
+        disabled: bool = False,
     ) -> None:
-        super().__init__(name=name, id=id, classes=classes)
+        super().__init__(name=name, id=id, classes=classes, disabled=disabled)
         self._data: dict[RowKey, dict[ColumnKey, CellType]] = {}
         """Contains the cells of the table, indexed by row key and column key.
         The final positioning of a cell on screen cannot be determined solely by this

src/textual/widgets/_directory_tree.py

@@ -29,6 +29,7 @@ class DirectoryTree(Tree[DirEntry]):
         name: The name of the widget, or None for no name. Defaults to None.
         id: The ID of the widget in the DOM, or None for no ID. Defaults to None.
         classes: A space-separated list of classes, or None for no classes. Defaults to None.
+        disabled: Whether the directory tree is disabled or not.
     """
 
     COMPONENT_CLASSES: ClassVar[set[str]] = {
@@ -87,6 +88,7 @@ class DirectoryTree(Tree[DirEntry]):
         name: str | None = None,
         id: str | None = None,
         classes: str | None = None,
+        disabled: bool = False,
     ) -> None:
         self.path = path
         super().__init__(
@@ -95,6 +97,7 @@ class DirectoryTree(Tree[DirEntry]):
             name=name,
             id=id,
             classes=classes,
+            disabled=disabled,
         )
 
     def process_label(self, label: TextType):

src/textual/widgets/_input.py

@@ -110,9 +110,6 @@ class Input(Widget, can_focus=True):
         height: 1;
         min-height: 1;
     }
-    Input.-disabled {
-        opacity: 0.6;
-    }
     Input:focus {
         border: tall $accent;
     }
@@ -179,6 +176,7 @@ class Input(Widget, can_focus=True):
         name: str | None = None,
         id: str | None = None,
         classes: str | None = None,
+        disabled: bool = False,
     ) -> None:
         """Initialise the `Input` widget.
 
@@ -190,8 +188,9 @@ class Input(Widget, can_focus=True):
             name: Optional name for the input widget.
             id: Optional ID for the widget.
             classes: Optional initial classes for the widget.
+            disabled: Whether the input is disabled or not.
         """
-        super().__init__(name=name, id=id, classes=classes)
+        super().__init__(name=name, id=id, classes=classes, disabled=disabled)
         if value is not None:
             self.value = value
         self.placeholder = placeholder

src/textual/widgets/_list_view.py

@@ -73,6 +73,7 @@ class ListView(Vertical, can_focus=True, can_focus_children=False):
         name: str | None = None,
         id: str | None = None,
         classes: str | None = None,
+        disabled: bool = False,
     ) -> None:
         """
         Args:
@@ -81,8 +82,11 @@ class ListView(Vertical, can_focus=True, can_focus_children=False):
             name: The name of the widget.
             id: The unique ID of the widget used in CSS/query selection.
             classes: The CSS classes of the widget.
+            disabled: Whether the ListView is disabled or not.
         """
-        super().__init__(*children, name=name, id=id, classes=classes)
+        super().__init__(
+            *children, name=name, id=id, classes=classes, disabled=disabled
+        )
         self._index = initial_index
 
     def on_mount(self) -> None:

src/textual/widgets/_static.py

@@ -36,6 +36,7 @@ class Static(Widget, inherit_bindings=False):
         name: Name of widget. Defaults to None.
         id: ID of Widget. Defaults to None.
         classes: Space separated list of class names. Defaults to None.
+        disabled: Whether the static is disabled or not.
     """
 
     DEFAULT_CSS = """
@@ -56,8 +57,9 @@ class Static(Widget, inherit_bindings=False):
         name: str | None = None,
         id: str | None = None,
         classes: str | None = None,
+        disabled: bool = False,
     ) -> None:
-        super().__init__(name=name, id=id, classes=classes)
+        super().__init__(name=name, id=id, classes=classes, disabled=disabled)
         self.expand = expand
         self.shrink = shrink
         self.markup = markup

src/textual/widgets/_switch.py

@@ -100,6 +100,7 @@ class Switch(Widget, can_focus=True):
         name: str | None = None,
         id: str | None = None,
         classes: str | None = None,
+        disabled: bool = False,
     ):
         """Initialise the switch.
 
@@ -109,8 +110,9 @@ class Switch(Widget, can_focus=True):
             name: The name of the switch.
             id: The ID of the switch in the DOM.
             classes: The CSS classes of the switch.
+            disabled: Whether the switch is disabled or not.
         """
-        super().__init__(name=name, id=id, classes=classes)
+        super().__init__(name=name, id=id, classes=classes, disabled=disabled)
         if value:
             self.slider_pos = 1.0
             self._reactive_value = value

src/textual/widgets/_text_log.py

@@ -43,8 +43,9 @@ class TextLog(ScrollView, can_focus=True):
         name: str | None = None,
         id: str | None = None,
         classes: str | None = None,
+        disabled: bool = False,
     ) -> None:
-        super().__init__(name=name, id=id, classes=classes)
+        super().__init__(name=name, id=id, classes=classes, disabled=disabled)
         self.max_lines = max_lines
         self._start_line: int = 0
         self.lines: list[Strip] = []

src/textual/widgets/_tree.py

@@ -473,8 +473,9 @@ class Tree(Generic[TreeDataType], ScrollView, can_focus=True):
         name: str | None = None,
         id: str | None = None,
         classes: str | None = None,
+        disabled: bool = False,
     ) -> None:
-        super().__init__(name=name, id=id, classes=classes)
+        super().__init__(name=name, id=id, classes=classes, disabled=disabled)
 
         text_label = self.process_label(label)
 

tests/snapshot_tests/snapshot_apps/disable_widgets.py

@@ -0,0 +1,84 @@
+from textual.app import App, ComposeResult
+from textual.containers import Vertical, Horizontal
+from textual.widgets import (
+    Header,
+    Footer,
+    Button,
+    DataTable,
+    Input,
+    ListView,
+    ListItem,
+    Label,
+    Markdown,
+    MarkdownViewer,
+    Tree,
+    TextLog,
+)
+
+
+class WidgetDisableTestApp(App[None]):
+
+    CSS = """
+    Horizontal {
+        height: auto;
+    }
+    DataTable, ListView, Tree, TextLog {
+        height: 2;
+    }
+
+    Markdown, MarkdownViewer {
+        height: 1fr;
+    }
+    """
+
+    @property
+    def data_table(self) -> DataTable:
+        data_table = DataTable[str]()
+        data_table.add_columns("Column 1", "Column 2", "Column 3", "Column 4")
+        data_table.add_rows(
+            [(str(n), str(n * 10), str(n * 100), str(n * 1000)) for n in range(100)]
+        )
+        return data_table
+
+    @property
+    def list_view(self) -> ListView:
+        return ListView(*[ListItem(Label(f"This is list item {n}")) for n in range(20)])
+
+    @property
+    def test_tree(self) -> Tree:
+        tree = Tree[None](label="This is a test tree")
+        for n in range(10):
+            tree.root.add_leaf(f"Leaf {n}")
+        tree.root.expand()
+        return tree
+
+    def compose(self) -> ComposeResult:
+        yield Header()
+        yield Vertical(
+            Horizontal(
+                Button(),
+                Button(variant="primary"),
+                Button(variant="success"),
+                Button(variant="warning"),
+                Button(variant="error"),
+            ),
+            self.data_table,
+            self.list_view,
+            self.test_tree,
+            TextLog(),
+            Input(),
+            Input(placeholder="This is an empty input with a placeholder"),
+            Input("This is some text in an input"),
+            Markdown("# Hello, World!"),
+            MarkdownViewer("# Hello, World!"),
+            id="test-container",
+        )
+        yield Footer()
+
+    def on_mount(self) -> None:
+        self.query_one(TextLog).write("Hello, World!")
+        self.query_one("#test-container", Vertical).disabled = True
+
+
+if __name__ == "__main__":
+    WidgetDisableTestApp().run()

tests/snapshot_tests/test_snapshots.py

@@ -231,3 +231,7 @@ def test_auto_width_input(snap_compare):
 
 def test_screen_switch(snap_compare):
     assert snap_compare(SNAPSHOT_APPS_DIR / "screen_switch.py", press=["a", "b"])
+
+
+def test_disabled_widgets(snap_compare):
+    assert snap_compare(SNAPSHOT_APPS_DIR / "disable_widgets.py")

tests/test_disabled.py

@@ -0,0 +1,84 @@
+"""Test Widget.disabled."""
+
+from textual.app import App, ComposeResult
+from textual.containers import Vertical
+from textual.widgets import (
+    Button,
+    DataTable,
+    DirectoryTree,
+    Input,
+    ListView,
+    Markdown,
+    MarkdownViewer,
+    Switch,
+    TextLog,
+    Tree,
+)
+
+
+class DisableApp(App[None]):
+    """Application for testing Widget.disabled."""
+
+    def compose(self) -> ComposeResult:
+        """Compose the child widgets."""
+        yield Vertical(
+            Button(),
+            DataTable(),
+            DirectoryTree("."),
+            Input(),
+            ListView(),
+            Switch(),
+            TextLog(),
+            Tree("Test"),
+            Markdown(),
+            MarkdownViewer(),
+            id="test-container",
+        )
+
+
+async def test_all_initially_enabled() -> None:
+    """All widgets should start out enabled."""
+    async with DisableApp().run_test() as pilot:
+        assert all(
+            not node.disabled for node in pilot.app.screen.query("#test-container > *")
+        )
+
+
+async def test_enabled_widgets_have_enabled_pseudo_class() -> None:
+    """All enabled widgets should have the :enabled pseudoclass."""
+    async with DisableApp().run_test() as pilot:
+        assert all(
+            node.has_pseudo_class("enabled") and not node.has_pseudo_class("disabled")
+            for node in pilot.app.screen.query("#test-container > *")
+        )
+
+
+async def test_all_individually_disabled() -> None:
+    """Post-disable all widgets should report being disabled."""
+    async with DisableApp().run_test() as pilot:
+        for node in pilot.app.screen.query("Vertical > *"):
+            node.disabled = True
+        assert all(
+            node.disabled for node in pilot.app.screen.query("#test-container > *")
+        )
+
+
+async def test_disabled_widgets_have_disabled_pseudo_class() -> None:
+    """All disabled widgets should have the :disabled pseudoclass."""
+    async with DisableApp().run_test() as pilot:
+        for node in pilot.app.screen.query("#test-container > *"):
+            node.disabled = True
+        assert all(
+            node.has_pseudo_class("disabled") and not node.has_pseudo_class("enabled")
+            for node in pilot.app.screen.query("#test-container > *")
+        )
+
+
+async def test_disable_via_container() -> None:
+    """All child widgets should appear (to CSS) as disabled by a container being disabled."""
+    async with DisableApp().run_test() as pilot:
+        pilot.app.screen.query_one("#test-container", Vertical).disabled = True
+        assert all(
+            node.has_pseudo_class("disabled") and not node.has_pseudo_class("enabled")
+            for node in pilot.app.screen.query("#test-container > *")
+        )