Merge pull request #808 from Textualize/get-widget

Get widget

src/textual/_compositor.py

@@ -13,25 +13,23 @@ without having to render the entire screen.
 
 from __future__ import annotations
 
+import sys
 from itertools import chain
 from operator import itemgetter
-import sys
+from typing import TYPE_CHECKING, Callable, Iterable, Iterator, NamedTuple, cast
-from typing import Callable, cast, Iterator, Iterable, NamedTuple, TYPE_CHECKING
 
 import rich.repr
-
+from rich.console import Console, ConsoleOptions, RenderableType, RenderResult
-from rich.console import Console, ConsoleOptions, RenderResult, RenderableType
 from rich.control import Control
 from rich.segment import Segment
 from rich.style import Style
 
 from . import errors
-from .geometry import Region, Offset, Size
-
 from ._cells import cell_len
-from ._profile import timer
 from ._loop import loop_last
+from ._profile import timer
 from ._types import Lines
+from .geometry import Offset, Region, Size
 
 if sys.version_info >= (3, 10):
     from typing import TypeAlias
@@ -203,6 +201,8 @@ class Compositor:
         # Regions that require an update
         self._dirty_regions: set[Region] = set()
 
+        self._layers_visible: dict[int, list[tuple[Widget, Region]]] | None = None
+
     @classmethod
     def _regions_to_spans(
         cls, regions: Iterable[Region]
@@ -257,6 +257,7 @@ class Compositor:
         """
         self._cuts = None
         self._layers = None
+        self._layers_visible = None
         self.root = parent
         self.size = size
 
@@ -475,6 +476,26 @@ class Compositor:
             )
         return self._layers
 
+    @property
+    def layers_visible(self) -> dict[int, list[tuple[Widget, Region]]]:
+        """Visible widgets and regions in layers order."""
+
+        if self._layers_visible is None:
+            layers_visible: dict[int, list[tuple[Widget, Region]]]
+            screen_region = self.size.region
+            _, screen_height = self.size
+            layers_visible = {y: [] for y in screen_region.line_range}
+
+            visible_intersection = screen_region.intersection
+
+            for widget, region, *_ in self:
+                (_x, y, _width, height) = region
+                if y + height > 0 and y < screen_height:
+                    for y in visible_intersection(region).line_range:
+                        layers_visible[y].append((widget, region))
+            self._layers_visible = layers_visible
+        return self._layers_visible
+
     def __iter__(self) -> Iterator[tuple[Widget, Region, Region, Size, Size]]:
         """Iterate map with information regarding each widget and is position
 
@@ -514,9 +535,10 @@ class Compositor:
             tuple[Widget, Region]: A tuple of the widget and its region.
         """
         # TODO: Optimize with some line based lookup
+
         contains = Region.contains
-        for widget, cropped_region, region, *_ in self:
+        for widget, region in self.layers_visible.get(y, []):
-            if contains(cropped_region, x, y) and widget.visible:
+            if contains(region, x, y) and widget.visible:
                 return widget, region
         raise errors.NoWidget(f"No widget under screen coordinate ({x}, {y})")
 
@@ -531,8 +553,8 @@ class Compositor:
             Iterable[tuple[Widget, Region]]: Sequence of (WIDGET, REGION) tuples.
         """
         contains = Region.contains
-        for widget, cropped_region, region, *_ in self:
+        for widget, region in self.layers_visible.get(y, []):
-            if contains(cropped_region, x, y) and widget.visible:
+            if contains(region, x, y) and widget.visible:
                 yield widget, region
 
     def get_style_at(self, x: int, y: int) -> Style:

src/textual/css/stylesheet.py

@@ -369,9 +369,12 @@ class Stylesheet:
         else:
             rules = reversed(self.rules)
         # Collect the rules defined in the stylesheet
+        node._has_hover_style = False
         for rule in rules:
             is_default_rules = rule.is_default_rules
             tie_breaker = rule.tie_breaker
+            if ":hover" in rule.selector_names:
+                node._has_hover_style = True
             for base_specificity in _check_rule(rule, css_path_nodes):
                 for key, rule_specificity, value in rule.styles.extract_rules(
                     base_specificity, is_default_rules, tie_breaker

src/textual/dom.py

@@ -128,6 +128,7 @@ class DOMNode(MessagePump):
         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)
+        self._has_hover_style: bool = False
 
         super().__init__()
 

src/textual/widget.py

@@ -1531,7 +1531,8 @@ class Widget(DOMNode):
 
     def watch_mouse_over(self, value: bool) -> None:
         """Update from CSS if mouse over state changes."""
-        self.app.update_styles(self)
+        if self._has_hover_style:
+            self.app.update_styles(self)
 
     def watch_has_focus(self, value: bool) -> None:
         """Update from CSS if has focus state changes."""

src/textual/widgets/_button.py

@@ -204,7 +204,7 @@ class Button(Static, can_focus=True):
 
     def watch_mouse_over(self, value: bool) -> None:
         """Update from CSS if mouse over state changes."""
-        if not self.disabled:
+        if self._has_hover_style and not self.disabled:
             self.app.update_styles(self)
 
     def validate_variant(self, variant: str) -> str:

src/textual/widgets/_static.py

@@ -86,12 +86,13 @@ class Static(Widget):
         """
         return self._renderable
 
-    def update(self, renderable: RenderableType = "") -> None:
+    def update(self, renderable: RenderableType = "", *, layout: bool = True) -> None:
         """Update the widget's content area with new text or Rich renderable.
 
         Args:
             renderable (RenderableType, optional): A new rich renderable. Defaults to empty renderable;
+            layout (bool, optional): Perform a layout. Defaults to True.
         """
         _check_renderable(renderable)
         self.renderable = renderable
-        self.refresh(layout=True)
+        self.refresh(layout=layout)