refactored reactive

Author: willmcgugan

src/textual/app.py

@@ -27,7 +27,7 @@
 from .message_pump import MessagePump
 from .message import Message
 from .view import DockView, View
-from .widget import Widget, Widget
+from .widget import Widget, Widget, Reactive
 
 log = logging.getLogger("rich")
 
@@ -216,11 +216,11 @@ async def process_messages(self) -> None:
             if traceback is not None:
                 self.console.print(traceback)
 
-    # async def dock(self, *widgets: WidgetBase, z: int = 0) -> None:
+    def require_repaint(self) -> None:
+        self.refresh()
 
-    #     dock = Dock("top", widgets, z)
-    #     self._docks.append(dock)
-    #     await self.view.mount(widgets)
+    def require_layout(self) -> None:
+        self.view.require_layout()
 
     async def message_update(self, message: Message) -> None:
         self.refresh()
@@ -375,21 +375,20 @@ async def action_bell(self) -> None:
     )
 
     class MyApp(App):
+        """Just a test app."""
+
         async def on_load(self, event: events.Load) -> None:
             await self.bind("q,ctrl+c", "quit")
             await self.bind("x", "bang")
             await self.bind("b", "toggle_sidebar")
-            self.side = False
+
+        show_bar: Reactive[bool] = Reactive(False)
+
+        def update_show_bar(self, show_bar: bool) -> None:
+            self.animator.animate(self.bar, "layout_offset_x", -40 if show_bar else 0)
 
         async def action_toggle_sidebar(self) -> None:
-            self.side = not self.side
-            self.animator.animate(
-                self.bar,
-                "layout_offset_x",
-                -40 if self.side else 0,
-                speed=60,
-                easing="in_out_cubic",
-            )
+            self.show_bar = not self.show_bar
 
         async def on_startup(self, event: events.Startup) -> None:
 

src/textual/page.py

@@ -91,7 +91,7 @@ def contents_size(self) -> Dimensions:
     def validate_y(self, value: int) -> int:
         return max(0, value)
 
-    def update_y(self, old: int, new: int) -> None:
+    def update_y(self, new: int) -> None:
         x, y = self._page.offset
         self._page.offset = Point(x, new)
 

src/textual/reactive.py

@@ -0,0 +1,65 @@
+from __future__ import annotations
+
+import sys
+from typing import Callable, Generic, TypeVar
+
+from .message_pump import MessagePump
+
+if sys.version_info >= (3, 8):
+    from typing import Protocol
+else:
+    from typing_extensions import Protocol
+
+
+class Reactable(Protocol):
+    def require_layout(self):
+        ...
+
+    def require_repaint(self):
+        ...
+
+
+ReactiveType = TypeVar("ReactiveType")
+
+
+class Reactive(Generic[ReactiveType]):
+    """Reactive descriptor."""
+
+    def __init__(
+        self,
+        default: ReactiveType,
+        *,
+        layout: bool = False,
+        repaint: bool = True,
+    ) -> None:
+        self._default = default
+        self.layout = layout
+        self.repaint = repaint
+
+    def __set_name__(self, owner: Reactable, name: str) -> None:
+        self.name = name
+        self.internal_name = f"__{name}"
+        setattr(owner, self.internal_name, self._default)
+
+    def __get__(self, obj: Reactable, obj_type: type[object]) -> ReactiveType:
+        return getattr(obj, self.internal_name)
+
+    def __set__(self, obj: Reactable, value: ReactiveType) -> None:
+        if getattr(obj, self.internal_name) != value:
+
+            current_value = getattr(obj, self.internal_name, None)
+            validate_function = getattr(obj, f"validate_{self.name}", None)
+            if callable(validate_function):
+                value = validate_function(value)
+
+            if current_value != value:
+
+                update_function = getattr(obj, f"update_{self.name}", None)
+                if callable(update_function):
+                    update_function(value)
+                setattr(obj, self.internal_name, value)
+
+                if self.layout:
+                    obj.require_layout()
+                elif self.repaint:
+                    obj.require_repaint()

src/textual/widget.py

@@ -30,6 +30,7 @@
 from .messages import UpdateMessage, LayoutMessage
 from .message_pump import MessagePump
 from .geometry import Point, Dimensions
+from .reactive import Reactive
 
 
 if TYPE_CHECKING:
@@ -42,49 +43,6 @@
 log = getLogger("rich")
 
 
-ReactiveType = TypeVar("ReactiveType")
-
-
-class Reactive(Generic[ReactiveType]):
-    def __init__(
-        self,
-        default: ReactiveType,
-        validator: Callable[[object, ReactiveType], ReactiveType] | None = None,
-        layout: bool = False,
-    ) -> None:
-        self._default = default
-        self.validator = validator
-        self.layout = layout
-
-    def __set_name__(self, owner: "Widget", name: str) -> None:
-        self.name = name
-        self.internal_name = f"__{name}"
-        setattr(owner, self.internal_name, self._default)
-
-    def __get__(self, obj: "Widget", obj_type: type[object]) -> ReactiveType:
-        return getattr(obj, self.internal_name)
-
-    def __set__(self, obj: "Widget", value: ReactiveType) -> None:
-        if getattr(obj, self.internal_name) != value:
-
-            current_value = getattr(obj, self.internal_name, None)
-            validate_function = getattr(obj, f"validate_{self.name}", None)
-            if callable(validate_function):
-                value = validate_function(value)
-
-            if current_value != value:
-                setattr(obj, self.internal_name, value)
-
-                update_function = getattr(obj, f"update_{self.name}", None)
-                if callable(update_function):
-                    update_function(current_value, value)
-
-                if self.layout:
-                    obj.require_layout()
-                else:
-                    obj.require_repaint()
-
-
 @rich.repr.auto
 class Widget(MessagePump):
     _id: ClassVar[int] = 0
@@ -223,7 +181,7 @@ async def on_event(self, event: events.Event) -> None:
         await super().on_event(event)
 
     async def on_idle(self, event: events.Idle) -> None:
-        if self.check_layout():            
+        if self.check_layout():
             self.reset_check_repaint()
             self.reset_check_layout()
             await self.update_layout()
@@ -255,4 +213,4 @@ def __init__(self, renderable: RenderableType, name: str | None = None) -> None:
         self.renderable = renderable
 
     def render(self) -> RenderableType:
-        return self.renderable
+        return self.renderable

src/textual/widgets/scroll_view.py

@@ -51,7 +51,7 @@ def validate_y(self, value: float) -> float:
     def validate_target_y(self, value: float) -> float:
         return clamp(value, 0, self._page.contents_size.height - self.size.height)
 
-    def update_y(self, old_value: float, new_value: float) -> None:
+    def update_y(self, new_value: float) -> None:
         self._page.y = round(new_value)
         self._vertical_scrollbar.position = round(new_value)