remove boilerplate

examples/calculator.py

@@ -54,7 +54,7 @@ class FigletText:
 class Numbers(Widget):
     """The digital display of the calculator."""
 
-    value: Reactive[str] = Reactive("0")
+    value = Reactive("0")
 
     def render(self) -> RenderableType:
         """Build a Rich renderable to render the calculator display."""
@@ -84,10 +84,10 @@ class Calculator(GridView):
         "=": YELLOW,
     }
 
-    display: Reactive[str] = Reactive("0")
-    show_ac: Reactive[bool] = Reactive(True)
+    display = Reactive("0")
+    show_ac = Reactive(True)
 
-    async def watch_display(self, value: str) -> None:
+    def watch_display(self, value: str) -> None:
         """Called when self.display is modified."""
         # self.numbers is a widget that displays the calculator result
         # Setting the attribute value changes the display
@@ -99,13 +99,13 @@ class Calculator(GridView):
         # Condition to show AC button over C
         return self.value in ("", "0") and self.display == "0"
 
-    async def watch_show_ac(self, show_ac: bool) -> None:
+    def watch_show_ac(self, show_ac: bool) -> None:
         """When the show_ac attribute change we need to update the buttons."""
         # Show AC and hide C or vice versa
         self.c.visible = not show_ac
         self.ac.visible = show_ac
 
-    async def on_mount(self, event: events.Mount) -> None:
+    def on_mount(self) -> None:
         """Event when widget is first mounted (added to a parent view)."""
 
         # Attributes to store the current calculation
@@ -153,7 +153,7 @@ class Calculator(GridView):
             *self.buttons.values(), clear=self.ac, numbers=self.numbers, zero=self.zero
         )
 
-    async def message_button_pressed(self, message: ButtonPressed) -> None:
+    def message_button_pressed(self, message: ButtonPressed) -> None:
         """A message sent by the button widget"""
 
         assert isinstance(message.sender, Button)

examples/code_viewer.py

@@ -5,7 +5,6 @@ from rich.console import RenderableType
 from rich.syntax import Syntax
 from rich.traceback import Traceback
 
-from textual import events
 from textual.app import App
 from textual.widgets import Header, Footer, FileClick, ScrollView, DirectoryTree
 
@@ -13,7 +12,7 @@ from textual.widgets import Header, Footer, FileClick, ScrollView, DirectoryTree
 class MyApp(App):
     """An example of a very simple Textual App"""
 
-    async def on_load(self, event: events.Load) -> None:
+    async def on_load(self) -> None:
         """Sent before going in to application mode."""
 
         # Bind our basic keys
@@ -28,7 +27,7 @@ class MyApp(App):
                 os.path.join(os.path.basename(__file__), "../../")
             )
 
-    async def on_mount(self, event: events.Mount) -> None:
+    async def on_mount(self) -> None:
         """Call after terminal goes in to application mode"""
 
         # Create our widgets

examples/grid.py

@@ -4,7 +4,7 @@ from textual.widgets import Placeholder
 
 
 class GridTest(App):
-    async def on_mount(self, event: events.Mount) -> None:
+    async def on_mount(self) -> None:
         """Make a simple grid arrangement."""
 
         grid = await self.view.dock_grid(edge="left", size=70, name="left")

src/textual/_callback.py

@@ -25,4 +25,5 @@ async def invoke(callback: Callable, *params: object) -> Any:
 
     result = callback(*params[:parameter_count])
     if isawaitable(result):
-        await result
+        result = await result
+    return result

src/textual/message_pump.py

@@ -255,7 +255,7 @@ class MessagePump:
         method = getattr(self, method_name, None)
         if method is not None:
             log(message, ">>>", self, verbosity=message.verbosity)
-            await method(message)
+            await invoke(method, message)
 
         if message.bubble and self._parent and not message._stop_propagation:
             if message.sender == self._parent:

src/textual/reactive.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-import inspect
+from inspect import isawaitable
 from functools import partial
 from typing import (
     Any,
@@ -16,7 +16,7 @@ from typing import (
 from . import log
 from . import events
 
-from ._callback import count_parameters
+from ._callback import count_parameters, invoke
 from ._types import MessageTarget
 
 if TYPE_CHECKING:
@@ -90,9 +90,11 @@ class Reactive(Generic[ReactiveType]):
         ) -> None:
             _rich_traceback_guard = True
             if count_parameters(watch_function) == 2:
-                await watch_function(old_value, value)
+                watch_result = watch_function(old_value, value)
             else:
-                await watch_function(value)
+                watch_result = watch_function(value)
+            if isawaitable(watch_result):
+                await watch_result
             await Reactive.compute(obj)
 
         watch_function = getattr(obj, f"watch_{name}", None)
@@ -125,7 +127,8 @@ class Reactive(Generic[ReactiveType]):
                 compute_method = getattr(obj, f"compute_{compute}")
             except AttributeError:
                 continue
-            value = await compute_method()
+            value = await invoke(compute_method)
+            # value = await compute_method()
             setattr(obj, compute, value)