fix for watchers

docs/examples/introduction/timers.css

@@ -8,12 +8,24 @@ TimerWidget {
     transition: background 200ms linear;
 }
 
+TimerWidget.started {   
+    text-style: bold;
+    background: $success;
+    color: $text-success;
+    border: tall $success-darken-2;
+}
+
+
 TimeDisplay {
     content-align: center middle;
     opacity: 60%;
     height: 3;
 }
 
+TimerWidget.started TimeDisplay {
+    opacity: 100%;
+}
+
 Button {
     width: 16;    
 }
@@ -23,14 +35,6 @@ Button {
 }
 
 
-TimerWidget.started {
-    opacity: 100%;
-    text-style: bold;
-    background: $success;
-    color: $text-success;
-    border: tall $success-darken-2;
-}
-
 TimerWidget.started #start {
     display: none
 }

docs/examples/introduction/timers.py

@@ -68,15 +68,15 @@ class TimerApp(App):
     def compose(self) -> ComposeResult:
         yield Header()
         yield Footer()
-        yield Container(TimerWidget(), TimerWidget(), TimerWidget())
+        yield Container(TimerWidget(), TimerWidget(), TimerWidget(), id="timers")
 
     def action_add_timer(self) -> None:
         new_timer = TimerWidget()
-        self.query_one(Container).mount(new_timer)
+        self.query_one("#timers").mount(new_timer)
         new_timer.scroll_visible()
 
     def action_remove_timer(self) -> None:
-        timers = self.query("Container TimerWidget")
+        timers = self.query("#timers TimerWidget")
         if timers:
             timers.last().remove()
 

src/textual/reactive.py

@@ -4,7 +4,6 @@ from inspect import isawaitable
 from functools import partial
 from typing import (
     Any,
-    Awaitable,
     Callable,
     Generic,
     Type,
@@ -44,7 +43,6 @@ class Reactive(Generic[ReactiveType]):
         self._default = default
         self.layout = layout
         self.repaint = repaint
-        self._first = True
 
     def __set_name__(self, owner: Type[MessageTarget], name: str) -> None:
 
@@ -68,19 +66,16 @@ class Reactive(Generic[ReactiveType]):
         return getattr(obj, self.internal_name)
 
     def __set__(self, obj: Reactable, value: ReactiveType) -> None:
-
         name = self.name
         current_value = getattr(obj, self.internal_name, None)
         validate_function = getattr(obj, f"validate_{name}", None)
+        first_set = getattr(obj, f"{self.internal_name}__first_set", True)
         if callable(validate_function):
             value = validate_function(value)
-
-        if current_value != value or self._first:
-
-            self._first = False
+        if current_value != value or first_set:
+            setattr(obj, f"{self.internal_name}__first_set", True)
             setattr(obj, self.internal_name, value)
             self.check_watchers(obj, name, current_value)
-
             if self.layout or self.repaint:
                 obj.refresh(repaint=self.repaint, layout=self.layout)
 

src/textual/widget.py

@@ -1183,16 +1183,16 @@ class Widget(DOMNode):
     async def broker_event(self, event_name: str, event: events.Event) -> bool:
         return await self.app.broker_event(event_name, event, default_namespace=self)
 
-    async def on_mouse_down(self, event: events.MouseUp) -> None:
+    async def _on_mouse_down(self, event: events.MouseUp) -> None:
         await self.broker_event("mouse.down", event)
 
-    async def on_mouse_up(self, event: events.MouseUp) -> None:
+    async def _on_mouse_up(self, event: events.MouseUp) -> None:
         await self.broker_event("mouse.up", event)
 
-    async def on_click(self, event: events.Click) -> None:
+    async def _on_click(self, event: events.Click) -> None:
         await self.broker_event("click", event)
 
-    async def on_key(self, event: events.Key) -> None:
+    async def _on_key(self, event: events.Key) -> None:
         await self.dispatch_key(event)
 
     def _on_mount(self, event: events.Mount) -> None:
@@ -1201,23 +1201,23 @@ class Widget(DOMNode):
             self.mount(*widgets)
             self.screen.refresh(repaint=False, layout=True)
 
-    def on_leave(self, event: events.Leave) -> None:
+    def _on_leave(self, event: events.Leave) -> None:
         self.mouse_over = False
 
-    def on_enter(self, event: events.Enter) -> None:
+    def _on_enter(self, event: events.Enter) -> None:
         self.mouse_over = True
 
-    def on_focus(self, event: events.Focus) -> None:
+    def _on_focus(self, event: events.Focus) -> None:
         self.emit_no_wait(events.DescendantFocus(self))
         self.has_focus = True
         self.refresh()
 
-    def on_blur(self, event: events.Blur) -> None:
+    def _on_blur(self, event: events.Blur) -> None:
         self.emit_no_wait(events.DescendantBlur(self))
         self.has_focus = False
         self.refresh()
 
-    def on_descendant_focus(self, event: events.DescendantFocus) -> None:
+    def _on_descendant_focus(self, event: events.DescendantFocus) -> None:
         self.descendant_has_focus = True
         if "focus-within" in self.pseudo_classes:
             sender = event.sender
@@ -1226,7 +1226,7 @@ class Widget(DOMNode):
                 if child is sender:
                     break
 
-    def on_descendant_blur(self, event: events.DescendantBlur) -> None:
+    def _on_descendant_blur(self, event: events.DescendantBlur) -> None:
         self.descendant_has_focus = False
         if "focus-within" in self.pseudo_classes:
             sender = event.sender
@@ -1235,37 +1235,37 @@ class Widget(DOMNode):
                 if child is sender:
                     break
 
-    def on_mouse_scroll_down(self, event) -> None:
+    def _on_mouse_scroll_down(self, event) -> None:
         if self.allow_vertical_scroll:
             if self.scroll_down(animate=False):
                 event.stop()
 
-    def on_mouse_scroll_up(self, event) -> None:
+    def _on_mouse_scroll_up(self, event) -> None:
         if self.allow_vertical_scroll:
             if self.scroll_up(animate=False):
                 event.stop()
 
-    def on_scroll_to(self, message: ScrollTo) -> None:
+    def _on_scroll_to(self, message: ScrollTo) -> None:
         if self.is_scrollable:
             self.scroll_to(message.x, message.y, animate=message.animate, duration=0.1)
             message.stop()
 
-    def on_scroll_up(self, event: ScrollUp) -> None:
+    def _on_scroll_up(self, event: ScrollUp) -> None:
         if self.is_scrollable:
             self.scroll_page_up()
             event.stop()
 
-    def on_scroll_down(self, event: ScrollDown) -> None:
+    def _on_scroll_down(self, event: ScrollDown) -> None:
         if self.is_scrollable:
             self.scroll_page_down()
             event.stop()
 
-    def on_scroll_left(self, event: ScrollLeft) -> None:
+    def _on_scroll_left(self, event: ScrollLeft) -> None:
         if self.is_scrollable:
             self.scroll_page_left()
             event.stop()
 
-    def on_scroll_right(self, event: ScrollRight) -> None:
+    def _on_scroll_right(self, event: ScrollRight) -> None:
         if self.is_scrollable:
             self.scroll_page_right()
             event.stop()