Allow runtime modification of timeout expiry at runtime

This is done through setting View.timeout while it's running

discord/ui/modal.py

@@ -88,9 +88,6 @@ class Modal(View):
 
     Attributes
     ------------
-    timeout: Optional[:class:`float`]
-        Timeout from last interaction with the UI before no longer accepting input.
-        If ``None`` then there is no timeout.
     title: :class:`str`
         The title of the modal.
     children: List[:class:`Item`]
@@ -184,9 +181,7 @@ class Modal(View):
 
     async def _scheduled_task(self, interaction: Interaction):
         try:
-            if self.timeout:
-                self.__timeout_expiry = time.monotonic() + self.timeout
-
+            self._refresh_timeout()
             allow = await self.interaction_check(interaction)
             if not allow:
                 return

discord/ui/view.py

@@ -154,9 +154,6 @@ class View:
 
     Attributes
     ------------
-    timeout: Optional[:class:`float`]
-        Timeout from last interaction with the UI before no longer accepting input.
-        If ``None`` then there is no timeout.
     children: List[:class:`Item`]
         The list of children attached to this view.
     """
@@ -188,7 +185,7 @@ class View:
         return children
 
     def __init__(self, *, timeout: Optional[float] = 180.0):
-        self.timeout = timeout
+        self.__timeout = timeout
         self.children: List[Item[Self]] = self._init_children()
         self.__weights = _ViewWeights(self.children)
         self.id: str = os.urandom(16).hex()
@@ -237,6 +234,29 @@ class View:
 
         return components
 
+    def _refresh_timeout(self) -> None:
+        if self.__timeout:
+            self.__timeout_expiry = time.monotonic() + self.__timeout
+
+    @property
+    def timeout(self) -> Optional[float]:
+        """Optional[:class:`float`]: The timeout in seconds from last interaction with the UI before no longer accepting input.
+        If ``None`` then there is no timeout.
+        """
+        return self.__timeout
+
+    @timeout.setter
+    def timeout(self, value: Optional[float]) -> None:
+        # If the timeout task is already running this allows it to update
+        # the expiry while it's running
+        if self.__timeout_task is not None:
+            if value is not None:
+                self.__timeout_expiry = time.monotonic() + value
+            else:
+                self.__timeout_expiry = None
+
+        self.__timeout = value
+
     @classmethod
     def from_message(cls, message: Message, /, *, timeout: Optional[float] = 180.0) -> View:
         """Converts a message's components into a :class:`View`.