Control.parent property (#2906)

* initial commit

* remove parent when unmounting

* update parent typing

* set parent when adding/replacing

---------

Co-authored-by: Feodor Fitsner <[email protected]>

Author: ndonkoHenri

sdk/python/packages/flet-core/src/flet_core/control.py

@@ -46,6 +46,7 @@ def __init__(
         self.__data: Any = None
         self.data = data
         self.__event_handlers = {}
+        self.parent: Optional[Control] = None
         if ref:
             ref.current = self
 
@@ -418,6 +419,7 @@ def build_update_commands(
                             index=index, added_controls=added_controls
                         )
                         assert self.__uid is not None
+                        ctrl.parent = self  # set as parent
                         commands.append(
                             Command(
                                 indent=0,
@@ -447,6 +449,7 @@ def build_update_commands(
                         index=index, added_controls=added_controls
                     )
                     assert self.__uid is not None
+                    ctrl.parent = self  # set as parent
                     commands.append(
                         Command(
                             indent=0,
@@ -515,6 +518,7 @@ def _build_add_commands(self, indent=0, index=None, added_controls=None):
                 indent=indent + 2, index=index, added_controls=added_controls
             )
             commands.extend(childCmd)
+            control.parent = self  # set as parent
 
         self.__previous_children.clear()
         self.__previous_children.extend(children)

sdk/python/packages/flet-core/src/flet_core/page.py

@@ -455,6 +455,7 @@ def __update_control_ids(self, added_controls, results):
     def __handle_mount_unmount(self, added_controls, removed_controls):
         for ctrl in removed_controls:
             ctrl.will_unmount()
+            ctrl.parent = None  # remove parent reference
             ctrl.page = None
         for ctrl in added_controls:
             ctrl.did_mount()