onDelete moved into GetLifeCycle

+import 'package:flutter/material.dart';
+
 /// Special callable class to keep the contract of a regular method, and avoid
 /// overrides if you extend the class that uses it, as Dart has no final
 /// methods.
@@ -6,23 +8,35 @@
 class _InternalFinalCallback<T> {
   T Function() callback;
 
-  _InternalFinalCallback();
+  _InternalFinalCallback({this.callback});
 
   T call() => callback.call();
 }
 
-mixin  GetLifeCycle {
+class _InternalFinalPrivateCallback<T> {
+  T Function() _callback;
+
+  _InternalFinalPrivateCallback();
+
+  T call() => _callback.call();
+}
+
+mixin GetLifeCycle {
   /// Called at the exact moment the widget is allocated in memory.
   /// It uses an internal "callable" type, to avoid any @overrides in subclases.
   /// This method should be internal and is required to define the
   /// lifetime cycle of the subclass.
   final onStart = _InternalFinalCallback<void>();
 
-  final onDelete = _InternalFinalCallback<void>();
+  /// Internal callback that starts the cycle of this controller.
+  final onDelete = _InternalFinalPrivateCallback<void>();
 
   /// Called immediately after the widget is allocated in memory.
   /// You might use this to initialize something for the controller.
-  void onInit() {}
+  @mustCallSuper
+  void onInit() {
+    onDelete._callback = _onDelete;
+  }
 
   /// Called 1 frame after onInit(). It is the perfect place to enter
   /// navigation events, like snackbar, dialogs, or a new route, or
@@ -36,6 +50,18 @@ mixin  GetLifeCycle {
   /// like TextEditingControllers, AnimationControllers.
   /// Might be useful as well to persist some data on disk.
   void onClose() {}
+
+  bool _isClosed = false;
+
+  /// Checks whether the controller has already been closed.
+  bool get isClosed => _isClosed;
+
+  // Internal callback that starts the cycle of this controller.
+  void _onDelete() {
+    if (_isClosed) return;
+    _isClosed = true;
+    onClose();
+  }
 }
 
 /// Allow track difference between GetxServices and GetxControllers

+import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
 import '../../../get_instance/src/lifecycle.dart';
 
@@ -15,14 +16,8 @@ abstract class DisposableInterface with GetLifeCycle {
   /// Checks whether the controller has already been initialized.
   bool get initialized => _initialized;
 
-  bool _isClosed = false;
-
-  /// Checks whether the controller has already been closed.
-  bool get isClosed => _isClosed;
-
   DisposableInterface() {
     onStart.callback = _onStart;
-    onDelete.callback = _onDelete;
   }
 
   // Internal callback that starts the cycle of this controller.
@@ -33,22 +28,17 @@ abstract class DisposableInterface with GetLifeCycle {
     SchedulerBinding.instance?.addPostFrameCallback((_) => onReady());
   }
 
-  // Internal callback that starts the cycle of this controller.
-  void _onDelete() {
-    if (_isClosed) return;
-    _isClosed = true;
-    onClose();
-  }
-
   /// Called immediately after the widget is allocated in memory.
   /// You might use this to initialize something for the controller.
   @override
-  void onInit() {}
+  @mustCallSuper
+  void onInit() => super.onInit();
 
   /// Called 1 frame after onInit(). It is the perfect place to enter
   /// navigation events, like snackbar, dialogs, or a new route, or
   /// async request.
   @override
+  @mustCallSuper
   void onReady() {}
 
   /// Called before [onDelete] method. [onClose] might be used to
@@ -58,5 +48,6 @@ abstract class DisposableInterface with GetLifeCycle {
   /// like TextEditingControllers, AnimationControllers.
   /// Might be useful as well to persist some data on disk.
   @override
+  @mustCallSuper
   void onClose() {}
 }

@@ -39,7 +39,6 @@ typedef Condition = bool Function();
 abstract class GetNotifier<T> extends Value<T> with GetLifeCycle {
   GetNotifier(T initial) : super(initial) {
     onStart.callback = _onStart;
-    onDelete.callback = _onDelete;
     _fillEmptyStatus();
   }
 
@@ -48,11 +47,6 @@ abstract class GetNotifier<T> extends Value<T> with GetLifeCycle {
   /// Checks whether the controller has already been initialized.
   bool get initialized => _initialized;
 
-  bool _isClosed = false;
-
-  /// Checks whether the controller has already been closed.
-  bool get isClosed => _isClosed;
-
   // Internal callback that starts the cycle of this controller.
   void _onStart() {
     if (_initialized) return;
@@ -61,13 +55,6 @@ abstract class GetNotifier<T> extends Value<T> with GetLifeCycle {
     SchedulerBinding.instance?.addPostFrameCallback((_) => onReady());
   }
 
-  // Internal callback that starts the cycle of this controller.
-  void _onDelete() {
-    if (_isClosed) return;
-    _isClosed = true;
-    onClose();
-  }
-
   RxStatus _status;
 
   bool get isNullOrEmpty {

@@ -12,7 +12,6 @@ class Mock {
 class DisposableController with GetLifeCycle {
   DisposableController() {
     onStart.callback = _onStart;
-    onDelete.callback = _onDelete;
   }
 
   // Internal callback that starts the cycle of this controller.
@@ -21,18 +20,13 @@ class DisposableController with GetLifeCycle {
     onInit();
   }
 
-  // Internal callback that starts the cycle of this controller.
-  void _onDelete() {
-    if (isClosed) return;
-    isClosed = true;
-    onClose();
-  }
-
   bool initialized = false;
 
   bool isClosed = false;
 
+  @override
   void onInit() async {
+    super.onInit();
     initialized = true;
   }
 }