Add indicator stopping

Author: Kamil Klyta

example/lib/indicators/check_mark_indicator.dart

@@ -1,5 +1,6 @@
 import 'package:custom_refresh_indicator/custom_refresh_indicator.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter/rendering.dart';
 import 'package:flutter/widgets.dart';
 
 class CheckMarkIndicator extends StatefulWidget {
@@ -22,6 +23,9 @@ class _CheckMarkIndicatorState extends State<CheckMarkIndicator>
   /// Whether to render check mark instead of spinner
   bool _renderCompleteState = false;
 
+
+  ScrollDirection prevScrollDirection = ScrollDirection.idle;
+
   @override
   Widget build(BuildContext context) {
     return CustomRefreshIndicator(
@@ -41,6 +45,13 @@ class _CheckMarkIndicatorState extends State<CheckMarkIndicator>
               builder: (BuildContext context, Widget? _) {
                 _helper.update(controller.state);
 
+                if (controller.scrollingDirection == ScrollDirection.reverse &&
+                    prevScrollDirection == ScrollDirection.forward) {
+                  controller.stopDrag();
+                }
+
+                prevScrollDirection = controller.scrollingDirection;
+
                 /// set [_renderCompleteState] to true when controller.state become completed
                 if (_helper.didStateChange(to: IndicatorState.complete)) {
                   _renderCompleteState = true;

lib/src/controller.dart

@@ -75,7 +75,8 @@ class IndicatorController extends ChangeNotifier {
         _scrollingDirection = scrollingDirection ?? ScrollDirection.idle,
         _direction = direction ?? AxisDirection.down,
         _value = value ?? 0.0,
-        _refreshEnabled = refreshEnabled ?? true;
+        _refreshEnabled = refreshEnabled ?? true,
+        _shouldStopDrag = false;
 
   @protected
   @visibleForTesting
@@ -159,10 +160,22 @@ class IndicatorController extends ChangeNotifier {
   bool get isIdle => _currentState == IndicatorState.idle;
 
   bool _refreshEnabled;
+  bool _shouldStopDrag;
 
   /// Whether custom refresh indicator can change [IndicatorState] from `idle` to `dragging`
   bool get isRefreshEnabled => _refreshEnabled;
 
+  void stopDrag() {
+    if (isDragging || isArmed) {
+      _shouldStopDrag = true;
+    } else {
+      throw StateError(
+        "stopDrag method can be used only during "
+        "drag or armed indicator state.",
+      );
+    }
+  }
+
   /// Disables list pull to refresh
   void disableRefresh() {
     _refreshEnabled = false;

lib/src/custom_refresh_indicator.dart

@@ -118,6 +118,10 @@ class _CustomRefreshIndicatorState extends State<CustomRefreshIndicator>
     __canStart = canStart;
   }
 
+  /// Indicating that indicator is currently stopping drag.
+  /// When true, user is not able to performe any action.
+  bool _isStopingDrag = false;
+
   late double _dragOffset;
 
   late AnimationController _animationController;
@@ -255,6 +259,19 @@ class _CustomRefreshIndicatorState extends State<CustomRefreshIndicator>
     /// will not be handled by this widget
     if (!widget.notificationPredicate(notification)) return false;
 
+    if (_isStopingDrag) {
+      controller._shouldStopDrag = false;
+      return false;
+    } else if (controller._shouldStopDrag) {
+      controller._shouldStopDrag = false;
+      _isStopingDrag = true;
+
+      _hide().whenComplete(() {
+        _isStopingDrag = false;
+      });
+      return false;
+    }
+
     if (notification is ScrollStartNotification)
       return _handleScrollStartNotification(notification);
     if (!_canStart) return false;
@@ -297,7 +314,7 @@ class _CustomRefreshIndicatorState extends State<CustomRefreshIndicator>
     controller.setIndicatorState(IndicatorState.idle);
   }
 
-  void _hide() async {
+  Future<void> _hide() async {
     controller.setIndicatorState(IndicatorState.hiding);
     _dragOffset = 0;
     _canStart = false;