opt: refresh indicator

Signed-off-by: bggRGjQaUbCoE <githubaccount56556@proton.me>

lib/common/widgets/refresh_indicator.dart

@@ -12,7 +12,7 @@ Widget refreshIndicator({
   return RefreshIndicator(
     displacement: displacement,
     onRefresh: onRefresh,
-    child: child,
+    child: (onCancelDrag) => child,
   );
 }
 
@@ -188,7 +188,7 @@ class RefreshIndicator extends StatefulWidget {
   /// will appear when child's Scrollable descendant is over-scrolled.
   ///
   /// Typically a [ListView] or [CustomScrollView].
-  final Widget child;
+  final Widget Function(ValueChanged<double> onCancelDrag) child;
 
   /// The distance from the child's top or bottom [edgeOffset] where
   /// the refresh indicator will settle. During the drag that exposes the refresh
@@ -270,6 +270,8 @@ class RefreshIndicator extends StatefulWidget {
   RefreshIndicatorState createState() => RefreshIndicatorState();
 }
 
+bool isRefreshing = false;
+
 /// Contains the state for a [RefreshIndicator]. This class can be used to
 /// programmatically show the refresh indicator, see the [show] method.
 class RefreshIndicatorState extends State<RefreshIndicator>
@@ -368,6 +370,8 @@ class RefreshIndicatorState extends State<RefreshIndicator>
         _start(notification.metrics.axisDirection);
   }
 
+  double? containerExtent;
+
   bool _handleScrollNotification(ScrollNotification notification) {
     if (!widget.notificationPredicate(notification)) {
       return false;
@@ -443,6 +447,7 @@ class RefreshIndicatorState extends State<RefreshIndicator>
       return false;
     }
     if (_mode == _RefreshIndicatorMode.drag) {
+      isRefreshing = true;
       notification.disallowIndicator();
       return true;
     }
@@ -470,6 +475,7 @@ class RefreshIndicatorState extends State<RefreshIndicator>
   }
 
   void _checkDragOffset(double containerExtent) {
+    this.containerExtent ??= containerExtent;
     assert(_mode == _RefreshIndicatorMode.drag ||
         _mode == _RefreshIndicatorMode.armed);
     double newValue =
@@ -487,6 +493,7 @@ class RefreshIndicatorState extends State<RefreshIndicator>
 
   // Stop showing the refresh indicator.
   Future<void> _dismiss(_RefreshIndicatorMode newMode) async {
+    isRefreshing = false;
     await Future<void>.value();
     // This can only be called from _show() when refreshing and
     // _handleScrollNotification in response to a ScrollEndNotification or
@@ -579,7 +586,10 @@ class RefreshIndicatorState extends State<RefreshIndicator>
       onNotification: _handleScrollNotification,
       child: NotificationListener<OverscrollIndicatorNotification>(
         onNotification: _handleIndicatorNotification,
-        child: widget.child,
+        child: widget.child((delta) {
+          _dragOffset = _dragOffset! + delta;
+          _checkDragOffset(containerExtent!);
+        }),
       ),
     );
     assert(() {

lib/common/widgets/spring_physics.dart

@@ -1,3 +1,4 @@
+import 'package:PiliPlus/common/widgets/refresh_indicator.dart';
 import 'package:PiliPlus/utils/storage.dart';
 import 'package:flutter/material.dart';
 
@@ -52,3 +53,41 @@ class CustomTabBarViewClampingScrollPhysics extends ClampingScrollPhysics {
         damping: GStorage.springDescription[2],
       );
 }
+
+class CustomScrollPosition extends ScrollPositionWithSingleContext {
+  CustomScrollPosition({
+    required super.physics,
+    required super.context,
+    required this.onCancelDrag,
+  });
+
+  final ValueChanged<double> onCancelDrag;
+
+  @override
+  void applyUserOffset(double delta) {
+    if (isRefreshing && delta < 0) {
+      onCancelDrag(delta);
+      return;
+    }
+    super.applyUserOffset(delta);
+  }
+}
+
+class CustomScrollController extends ScrollController {
+  CustomScrollController(this.onCancelDrag);
+
+  final ValueChanged<double> onCancelDrag;
+
+  @override
+  CustomScrollPosition createScrollPosition(
+    ScrollPhysics physics,
+    ScrollContext context,
+    ScrollPosition? oldPosition,
+  ) {
+    return CustomScrollPosition(
+      physics: physics.applyTo(const AlwaysScrollableScrollPhysics()),
+      context: context,
+      onCancelDrag: onCancelDrag,
+    );
+  }
+}

lib/pages/rcmd/view.dart

@@ -1,8 +1,9 @@
 import 'dart:async';
 
 import 'package:PiliPlus/common/widgets/refresh_indicator.dart';
+import 'package:PiliPlus/common/widgets/spring_physics.dart';
 import 'package:PiliPlus/http/loading_state.dart';
-import 'package:flutter/material.dart';
+import 'package:flutter/material.dart' hide RefreshIndicator;
 import 'package:flutter/rendering.dart';
 import 'package:get/get.dart';
 import 'package:PiliPlus/common/constants.dart';
@@ -67,12 +68,12 @@ class _RcmdPageState extends State<RcmdPage>
       decoration: BoxDecoration(
         borderRadius: StyleString.mdRadius,
       ),
-      child: refreshIndicator(
+      child: RefreshIndicator(
         onRefresh: () async {
           await _controller.onRefresh();
         },
-        child: CustomScrollView(
-          controller: _controller.scrollController,
+        child: (onCancelDrag) => CustomScrollView(
+          controller: CustomScrollController(onCancelDrag),
           physics: const AlwaysScrollableScrollPhysics(),
           slivers: [
             SliverPadding(