opt: load previous

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

lib/common/widgets/loading_widget.dart

@@ -10,7 +10,6 @@ Widget errorWidget({errMsg, callback}) => HttpError(
     );
 
 Widget scrollErrorWidget({errMsg, callback}) => CustomScrollView(
-      controller: ScrollController(),
       slivers: [
         HttpError(
           errMsg: errMsg,

lib/common/widgets/scroll_physics.dart

@@ -54,7 +54,9 @@ class CustomTabBarViewClampingScrollPhysics extends ClampingScrollPhysics {
 }
 
 class PositionRetainedScrollPhysics extends AlwaysScrollableScrollPhysics {
-  const PositionRetainedScrollPhysics({super.parent});
+  const PositionRetainedScrollPhysics({super.parent, this.shouldRetain = true});
+
+  final bool shouldRetain;
 
   @override
   PositionRetainedScrollPhysics applyTo(ScrollPhysics? ancestor) {
@@ -75,9 +77,9 @@ class PositionRetainedScrollPhysics extends AlwaysScrollableScrollPhysics {
       velocity: velocity,
     );
 
-    final diff = newPosition.maxScrollExtent - oldPosition.maxScrollExtent;
+    late final diff = newPosition.maxScrollExtent - oldPosition.maxScrollExtent;
 
-    if (oldPosition.pixels == 0 && diff > 0) {
+    if (shouldRetain && oldPosition.pixels == 0 && diff > 0) {
       return position + diff;
     } else {
       return position;

lib/pages/member/new/content/member_contribute/content/video/member_video.dart

@@ -72,7 +72,10 @@ class _MemberVideoState extends State<MemberVideo>
                     await _controller.onRefresh();
                   },
                   child: CustomScrollView(
-                    physics: const PositionRetainedScrollPhysics(),
+                    physics: PositionRetainedScrollPhysics(
+                      shouldRetain: _controller.isLocating == true,
+                      parent: ClampingScrollPhysics(),
+                    ),
                     slivers: [
                       SliverPersistentHeader(
                         pinned: false,

lib/pages/member/new/content/member_contribute/content/video/member_video_ctr.dart

@@ -212,4 +212,10 @@ class MemberVideoCtr extends CommonController {
       }
     }
   }
+
+  @override
+  Future onReload() {
+    isLocating = null;
+    return super.onReload();
+  }
 }

lib/pages/video/detail/member/horizontal_member_page.dart

@@ -180,7 +180,10 @@ class _HorizontalMemberPageState extends State<HorizontalMemberPage> {
           color: Colors.transparent,
           child: CustomScrollView(
             controller: _controller.scrollController,
-            physics: const PositionRetainedScrollPhysics(),
+            physics: PositionRetainedScrollPhysics(
+              shouldRetain: _controller.hasPrev,
+              parent: ClampingScrollPhysics(),
+            ),
             slivers: [
               _buildSliverHeader,
               SliverPadding(

lib/pages/video/detail/note/note_list_page.dart

@@ -1,6 +1,6 @@
 import 'package:PiliPlus/common/skeleton/video_reply.dart';
+import 'package:PiliPlus/common/widgets/http_error.dart';
 import 'package:PiliPlus/common/widgets/icon_button.dart';
-import 'package:PiliPlus/common/widgets/loading_widget.dart';
 import 'package:PiliPlus/common/widgets/network_img_layer.dart';
 import 'package:PiliPlus/common/widgets/refresh_indicator.dart';
 import 'package:PiliPlus/http/loading_state.dart';
@@ -173,16 +173,21 @@ class _NoteListPageState extends CommonSlidePageState<NoteListPage> {
                 ],
               ),
             )
-          : scrollErrorWidget(
-              callback: _controller.onReload,
-            ),
-      Error() => scrollErrorWidget(
-          errMsg: loadingState.errMsg,
-          callback: _controller.onReload,
-        ),
+          : errWidget(),
+      Error() => errWidget(loadingState.errMsg),
       LoadingState() => throw UnimplementedError(),
     };
   }
+
+  Widget errWidget([errMsg]) => CustomScrollView(
+        controller: _controller.scrollController,
+        slivers: [
+          HttpError(
+            errMsg: errMsg,
+            callback: _controller.onReload,
+          )
+        ],
+      );
 }
 
 Widget _itemWidget(BuildContext context, dynamic item) {

lib/pages/video/detail/widgets/media_list_panel.dart

@@ -2,7 +2,6 @@ import 'package:PiliPlus/common/widgets/dialog.dart';
 import 'package:PiliPlus/common/widgets/icon_button.dart';
 import 'package:PiliPlus/common/widgets/image_save.dart';
 import 'package:PiliPlus/common/widgets/refresh_indicator.dart';
-import 'package:PiliPlus/common/widgets/scroll_physics.dart';
 import 'package:PiliPlus/common/widgets/stat/stat.dart';
 import 'package:PiliPlus/pages/common/common_collapse_slide_page.dart';
 import 'package:flutter/material.dart';
@@ -127,7 +126,9 @@ class _MediaListPanelState
               widget.onDelete != null && widget.mediaList.length > 1;
           return ScrollablePositionedList.separated(
             itemScrollController: _scrollController,
-            physics: const PositionRetainedScrollPhysics(),
+            // physics: const PositionRetainedScrollPhysics(
+            //   parent: ClampingScrollPhysics(),
+            // ),
             itemCount: widget.mediaList.length,
             padding: EdgeInsets.only(
               top: 7,