From a4531b6d111954940bc7fdefc8ed2b0cdeadee74 Mon Sep 17 00:00:00 2001
From: Arseny Savchenko <dinaraparanid@gmail.com>
Date: Tue, 26 Nov 2024 21:15:44 +0300
Subject: [PATCH 1/3] fetch index fix

---
 .gitignore                                         | 2 +-
 lib/src/widget/bidirectional_paging_list_view.dart | 4 ++--
 lib/src/widget/paging_sliver_list.dart             | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/.gitignore b/.gitignore
index 96486fd..0a7abe4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -23,7 +23,7 @@ migrate_working_dir/
 
 # Flutter/Dart/Pub related
 # Libraries should not include pubspec.lock, per https://dart.dev/guides/libraries/private-files#pubspeclock.
-/pubspec.lock
+*.lock
 **/doc/api/
 .dart_tool/
 .packages
diff --git a/lib/src/widget/bidirectional_paging_list_view.dart b/lib/src/widget/bidirectional_paging_list_view.dart
index ac5d645..bc14c6c 100644
--- a/lib/src/widget/bidirectional_paging_list_view.dart
+++ b/lib/src/widget/bidirectional_paging_list_view.dart
@@ -474,9 +474,9 @@ class _BidirectionalPagingListViewState<Key, Value>
       // Check if the index corresponds to near the top or bottom based on the
       // 'reverse' flag.
       final nearTop =
-          reverse ? index == itemCount - fetchIndex : index == fetchIndex;
+          reverse ? index >= itemCount - fetchIndex : index <= fetchIndex;
       final nearBottom =
-          reverse ? index == fetchIndex : index == itemCount - fetchIndex;
+          reverse ? index <= fetchIndex : index >= itemCount - fetchIndex;
 
       // Generate prepend notification.
       if (nearTop) onBuildingPrependLoadTriggerItem?.call();
diff --git a/lib/src/widget/paging_sliver_list.dart b/lib/src/widget/paging_sliver_list.dart
index 95830a2..b85db16 100644
--- a/lib/src/widget/paging_sliver_list.dart
+++ b/lib/src/widget/paging_sliver_list.dart
@@ -271,12 +271,12 @@ class _PagingSliverListState<Key, Value>
       if (prefetchIndex == null) return;
 
       // Generate prepend notification.
-      if (index == prefetchIndex) {
+      if (index <= prefetchIndex) {
         onBuildingPrependLoadTriggerItem?.call();
       }
 
       // Generate append notification.
-      if (index == itemCount - prefetchIndex) {
+      if (index >= itemCount - prefetchIndex) {
         onBuildingAppendLoadTriggerItem?.call();
       }
     }

From 9e75b787560ca3cbe452e8953787b1802d89f3f6 Mon Sep 17 00:00:00 2001
From: Arseny Savchenko <dinaraparanid@gmail.com>
Date: Wed, 27 Nov 2024 16:37:47 +0300
Subject: [PATCH 2/3] append & prepend multiple loading fix

---
 lib/src/page_fetcher.dart                          | 14 ++++++++++----
 lib/src/widget/bidirectional_paging_list_view.dart |  8 ++++----
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/lib/src/page_fetcher.dart b/lib/src/page_fetcher.dart
index 60b9a0e..674dc01 100644
--- a/lib/src/page_fetcher.dart
+++ b/lib/src/page_fetcher.dart
@@ -136,10 +136,16 @@ class PageFetcher<Key, Value> extends ValueNotifier<PagingState<Key, Value>> {
         log.fine('$loadType cancelled');
       },
       () async {
-        assert(
-          loadType != LoadType.refresh,
-          'Use doInitialLoad for LoadType == refresh',
-        );
+        switch (loadType) {
+          case LoadType.append:
+            if (value.appendLoadState == const LoadState.loading()) return;
+
+          case LoadType.prepend:
+            if (value.prependLoadState == const LoadState.loading()) return;
+
+          case LoadType.refresh:
+            throw ArgumentError('Use doInitialLoad for LoadType == refresh');
+        }
 
         final loadKey = _nextLoadKeyOrNull(loadType);
         if (loadKey == null) return;
diff --git a/lib/src/widget/bidirectional_paging_list_view.dart b/lib/src/widget/bidirectional_paging_list_view.dart
index bc14c6c..6252a96 100644
--- a/lib/src/widget/bidirectional_paging_list_view.dart
+++ b/lib/src/widget/bidirectional_paging_list_view.dart
@@ -473,10 +473,10 @@ class _BidirectionalPagingListViewState<Key, Value>
 
       // Check if the index corresponds to near the top or bottom based on the
       // 'reverse' flag.
-      final nearTop =
-          reverse ? index >= itemCount - fetchIndex : index <= fetchIndex;
-      final nearBottom =
-          reverse ? index <= fetchIndex : index >= itemCount - fetchIndex;
+      final nearUp = index <= fetchIndex;
+      final nearDown = index >= itemCount - fetchIndex;
+      final nearTop = reverse ? nearDown : nearUp;
+      final nearBottom = reverse ? nearUp : nearDown;
 
       // Generate prepend notification.
       if (nearTop) onBuildingPrependLoadTriggerItem?.call();

From f8b91a97325c9c1ce508be982bd3518e6a27813b Mon Sep 17 00:00:00 2001
From: Arseny Savchenko <dinaraparanid@gmail.com>
Date: Wed, 27 Nov 2024 16:47:51 +0300
Subject: [PATCH 3/3] append & prepend multiple loading fix

---
 lib/src/page_fetcher.dart | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/src/page_fetcher.dart b/lib/src/page_fetcher.dart
index 674dc01..7b908ae 100644
--- a/lib/src/page_fetcher.dart
+++ b/lib/src/page_fetcher.dart
@@ -136,6 +136,7 @@ class PageFetcher<Key, Value> extends ValueNotifier<PagingState<Key, Value>> {
         log.fine('$loadType cancelled');
       },
       () async {
+        // Ignore function call if pager is already loading
         switch (loadType) {
           case LoadType.append:
             if (value.appendLoadState == const LoadState.loading()) return;