feat: add option to set the initial index

CHANGELOG.md

@@ -1,8 +1,12 @@
+## [3.1.0]
+
+- Adds option to set the initial index of the swiper.
+
 ## [3.0.0]
 
 - **BREAKING CHANGES**:
-  - Add currentIndex and previousIndex to the onSwipe callback
+  - Adds currentIndex and previousIndex to the onSwipe callback.
-  - Render the items through a builder function
+  - Renders the items through a builder function.
 
 ## [2.1.0]
 

README.md

@@ -97,6 +97,7 @@ class Example extends StatelessWidget {
 | ------------- |:-------------|:-----|:-----:|
 | cardBuilder      | - | Widget builder for rendering cards | true
 | cardsCount      | - | Cards count | true
+| initialIndex | 0 | index of the first card when the swiper is initialized | false
 | controller      | - | Trigger swipe | false
 | padding      | EdgeInsets.symmetric(horizontal: 20, vertical: 25) | Control swiper padding | false
 | duration      | 200 milliseconds    |   The duration that every animation should last | false

lib/src/card_swiper.dart

@@ -13,6 +13,9 @@ class CardSwiper<T extends Widget> extends StatefulWidget {
   /// cards count
   final int cardsCount;
 
+  /// index of the first card when the swiper is initialized
+  final int initialIndex;
+
   /// controller to trigger actions
   final CardSwiperController? controller;
 
@@ -63,6 +66,7 @@ class CardSwiper<T extends Widget> extends StatefulWidget {
     required this.cardBuilder,
     required this.cardsCount,
     this.controller,
+    this.initialIndex = 0,
     this.padding = const EdgeInsets.symmetric(horizontal: 20, vertical: 25),
     this.duration = const Duration(milliseconds: 200),
     this.maxAngle = 30,
@@ -97,6 +101,10 @@ class CardSwiper<T extends Widget> extends StatefulWidget {
           numberOfCardsDisplayed >= 1 && numberOfCardsDisplayed <= cardsCount,
           'you must display at least one card, and no more than the length of cards parameter',
         ),
+        assert(
+          initialIndex >= 0 && initialIndex < cardsCount,
+          'initialIndex must be between 0 and cardsCount',
+        ),
         super(key: key);
 
   @override
@@ -125,7 +133,7 @@ class _CardSwiperState<T extends Widget> extends State<CardSwiper<T>>
 
   double get _maxAngle => widget.maxAngle * (pi / 180);
 
-  int? _currentIndex = 0;
+  int? _currentIndex;
   int? get _nextIndex => getValidIndexOffset(1);
   bool get _canSwipe => _currentIndex != null && !widget.isDisabled;
 
@@ -133,6 +141,8 @@ class _CardSwiperState<T extends Widget> extends State<CardSwiper<T>>
   void initState() {
     super.initState();
 
+    _currentIndex = widget.initialIndex;
+
     widget.controller?.addListener(_controllerListener);
 
     _animationController = AnimationController(

pubspec.yaml

@@ -2,7 +2,7 @@ name: flutter_card_swiper
 description: This is a Tinder-like card swiper package. It allows you to swipe left, right, up, and down and define your own business logic for each direction.
 homepage: https://github.com/ricardodalarme/flutter_card_swiper
 issue_tracker: https://github.com/ricardodalarme/flutter_card_swiper/issues
-version: 3.0.0
+version: 3.1.0
 
 environment:
   sdk: ">=2.12.0 <3.0.0"