feat(controller): add method to jump to index without animation (#25)

CHANGELOG.md

@@ -1,6 +1,7 @@
 
 ## [7.0.0]
 
+- Adds `moveTo` method to `CardSwiperController` to move to a specific card index.
 - **BREAKING CHANGE**:
   - Upgrade min dart sdk to 3.0.0
   - Replace `swipe`, `swipeLeft`, `swipeRight`, `swipeUp`, `swipeDown` with `swipe(CardSwiperDirection direction)`

README.md

@@ -126,6 +126,7 @@ The `Controller` is used to swipe the card from outside of the widget. You can c
 | ----------- | :--------------------------------------------- |
 | swipe       | Swipes the card to a specific direction.       |
 | undo        | Bring back the last card that was swiped away. |
+| moveTo      | Change the top card to a specific index.       |
 
 <hr/>
 

lib/src/controller/card_swiper_controller.dart

@@ -20,7 +20,12 @@ class CardSwiperController {
     _eventController.add(const ControllerUndoEvent());
   }
 
+  // Change the top card to a specific index.
+  void moveTo(int index) {
+    _eventController.add(ControllerMoveEvent(index));
+  }
+
   Future<void> dispose() async {
-   await _eventController.close();
+    await _eventController.close();
   }
 }

lib/src/controller/controller_event.dart

@@ -1,15 +1,19 @@
 import 'package:flutter_card_swiper/flutter_card_swiper.dart';
 
-abstract class ControllerEvent {
+sealed class ControllerEvent {
   const ControllerEvent();
 }
 
 class ControllerSwipeEvent extends ControllerEvent {
   final CardSwiperDirection direction;
-
   const ControllerSwipeEvent(this.direction);
 }
 
 class ControllerUndoEvent extends ControllerEvent {
   const ControllerUndoEvent();
 }
+
+class ControllerMoveEvent extends ControllerEvent {
+  final int index;
+  const ControllerMoveEvent(this.index);
+}

lib/src/widget/card_swiper_state.dart

@@ -161,7 +161,7 @@ class _CardSwiperState<T extends Widget> extends State<CardSwiper>
     return switch (event) {
       ControllerSwipeEvent(:final direction) => _swipe(direction),
       ControllerUndoEvent() => _undo(),
-      _ => null
+      ControllerMoveEvent(:final index) => _moveTo(index),
     };
   }
 
@@ -281,6 +281,15 @@ class _CardSwiperState<T extends Widget> extends State<CardSwiper>
     _cardAnimation.animateUndo(context, direction);
   }
 
+  void _moveTo(int index) {
+    if (index == _currentIndex) return;
+    if (index < 0 || index >= widget.cardsCount) return;
+
+    setState(() {
+      _undoableIndex.state = index;
+    });
+  }
+
   int numberOfCardsOnScreen() {
     if (widget.isLoop) {
       return widget.numberOfCardsDisplayed;

test/controller/card_swiper_controller_test.dart

@@ -2,9 +2,9 @@ import 'package:flutter_card_swiper/flutter_card_swiper.dart';
 import 'package:flutter_card_swiper/src/controller/controller_event.dart';
 import 'package:flutter_test/flutter_test.dart';
 
-import 'test_helpers/card_builder.dart';
-import 'test_helpers/finders.dart';
-import 'test_helpers/pump_app.dart';
+import '../test_helpers/card_builder.dart';
+import '../test_helpers/finders.dart';
+import '../test_helpers/pump_app.dart';
 
 void main() {
   group('CardSwiperController', () {
@@ -34,6 +34,21 @@ void main() {
       controller.undo();
     });
 
+    test('Swipe event adds ControllerSwipeEvent to the stream', () {
+      final controller = CardSwiperController();
+      const index = 42;
+
+      expectLater(
+        controller.events,
+        emits(
+          isA<ControllerMoveEvent>()
+              .having((event) => event.index, 'index', index),
+        ),
+      );
+
+      controller.moveTo(index);
+    });
+
     test('Dispose closes the stream', () {
       final controller = CardSwiperController();