f_card_swiper/lib/swipeable_cards_stack.dart

368 lines
11 KiB
Dart

library swipeable_cards_stack;
import 'dart:math';
import 'package:flutter/material.dart';
import 'package:swipeable_cards_stack/swipeable_cards_stack_controller.dart';
export 'swipeable_cards_stack_controller.dart';
const List<Alignment> cardsAlign = [
Alignment(0.0, 1.0),
Alignment(0.0, 0.8),
Alignment(0.0, 0.0)
];
final List<Size> cardsSize = List.filled(3, const Size(1, 1));
class SwipeableCardsStack extends StatefulWidget {
final SwipeableCardsStackController? cardController;
//First 3 widgets
final List<Widget> items;
final Function? onCardSwiped;
final double cardWidthTopMul;
final double cardWidthMiddleMul;
final double cardWidthBottomMul;
final double cardHeightTopMul;
final double cardHeightMiddleMul;
final double cardHeightBottomMul;
final Function? appendItemCallback;
final bool enableSwipeUp;
final bool enableSwipeDown;
SwipeableCardsStack({
Key? key,
this.cardController,
required BuildContext context,
required this.items,
this.onCardSwiped,
this.cardWidthTopMul = 0.9,
this.cardWidthMiddleMul = 0.85,
this.cardWidthBottomMul = 0.8,
this.cardHeightTopMul = 0.6,
this.cardHeightMiddleMul = 0.55,
this.cardHeightBottomMul = 0.5,
this.appendItemCallback,
this.enableSwipeUp = true,
this.enableSwipeDown = true,
}) : super(key: key) {
cardsSize[0] = Size(
MediaQuery.of(context).size.width * cardWidthTopMul,
MediaQuery.of(context).size.height * cardHeightTopMul,
);
cardsSize[1] = Size(
MediaQuery.of(context).size.width * cardWidthMiddleMul,
MediaQuery.of(context).size.height * cardHeightMiddleMul,
);
cardsSize[2] = Size(
MediaQuery.of(context).size.width * cardWidthBottomMul,
MediaQuery.of(context).size.height * cardHeightBottomMul,
);
}
@override
State<SwipeableCardsStack> createState() => _SwipeableCardsStackState();
}
class _SwipeableCardsStackState extends State<SwipeableCardsStack>
with SingleTickerProviderStateMixin {
int cardsCounter = 0;
int index = 0;
Widget? appendCard;
List<Widget?> cards = [];
late AnimationController _controller;
bool enableSwipe = true;
final Alignment defaultFrontCardAlign = const Alignment(0.0, 0.0);
Alignment frontCardAlign = cardsAlign[2];
double frontCardRot = 0.0;
void _triggerSwipe(Direction dir) {
final swipedCallback = widget.onCardSwiped ?? (_, __, ___) => true;
bool? shouldAnimate = false;
if (dir == Direction.left) {
shouldAnimate = swipedCallback(Direction.left, index, cards[0]);
frontCardAlign = const Alignment(-0.001, 0.0);
} else if (dir == Direction.right) {
shouldAnimate = swipedCallback(Direction.right, index, cards[0]);
frontCardAlign = const Alignment(0.001, 0.0);
} else if (dir == Direction.up) {
shouldAnimate = swipedCallback(Direction.up, index, cards[0]);
frontCardAlign = const Alignment(0.0, -0.001);
} else if (dir == Direction.down) {
shouldAnimate = swipedCallback(Direction.down, index, cards[0]);
frontCardAlign = const Alignment(0.0, 0.001);
}
shouldAnimate ??= true;
if (shouldAnimate) {
animateCards();
}
}
void _appendItem(Widget newCard) {
appendCard = newCard;
}
void _enableSwipe(bool isSwipeEnabled) {
setState(() {
enableSwipe = isSwipeEnabled;
});
}
@override
void initState() {
super.initState();
final cardController = widget.cardController;
if (cardController != null) {
cardController.listener = _triggerSwipe;
cardController.addItem = _appendItem;
cardController.enableSwipeListener = _enableSwipe;
}
// Init cards
for (cardsCounter = 0; cardsCounter < 3; cardsCounter++) {
if (widget.items.isNotEmpty && cardsCounter < widget.items.length) {
cards.add(widget.items[cardsCounter]);
} else {
cards.add(null);
}
}
frontCardAlign = cardsAlign[2];
// Init the animation controller
_controller = AnimationController(
duration: const Duration(milliseconds: 700),
vsync: this,
);
_controller.addListener(() => setState(() {}));
_controller.addStatusListener((AnimationStatus status) {
if (status == AnimationStatus.completed) changeCardsOrder();
});
}
@override
Widget build(BuildContext context) {
return Expanded(
child: IgnorePointer(
ignoring: !enableSwipe,
child: Stack(
children: <Widget>[
if (cards[2] != null) backCard(),
if (cards[1] != null) middleCard(),
if (cards[0] != null) frontCard(),
// Prevent swiping if the cards are animating
if (_controller.status != AnimationStatus.forward)
SizedBox.expand(
child: GestureDetector(
// While dragging the first card
onPanUpdate: (DragUpdateDetails details) {
// Add what the user swiped in the last frame to the alignment of the card
setState(() {
frontCardAlign = Alignment(
frontCardAlign.x +
20 *
details.delta.dx /
MediaQuery.of(context).size.width,
frontCardAlign.y +
20 *
details.delta.dy /
MediaQuery.of(context).size.height,
);
frontCardRot = frontCardAlign.x; // * rotation speed;
});
},
// When releasing the first card
onPanEnd: (_) {
// If the front card was swiped far enough to count as swiped
final onCardSwiped =
widget.onCardSwiped ?? (_, __, ___) => true;
bool? shouldAnimate = false;
if (frontCardAlign.x > 3.0) {
shouldAnimate =
onCardSwiped(Direction.right, index, cards[0]);
} else if (frontCardAlign.x < -3.0) {
shouldAnimate =
onCardSwiped(Direction.left, index, cards[0]);
} else if (frontCardAlign.y < -3.0 &&
widget.enableSwipeUp) {
shouldAnimate =
onCardSwiped(Direction.up, index, cards[0]);
} else if (frontCardAlign.y > 3.0 &&
widget.enableSwipeDown) {
shouldAnimate =
onCardSwiped(Direction.down, index, cards[0]);
} else {
// Return to the initial rotation and alignment
setState(() {
frontCardAlign = defaultFrontCardAlign;
frontCardRot = 0.0;
});
}
shouldAnimate ??= true;
if (shouldAnimate) {
animateCards();
}
},
),
)
else
const SizedBox(),
],
),
),
);
}
Widget backCard() {
return Align(
alignment: _controller.status == AnimationStatus.forward
? CardsAnimation.backCardAlignmentAnim(_controller).value
: cardsAlign[0],
child: SizedBox.fromSize(
size: _controller.status == AnimationStatus.forward
? CardsAnimation.backCardSizeAnim(_controller).value
: cardsSize[2],
child: cards[2],
),
);
}
Widget middleCard() {
return Align(
alignment: _controller.status == AnimationStatus.forward
? CardsAnimation.middleCardAlignmentAnim(_controller).value
: cardsAlign[1],
child: SizedBox.fromSize(
size: _controller.status == AnimationStatus.forward
? CardsAnimation.middleCardSizeAnim(_controller).value
: cardsSize[1],
child: cards[1],
),
);
}
Widget frontCard() {
return Align(
alignment: _controller.status == AnimationStatus.forward
? CardsAnimation.frontCardDisappearAlignmentAnim(
_controller,
frontCardAlign,
).value
: frontCardAlign,
child: Transform.rotate(
angle: (pi / 180.0) * frontCardRot,
child: SizedBox.fromSize(size: cardsSize[0], child: cards[0]),
),
);
}
void changeCardsOrder() {
setState(() {
// Swap cards (back card becomes the middle card; middle card becomes the front card)
cards[0] = cards[1];
cards[1] = cards[2];
cards[2] = appendCard;
appendCard = null;
cardsCounter++;
index++;
frontCardAlign = defaultFrontCardAlign;
frontCardRot = 0.0;
});
}
void animateCards() {
_controller
..stop()
..value = 0.0
..forward();
}
}
class CardsAnimation {
static Animation<Alignment> backCardAlignmentAnim(
AnimationController parent,
) {
return AlignmentTween(begin: cardsAlign[0], end: cardsAlign[1]).animate(
CurvedAnimation(
parent: parent,
curve: const Interval(0.4, 0.7, curve: Curves.easeIn),
),
);
}
static Animation<Size?> backCardSizeAnim(AnimationController parent) {
return SizeTween(begin: cardsSize[2], end: cardsSize[1]).animate(
CurvedAnimation(
parent: parent,
curve: const Interval(0.4, 0.7, curve: Curves.easeIn),
),
);
}
static Animation<Alignment> middleCardAlignmentAnim(
AnimationController parent,
) {
return AlignmentTween(begin: cardsAlign[1], end: cardsAlign[2]).animate(
CurvedAnimation(
parent: parent,
curve: const Interval(0.2, 0.5, curve: Curves.easeIn),
),
);
}
static Animation<Size?> middleCardSizeAnim(AnimationController parent) {
return SizeTween(begin: cardsSize[1], end: cardsSize[0]).animate(
CurvedAnimation(
parent: parent,
curve: const Interval(0.2, 0.5, curve: Curves.easeIn),
),
);
}
static Animation<Alignment> frontCardDisappearAlignmentAnim(
AnimationController parent,
Alignment beginAlign,
) {
if (beginAlign.x == -0.001 ||
beginAlign.x == 0.001 ||
beginAlign.x > 3.0 ||
beginAlign.x < -3.0) {
return AlignmentTween(
begin: beginAlign,
end: Alignment(
beginAlign.x > 0 ? beginAlign.x + 30.0 : beginAlign.x - 30.0,
0.0,
), // Has swiped to the left or right?
).animate(
CurvedAnimation(
parent: parent,
curve: const Interval(0.0, 0.5, curve: Curves.easeIn),
),
);
} else {
return AlignmentTween(
begin: beginAlign,
end: Alignment(
0.0,
beginAlign.y > 0 ? beginAlign.y + 30.0 : beginAlign.y - 30.0,
), // Has swiped to the top or bottom?
).animate(
CurvedAnimation(
parent: parent,
curve: const Interval(0.0, 0.5, curve: Curves.easeIn),
),
);
}
}
}