f_card_swiper/lib/src/card_swiper.dart

428 lines
12 KiB
Dart

import 'dart:math';
import 'package:flutter/widgets.dart';
import 'package:flutter_card_swiper/src/card_swiper_controller.dart';
import 'package:flutter_card_swiper/src/enums.dart';
import 'package:flutter_card_swiper/src/typedefs.dart';
class CardSwiper<T extends Widget> extends StatefulWidget {
/// list of widgets for the swiper
final List<T> cards;
/// controller to trigger actions
final CardSwiperController? controller;
/// duration of every animation
final Duration duration;
/// padding of the swiper
final EdgeInsetsGeometry padding;
/// maximum angle the card reaches while swiping
final double maxAngle;
/// threshold from which the card is swiped away
final int threshold;
/// scale of the card that is behind the front card
final double scale;
/// set to true if swiping should be disabled, exception: triggered from the outside
final bool isDisabled;
/// function that gets called with the new index and detected swipe direction when the user swiped or swipe is triggered by controller
final CardSwiperOnSwipe? onSwipe;
/// function that gets called when there is no widget left to be swiped away
final CardSwiperOnEnd? onEnd;
/// function that gets triggered when the swiper is disabled
final CardSwiperOnTapDisabled? onTapDisabled;
/// direction in which the card gets swiped when triggered by controller, default set to right
final CardSwiperDirection direction;
/// set to false if you want your card to move only across the vertical axis when swiping
final bool isHorizontalSwipingEnabled;
/// set to false if you want your card to move only across the horizontal axis when swiping
final bool isVerticalSwipingEnabled;
const CardSwiper({
Key? key,
required this.cards,
this.controller,
this.padding = const EdgeInsets.symmetric(horizontal: 20, vertical: 25),
this.duration = const Duration(milliseconds: 200),
this.maxAngle = 30,
this.threshold = 50,
this.scale = 0.9,
this.isDisabled = false,
this.onTapDisabled,
this.onSwipe,
this.onEnd,
this.direction = CardSwiperDirection.right,
this.isHorizontalSwipingEnabled = true,
this.isVerticalSwipingEnabled = true,
}) : assert(
maxAngle >= 0 && maxAngle <= 360,
'maxAngle must be between 0 and 360',
),
assert(
threshold >= 1 && threshold <= 100,
'threshold must be between 1 and 100',
),
assert(
direction != CardSwiperDirection.none,
'direction must not be none',
),
assert(
scale >= 0 && scale <= 1,
'scale must be between 0 and 1',
),
super(key: key);
@override
State createState() => _CardSwiperState<T>();
}
class _CardSwiperState<T extends Widget> extends State<CardSwiper<T>>
with SingleTickerProviderStateMixin {
double _left = 0;
double _top = 0;
double _total = 0;
double _angle = 0;
late double _scale = widget.scale;
double _difference = 40;
int _currentIndex = 0;
SwipeType _swipeType = SwipeType.none;
bool _tapOnTop = false; //position of starting drag point on card
late AnimationController _animationController;
late Animation<double> _leftAnimation;
late Animation<double> _topAnimation;
late Animation<double> _scaleAnimation;
late Animation<double> _differenceAnimation;
CardSwiperDirection detectedDirection = CardSwiperDirection.none;
double get _maxAngle => widget.maxAngle * (pi / 180);
bool get _isLastCard => _currentIndex == widget.cards.length - 1;
int get _nextCardIndex => _isLastCard ? 0 : _currentIndex + 1;
@override
void initState() {
super.initState();
widget.controller?.addListener(_controllerListener);
_animationController = AnimationController(
duration: widget.duration,
vsync: this,
)
..addListener(_animationListener)
..addStatusListener(_animationStatusListener);
}
@override
void dispose() {
super.dispose();
_animationController.dispose();
widget.controller?.dispose();
}
@override
Widget build(BuildContext context) {
return LayoutBuilder(
builder: (BuildContext context, BoxConstraints constraints) {
return Padding(
padding: widget.padding,
child: LayoutBuilder(
builder: (BuildContext context, BoxConstraints constraints) {
return Stack(
clipBehavior: Clip.none,
fit: StackFit.expand,
children: [
_backItem(constraints),
_frontItem(constraints),
],
);
},
),
);
},
);
}
Widget _frontItem(BoxConstraints constraints) {
return Positioned(
left: _left,
top: _top,
child: GestureDetector(
child: Transform.rotate(
angle: _angle,
child: ConstrainedBox(
constraints: constraints,
child: widget.cards[_currentIndex],
),
),
onTap: () {
if (widget.isDisabled) {
widget.onTapDisabled?.call();
}
},
onPanStart: (tapInfo) {
if (!widget.isDisabled) {
final renderBox = context.findRenderObject()! as RenderBox;
final position = renderBox.globalToLocal(tapInfo.globalPosition);
if (position.dy < renderBox.size.height / 2) _tapOnTop = true;
}
},
onPanUpdate: (tapInfo) {
if (!widget.isDisabled) {
setState(() {
if (widget.isHorizontalSwipingEnabled) {
_left += tapInfo.delta.dx;
}
if (widget.isVerticalSwipingEnabled) {
_top += tapInfo.delta.dy;
}
_total = _left + _top;
_calculateAngle();
_calculateScale();
_calculateDifference();
});
}
},
onPanEnd: (tapInfo) {
if (!widget.isDisabled) {
_tapOnTop = false;
_onEndAnimation();
_animationController.forward();
}
},
),
);
}
Widget _backItem(BoxConstraints constraints) {
return Positioned(
top: _difference,
left: 0,
child: Transform.scale(
scale: _scale,
child: ConstrainedBox(
constraints: constraints,
child: widget.cards[_nextCardIndex],
),
),
);
}
//swipe widget from the outside
void _controllerListener() {
switch (widget.controller!.state) {
case CardSwiperState.swipe:
_swipe(context, widget.direction);
break;
case CardSwiperState.swipeLeft:
_swipe(context, CardSwiperDirection.left);
break;
case CardSwiperState.swipeRight:
_swipe(context, CardSwiperDirection.right);
break;
case CardSwiperState.swipeTop:
_swipe(context, CardSwiperDirection.top);
break;
case CardSwiperState.swipeBottom:
_swipe(context, CardSwiperDirection.bottom);
break;
default:
break;
}
}
//when value of controller changes
void _animationListener() {
if (_animationController.status == AnimationStatus.forward) {
setState(() {
_left = _leftAnimation.value;
_top = _topAnimation.value;
_scale = _scaleAnimation.value;
_difference = _differenceAnimation.value;
});
}
}
//when the status of animation changes
void _animationStatusListener(AnimationStatus status) {
if (status == AnimationStatus.completed) {
setState(() {
if (_swipeType == SwipeType.swipe) {
widget.onSwipe?.call(_currentIndex, detectedDirection);
if (_isLastCard) {
widget.onEnd?.call();
_currentIndex = 0;
} else {
_currentIndex++;
}
}
_animationController.reset();
_left = 0;
_top = 0;
_total = 0;
_angle = 0;
_scale = widget.scale;
_difference = 40;
_swipeType = SwipeType.none;
});
}
}
void _calculateAngle() {
if (_angle <= _maxAngle && _angle >= -_maxAngle) {
_angle = (_maxAngle / 100) * (_left / 10);
if (_tapOnTop) _angle *= -1;
}
}
void _calculateScale() {
if (_scale <= 1.0 && _scale >= widget.scale) {
_scale = (_total > 0)
? widget.scale + (_total / 5000)
: widget.scale + -1 * (_total / 5000);
}
}
void _calculateDifference() {
if (_difference >= 0 && _difference <= _difference) {
_difference = (_total > 0) ? 40 - (_total / 10) : 40 + (_total / 10);
}
}
void _onEndAnimation() {
if (_left < -widget.threshold || _left > widget.threshold) {
_swipeHorizontal(context);
} else if (_top < -widget.threshold || _top > widget.threshold) {
_swipeVertical(context);
} else {
_goBack(context);
}
}
void _swipe(BuildContext context, CardSwiperDirection direction) {
if (widget.cards.isEmpty) return;
switch (direction) {
case CardSwiperDirection.left:
_left = -1;
_swipeHorizontal(context);
break;
case CardSwiperDirection.right:
_left = widget.threshold + 1;
_swipeHorizontal(context);
break;
case CardSwiperDirection.top:
_top = -1;
_swipeVertical(context);
break;
case CardSwiperDirection.bottom:
_top = widget.threshold + 1;
_swipeVertical(context);
break;
default:
break;
}
_animationController.forward();
}
//moves the card away to the left or right
void _swipeHorizontal(BuildContext context) {
_leftAnimation = Tween<double>(
begin: _left,
end: (_left == 0 && widget.direction == CardSwiperDirection.right) ||
_left > widget.threshold
? MediaQuery.of(context).size.width
: -MediaQuery.of(context).size.width,
).animate(_animationController);
_topAnimation = Tween<double>(
begin: _top,
end: _top + _top,
).animate(_animationController);
_scaleAnimation = Tween<double>(
begin: _scale,
end: 1.0,
).animate(_animationController);
_differenceAnimation = Tween<double>(
begin: _difference,
end: 0,
).animate(_animationController);
_swipeType = SwipeType.swipe;
if (_left > widget.threshold ||
_left == 0 && widget.direction == CardSwiperDirection.right) {
detectedDirection = CardSwiperDirection.right;
} else {
detectedDirection = CardSwiperDirection.left;
}
}
//moves the card away to the top or bottom
void _swipeVertical(BuildContext context) {
_leftAnimation = Tween<double>(
begin: _left,
end: _left + _left,
).animate(_animationController);
_topAnimation = Tween<double>(
begin: _top,
end: (_top == 0 && widget.direction == CardSwiperDirection.bottom) ||
_top > widget.threshold
? MediaQuery.of(context).size.height
: -MediaQuery.of(context).size.height,
).animate(_animationController);
_scaleAnimation = Tween<double>(
begin: _scale,
end: 1.0,
).animate(_animationController);
_differenceAnimation = Tween<double>(
begin: _difference,
end: 0,
).animate(_animationController);
_swipeType = SwipeType.swipe;
if (_top > widget.threshold ||
_top == 0 && widget.direction == CardSwiperDirection.bottom) {
detectedDirection = CardSwiperDirection.bottom;
} else {
detectedDirection = CardSwiperDirection.top;
}
}
//moves the card back to starting position
void _goBack(BuildContext context) {
_leftAnimation = Tween<double>(
begin: _left,
end: 0,
).animate(_animationController);
_topAnimation = Tween<double>(
begin: _top,
end: 0,
).animate(_animationController);
_scaleAnimation = Tween<double>(
begin: _scale,
end: widget.scale,
).animate(_animationController);
_differenceAnimation = Tween<double>(
begin: _difference,
end: 40,
).animate(_animationController);
_swipeType = SwipeType.back;
}
}