flicked_cards

Build Status Codecov Pub Package MIT License

A gesture driven card swipping widget supporting custom animations.

Features

  • Awesome default behaviours provided
  • Progress through cards swipping both direction or in a single direction
  • Extensible through custom provided animations
  • Support piling or popping (depending on animation spec)

Examples

Here are some of the animation provided out of the box, take a look at the example to see all.

Cards used in these examples where taken from Brocodev

Example usage

FlickedCards(
  count: Superhero.marvelHeroes.length,
  debug: false,
  animationStyle: FlipAnimation(),
  onSwiped: (idx, dir) => print('>>> $dir $idx'),
  builder: (index, progress, context) {
    final superHeroe = Superhero.marvelHeroes[index];
    return Container(
      child: Center(
        child: SuperheroCard(
            superhero: superHeroe,
            factorChange: 1 - progress),
      ),
    );
  },
)

Custom animations

flicked_cards provides an easy way to create custom animations but it is required to have a basic understanding of how cards can be layed out and how to position them depending on the drag progress and some of the properties in AnimationConfig.

Animations will be provided a progress value in the range (-1, 1) you should try to make you animation symmetric around 0 when posible. Like this:

You will have to reason about relative card indices:

Interface for animations

All animations will need to implement CardAnimation which basically defines:

  • animation of a particular card depending on swipe progress required
  • opacity of a particular card depending on swipe progress optional
  • where to apply transformations on cards (Fractional Offset)
typedef SwipeAnimation = Matrix4 Function(double progress);
typedef OpacityAnimation = double Function(double progress);

abstract class CardAnimation {
  AnimationConfig get config;
  LayoutConfig get layoutConfig;

  SwipeAnimation animationForCard({required int relativeIndex});

  OpacityAnimation opacityForCard({required int relativeIndex}) {
    return (_) => 1;
  }

  FractionalOffset fractionalOffsetForCard({required int relativeIndex});
}

Additionally to make this process a bit easier, 2 extra abstract classes that implement CardAnimation which are:

  • SymmetricCardAnimation
  • AsymmetricCardAnimation

Carousel animation is an example of a SymmetricCardAnimation take a look here

If struggling to make the animationlook at how the animations provided out of the box where implemented: here

Available layouts

Internally cards are placed in Stack widget so an animation can choose to work with a single or both of the following layouts:

Note that depending on the index some of cards will not be displayed:

TODO

  • Add sensitivity parameter for wider screens.
  • Fix Deck Animation not constant card separation make last and before aligned

Libraries

flicked_cards