React Native FoldView

FoldingCell implementation in JavaScript. This project was inspired by the folding cell animation seen on Dribbble.

Questions?

Feel free to reach out to me on Twitter @jmurzy.

Read it on Medium

To learn more about how FoldView was implemented, check out the article on Medium: Implementing FoldView in React Native.

Example

The demo app from the GIF can be found at examples/Simple.

To build and run the example app:

git clone https://github.com/jmurzy/react-native-foldview

cd react-native-foldview/examples/Simple
npm install

To deploy to iOS simulator:

npm run ios

Installation

Using npm:

$ npm install --save react-native-foldview

Using yarn:

$ yarn add react-native-foldview

Usage

import React, { Component } from 'react';

import FoldView from 'react-native-foldview';

const Frontface = (props) => (/*...*/);
const Backface = (props) => (/*...*/);
const Base = (props) => (/*...*/);

export default class Row extends Component {

  constructor(props) {
    super(props);

    this.state = {
      expanded: false,
    };
  }

  componentWillMount() {
    this.flip = this.flip.bind(this);
  }

  flip() {
    this.setState({
      expanded: !this.state.expanded,
    });
  }

  renderFrontface() {
    return (
      <Frontface />
    );
  }

  renderBackface() {
    /**
     * You can nest <FoldView>s here to achieve the folding effect shown in the GIF above.
     * A reference implementation can be found in examples/Simple.
     */
    return (
      <Backface />
    );
  }

  render() {
    return (
      <FoldView
        expanded={this.state.expanded}
        renderBackface={this.renderBackface}
        renderFrontface={this.renderFrontface}
      >
        <Base />
      </FoldView>
    );
  }
}

Props

Prop	Type	Description
children	ReactElement<any>	React Element(s) to render.
flipDuration	?number	Length of flip animation in milliseconds. Default 280.
renderBackface	() => ReactElement<any>	Callback that renders a backface.
renderFrontface	() => ReactElement<any>	Callback that renders a frontface.
renderLoading	?() => ReactElement<any>	Callback that renders a temporary view to display before base layout occurs. If not provided, renderFrontface is used instead.

Root-only Props

FoldViews can be nested. The following props can only be set on the root FoldView.

Prop	Type	Description
collapse	?(foldviews: Array<IFoldView>) => Promise	Called when FoldView should collapse allowing you to have control over which FoldViews(s) to collapse. Default behavior is to wait until a FoldView is collapsed before collapsing the next one.
expand	?(foldviews: Array<IFoldView>) => Promise	Called when FoldView should expand allowing you to have control over which FoldView(s) to expand. Default behavior is to wait until a FoldView is expanded before expanding the next one.
expanded	boolean	Allows you to expand and collapse the FoldView content.
onAnimationEnd	?(duration: number, height: number) => void	Called when a collapse animation ends.
onAnimationStart	?(duration: number, height: number) => void	Called before an expand animation starts.
perspective	?number	Defines the space within which the 3D animation occurs.

Advanced Usage

You can customize the behavior of expand and collapse animations using the expand and collapse props on the root FoldView. For example, it's very much possible to collapse all FoldViews in a given stack altogether rather than one by one. You can do so as follows:

const collapse = async (foldViews) => {
  /**
   * Internally, FoldView turns off rasterization when collapsed as an optimization to decrease
   * memory usage. It's important to wrap your calls in a `Promise` here to avoid early disabling
   * of rasterization.
   */
  await Promise.all(foldViews.map(foldView => foldView.collapse()));
}

<FoldView
  collapse={collapse}
  renderBackface={/* ... */}
  renderFrontface={/* ... */}
>
  { /* ... */ }
</FoldView>

Platform Support

This library heavily depends on the overflow style property. Unfortunately, overflow defaults to hidden on Android and cannot be changed. Although it looks like a possible fix is in the making, currently, FoldingView is only supported on iOS.

Contributing

Contributions are very welcome: bug fixes, features, documentation, tests. Just make sure the CI is 👌.

#### Hacking

Unfortunately, React Native packager does not support symlinking so you cannot use npm link when hacking on this library. You can learn more about that, here.

The library code is specified as a [local dependency](local dependency) in the example's package.json. In order to hack on the library code, you need to sync it into examples/Simple/node_modules. To do so, run:

npm run watch

This will automatically watch the src directory and sync your changes into examples/Simple/node_modules every time something changes.

#### License All pull requests that get merged will be made available under [the MIT license](https://github.com/jmurzy/react-native-foldview/blob/master/LICENSE.md), as the rest of the repository.