react-native-snap-carousel

Swiper component for React Native with previews, snapping effect and RTL support. Compatible with Android & iOS. Pull requests are very welcome!

Showcase
Breaking change
Usage
Props
Methods
Properties
Example
Tips and tricks
RTL support
TODO
Credits

Showcase

You can try these examples live in Archriss' showcase app on Android and iOS.

Since it has been asked multiple times, please note that we do not plan on Open-Sourcing the code of our showcase app. Still, we've put together an example for you to play with, and you can find some insight about our map implementation in this comment.

App currently uses version 1.4.0 of the plugin. Especially, this means that you should expect slider's layout to break with RTL devices (see #38) since support was added in version 2.1.0.

Breaking change

Since version 2.0.0, items are now direct children of the component. As a result, props items and renderItem have been removed.

Usage

$ npm install --save react-native-snap-carousel

import Carousel from 'react-native-snap-carousel';

    // Example with different children
    render () {
        <Carousel
          ref={(carousel) => { this._carousel = carousel; }}
          sliderWidth={sliderWidth}
          itemWidth={itemWidth}
        >
            <View style={styles.slide1} />
            <Text style={styles.slide2} />
            <Image style={styles.slide3} />
        </Carousel>
    }

    // Example of appending the same component multiple times while looping through an array of data
    render () {
        const slides = this.state.entries.map((entry, index) => {
            return (
                <View key={`entry-${index}`} style={styles.slide}>
                    <Text style={styles.title}>{ entry.title }</Text>
                </View>
            );
        });

        <Carousel
          ref={(carousel) => { this._carousel = carousel; }}
          sliderWidth={sliderWidth}
          itemWidth={itemWidth}
        >
            { slides }
        </Carousel>
    }

Props

Required

Prop	Description	Type	Default
itemWidth	Width in pixels of your slides, must be the same for all of them	Number	Required
sliderWidth	Width in pixels of your slider	Number	Required

Behavior

Prop	Description	Type	Default
activeSlideOffset	From slider's center, minimum slide distance to be scrolled before being set to active	Number	`25`
enableMomentum	See momentum	Boolean	`false`
enableSnap	If enabled, releasing the touch will scroll to the center of the nearest/active item	Number	`true`
firstItem	Index of the first item to display	Number	`0`
shouldOptimizeUpdates	whether to implement a `shouldComponentUpdate` strategy to minimize updates	Boolean	`true`
snapOnAndroid	Snapping on android is kinda choppy, especially when swiping quickly so you can disable it	Boolean	`true`
swipeThreshold	Delta x when swiping to trigger the snap	Number	`20`

Autoplay

Prop	Description	Type	Default
autoplay	Trigger autoplay on mount	Boolean	`false`
autoplayDelay	Delay before enabling autoplay on startup & after releasing the touch	Number	`5000`
autoplayInterval	Delay in ms until navigating to the next item	Number	`3000`

Style and animation

Prop	Description	Type	Default
animationFunc	Animated animation to use. Provide the name of the method	String	`timing`
animationOptions	Animation options to be merged with the default ones. Can be used w/ animationFunc	Object	`{ easing: Easing.elastic(1) }`
carouselHorizontalPadding	Override container's inner padding (needed for slides's centering). Warning: be aware that overriding the default value can mess with carousel's behavior.	Number	`(sliderWidth - itemWidth) / 2`
containerCustomStyle	Optional styles for Scrollview's global wrapper	ScrollView Style Object	`{}`
contentContainerCustomStyle	Optional styles for Scrollview's items container	ScrollView Style Object	`{}`
inactiveSlideOpacity	Value of the opacity effect applied to inactive slides	Number	`1`
inactiveSlideScale	Value of the 'scale' transform applied to inactive slides	Number	`0.9`
slideStyle	Optional style for each item's container (the one whose scale and opacity are animated)	Animated View Style Object	{}

Callbacks

Prop	Description	Type	Default
onSnapToItem(slideIndex)	Callback fired when navigating to an item	Function	`undefined`

`ScrollView`

In addition to these props, you can use any prop from the ScrollView component.

Here are a few useful ones:removeClippedSubviews, showsHorizontalScrollIndicator, overScrollMode (android), bounces (ios), decelerationRate (ios), scrollEventThrottle (ios)

Methods

Reference to the component

In order to use the following methods, you need to create a reference to the carousel's instance. There are two ways of doing it.

ref as a callback attribute (recommended)

<Carousel
  // other props
  ref={(carousel) => { this._carousel = carousel; }}
/>

// methods can then be called this way
onPress={() => { this._carousel.snapToNext(); }}

ref as a string attribute (legacy)

<Carousel
  // other props
  ref={'carousel'}
/>

// methods can then be called this way
onPress={() => { this.refs.carousel.snapToNext(); }}

Available methods

startAutoplay (instantly = false) Start the autoplay manually
stopAutoplay () Stop the autoplay manually
snapToItem (index, animated = true) Snap to an item manually
snapToNext (animated = true) Snap to next item manually
snapToPrev (animated = true) Snap to previous item manually

Properties

You need a reference to the carousel's instance (see above if needed).

currentIndex Current active item (int, starts at 0)

Example

You can find the following example in the /example folder.

Tips and tricks

Momentum

Since 1.5.0, the snapping effect can now be based on momentum instead of when you're releasing your finger. It means that the component will wait until the ScrollView isn't moving anymore to snap. By default, the inertia isn't too high on Android. However, we had to tweak the default iOS value a bit to make sure the snapping isn't delayed for too long. You can adjust this value to your needs thanks to this prop.

As a rule of thumb, we recommend setting enableMomentum to false (default) and decelerationRate to 'fast' when you are displaying only one main slide (as in the showcase above), and to use true and 0.9 otherwise. This should help providing a better snap feeling.

Margin between slides

If you need some extra horizontal margin between slides (besides the one resulting from the scale effect), you should add it as paddingHorizontal on the slide container. Make sure to take this into account when calculating item's width.

const sliderWidth = Dimensions.get('window').width * 0.75;
const slideWidth = 250;
const horizontalMargin = 20;
const itemWidth = slideWidth + horizontalMargin * 2;

const styles = Stylesheet.create({
    slide: {
        width: itemWidth
        // other styles for your item's container
    }
};

<Carousel
  sliderWidth={sliderWidth}
  itemWidth={itemWidth}
>
    ...
</Carousel>

RTL support

Experimental feature

Since version 2.1.0, the plugin is compatible with RTL layouts. Our implementation relies on miscellaneous hacks that work around a React Native bug with horizontal ScrollView.

As such, this feature should be considered experimental since it might break with newer versions of React Native.

Known issue

There is one kown issue with RTL layouts: during init, the last slide will shortly be seen. You can work around this by delaying slider's visibility with a small timer (FYI, version 0.43.0 of React Native introduced a display style prop that could either be set to flex or none).

TODO

Credits

Written by Maxime Bertonnier and Benoît Delmaire at Archriss.

roxwhale / react-native-snap-carousel Goto Github PK