React Native Gallery Toolkit

Reanimated 2 and Gesturer Handler powered Gallery implementation

• Installation
• Standalone gallery
  • Limitations
  • Base props
  • Advance props
  • Handlers
  • Methods
• Pager
• Transformer
• Examples
  • Running on iOS
  • Running on Android
• LICENSE

Important!

The library uses Reanimated 2 alpha. It means that it may be unstable. Also, the library itself is in the alpha testing stage and may contain bugs.

Installation

Use npm or yarn to install the library

npm i --save react-native-gallery-toolkit

Also, you need to install [email protected] (then new 2 version) and react-native-gesture-handler, and follow their installation instructions.

Expo is not currently supported because it doesn't support Reanimated 2.

Important!

There is a bug in [email protected] that causes gesture event handlers to reattach on each render. You can apply this patch to workaround it.

Standalone gallery

Standalone gallery renders Pager which supports thousands of images thanks to virtualization. Each page renders ImageTransformer component which gives ability to pinch-to-zoom, double tap to zoom, also you can run custom callbacks and worklets on on tab, double tap, pan.

import {
  StandaloneGallery,
  GalleryItemType,
  StandaloneGalleryHandler,
} from 'react-native-gallery-toolkit';

const images: GalleryItemType[] = [
  {
    id: '1',
    width: 300,
    height: 300,
    uri: 'https://placekitten.com/300/300',
  },
  {
    id: '2',
    width: 400,
    height: 200,
    uri: 'https://placekitten.com/400/200',
  },
];

export default function App() {
  return <StandaloneGallery items={images} />;
}

See Full featured example for example of usage of all the props.

Limitations

• Only portrait orientation currently supported
• There is no way to change dimensions without full re-render of the gallery
• Debugging is not supported because of Reanimated v2 uses TurboModules. Use flipper to debug your JS Context.
• On Android tap on hold on the screen while page changes doesn't trigger animation to stop due to bug in Gesture Handler.

Base props

Prop	Description	Type	Default
items	The array of items to render. But can also accept Map, Set, or Object with keys. If the type is not array, then getTotalCount and getItem should be defined too.	Array<{ width: number, height: number, id: string, uri: string }>	undefined
width?	Viewport width	number	Dimensions.get('window').width
height?	Viewport height	number	Dimensions.get('window').height
numToRender?	How many pages should be rendered at the same time	number	2
gutterWidth?	The width of the gutter between pages	number	0
initialIndex?	The initial page index	number	0
keyExtractor?	Callback which extract the key of the page. Receives current item of the provided items as well as current index	(item: T, index: number) => string	Uses index as a key by default

Advance props

Prop	Description	Type	Default
getTotalCount?	If the type of items is not an array, then this method should be defined to provide the total count of items	(data: T) => number	Required when items is not an array
getItem?	If the type of items is not an array, then this method should be defined to provide the current item based on the index. Can return either the item or undefined.	(data: T, index: number) => ItemT or undefined	Required when items is not an array
renderImage?	Callback that can be used to render custom image component. As an example, it can be used to render custom loading/error states	(props: RenderImageProps) => JSX.Element	() => Image
renderPage?	Callback that can be used to render custom page. Can be used to display some non-image pages such as Video, for instance	(props: ImageRendererProps<T>, index: number) => JSX.Element	ImageTransformer

Handlers

Prop	Description	Type	Is worklet?	Default
onIndexChange?	Fires when active index changes	(nextIndex: number) => void	Function or Worklet	undefined
onTap?	Executes when tap image transformer receives tap	() => void	Function or Worklet	undefined
onDoubleTap?	Executes when tap image transformer receives double-tap	() => void	Function or Worklet	undefined
onInteraction?	Is called when either pan or scale has happened.	(type: 'scale' or 'pan') => void	Function or Worklet	undefined
onPagerTranslateChange?	Executes on pager's horizontal pan	(translateX: number) => void	Function or Worklet	undefined
onGesture?	Executes on pager's gesture	(event: PanGestureHandlerGestureEvent, isActive: SharedValue<boolean>) => void	Function or Worklet	undefined
shouldPagerHandleGestureEvent?	Worklet that will be passed to pager's shouldHandleEvent to determine should pager handle this event. Can be used to handle "swipe down to close".	(event: PanGestureHandlerGestureEvent) => boolean	Only Worklet	undefined

Methods

Name	Description	Type
goNext	Changes the active index forward	() => void
goBack	Changes the active index backward	() => void
setIndex	Sets the active index	(nextIndex: number) => void

Pager

WIP

Transformer

WIP

Examples

The source code for the example (showcase) app is under the Example/ directory. Clone the repo, go to the Example/ folder and run:

npm install

Running on iOS

Before running the app, install the cocoapods dependencies:

npx pod-install

Now, you can start the app:

npm run ios

Running on Android

npm run android

LICENSE

MIT