React Native Drag to Sort Grid

This is a React Native package designed specifically to take advantage of the new React Native Reanimated 2 library. As a result, this package enables silky smooth gesture based animations that are capable of running at 60fps, even on an Android emulator running in debug mode. As a result, the performance of this package is substantially better than most other draggable grid packages available at the moment.

React Native Reanimated 2 offloads animations to the UI thread (as opposed to the JavaScript thread), which means the code for this package is written in a slightly different way than usual, to make use of worklets. Fortunately React Native Reanimated 2 allows us to write code in a more declarative way, and so the code is much more stylistically similar to typical React code.

React Native Drag to Sort Grid - API

This package was written using typescript, so comes with typescript definitions built-in. To use this package import DraggableGrid like this:

import DraggableGrid from 'react-native-drag-to-sort-grid';

Once imported, the DraggableGrid takes the following props, and can use generics like this <DraggableGrid<YourItemType> />

Props

Name	Type	Description
data	(T & { index: number | null })[]	The data for each element, including the index of the element in the unsorted data array
initialOrder	number[]	An array containing the initial order of each element in the unsorted data array (e.g. [1, 0] means data[1] is the first element, and data[0] is the second)
itemWidth	number	The width of one grid tile
itemHeight	number	The height of one grid tile
itemMargin	number	The horizonal and vertical margin of each tile
offsetY	number	The Y offset applied to the top of the grid
renderItem	(item: T, index: number) => JSX.Element	Render prop to render the content of the tile. The data item is passed as a param
deleteRenderItem	(item: T, index: number) => JSX.Element	Render prop to render the delete button of the tile
deleteStyle	ViewStyle	The style passed to the element that wraps the deleteRenderItem. A top, left, right or bottom should be used to position the deleteRenderItem
onOrderingFinished	(newOrder: number[]) => void	Callback function which is called whenever the order of tiles is changed

Recommended usage

Whenever an element is deleted from the data array, the DraggableGrid component should be unmounted and then re-mounted, with a new initialOrder passed as a prop. This is so that the internal order SharedValue can be reinitialised correctly.

The justification for this design decision is that if this were to be attempted using a useEffect inside the DraggableGrid component then this update would be a few frames out of sync, resulting in janky visuals and potentially crashes depending on how this package is being used. This is a tradeoff of the animations taking place on the UI thread instead of the JavaScript thread.

Running the example

1. Clone this repo
2. cd react-native-drag-to-sort-grid-mono/example
3. Run yarn
4. Run npx pod-install
5. Run yarn ios or yarn android