Concentric Sheet

React Native Modal replacement for iOS sheet presentation.

This package keeps React Native's Modal behavior, and adds runtime access to native UIViewController / UISheetPresentationController options such as:

• Detents (medium, large)
• Custom detent heights ([78, 350])
• Grabber visibility
• Preferred corner radius
• Selected detent
• Largest undimmed detent
• Edge-attached behavior
• Interactive dismissal lock (isModalInPresentation)
• Preferred content width/height

Install

bun add concentric-sheet react-native-nitro-modules

Then install iOS pods in your app:

bunx pod-install ./ios

Usage

import React from 'react'
import { View, Text, Button } from 'react-native'
import { Modal } from 'concentric-sheet'

export function Example() {
  const [visible, setVisible] = React.useState(false)

  return (
    <>
      <Button title="Open" onPress={() => setVisible(true)} />
      <Modal
        visible={visible}
        onRequestClose={() => setVisible(false)}
        detents={['medium', 'large']}
        prefersGrabberVisible
        preferredCornerRadius={24}
      >
        <View style={{ flex: 1, padding: 20 }}>
          <Text>Native sheet modal</Text>
          <Button title="Close" onPress={() => setVisible(false)} />
        </View>
      </Modal>
    </>
  )
}

API

Modal accepts all React Native Modal props, plus:

• detents?: ('medium' | 'large')[]
• customDetentHeights?: number[] (iOS 16+)
• selectedDetentIdentifier?: 'medium' | 'large'
• selectedCustomDetentHeight?: number (iOS 16+)
• largestUndimmedDetentIdentifier?: 'medium' | 'large'
• largestUndimmedCustomDetentHeight?: number (iOS 16+)
• prefersGrabberVisible?: boolean
• preferredCornerRadius?: number
• prefersScrollingExpandsWhenScrolledToEdge?: boolean
• prefersEdgeAttachedInCompactHeight?: boolean
• widthFollowsPreferredContentSizeWhenEdgeAttached?: boolean
• isModalInPresentation?: boolean
• preferredContentWidth?: number
• preferredContentHeight?: number
• modalViewBackground?: 'clear' | 'systemBackground'
• cornerConfiguration?: { type: 'none' | 'fixed' | 'containerConcentric' | 'capsule', radius?: number, minimumRadius?: number, maximumRadius?: number }

Imperative helpers:

• applyPresentedModalConfig(config)
• dismissPresentedNativeModal(animated?)

TODO

• [ ] Android support

Contributing

The native Swift implementation lives in ios/SheetModalController.swift.

The Nitro TypeScript API is defined in src/. When you change props or the spec, regenerate the native bridge code by running:

bunx nitrogen

Commit the generated files in nitrogen/ alongside your changes.

DCO

All commits must be signed off per the Developer Certificate of Origin. Use the -s flag when committing:

git commit -s -m "your commit message"

Notes

• iOS-only native implementation.
• UISheetPresentationController options require iOS 15+.
• cornerConfiguration requires iOS 26+.
• For sheet behavior, use presentationStyle="pageSheet" or formSheet.
• Setting largestUndimmedDetentIdentifier can disable outside-tap dismissal at/under that detent because the dimming view is removed.