iOS 27 is full of references to a folding iPhone. Apple didn’t mention it once at WWDC.

Introduction

Apple's iOS 27 developer beta has revealed intriguing hints about a future foldable iPhone, with code references to "foldState," "mechanicalAngleDegrees," and "angleDegrees." While Apple hasn't officially announced a foldable iPhone at WWDC 2026, these software clues provide a glimpse into how developers might interact with foldable hardware. This tutorial will guide you through creating a mock foldable device simulator using React Native, helping you understand how apps might adapt to different screen states and orientations. This is a practical demonstration of how developers can prepare for foldable hardware by simulating its behavior.

Prerequisites

• Basic knowledge of React Native development
• Node.js and npm installed on your system
• React Native CLI or Expo CLI installed
• Familiarity with React components and state management

Step-by-step Instructions

1. Initialize a New React Native Project

We'll start by creating a new React Native project. This will serve as our development environment to simulate foldable device behavior.

react-native init FoldableSimulator

Change into the project directory:

cd FoldableSimulator

Why: This sets up the basic React Native project structure, including all necessary files and dependencies to begin development.

2. Install Required Dependencies

Next, we'll install the necessary libraries for screen orientation detection and state management.

npm install react-native-orientation-locker

We'll also need to install React Native Gesture Handler for handling foldable device gestures:

npm install react-native-gesture-handler

Why: These libraries will help us detect device orientation and simulate how a foldable screen might change states.

3. Configure Orientation Locking

Open the App.js file and add the necessary imports:

import React, { useState, useEffect } from 'react';
import { View, Text, StyleSheet, TouchableOpacity } from 'react-native';
import Orientation from 'react-native-orientation-locker';

const App = () => {
  const [foldState, setFoldState] = useState('unfolded');
  const [angle, setAngle] = useState(0);

  useEffect(() => {
    const subscription = Orientation.addOrientationListener((orientation) => {
      // Simulate fold state based on orientation
      if (orientation === 'LANDSCAPE-LEFT' || orientation === 'LANDSCAPE-RIGHT') {
        setFoldState('folded');
        setAngle(180);
      } else {
        setFoldState('unfolded');
        setAngle(0);
      }
    });

    return () => {
      Orientation.removeOrientationListener(subscription);
    };
  }, []);

  // Rest of the component
};

Why: This sets up the orientation listener to detect when the device changes orientation, which is a key part of how foldable devices behave.

4. Create Foldable State UI Components

Now, we'll create UI components that visually represent the foldable state:

const FoldableIndicator = ({ state, angle }) => {
  return (
    <View style={styles.foldIndicator}>
      <Text style={styles.foldText}>Fold State: {state}</Text>
      <Text style={styles.angleText}>Angle: {angle}°</Text>
    </View>
  );
};

const FoldableScreen = ({ state }) => {
  const isFolded = state === 'folded';
  
  return (
    <View style={[styles.screen, isFolded ? styles.foldedScreen : styles.unfoldedScreen]}>
      <Text style={styles.screenText}>{isFolded ? 'Folded Screen' : 'Unfolded Screen'}</Text>
    </View>
  );
};

Why: These components visually represent the current state of the foldable device, helping us understand how the UI might adapt.

5. Implement Simulated Foldable Controls

Next, we'll add controls to manually simulate the fold/unfold states:

const FoldableControls = ({ onFold, onUnfold }) => {
  return (
    <View style={styles.controls}>
      <TouchableOpacity style={styles.button} onPress={onFold}>
        <Text style={styles.buttonText}>Fold</Text>
      </TouchableOpacity>
      <TouchableOpacity style={styles.button} onPress={onUnfold}>
        <Text style={styles.buttonText}>Unfold</Text>
      </TouchableOpacity>
    </View>
  );
};

Why: This allows us to manually test different fold states without needing to physically rotate the device.

6. Update App Component with Full Logic

Integrate everything into the main App component:

const App = () => {
  const [foldState, setFoldState] = useState('unfolded');
  const [angle, setAngle] = useState(0);

  const handleFold = () => {
    setFoldState('folded');
    setAngle(180);
  };

  const handleUnfold = () => {
    setFoldState('unfolded');
    setAngle(0);
  };

  return (
    <View style={styles.container}>
      <FoldableIndicator state={foldState} angle={angle} />
      <FoldableScreen state={foldState} />
      <FoldableControls onFold={handleFold} onUnfold={handleUnfold} />
    </View>
  );
};

Why: This brings all the components together into a functional simulator that demonstrates how a foldable device might behave.

7. Add Styling

Finally, add some basic styling to make the UI more visually appealing:

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#f0f0f0',
  },
  foldIndicator: {
    padding: 10,
    backgroundColor: '#333',
    color: 'white',
    marginBottom: 20,
  },
  foldText: {
    color: 'white',
    fontSize: 16,
  },
  angleText: {
    color: 'white',
    fontSize: 14,
  },
  screen: {
    width: '80%',
    height: 200,
    justifyContent: 'center',
    alignItems: 'center',
    marginBottom: 20,
  },
  unfoldedScreen: {
    backgroundColor: '#007AFF',
  },
  foldedScreen: {
    backgroundColor: '#FF9500',
  },
  screenText: {
    color: 'white',
    fontSize: 18,
    fontWeight: 'bold',
  },
  controls: {
    flexDirection: 'row',
    justifyContent: 'space-around',
    width: '80%',
  },
  button: {
    padding: 10,
    backgroundColor: '#007AFF',
    borderRadius: 5,
  },
  buttonText: {
    color: 'white',
    fontWeight: 'bold',
  },
});

Why: Proper styling ensures the simulator is visually clear and easy to understand, making it more practical for developers to test UI adaptations.

Summary

This tutorial has walked you through creating a foldable device simulator using React Native. By simulating the foldState, mechanicalAngleDegrees, and angleDegrees concepts found in iOS 27, you've learned how developers can prepare for future foldable hardware. The simulator demonstrates how UI components might change based on screen state, helping developers design adaptive interfaces that respond to different device configurations. While this is a simplified simulation, it mirrors real-world development practices that will be essential as foldable devices become mainstream.