expo-camera

What is expo-camera?

The expo-camera package is a part of the Expo ecosystem and provides a comprehensive API for accessing and using the device's camera in React Native applications. It allows developers to capture photos, record videos, and access various camera settings and features.

What are expo-camera's main functionalities?

Capture Photos

This feature allows you to capture photos using the device's camera. The code sample demonstrates how to set up the Camera component and take a picture when a button is pressed.

```javascript
import React, { useRef } from 'react';
import { View, Button } from 'react-native';
import { Camera } from 'expo-camera';

export default function App() {
  const cameraRef = useRef(null);

  const takePicture = async () => {
    if (cameraRef.current) {
      const photo = await cameraRef.current.takePictureAsync();
      console.log(photo);
    }
  };

  return (
    <View style={{ flex: 1 }}>
      <Camera style={{ flex: 1 }} ref={cameraRef} />
      <Button title="Take Picture" onPress={takePicture} />
    </View>
  );
}
```

Record Videos

This feature allows you to record videos using the device's camera. The code sample demonstrates how to set up the Camera component and start/stop video recording when a button is pressed.

```javascript
import React, { useRef, useState } from 'react';
import { View, Button } from 'react-native';
import { Camera } from 'expo-camera';

export default function App() {
  const cameraRef = useRef(null);
  const [isRecording, setIsRecording] = useState(false);

  const recordVideo = async () => {
    if (cameraRef.current) {
      if (isRecording) {
        cameraRef.current.stopRecording();
      } else {
        setIsRecording(true);
        const video = await cameraRef.current.recordAsync();
        console.log(video);
        setIsRecording(false);
      }
    }
  };

  return (
    <View style={{ flex: 1 }}>
      <Camera style={{ flex: 1 }} ref={cameraRef} />
      <Button title={isRecording ? "Stop Recording" : "Record Video"} onPress={recordVideo} />
    </View>
  );
}
```

Access Camera Settings

This feature allows you to access and modify camera settings such as switching between the front and back cameras. The code sample demonstrates how to request camera permissions and toggle the camera type.

```javascript
import React, { useState, useEffect } from 'react';
import { View, Text } from 'react-native';
import { Camera } from 'expo-camera';

export default function App() {
  const [hasPermission, setHasPermission] = useState(null);
  const [cameraType, setCameraType] = useState(Camera.Constants.Type.back);

  useEffect(() => {
    (async () => {
      const { status } = await Camera.requestPermissionsAsync();
      setHasPermission(status === 'granted');
    })();
  }, []);

  if (hasPermission === null) {
    return <View />;
  }
  if (hasPermission === false) {
    return <Text>No access to camera</Text>;
  }

  return (
    <View style={{ flex: 1 }}>
      <Camera style={{ flex: 1 }} type={cameraType} />
      <Button
        title="Flip Camera"
        onPress={() => {
          setCameraType(
            cameraType === Camera.Constants.Type.back
              ? Camera.Constants.Type.front
              : Camera.Constants.Type.back
          );
        }}
      />
    </View>
  );
}
```

Other packages similar to expo-camera

react-native-camera

The react-native-camera package is a popular alternative to expo-camera. It provides similar functionalities such as capturing photos, recording videos, and accessing camera settings. However, it requires linking and additional setup compared to the more streamlined experience of expo-camera within the Expo ecosystem.

react-native-vision-camera

The react-native-vision-camera package offers advanced camera functionalities, including frame processing and integration with machine learning models. It is more feature-rich compared to expo-camera but also requires more complex setup and configuration.

README

The README file is missing