App.tsx

import React, {useEffect, useState} from 'react';
import type {PropsWithChildren} from 'react';

import {
  SafeAreaView,
  ScrollView,
  StatusBar,
  StyleSheet,
  Text,
  useColorScheme,
  View,
} from 'react-native';

import {Colors} from 'react-native/Libraries/NewAppScreen';

type SectionProps = PropsWithChildren<{
  title: string;
}>;

interface CustomFile {
  name: string;
  size: number;
}

function Section({children, title}: SectionProps): React.JSX.Element {
  const isDarkMode = useColorScheme() === 'dark';
  return (
    <View style={styles.sectionContainer}>
      <Text
        style={[
          styles.sectionTitle,
          {
            color: isDarkMode ? Colors.white : Colors.black,
          },
        ]}>
        {title}
      </Text>
      <Text
        style={[
          styles.sectionDescription,
          {
            color: isDarkMode ? Colors.light : Colors.dark,
          },
        ]}>
        {children}
      </Text>
    </View>
  );
}

function App() {
  const isDarkMode = useColorScheme() === 'dark';

  const backgroundStyle = {
    backgroundColor: isDarkMode ? Colors.darker : Colors.lighter,
  };

  const [dirs, setDirs] = useState<CustomFile[]>([]);

  useEffect(() => {
    var files = [];
    for (let i = 0; i < 100; i++) {
      files.push({name: `file${i}.jsx`, size: 312});
    }
    setDirs(files);
  }, []);

  const [totalSize, setSize] = useState(0);

  useEffect(() => {
    let total = 0;
    dirs.forEach(dir => {
      total += dir.size;
    });
    setSize(total);
  }, [dirs]);

  return (
    <SafeAreaView style={backgroundStyle}>
      <StatusBar
        barStyle={isDarkMode ? 'light-content' : 'dark-content'}
        backgroundColor={backgroundStyle.backgroundColor}
      />
      <ScrollView
        contentInsetAdjustmentBehavior="automatic"
        style={backgroundStyle}>
        <View
          style={{
            backgroundColor: isDarkMode ? Colors.black : Colors.white,
          }}>
          <Section title="파일 나열">
            {dirs &&
              dirs.map(file => {
                return <Text> {file.name}</Text>;
              })}
          </Section>
          <Section title="나의 저장 공간">
            <Text> {totalSize}MB</Text>;
          </Section>
        </View>
      </ScrollView>
    </SafeAreaView>
  );
}

const styles = StyleSheet.create({
  sectionContainer: {
    marginTop: 32,
    paddingHorizontal: 24,
  },
  sectionTitle: {
    fontSize: 24,
    fontWeight: '600',
  },
  sectionDescription: {
    marginTop: 8,
    fontSize: 18,
    fontWeight: '400',
  },
  highlight: {
    fontWeight: '700',
  },
});

export default App;