@expo/vector-icons/vendor/react-native-vector-icons/lib/create-icon-set.js

Built-in support for 10 popular icon fonts and the tooling to create your own Icon components from your font and glyph map. This is a wrapper around react-native-vector-icons to make it compatible with Expo.

import React, { Component } from 'react';
import PropTypes from 'prop-types';
import {
  NativeModules,
  Platform,
  PixelRatio,
  processColor,
  Text,
} from './react-native';

import createIconButtonComponent from './icon-button';
import createTabBarItemIOSComponent from './tab-bar-item-ios';
import createToolbarAndroidComponent from './toolbar-android';

const NativeIconAPI =
  NativeModules.RNVectorIconsManager || NativeModules.RNVectorIconsModule;

const DEFAULT_ICON_SIZE = 12;
const DEFAULT_ICON_COLOR = 'black';

export default function createIconSet(glyphMap, fontFamily, fontFile) {
  let fontReference = fontFamily;
  // Android doesn't care about actual fontFamily name, it will only look in fonts folder.
  if (Platform.OS === 'android' && fontFile) {
    fontReference = fontFile.replace(/\.(otf|ttf)$/, '');
  }

  if (Platform.OS === 'windows' && fontFile) {
    fontReference = `Assets/${fontFile}#${fontFamily}`;
  }

  const IconNamePropType = PropTypes.oneOf(Object.keys(glyphMap));

  class Icon extends Component {
    static propTypes = {
      name: IconNamePropType.isRequired,
      size: PropTypes.number,
      color: PropTypes.string,
      children: PropTypes.node,
      style: PropTypes.any, // eslint-disable-line react/forbid-prop-types
    };

    static defaultProps = {
      size: DEFAULT_ICON_SIZE,
      allowFontScaling: false,
    };

    setNativeProps(nativeProps) {
      if (this.root) {
        this.root.setNativeProps(nativeProps);
      }
    }

    root = null;
    handleRef = ref => {
      this.root = ref;
    };

    render() {
      const { name, size, color, style, ...props } = this.props;

      let glyph = glyphMap[name] || '?';
      if (typeof glyph === 'number') {
        glyph = String.fromCharCode(glyph);
      }

      const styleDefaults = {
        fontSize: size,
        color,
      };

      const styleOverrides = {
        fontFamily: fontReference,
        fontWeight: 'normal',
        fontStyle: 'normal',
      };

      props.style = [styleDefaults, style, styleOverrides];
      props.ref = this.handleRef;

      return <Text {...props}>{glyph}{this.props.children}</Text>;
    }
  }

  const imageSourceCache = {};

  function getImageSource(
    name,
    size = DEFAULT_ICON_SIZE,
    color = DEFAULT_ICON_COLOR
  ) {
    if (!NativeIconAPI) {
      if (Platform.OS === 'android') {
        throw new Error(
          'RNVectorIconsModule not available, did you properly integrate the module?'
        );
      }
      throw new Error(
        'RNVectorIconsManager not available, did you add the library to your project and link with libRNVectorIcons.a?'
      );
    }

    let glyph = glyphMap[name] || '?';
    if (typeof glyph === 'number') {
      glyph = String.fromCharCode(glyph);
    }

    const processedColor = processColor(color);
    const cacheKey = `${glyph}:${size}:${processedColor}`;
    const scale = PixelRatio.get();

    return new Promise((resolve, reject) => {
      const cached = imageSourceCache[cacheKey];
      if (typeof cached !== 'undefined') {
        if (!cached || cached instanceof Error) {
          reject(cached);
        } else {
          resolve({ uri: cached, scale });
        }
      } else {
        NativeIconAPI.getImageForFont(
          fontReference,
          glyph,
          size,
          processedColor,
          (err, image) => {
            const error = typeof err === 'string' ? new Error(err) : err;
            imageSourceCache[cacheKey] = image || error || false;
            if (!error && image) {
              resolve({ uri: image, scale });
            } else {
              reject(error);
            }
          }
        );
      }
    });
  }

  Icon.Button = createIconButtonComponent(Icon);
  Icon.TabBarItem = createTabBarItemIOSComponent(
    IconNamePropType,
    getImageSource
  );
  Icon.TabBarItemIOS = Icon.TabBarItem;
  Icon.ToolbarAndroid = createToolbarAndroidComponent(
    IconNamePropType,
    getImageSource
  );
  Icon.getImageSource = getImageSource;

  return Icon;
}