@shopgate/engage/styles/theme/createTheme/transitions.js

Shopgate's ENGAGE library.

import { isDev } from '@shopgate/engage/core/helpers';

// Follow https://material.google.com/motion/duration-easing.html#duration-easing-natural-easing-curves
// to learn the context in which each easing should be used.
export const easing = {
  // This is the most common easing curve.
  easeInOut: 'cubic-bezier(0.4, 0, 0.2, 1)',
  // Objects enter the screen at full velocity from off-screen and
  // slowly decelerate to a resting point.
  easeOut: 'cubic-bezier(0.0, 0, 0.2, 1)',
  // Objects leave the screen at full velocity. They do not decelerate when off-screen.
  easeIn: 'cubic-bezier(0.4, 0, 1, 1)',
  // The sharp curve is used by objects that may return to the screen at any time.
  sharp: 'cubic-bezier(0.4, 0, 0.6, 1)'
};

// Follow https://material.io/guidelines/motion/duration-easing.html#duration-easing-common-durations
// to learn when use what timing
export const duration = {
  shortest: 150,
  shorter: 200,
  short: 250,
  // most basic recommended timing
  standard: 300,
  // this is to be used in complex animations
  complex: 375,
  // recommended when something is entering screen
  enteringScreen: 225,
  // recommended when something is leaving screen
  leavingScreen: 195
};

/**
 * Converts milliseconds to a string representation.
 * @param {number} milliseconds Input in milliseconds.
 * @returns {string}
 */
function formatMs(milliseconds) {
  return `${Math.round(milliseconds)}ms`;
}

/**
 * @param {string|Array} props
 * @param {object} param
 * @param {string} param.prop
 * @param {number} param.duration
 * @param {string} param.easing
 * @param {number} param.delay
 */
export default {
  easing,
  duration,
  create: (props = ['all'], options = {}) => {
    const {
      duration: durationOption = duration.standard,
      easing: easingOption = easing.easeInOut,
      delay = 0,
      ...other
    } = options;
    if (isDev) {
      /* eslint-disable require-jsdoc */
      const isString = value => typeof value === 'string';
      const isNumber = value => !Number.isNaN(parseFloat(value));
      /* eslint-enable require-jsdoc */
      if (!isString(props) && !Array.isArray(props)) {
        console.error('Shopgate Theme: Argument "props" must be a string or Array.');
      }
      if (!isNumber(durationOption) && !isString(durationOption)) {
        console.error(`Shopgate Theme: Argument "duration" must be a number or a string but found ${durationOption}.`);
      }
      if (!isString(easingOption)) {
        console.error('Shopgate Theme: Argument "easing" must be a string.');
      }
      if (!isNumber(delay) && !isString(delay)) {
        console.error('Shopgate Theme: Argument "delay" must be a number or a string.');
      }
      if (Object.keys(other).length !== 0) {
        console.error(`Shopgate Theme: Unrecognized argument(s) [${Object.keys(other).join(',')}].`);
      }
    }
    return (Array.isArray(props) ? props : [props]).map(animatedProp => `${animatedProp} ${typeof durationOption === 'string' ? durationOption : formatMs(durationOption)} ${easingOption} ${typeof delay === 'string' ? delay : formatMs(delay)}`).join(',');
  },
  getAutoHeightDuration(height) {
    if (!height) {
      return 0;
    }
    const constant = height / 36;

    // https://www.wolframalpha.com/input/?i=(4+%2B+15+*+(x+%2F+36+)+**+0.25+%2B+(x+%2F+36)+%2F+5)+*+10
    return Math.round((4 + 15 * constant ** 0.25 + constant / 5) * 10);
  }
};