polished/lib/mixins/retinaImage.js

A lightweight toolset for writing styles in Javascript.

"use strict";

exports.__esModule = true;
exports["default"] = retinaImage;
var _hiDPI = _interopRequireDefault(require("./hiDPI"));
var _errors = _interopRequireDefault(require("../internalHelpers/_errors"));
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }
function _extends() { _extends = Object.assign ? Object.assign.bind() : function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; }; return _extends.apply(this, arguments); }
/**
 * A helper to generate a retina background image and non-retina
 * background image. The retina background image will output to a HiDPI media query. The mixin uses
 * a _2x.png filename suffix by default.
 *
 * @example
 * // Styles as object usage
 * const styles = {
 *  ...retinaImage('my-img')
 * }
 *
 * // styled-components usage
 * const div = styled.div`
 *   ${retinaImage('my-img')}
 * `
 *
 * // CSS as JS Output
 * div {
 *   backgroundImage: 'url(my-img.png)',
 *   '@media only screen and (-webkit-min-device-pixel-ratio: 1.3),
 *    only screen and (min--moz-device-pixel-ratio: 1.3),
 *    only screen and (-o-min-device-pixel-ratio: 1.3/1),
 *    only screen and (min-resolution: 144dpi),
 *    only screen and (min-resolution: 1.5dppx)': {
 *     backgroundImage: 'url(my-img_2x.png)',
 *   }
 * }
 */
function retinaImage(filename, backgroundSize, extension, retinaFilename, retinaSuffix) {
  var _ref;
  if (extension === void 0) {
    extension = 'png';
  }
  if (retinaSuffix === void 0) {
    retinaSuffix = '_2x';
  }
  if (!filename) {
    throw new _errors["default"](58);
  }
  // Replace the dot at the beginning of the passed extension if one exists
  var ext = extension.replace(/^\./, '');
  var rFilename = retinaFilename ? retinaFilename + "." + ext : "" + filename + retinaSuffix + "." + ext;
  return _ref = {
    backgroundImage: "url(" + filename + "." + ext + ")"
  }, _ref[(0, _hiDPI["default"])()] = _extends({
    backgroundImage: "url(" + rFilename + ")"
  }, backgroundSize ? {
    backgroundSize: backgroundSize
  } : {}), _ref;
}
module.exports = exports.default;