react-lazily-render/dist/esnext/utils/getViewportBounds.js

Lazily render react components

function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; var ownKeys = Object.keys(source); if (typeof Object.getOwnPropertySymbols === 'function') { ownKeys = ownKeys.concat(Object.getOwnPropertySymbols(source).filter(function (sym) { return Object.getOwnPropertyDescriptor(source, sym).enumerable; })); } ownKeys.forEach(function (key) { _defineProperty(target, key, source[key]); }); } return target; }

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

import getElementBounds from './getElementBounds';
export default function (container) {
  if (!container) {
    return undefined;
  }

  if (container === window) {
    return {
      top: window.pageYOffset,
      left: window.pageXOffset,
      bottom: window.pageYOffset + window.innerHeight,
      right: window.pageXOffset + window.innerWidth
    };
  } else {
    var bounds = getElementBounds(container);

    if (bounds) {
      return _objectSpread({}, bounds, {
        bottom: bounds.top + container.offsetHeight,
        right: bounds.left + container.offsetWidth
      });
    } else {
      return undefined;
    }
  }
}