hy-push-state/lib/mixin/scrolling.js

Turn static web sites into dynamic web apps

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.scrollMixin = void 0;

var _common = require("../common");

var _constants = require("./constants");

function _typeof(obj) { "@babel/helpers - typeof"; if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }

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; }

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }

function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); return Constructor; }

function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }

function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }

function _createSuper(Derived) { var hasNativeReflectConstruct = _isNativeReflectConstruct(); return function () { var Super = _getPrototypeOf(Derived), result; if (hasNativeReflectConstruct) { var NewTarget = _getPrototypeOf(this).constructor; result = Reflect.construct(Super, arguments, NewTarget); } else { result = Super.apply(this, arguments); } return _possibleConstructorReturn(this, result); }; }

function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) === "object" || typeof call === "function")) { return call; } return _assertThisInitialized(self); }

function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }

function _isNativeReflectConstruct() { if (typeof Reflect === "undefined" || !Reflect.construct) return false; if (Reflect.construct.sham) return false; if (typeof Proxy === "function") return true; try { Date.prototype.toString.call(Reflect.construct(Date, [], function () {})); return true; } catch (e) { return false; } }

function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__ || Object.getPrototypeOf(o); }; return _getPrototypeOf(o); }

// ### Managing scroll positions
// The following functions deal with managing the scroll position of the site.
var scrollMixin = function scrollMixin(C) {
  return /*#__PURE__*/function (_C) {
    _inherits(_class, _C);

    var _super = _createSuper(_class);

    function _class() {
      _classCallCheck(this, _class);

      return _super.apply(this, arguments);
    }

    _createClass(_class, [{
      key: "assignScrollPosition",
      // TODO: doc
      value: function assignScrollPosition(state) {
        var id = this.histId();
        return Object.assign(state, _defineProperty({}, id, Object.assign(state[id] || {}, {
          scrollTop: (0, _common.getScrollTop)(),
          scrollHeight: (0, _common.getScrollHeight)()
        })));
      } // TODO

    }, {
      key: "manageScrollPostion",
      value: function manageScrollPostion(_ref) {
        var type = _ref.type,
            hash = _ref.url.hash;

        switch (type) {
          case _constants.PUSH:
            // FIXME: make configurable
            this.scrollHashIntoView(hash, {
              behavior: "smooth",
              block: "start",
              inline: "nearest"
            });
            break;

          case _constants.POP:
            {
              this.restoreScrollPostion();
              break;
            }

          case INIT:
            break;

          default:
            {
              if (process.env.DEBUG) console.warn("Type '".concat(type, "' not reconginzed."));
              break;
            }
        }
      } // Given a hash, find the element of the same id on the page, and scroll it into view.
      // If no hash is provided, scroll to the top instead.

    }, {
      key: "scrollHashIntoView",
      value: function scrollHashIntoView(hash, options) {
        if (hash) {
          var el = document.getElementById(decodeURIComponent(hash.substr(1)));
          if (el) el.scrollIntoView(options);else if (process.env.DEBUG) console.warn("Can't find element with id ".concat(hash));
        } else {
          window.scroll(window.pageXOffset, 0);
        }
      } // Takes the current history state, and restores the scroll position.

    }, {
      key: "restoreScrollPostion",
      value: function restoreScrollPostion() {
        var id = this.histId();

        var _ref2 = window.history.state && window.history.state[id] || {},
            scrollTop = _ref2.scrollTop,
            scrollHeight = _ref2.scrollHeight;

        if (scrollTop != null) {
          // FIXME: Setting `min-height` to ensure that we can scroll back to the previous position?
          // FIXME: Use `attributeStyleMap`?

          /* document.body.style.minHeight = `${scrollHeight}px`; */
          window.scroll(window.pageXOffset, scrollTop);
        }
      } // Only restore position on page reload when the user hasn't started scorlling yet.

    }, {
      key: "restoreScrollPostionOnReload",
      value: function restoreScrollPostionOnReload() {
        var userHasScrolled = (0, _common.getScrollTop)() != 0;
        if (!userHasScrolled) this.restoreScrollPostion();
      }
    }]);

    return _class;
  }(C);
};

exports.scrollMixin = scrollMixin;