text: /** 
   * @constructor
   * @struct 
   */
  let Loader = function (parent) {
      parent.innerHTML = "";
      //view
      /** @type {Element} */
      this.elem = Draw.htmlElem("div", {
          "class": "trakMapContainer"
      }, parent);
  
      /** @type {TrakMap} */ this.trakMap;
      /** @type {Element} */ this.parent = parent;
  
      /** @type {SaveLoad} */ this.saveLoad = new SaveLoad();
      this.pageSize = Loader.A3SIZE;
  
      this.newFile();
  };
  
  Loader.prototype.restoreUnsafe = function (obj) {
      this.trakMap.restore(obj);
  };
  Loader.prototype.restore = function (obj) {
      this.trakMap.makeSafeModification(() => this.restoreUnsafe(obj));
  };
  
  Loader.prototype.draw = function () {
      this.elem.innerHTML = "";
  
      var menubar = Draw.htmlElem("div", {
          "class": "menubar"
      }, this.elem);
  
      var fileSegment = Draw.menuBarSegment("File", menubar);
      Draw.iconBar([{
          icon: "icons/new.svg",
          action: this.newFile.bind(this)
      }, {
          icon: "icons/open.svg",
          action: this.open.bind(this)
      }, {
          icon: "icons/save.svg",
          action: this.save.bind(this)
      }, {
          icon: "icons/save-as.svg",
          action: this.saveAs.bind(this)
      }], {}, fileSegment.body);
  
      let priorityGroupSegment = Draw.menuBarSegment("Group", menubar);
      Draw.iconBar([{
          icon: "icons/plus.svg",
          action: () => this.trakMap.newPriorityGroup()
      }], {}, priorityGroupSegment.body);
  
      let modeSegment = Draw.menuBarSegment("Mode", menubar);
      Draw.iconBar([{
          icon: "icons/arrow-two-left-right.svg",
          action: () => this.trakMap.toggleMode()
      }], {}, modeSegment.body);
  
      let printSegment = Draw.menuBarSegment("Print", menubar);
      Draw.iconBar([{
          icon: "icons/print.svg",
          action: this.print.bind(this)
      }], {}, printSegment.body);
      this.printSizeSelector({
          "class": "pageSizeSelector"
      }, printSegment.body);
  
      let aboutSegment = Draw.menuBarSegment("About", menubar);
      Draw.iconBar([{
          icon: "icons/info.svg",
          action: () => alert(Loader.aboutText)
      }, {
          icon: "icons/question.svg",
          action: () => window.open("https://andymac-2.github.io/trakmap/instructions")
      }], {}, aboutSegment.body);
  
      Draw.elem("div", {
          "class": "menuBarPlaceholder"
      }, this.elem);
  
      this.trakMap.draw();
      this.elem.appendChild(this.trakMap.elem);
  };
  
  // user events
  Loader.prototype.newFile = function () {
      this.saveLoad.reset();
      this.trakMap = new TrakMap(TrakMap.NEWFILE);
      this.draw();
  };
  
  Loader.prototype.open = function () {
      this.saveLoad.open(
          (obj) => this.restore(obj),
          (err) => {
              console.error(err);
          });
  };
  
  Loader.prototype.save = function () {
      var string = JSON.stringify(this.trakMap.save(), null, "\t");
  
      let success = () => { };
      let failure = error => {
          console.error(error);
      };
  
      if (this.saveLoad.isFileOpen()) {
          this.saveLoad.save(success, failure, string);
      }
      else {
          this.saveLoad.saveAs(success, failure, this.trakMap.title + ".json", string);
      }
  };
  Loader.prototype.saveAs = function () {
      let string = JSON.stringify(this.trakMap.save(), null, "\t");
      let success = () => { };
      let failure = error => {
          console.error(error);
      };
  
      this.saveLoad.saveAs(success, failure, this.trakMap.title + ".json", string);
  };
  
  // correspond to Loader.PAGESIZENAMES
  /** @const {number} */ Loader.PX_PER_MM = 5;
  /** @const {number} */ Loader.PAGEMARGIN = 35;
  /** @const {Array<Object<number>>}*/ Loader.PAGESIZES = [
      { height: 1682, width: 2378 },
      { height: 1189, width: 1682 },
      { height: 841, width: 1189 },
      { height: 594, width: 841 },
      { height: 420, width: 594 },
      { height: 297, width: 420 },
      { height: 210, width: 297 },
      { width: 1682, height: 2378 },
      { width: 1189, height: 1682 },
      { width: 841, height: 1189 },
      { width: 594, height: 841 },
      { width: 420, height: 594 },
      { width: 297, height: 420 },
      { width: 210, height: 297 },
  ].map(elem => {
      if (elem.width > elem.height) {
          return {
              height: elem.height - Loader.PAGEMARGIN * 2,
              width: elem.width - Loader.PAGEMARGIN * 2,
          };
      }
      else {
          return elem;
      }
  });
  /** @const {Object<number>}*/ Loader.A3SIZE = Loader.PAGESIZES[12];
  // correspond to Loader.PAGESIZES
  /** @const Array<string> */ Loader.PAGESIZENAMES = [
      "XXXS Landscape",
      "XXS Landscape",
      "XS Landscape",
      "S Landscape",
      "M Landscape",
      "L Landscape",
      "XL Landscape",
      "XXXS Portrait",
      "XXS Portrait",
      "XS Portrait",
      "S Portrait",
      "M Portrait",
      "L Portrait",
      "XL Portrait",
      "Fit to page width" // has an undefined value in pagesizes table
  ];
  Loader.prototype.printSizeSelector = function (attrs, parent) {
      var onchange = (evt) => {
          // Will have a null value for "fit to page size"
          let size = Loader.PAGESIZES[evt.currentTarget.value];
          this.pageSize = size ? size : null;
      }
      Draw.dropDownSegment(
          "Zoom Level:", onchange, Loader.PAGESIZENAMES, attrs, parent);
  };
  Loader.prototype.print = function () {
      let trakMap = new TrakMap(this.trakMap.save());
      trakMap.draw();
  
      if (this.pageSize === null) { // fit to width
          this.parent.innerHTML = trakMap.elem.outerHTML;
          this.parent.children[0].setAttribute("class", "trakMapPage");
      }
      else { // milti-page
          this.parent.innerHTML = "";
          let bottom = trakMap.getBottom();
          let right = trakMap.getRight();
          const width = this.pageSize.width * Loader.PX_PER_MM;
          const height = this.pageSize.height * Loader.PX_PER_MM;
  
          let firstRow = true;
          let firstColumn = true;
          for (var left = trakMap.getLeft(); left < right; left += width * 0.9) {
              if (firstColumn) {
                  right -= width * 0.1;
                  firstColumn = false;
              }
              for (var top = trakMap.getTop(); top < bottom; top += height * 0.9) {
                  if (firstRow) {
                      bottom -= height * 0.1;
                      firstRow = false;
                  }
                  let elem = Draw.elem("div", {}, this.parent);
                  elem.innerHTML = trakMap.elem.outerHTML;
                  elem.children[0].setAttribute("class", "trakMapPage");
                  elem.children[0].setAttribute("viewBox", "" +
                      left + " " + top + " " +
                      width + " " + height + " ");
              }
          }
      }
  
      window.print();
      this.parent.innerHTML = "";
      this.parent.appendChild(this.elem);
  };
  
  
  /** @const {string} */ Loader.aboutText = "TrakMap, Version: " + VERSION + `
  
  For help and support, please visit:
  
  https://andymac-2.github.io/trakmap/instructions
  
  
  
  Copyright 2018 Andrew Pritchard
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
      http://www.apache.org/licenses/LICENSE-2.0
  
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
  
  
  ELUSIVE ICONS:
  
  Elusive Icons by Team Redux - http://reduxframework.com/
  
  SIL OPEN FONT LICENSE
  
  Version 1.1 - 26 February 2007
  PREAMBLE
  
  The goals of the Open Font License (OFL) are to stimulate worldwide
  development of collaborative font projects, to support the font creation
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  The OFL allows the licensed fonts to be used, studied, modified and
  redistributed freely as long as they are not sold by themselves. The
  fonts, including any derivative works, can be bundled, embedded,
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  names are not used by derivative works. The fonts and derivatives,
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  writer or other person who contributed to the Font Software.
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  Permission is hereby granted, free of charge, to any person obtaining
  a copy of the Font Software, to use, study, copy, merge, embed, modify,
  redistribute, and sell modified and unmodified copies of the Font
  Software, subject to the following conditions:
  
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  in Original or Modified Versions, may be sold by itself.
  
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  DISCLAIMER
  
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  GLYPH + SMART ICONS:
  
  License http://creativecommons.org/licenses/by-sa/4.0/ (CC BY-SA 4.0)  A project by https://smarticons.co SmartIcons
  
  
  
  MATERIAL DESIGN ICONS:
  
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