index.html.in

   1 <!doctype html>
   2 <html lang="en-US">
   3   <head>
   4     <meta charset="utf-8">
   5     <meta name="viewport" content="width=device-width, initial-scale=1" />
   6     <link rel="icon"
   7           type="image/svg+xml"
   8           href="data:image/svg+xml;base64,@FAVICON@" />
   9
  10     <title>
  11       CharmBypass: got that transit equity
  12     </title>
  13
  14     <style>
  15       body {
  16         /* For consistency with the SVG */
  17         font-family: sans-serif;
  18       }
  19
  20       fieldset {
  21         margin-top: 1em;
  22         padding-top: 1em;
  23       }
  24
  25       input[type=submit] {
  26         margin-top: 1em;
  27         margin-bottom: 1em;
  28       }
  29
  30       legend {
  31         font-weight: bold;
  32       }
  33
  34       /* Display form errors for the one browser that doesn't support
  35        * them natively, mobile Firefox. We use "visibility" to toggle
  36        * it on and off, but "display" to hide it completely in non-
  37        * stupid web browsers. */
  38       #marc-form-errors {
  39         color: #a00;
  40         visibility: hidden;
  41         display: none;
  42       }
  43
  44       svg {
  45         /* Set the height to 100% of the screen, which we'll keep; and the
  46          * initial position to (0,0), which we're going to change
  47          * every time the window is resized, because the exact amount
  48          * that we have to slide the SVG to the left to get the ticket
  49          * into the center will change. */
  50         position: fixed;
  51         top: 0;
  52         left: 0;
  53         height: 100%;
  54
  55         /* Hide everything by default. We only show it once the user has
  56          * submitted the menu form */
  57         display: none;
  58       }
  59
  60       /* The blinking fade in/out animation for the ticket date and time */
  61       @keyframes blink {
  62         25% { opacity: 0.5; }
  63         50% { opacity: 0;   }
  64         75% { opacity: 0.5; }
  65       }
  66
  67       #tickettime, #ticketdate {
  68         /* 300 two-second blinks is ten minutes */
  69         animation: blink 2s linear 300;
  70       }
  71
  72       /* Define, load, and specify the custom font we use for the ticket
  73        * date, time, and service name. */
  74       @font-face {
  75         font-family: "CharmBypass Regular";
  76         src:
  77           url("data:font/woff2;base64,@CBPREGULAR@") format("woff2")
  78       }
  79
  80       #origindest, #servicename, #tickettime, #ticketdate, #codetext, #zone {
  81         font-family: "CharmBypass Regular", sans-serif;
  82       }
  83
  84       @font-face {
  85         font-family: "CharmBypass Bold";
  86         src:
  87           url("data:font/woff2;base64,@CBPBOLD@") format("woff2")
  88       }
  89
  90       #serviceid {
  91         font-family: "CharmBypass Bold", sans-serif;
  92       }
  93
  94       /************************/
  95       /* Scrolling animations */
  96       /************************/
  97
  98       /* Bus */
  99       @keyframes busroll {
 100         from { transform: translateX(0%);    }
 101         to   { transform: translateX(-100%); }
 102       }
 103
 104       #bus {
 105         animation: busroll 15s linear infinite;
 106       }
 107
 108
 109       /* Tram */
 110       @keyframes tramroll {
 111         from { transform: translateX(0%);   }
 112         to   { transform: translateX(100%); }
 113       }
 114
 115       #tram {
 116         animation: tramroll 15s linear infinite;
 117       }
 118
 119
 120       /* Train */
 121       @keyframes trainroll {
 122         from { transform: translateX(0%);   }
 123         to   { transform: translateX(100%); }
 124       }
 125
 126       #train {
 127         animation: trainroll 10s linear infinite;
 128       }
 129
 130
 131       /* Clouds */
 132       @keyframes cloudsfloat {
 133         from { transform: translateX(0%);   }
 134         to   { transform: translateX(-50%); }
 135       }
 136
 137       #clouds {
 138         animation: cloudsfloat 25s linear infinite;
 139       }
 140
 141       @keyframes cloudscopyfloat {
 142         from { transform: translateX(0%);   }
 143         to   { transform: translateX(-50%); }
 144       }
 145
 146       #cloudscopy {
 147         animation: cloudscopyfloat 25s linear infinite;
 148       }
 149
 150
 151       /* Trees */
 152       @keyframes treespass {
 153         from { transform: translateX(0%);   }
 154         to   { transform: translateX(-50%); }
 155       }
 156
 157       #trees {
 158         /* The trees move a little faster than the clouds */
 159         animation: treespass 16s linear infinite;
 160       }
 161
 162       @keyframes treescopypass {
 163         from { transform: translateX(0%);   }
 164         to   { transform: translateX(-50%); }
 165       }
 166
 167       #treescopy {
 168         /* The trees move a little faster than the clouds */
 169         animation: treescopypass 16s linear infinite;
 170       }
 171
 172
 173       /* City skyline */
 174       @keyframes cityscroll {
 175         from { transform: translateX(0%);   }
 176         to   { transform: translateX(-50%); }
 177       }
 178
 179       #city {
 180         /* The city moves faster than the clouds but slower
 181          * than the trees */
 182         animation: cityscroll 20s linear infinite;
 183       }
 184
 185       @keyframes citycopyscroll {
 186         from { transform: translateX(0%);   }
 187         to   { transform: translateX(-50%); }
 188       }
 189
 190       #citycopy {
 191         /* The city moves faster than the clouds but slower
 192          * than the trees */
 193         animation: citycopyscroll 20s linear infinite;
 194       }
 195     </style>
 196   </head>
 197
 198   <body>
 199     <div id="menu">
 200       <h1>CharmBypass</h1>
 201       <p><strong>got that <em>transit equity</em></strong></p>
 202
 203       <ol>
 204         <li>
 205           <a href="https://michael.orlitzky.com/articles/charmbypass_pt._1%3A_introduction.xhtml">
 206             Introduction
 207           </a>
 208         </li>
 209         <li>
 210           <a href="https://michael.orlitzky.com/articles/charmbypass_pt._2%3A_analysis.xhtml">
 211             Analysis
 212           </a>
 213         </li>
 214       </ol>
 215
 216       <form>
 217         <fieldset>
 218           <legend>Local Bus, Light Rail, or Metro</legend>
 219           <div>
 220             <label for="code1">
 221               Daily security code (optional):
 222             </label>
 223             <input id="code1"
 224                    name="code"
 225                    type="text"
 226                    size="2"
 227                    minlength="2"
 228                    maxlength="2"
 229                    pattern="[a-zA-Z0-9]*" />
 230           </div>
 231           <input type="hidden" name="servicename" value="BaltimoreLink" />
 232           <input type="submit" name="go" value="Generate Ticket" />
 233         </fieldset>
 234       </form>
 235       <form>
 236         <fieldset>
 237           <legend>Commuter Bus</legend>
 238           <input type="hidden" name="serviceid" value="R" />
 239           <input type="hidden" name="servicename" value="Commuter Bus" />
 240
 241           <div>
 242             <label for="code2">
 243               Daily security code (optional):
 244             </label>
 245             <input id="code2"
 246                    name="code"
 247                    type="text"
 248                    size="2"
 249                    minlength="2"
 250                    maxlength="2"
 251                    pattern="[a-zA-Z0-9]*" />
 252           </div>
 253
 254           <p>
 255             Zone<sup>&dagger;</sup>:
 256           </p>
 257           <div>
 258             <input type="radio" required
 259                    name="zone"
 260                    id="zone1"
 261                    value="Zone 1" />
 262             <label for="zone1">Zone 1</label>
 263           </div>
 264           <div>
 265             <input type="radio" required
 266                    name="zone"
 267                    id="zone2"
 268                    value="Zone 2" />
 269             <label for="zone2">Zone 2</label>
 270           </div>
 271           <div>
 272             <input type="radio" required checked
 273                    name="zone"
 274                    id="zone3"
 275                    value="Zone 3" />
 276             <label for="zone3">Zone 3</label>
 277           </div>
 278           <div>
 279             <input type="radio" required
 280                    name="zone"
 281                    id="zone4"
 282                    value="Zone 4" />
 283             <label for="zone4">Zone 4</label>
 284           </div>
 285           <div>
 286             <input type="radio" required
 287                    name="zone"
 288                    id="zone5"
 289                    value="Zone 5" />
 290             <label for="zone5">Zone 5</label>
 291           </div>
 292
 293           <input type="submit" name="go" value="Generate Ticket" />
 294
 295           <p>
 296             <sup>&dagger;</sup>
 297             On the MTA's PDF schedule for your route
 298           </p>
 299         </fieldset>
 300       </form>
 301       <form>
 302         <fieldset>
 303           <legend>MARC Train</legend>
 304
 305           <div>
 306             <label for="code3">
 307               Daily security code (optional):
 308             </label>
 309             <input id="code3"
 310                    name="code"
 311                    type="text"
 312                    size="2"
 313                    minlength="2"
 314                    maxlength="2"
 315                    pattern="[a-zA-Z0-9]*" />
 316           </div>
 317
 318           <p>Origin:</p>
 319           <div>
 320             <input type="radio" required checked
 321                    name="origin"
 322                    id="origin1"
 323                    value="BAL" />
 324             <label for="origin1">Baltimore/Penn (Penn Line)</label>
 325           </div>
 326           <div>
 327             <input type="radio" required
 328                    name="origin"
 329                    id="origin2"
 330                    value="BCA" />
 331             <label for="origin2">Baltimore/Camden (Camden Line)</label>
 332           </div>
 333           <div>
 334             <input type="radio" required
 335                    name="origin"
 336                    id="origin3"
 337                    value="BWE" />
 338             <label for="origin3">Bowie State (Penn Line)</label>
 339           </div>
 340           <div>
 341             <input type="radio" required
 342                    name="origin"
 343                    id="origin4"
 344                    value="BWI" />
 345             <label for="origin4">BWI Airport (Penn Line)</label>
 346           </div>
 347           <div>
 348             <input type="radio" required
 349                    name="origin"
 350                    id="origin5"
 351                    value="CPK" />
 352             <label for="origin5">College Park (Camden Line)</label>
 353           </div>
 354           <div>
 355             <input type="radio" required
 356                    name="origin"
 357                    id="origin6"
 358                    value="SEB" />
 359             <label for="origin6">Seabrook (Penn Line)</label>
 360           </div>
 361           <div>
 362             <input type="radio" required
 363                    name="origin"
 364                    id="origin7"
 365                    value="WAS" />
 366             <label for="origin7">Washington D.C.</label>
 367           </div>
 368           <div>
 369             <input type="radio" required
 370                    name="origin"
 371                    id="origin8"
 372                    value="WBL" />
 373             <label for="origin8">West Baltimore (Penn Line)</label>
 374           </div>
 375
 376           <p>Destination:</p>
 377           <div>
 378             <input type="radio" required
 379                    name="destination"
 380                    id="destination1"
 381                    value="BAL" />
 382             <label for="destination1">Baltimore/Penn (Penn Line)</label>
 383           </div>
 384           <div>
 385             <input type="radio" required
 386                    name="destination"
 387                    id="destination2"
 388                    value="BCA" />
 389             <label for="destination2">Baltimore/Camden (Camden Line)</label>
 390           </div>
 391           <div>
 392             <input type="radio" required
 393                    name="destination"
 394                    id="destination3"
 395                    value="BWE" />
 396             <label for="destination3">Bowie State (Penn Line)</label>
 397           </div>
 398           <div>
 399             <input type="radio" required
 400                    name="destination"
 401                    id="destination4"
 402                    value="BWI" />
 403             <label for="destination4">BWI Airport (Penn Line)</label>
 404           </div>
 405           <div>
 406             <input type="radio" required
 407                    name="destination"
 408                    id="destination5"
 409                    value="CPK" />
 410             <label for="destination5">College Park (Camden Line)</label>
 411           </div>
 412           <div>
 413             <input type="radio" required
 414                    name="destination"
 415                    id="destination6"
 416                    value="SEB" />
 417             <label for="destination6">Seabrook (Penn Line)</label>
 418           </div>
 419           <div>
 420             <input type="radio" required checked
 421                    name="destination"
 422                    id="destination7"
 423                    value="WAS" />
 424             <label for="destination7">Washington D.C.</label>
 425           </div>
 426           <div>
 427             <input type="radio" required
 428                    name="destination"
 429                    id="destination8"
 430                    value="WBL" />
 431             <label for="destination8">West Baltimore (Penn Line)</label>
 432           </div>
 433
 434           <p id="marc-form-errors">OK</p>
 435
 436           <input type="hidden" name="serviceid" value="R" />
 437           <input type="hidden" name="servicename" value="MARC Train" />
 438           <input type="submit"
 439                  name="go"
 440                  id="marc-submit"
 441                  value="Generate Ticket" />
 442         </fieldset>
 443       </form>
 444     </div>
 445
 446     @SVGDATA@
 447
 448     <script>
 449
 450       /**
 451        * Center the ticket within the browser by translating the SVG
 452        * until the ticket and the viewport centerlines coincide.
 453        */
 454       function center_ticket() {
 455         /* We're relying on the SVG being the full height of the
 456          * viewport already, and on the aspect ratio being
 457          * preserved. First, find the center of the ticket. */
 458         const r = document.getElementById("ticket").getBoundingClientRect();
 459         const c = r.left + (r.width / 2);
 460
 461         /* That's the center-line of the ticket. We want to move it to
 462          * the center-line of the viewport. */
 463         const vc = document.documentElement.clientWidth / 2;
 464
 465         /* This is how much we need to translate the SVG */
 466         const hdelta = vc - c;
 467
 468         /* But before we can set the absolute left-coordinate of the
 469          * SVG, we need to know where it is now. Note: without the
 470          * "px" this doesn't default to pixels like CSS does. */
 471         const svg = document.querySelector("svg");
 472         svg.style.left = (svg.getBoundingClientRect().left + hdelta) + "px";
 473       }
 474
 475
 476       /**
 477        * Set the service identifier from the querystring if it's there.
 478        * Otherwise, leave it at the default of "F".
 479        */
 480       function set_service_id() {
 481         const sid = document.getElementById("serviceid");
 482
 483         /* Get the "serviceid" from the querystring if it's there */
 484         const params = new URLSearchParams(document.location.search);
 485         if (params.get("serviceid")) {
 486           sid.textContent = params.get("serviceid");
 487         }
 488       }
 489
 490
 491       /**
 492        * Set the service name from the querystring if it's there.
 493        * Otherwise, leave it at the default of "BaltimoreLink".
 494        */
 495       function set_service_name() {
 496         const sid = document.getElementById("servicename");
 497
 498         /* Get the "servicename" from the querystring if it's there */
 499         const params = new URLSearchParams(document.location.search);
 500         if (params.get("servicename")) {
 501           sid.textContent = params.get("servicename");
 502         }
 503       }
 504
 505
 506       /**
 507        * Set the zone from the given "zone" parameter and then unhide it.
 508        */
 509       function set_zone(zone) {
 510         const z = document.getElementById("zone");
 511
 512         z.textContent = zone;
 513         z.style.display = "block"; /* hidden by default */
 514       }
 515
 516
 517       /**
 518        * Resize the  ticket background based on the service name.
 519        * The BaltimoreLink, Commuter Bus, and MARC Train tickets
 520        * are all different heights and are arranged vertically a
 521        * bit different.
 522        *
 523        * Rather than design three completelty separate tickets and
 524        * then have to keep track of which one we're using, I have
 525        * instead decided to use one ticket and to reposition it
 526        * on-the-fly based on the service name. This is necessarily
 527        * a bit ugly because it involves a lot of magic numbers that
 528        * can only be explained if you open up inkscape with a CharmPass
 529        * screenshot to see where things belong and how to get them there.
 530        *
 531        * The SVG was designed with BaltimoreLink in mind, so this
 532        * is a no-op if the service is BaltimoreLink.
 533        */
 534       function resize_ticket() {
 535         /* Get the "servicename" from the querystring if it's there */
 536         const params = new URLSearchParams(document.location.search);
 537         const tbg = document.getElementById("ticketbg");
 538         const t = document.getElementById("ticket");
 539         const sn = document.getElementById("servicename");
 540
 541         if (params.get("servicename") === "Commuter Bus") {
 542           /* The top of the background is initially at y=246.859, and
 543            * we scale it by a factor of 1.12 to y=276.482 for a change
 544            * of 29.623. So after we scale it, we translate it upwards
 545            * by that amount to put it back where it started. */
 546           tbg.setAttribute("transform", "translate(0 -29.623) scale(1 1.12)");
 547
 548           /* Now translate the entire ticket up by the magic amount, 1/5
 549            * of the size change we made to the background. This ratio
 550            * was found by measuring pixels in side-by-side screenshots
 551            * of BaltimoreLink and Commuter Bus tickets. */
 552           t.setAttribute("transform", "translate(0 -9.33)");
 553
 554           /* More magic numbers discovered by comparing the two
 555            * tickets overlayed in inkscape */
 556           sn.setAttribute("transform", "translate(0 64.28)");
 557         }
 558         else if (params.get("servicename") === "MARC Train") {
 559           /* insane tricks are explained above */
 560           tbg.setAttribute("transform",
 561                            "translate(0 -72.378) scale(1 1.2932)");
 562           t.setAttribute("transform", "translate(0 -67.17)");
 563           sn.setAttribute("transform", "translate(0 131.0)");
 564         }
 565       }
 566
 567
 568       /**
 569        * Set the security code from the querystring if it was given;
 570        * otherwise generate a random code.
 571        */
 572       function set_code() {
 573         const ct = document.getElementById("codetext");
 574
 575         /* Get the "code" from the querystring if it's there */
 576         const params = new URLSearchParams(document.location.search);
 577         if (params.get("code")) {
 578           ct.textContent = params.get("code").toUpperCase();
 579         }
 580         else {
 581           /* Otherwise, use a random code */
 582           const bucket = ["0","1","2","3","4","5","6","7","8","9",
 583                           "A","B","C","D","E","F","G","H","I","J",
 584                           "K","L","M","N","O","P","Q","R","S","T",
 585                           "U","V","W","X","Y","Z"];
 586
 587           /* Two random ints between 0 and 35 */
 588           const i1 = Math.floor(Math.random() * 36);
 589           const i2 = Math.floor(Math.random() * 36);
 590           const d1 = bucket[i1];
 591           const d2 = bucket[i2];
 592           ct.textContent = d1 + d2;
 593         }
 594       }
 595
 596
 597       /**
 598        * Center the security code within its container.
 599        *
 600        * Some codes like "II" and "WW" can take up wildly different
 601        * amounts of horizonetal space, but they should always be
 602        * centered inside their little red box. This turns out to be
 603        * harder than it sounds because we can only find the width of
 604        * the code in browser coordinates, whereas its "x" coordinate
 605        * is in SVG coordinates. Anyway, we do it.
 606        */
 607       function center_code() {
 608         /* Center the security code inside its red box */
 609         const ct = document.getElementById("codetext");
 610         const bg = document.getElementById("codebg");
 611
 612         /* First, find the center of the red box */
 613         const r1 = bg.getBoundingClientRect();
 614         const c1 = r1.left + (r1.width / 2);
 615
 616         /* Now the center of the code text */
 617         const r2 = ct.getBoundingClientRect();
 618         const c2 = r2.left + (r2.width / 2);
 619
 620         /* What do we add to c2 to make it equal to c1? */
 621         const hdelta = c1 - c2;
 622
 623         /* We've measured everything so far in "client rect"
 624          * coordinates, because that's the only available measurement
 625          * we have for the width of the <text> element. But when we
 626          * reposition that <text> element, it will be by adjusting its
 627          * "x" attribute, and that attribute uses a different coordinate
 628          * system than the client rect does. Specifically, "x" refers to
 629          * an offset within the SVG's coordinate system, and the client
 630          * rect coordinates are pixels on-screen. To convert between the
 631          * two, we can take the "width" attribute of the background
 632          * element and compare it to the width of the background
 633          * element's client rect. Since the size of the background is
 634          * fixed, this should give us a multiplier that turns client rect
 635          * distances (what we have) into SVG distances (what we want) */
 636         const client_to_svg = parseFloat(bg.getAttribute("width"))/r1.width;
 637
 638         /* Convert hdelta from client rect to SVG coordinates */
 639         const svg_hdelta = hdelta * client_to_svg;
 640
 641         /* Since this <text> element has an "x" attribute it's easier for
 642          * us to shift that than it is to mess with the "left" style. */
 643         ct.setAttribute("x", parseFloat(ct.getAttribute("x")) + svg_hdelta);
 644       }
 645
 646       /**
 647        * Set the ticket's expiration date and time.
 648        *
 649        * BaltimoreLink and MARC Train tickets expire after 90 minutes;
 650        * while Commuter Bus tickets expire after 10 minutes.
 651        */
 652       function set_ticket_expiry() {
 653         /* There are two parameters, time and date, that we store in one
 654          * underlying "date" variable. */
 655         const date = new Date();
 656
 657         /* BaltimoreLink and MARC Train */
 658         let minutes = 90;
 659         const params = new URLSearchParams(document.location.search);
 660         if (params.get("servicename") === "Commuter Bus") {
 661           /* Commuter bus tickets are only valid for ten minutes */
 662           minutes = 10;
 663         }
 664
 665         /* We use the low-level get/setTime to change the number of
 666          * milliseconds since the epoch that this date represents
 667          * Obviously correct, and avoids all suspicious corner cases
 668          * for a few more decades. */
 669         date.setTime(date.getTime() + (minutes*60*1000));
 670
 671         tt = document.getElementById("tickettime");
 672         tt.textContent = date.toLocaleTimeString();
 673
 674         const td = document.getElementById("ticketdate");
 675         const dateopts = {
 676           day: "2-digit",
 677           month: "2-digit",
 678           year: "2-digit"
 679         };
 680         td.textContent = date.toLocaleDateString("en-US", dateopts);
 681       }
 682
 683
 684       /**
 685        * Swap the day/night sky colors.
 686        *
 687        * We use CSS classes to keep track of the current state because
 688        * it's a tiny bit cleaner than a global variable, but for some
 689        * reason we can't use those same classes to actually change the
 690        * color. (The classes, change, but the color doesn't.) Rather
 691        * than waste time trying to explain this, we just set the "fill"
 692        * attribute ourselves whenever we swap classes.
 693        */
 694       function swap_day_night() {
 695         const sky = document.getElementById("sky");
 696
 697         if (sky.getAttribute("class") === "night") {
 698           sky.setAttribute("fill", "#efb02f");
 699           sky.setAttribute("class", "day");
 700         }
 701         else {
 702           /* Put this case second so that the first time the
 703            * screen is tapped (when there are no classes on
 704            * the sky element) the color still changes. */
 705           sky.setAttribute("fill", "#143b66");
 706           sky.setAttribute("class", "night");
 707         }
 708       }
 709
 710
 711       /**
 712        * Compute the zone (string) for the given origin/destination pair.
 713        *
 714        * If we don't know it or if you chose in invalid pair (destination
 715        * not on the same line as your origin?) then null is returned.
 716        */
 717       function compute_marc_zone(src, dest) {
 718
 719         /* Sorted on the first component, then the second.
 720          *
 721          * Key:
 722          *
 723          *   $6.00 => 1
 724          *   $7.00 => 2
 725          *   $8.00 => 3
 726          *   $9.00 => 4
 727          */
 728         const zone_map = {
 729           BAL_BWE: 2,
 730           BAL_BWI: 1,
 731           BAL_SEB: 3,
 732           BAL_WAS: 4,
 733           BAL_WBL: 1,
 734           BCA_CPK: 3,
 735           BCA_WAS: 4,
 736           BWE_BWI: 1,
 737           BWE_SEB: 1,
 738           BWE_WAS: 2,
 739           BWE_WBL: 2,
 740           BWI_SEB: 2,
 741           BWI_WAS: 3,
 742           BWI_WBL: 1,
 743           SEB_WAS: 1,
 744           SEB_WBL: 3,
 745           WAS_WBL: 4
 746         };
 747
 748         /* Forward direction key for zone_map */
 749         const fwd = src + "_" +  dest;
 750
 751         /* Reverse direction key for zone_map. The zone_map only
 752          * has them listed in one direction, so we check both
 753          * directions here. */
 754         const rev = dest + "_" +  src;
 755
 756         /* The default. Obviously wrong for when we don't
 757          * have the necessary data. */
 758         let zone = -1;
 759
 760         if (zone_map[fwd]) {
 761           zone = zone_map[fwd];
 762         }
 763         else if (zone_map[rev]) {
 764           zone = zone_map[rev];
 765         }
 766
 767         /* Convert the number to a string */
 768         switch (zone) {
 769           case 1:
 770             return "One Zone";
 771           case 2:
 772             return "Two Zone";
 773           case 3:
 774             return "Three Zone";
 775           case 4:
 776             return "Four Zone";
 777           default:
 778             return null;
 779         }
 780       }
 781
 782
 783       /**
 784        * Compute and set the zone.
 785        *
 786        * We can be given a zone in two ways. First, on Commuter Bus
 787        * tickets, it is given explicitly via the querystring. But
 788        * It can also be specified implicitly via the origin and
 789        * destination on a MARC Train ticket. Here we try both and
 790        * then call set_zone() with the result if something worked.
 791        */
 792       function compute_and_set_zone() {
 793         const params = new URLSearchParams(document.location.search);
 794         const src = params.get("origin");
 795         const dest = params.get("destination");
 796
 797         if (src && dest) {
 798           /* MARC Train. We can assume that compute_marc_zone() doesn't
 799            * return null because that's part of our form validation. */
 800           const zone = compute_marc_zone(src, dest);
 801           set_zone(zone);
 802         }
 803         else if (params.get("zone")) {
 804           /* Commuter Bus */
 805           set_zone(params.get("zone"));
 806         }
 807       }
 808
 809
 810       /**
 811        * Set the origin and destination for the MARC Train if they
 812        * were provided, and unhide them if so.
 813        */
 814       function set_marc_origin_destination() {
 815         const params = new URLSearchParams(document.location.search);
 816         if (!params.get("origin") || !params.get("destination")) {
 817           return;
 818         }
 819
 820         const src = params.get("origin");
 821         const dest = params.get("destination");
 822
 823         /* origindest contains both the origin and destination */
 824         const origindest = document.getElementById("origindest");
 825
 826         const origin = document.getElementById("origin");
 827         const destination = document.getElementById("destination");
 828
 829         origin.textContent = params.get("origin");
 830         destination.textContent = params.get("destination");
 831
 832         origindest.style.display = "block"; /* hidden by default */
 833       }
 834
 835
 836       /**
 837        * Hide the menu and display the ticket. This is what happens
 838        * when you submit the form.
 839        */
 840       function go() {
 841         /* To create our "window" onto the scene, we're going to slide the
 842          * SVG off the left-hand side of the screen, and we don't want
 843          * scroll bars to appear. */
 844         document.body.style.overflow = "hidden";
 845         document.body.style.margin = "0";
 846         document.body.style.padding = "0";
 847
 848         const svg = document.querySelector("svg");
 849         const menu = document.getElementById("menu");
 850         svg.style.display = "initial";
 851         menu.style.display = "none";
 852       }
 853
 854       /**
 855        * Determine if the user agent is mobile Firefox.
 856        */
 857       function ua_is_mobile_ff() {
 858         const ua = navigator.userAgent.toLowerCase();
 859         return (ua.includes("firefox") && ua.includes("mobile"));
 860       }
 861
 862       /**
 863        * Validate the MARC form's origin/destination.
 864        *
 865        * We don't want the user to be able to choose a pair of stops that
 866        * aren't actually connected by the same MARC line. If we don't have
 867        * zone information for the (origin,destination) pair, that indicates
 868        * that it's probably not a valid choice; otherwise I would have
 869        * filled in the information from the CharmPass app already.
 870        *
 871        * All browsers except mobile Firefox let us call setCustomValidity()
 872        * to provide an error message that is displayed if the user tries
 873        * to submit invalid choices. But amazingly, mobile Firefox does not:
 874        *
 875        *   https://bugzilla.mozilla.org/show_bug.cgi?id=1510450
 876        *
 877        * Instead we have to work around it (in that one browser) by
 878        * showing/hiding a paragraph that we fill with the errors.
 879        */
 880       function validate_origin_destination(event) {
 881         const origins = document.getElementsByName("origin");
 882         const destinations = document.getElementsByName("destination");
 883         const mfe = document.getElementById("marc-form-errors");
 884         const marcsubmit = document.getElementById("marc-submit");
 885
 886         if (ua_is_mobile_ff()) {
 887           /* Even though this is only for one browser, empty paragraphs
 888            * are handled inconsistently and should be avoided as a rule.
 889            * So, we make it say "OK" before we hide it. */
 890           mfe.textContent = "OK";
 891           mfe.style.visibility = "hidden";
 892           marcsubmit.disabled = false;
 893         }
 894
 895         let src = null;
 896         let dest = null;
 897         origins.forEach((x) => { if (x.checked) src = x; })
 898         destinations.forEach((x) => {
 899           if (x.checked) dest = x;
 900
 901           /* clear all errors before possibly setting one */
 902           x.setCustomValidity('');
 903         })
 904
 905         if (src.value === dest.value) {
 906           let err = "Origin and destination are the same";
 907           dest.setCustomValidity(err);
 908
 909           if (ua_is_mobile_ff()) {
 910             mfe.textContent = err;
 911             mfe.style.visibility = "visible";
 912             marcsubmit.disabled = true;
 913           }
 914         }
 915         else if (compute_marc_zone(src.value, dest.value) === null) {
 916           let err = "Origin and destination are on different lines";
 917           dest.setCustomValidity(err);
 918
 919           if (ua_is_mobile_ff()) {
 920             mfe.textContent = err;
 921             mfe.style.visibility = "visible";
 922             marcsubmit.disabled = true;
 923           }
 924         }
 925       }
 926
 927       /*****************************************************/
 928       /* Add event handlers for all of the functions above */
 929       /*****************************************************/
 930
 931       const params = new URLSearchParams(document.location.search);
 932       if (params.get("go")) {
 933         /* First unhide the SVG (swap it with the form) */
 934         window.addEventListener("load", go);
 935
 936         /* Center the ticket once when the page has loaded */
 937         window.addEventListener("load", center_ticket);
 938
 939         /* Re-center the ticket when the window is resized */
 940         window.addEventListener("resize", center_ticket);
 941
 942         /* Set the service identifier when the page has loaded */
 943         window.addEventListener("load", set_service_id);
 944
 945         /* Set the service name when the page has loaded */
 946         window.addEventListener("load", set_service_name);
 947
 948         /* Resize the ticket background if necessary */
 949         window.addEventListener("load", resize_ticket);
 950
 951         /* Set the security code text when the page has loaded */
 952         window.addEventListener("load", set_code);
 953
 954         /* Center the security code text when the page has loaded; in
 955          * particular, after we set the code. */
 956         window.addEventListener("load", center_code);
 957
 958         /* Set the ticket expiration date/time upon page load */
 959         window.addEventListener("load", set_ticket_expiry);
 960
 961         /* Set the MARC Train origin and destination, if applicable */
 962         window.addEventListener("load", set_marc_origin_destination);
 963
 964         /* Compute and set the zone, if applicable */
 965         window.addEventListener("load", compute_and_set_zone);
 966
 967         /* Swap colors when the screen is tapped */
 968         document.body.addEventListener("click", swap_day_night);
 969       }
 970       else {
 971         /* If we haven't submitted the form yet, set up change handlers
 972          * for the origin/destination radio buttons that validate that
 973          * the origin and destination are on the same line. */
 974         document.getElementsByName("origin").forEach(
 975          (x) => x.addEventListener("change", validate_origin_destination)
 976         );
 977         document.getElementsByName("destination").forEach(
 978          (x) => x.addEventListener("change", validate_origin_destination)
 979         );
 980
 981         /* Also do it when the page loads, because firefox likes to
 982          * remember your selection even after the page reloads. */
 983         window.addEventListener("load", validate_origin_destination);
 984
 985         /* Finally, we have to babysit mobile Firefox, who doesn't
 986          * support HTML5 form validation going into 2024. Turn on
 987          * the little form errors paragraph so we can toggle its
 988          * visibility (and make it display the error) when the user
 989          * makes an invalid selection. */
 990         window.addEventListener("load", () => {
 991           if (ua_is_mobile_ff()) {
 992             const mfe = document.getElementById("marc-form-errors");
 993             mfe.style.display = "block";
 994           }
 995         });
 996       }
 997
 998     </script>
 999   </body>
1000 </html>