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: that transit equity y'all
  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 23s 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 17s 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 11s 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 40s linear infinite;
 139       }
 140
 141       @keyframes cloudscopyfloat {
 142         from { transform: translateX(0%);   }
 143         to   { transform: translateX(-50%); }
 144       }
 145
 146       #cloudscopy {
 147         animation: cloudscopyfloat 40s 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 30s 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 30s 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 35s 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 35s linear infinite;
 194       }
 195     </style>
 196   </head>
 197
 198   <body>
 199     <div id="menu">
 200       <h1>CharmBypass</h1>
 201       <h2>that transit equity y'all</h2>
 202
 203       <p>
 204         <em>Hint:</em> If they start checking it, the daily security
 205         code stays the same all day and is the same on a $2 bus ticket
 206         as it is on a $9 MARC ticket. It's also the same on every phone.
 207       </p>
 208
 209       <form>
 210         <fieldset>
 211           <legend>Local Bus, Light Rail, or Metro</legend>
 212           <div>
 213             <label for="code1">
 214               Daily security code (optional):
 215             </label>
 216             <input id="code1"
 217                    name="code"
 218                    type="text"
 219                    size="2"
 220                    minlength="2"
 221                    maxlength="2"
 222                    pattern="[a-zA-Z0-9]*" />
 223           </div>
 224           <input type="hidden" name="servicename" value="BaltimoreLink" />
 225           <input type="submit" name="go" value="Generate Ticket" />
 226         </fieldset>
 227       </form>
 228       <form>
 229         <fieldset>
 230           <legend>Commuter Bus</legend>
 231           <input type="hidden" name="serviceid" value="R" />
 232           <input type="hidden" name="servicename" value="Commuter Bus" />
 233
 234           <div>
 235             <label for="code2">
 236               Daily security code (optional):
 237             </label>
 238             <input id="code2"
 239                    name="code"
 240                    type="text"
 241                    size="2"
 242                    minlength="2"
 243                    maxlength="2"
 244                    pattern="[a-zA-Z0-9]*" />
 245           </div>
 246
 247           <p>
 248             <abbr title="Found on the MTA's PDF schedule for your route">
 249               Zone</abbr>:
 250           </p>
 251           <div>
 252             <input type="radio" required
 253                    name="zone"
 254                    id="zone1"
 255                    value="Zone 1" />
 256             <label for="zone1">Zone 1</label>
 257           </div>
 258           <div>
 259             <input type="radio" required
 260                    name="zone"
 261                    id="zone2"
 262                    value="Zone 2" />
 263             <label for="zone2">Zone 2</label>
 264           </div>
 265           <div>
 266             <input type="radio" required checked
 267                    name="zone"
 268                    id="zone3"
 269                    value="Zone 3" />
 270             <label for="zone3">Zone 3</label>
 271           </div>
 272           <div>
 273             <input type="radio" required
 274                    name="zone"
 275                    id="zone4"
 276                    value="Zone 4" />
 277             <label for="zone4">Zone 4</label>
 278           </div>
 279           <div>
 280             <input type="radio" required
 281                    name="zone"
 282                    id="zone5"
 283                    value="Zone 5" />
 284             <label for="zone5">Zone 5</label>
 285           </div>
 286
 287           <input type="submit" name="go" value="Generate Ticket" />
 288         </fieldset>
 289       </form>
 290       <form>
 291         <fieldset>
 292           <legend>MARC Train</legend>
 293
 294           <div>
 295             <label for="code3">
 296               Daily security code (optional):
 297             </label>
 298             <input id="code3"
 299                    name="code"
 300                    type="text"
 301                    size="2"
 302                    minlength="2"
 303                    maxlength="2"
 304                    pattern="[a-zA-Z0-9]*" />
 305           </div>
 306
 307           <p>Origin:</p>
 308           <div>
 309             <input type="radio" required checked
 310                    name="origin"
 311                    id="origin1"
 312                    value="BAL" />
 313             <label for="origin1">Baltimore/Penn (Penn Line)</label>
 314           </div>
 315           <div>
 316             <input type="radio" required
 317                    name="origin"
 318                    id="origin2"
 319                    value="BCA" />
 320             <label for="origin2">Baltimore/Camden (Camden Line)</label>
 321           </div>
 322           <div>
 323             <input type="radio" required
 324                    name="origin"
 325                    id="origin3"
 326                    value="BWE" />
 327             <label for="origin3">Bowie State (Penn Line)</label>
 328           </div>
 329           <div>
 330             <input type="radio" required
 331                    name="origin"
 332                    id="origin4"
 333                    value="BWI" />
 334             <label for="origin4">BWI Airport (Penn Line)</label>
 335           </div>
 336           <div>
 337             <input type="radio" required
 338                    name="origin"
 339                    id="origin5"
 340                    value="CPK" />
 341             <label for="origin5">College Park (Camden Line)</label>
 342           </div>
 343           <div>
 344             <input type="radio" required
 345                    name="origin"
 346                    id="origin6"
 347                    value="SEB" />
 348             <label for="origin6">Seabrook (Penn Line)</label>
 349           </div>
 350           <div>
 351             <input type="radio" required
 352                    name="origin"
 353                    id="origin7"
 354                    value="WAS" />
 355             <label for="origin7">Washington D.C.</label>
 356           </div>
 357           <div>
 358             <input type="radio" required
 359                    name="origin"
 360                    id="origin8"
 361                    value="WBL" />
 362             <label for="origin8">West Baltimore (Penn Line)</label>
 363           </div>
 364
 365           <p>Destination:</p>
 366           <div>
 367             <input type="radio" required
 368                    name="destination"
 369                    id="destination1"
 370                    value="BAL" />
 371             <label for="destination1">Baltimore/Penn (Penn Line)</label>
 372           </div>
 373           <div>
 374             <input type="radio" required
 375                    name="destination"
 376                    id="destination2"
 377                    value="BCA" />
 378             <label for="destination2">Baltimore/Camden (Camden Line)</label>
 379           </div>
 380           <div>
 381             <input type="radio" required
 382                    name="destination"
 383                    id="destination3"
 384                    value="BWE" />
 385             <label for="destination3">Bowie State (Penn Line)</label>
 386           </div>
 387           <div>
 388             <input type="radio" required
 389                    name="destination"
 390                    id="destination4"
 391                    value="BWI" />
 392             <label for="destination4">BWI Airport (Penn Line)</label>
 393           </div>
 394           <div>
 395             <input type="radio" required
 396                    name="destination"
 397                    id="destination5"
 398                    value="CPK" />
 399             <label for="destination5">College Park (Camden Line)</label>
 400           </div>
 401           <div>
 402             <input type="radio" required
 403                    name="destination"
 404                    id="destination6"
 405                    value="SEB" />
 406             <label for="destination6">Seabrook (Penn Line)</label>
 407           </div>
 408           <div>
 409             <input type="radio" required checked
 410                    name="destination"
 411                    id="destination7"
 412                    value="WAS" />
 413             <label for="destination7">Washington D.C.</label>
 414           </div>
 415           <div>
 416             <input type="radio" required
 417                    name="destination"
 418                    id="destination8"
 419                    value="WBL" />
 420             <label for="destination8">West Baltimore (Penn Line)</label>
 421           </div>
 422
 423           <p id="marc-form-errors">OK</p>
 424
 425           <input type="hidden" name="serviceid" value="R" />
 426           <input type="hidden" name="servicename" value="MARC Train" />
 427           <input type="submit"
 428                  name="go"
 429                  id="marc-submit"
 430                  value="Generate Ticket" />
 431         </fieldset>
 432       </form>
 433     </div>
 434
 435     @SVGDATA@
 436
 437     <script>
 438
 439       /**
 440        * Center the ticket within the browser by translating the SVG
 441        * until the ticket and the viewport centerlines coincide.
 442        */
 443       function center_ticket() {
 444         /* We're relying on the SVG being the full height of the
 445          * viewport already, and on the aspect ratio being
 446          * preserved. First, find the center of the ticket. */
 447         const r = document.getElementById("ticket").getBoundingClientRect();
 448         const c = r.left + (r.width / 2);
 449
 450         /* That's the center-line of the ticket. We want to move it to
 451          * the center-line of the viewport. */
 452         const vc = document.documentElement.clientWidth / 2;
 453
 454         /* This is how much we need to translate the SVG */
 455         const hdelta = vc - c;
 456
 457         /* But before we can set the absolute left-coordinate of the
 458          * SVG, we need to know where it is now. Note: without the
 459          * "px" this doesn't default to pixels like CSS does. */
 460         const svg = document.querySelector("svg");
 461         svg.style.left = (svg.getBoundingClientRect().left + hdelta) + "px";
 462       }
 463
 464
 465       /**
 466        * Set the service identifier from the querystring if it's there.
 467        * Otherwise, leave it at the default of "F".
 468        */
 469       function set_service_id() {
 470         const sid = document.getElementById("serviceid");
 471
 472         /* Get the "serviceid" from the querystring if it's there */
 473         const params = new URLSearchParams(document.location.search);
 474         if (params.get("serviceid")) {
 475           sid.textContent = params.get("serviceid");
 476         }
 477       }
 478
 479
 480       /**
 481        * Set the service name from the querystring if it's there.
 482        * Otherwise, leave it at the default of "BaltimoreLink".
 483        */
 484       function set_service_name() {
 485         const sid = document.getElementById("servicename");
 486
 487         /* Get the "servicename" from the querystring if it's there */
 488         const params = new URLSearchParams(document.location.search);
 489         if (params.get("servicename")) {
 490           sid.textContent = params.get("servicename");
 491         }
 492       }
 493
 494
 495       /**
 496        * Set the zone from the given "zone" parameter and then unhide it.
 497        */
 498       function set_zone(zone) {
 499         const z = document.getElementById("zone");
 500
 501         z.textContent = zone;
 502         z.style.display = "block"; /* hidden by default */
 503       }
 504
 505
 506       /**
 507        * Resize the  ticket background based on the service name.
 508        * The BaltimoreLink, Commuter Bus, and MARC Train tickets
 509        * are all different heights and are arranged vertically a
 510        * bit different.
 511        *
 512        * Rather than design three completelty separate tickets and
 513        * then have to keep track of which one we're using, I have
 514        * instead decided to use one ticket and to reposition it
 515        * on-the-fly based on the service name. This is necessarily
 516        * a bit ugly because it involves a lot of magic numbers that
 517        * can only be explained if you open up inkscape with a CharmPass
 518        * screenshot to see where things belong and how to get them there.
 519        *
 520        * The SVG was designed with BaltimoreLink in mind, so this
 521        * is a no-op if the service is BaltimoreLink.
 522        */
 523       function resize_ticket() {
 524         /* Get the "servicename" from the querystring if it's there */
 525         const params = new URLSearchParams(document.location.search);
 526         const tbg = document.getElementById("ticketbg");
 527         const t = document.getElementById("ticket");
 528         const sn = document.getElementById("servicename");
 529
 530         if (params.get("servicename") === "Commuter Bus") {
 531           /* The top of the background is initially at y=246.859, and
 532            * we scale it by a factor of 1.12 to y=276.482 for a change
 533            * of 29.623. So after we scale it, we translate it upwards
 534            * by that amount to put it back where it started. */
 535           tbg.setAttribute("transform", "translate(0 -29.623) scale(1 1.12)");
 536
 537           /* Now translate the entire ticket up by the magic amount, 1/5
 538            * of the size change we made to the background. This ratio
 539            * was found by measuring pixels in side-by-side screenshots
 540            * of BaltimoreLink and Commuter Bus tickets. */
 541           t.setAttribute("transform", "translate(0 -9.33)");
 542
 543           /* More magic numbers discovered by comparing the two
 544            * tickets overlayed in inkscape */
 545           sn.setAttribute("transform", "translate(0 64.28)");
 546         }
 547         else if (params.get("servicename") === "MARC Train") {
 548           /* insane tricks are explained above */
 549           tbg.setAttribute("transform",
 550                            "translate(0 -72.378) scale(1 1.2932)");
 551           t.setAttribute("transform", "translate(0 -67.17)");
 552           sn.setAttribute("transform", "translate(0 131.0)");
 553         }
 554       }
 555
 556
 557       /**
 558        * Set the security code from the querystring if it was given;
 559        * otherwise generate a random code.
 560        */
 561       function set_code() {
 562         const ct = document.getElementById("codetext");
 563
 564         /* Get the "code" from the querystring if it's there */
 565         const params = new URLSearchParams(document.location.search);
 566         if (params.get("code")) {
 567           ct.textContent = params.get("code").toUpperCase();
 568         }
 569         else {
 570           /* Otherwise, use a random code */
 571           const bucket = ["0","1","2","3","4","5","6","7","8","9",
 572                           "A","B","C","D","E","F","G","H","I","J",
 573                           "K","L","M","N","O","P","Q","R","S","T",
 574                           "U","V","W","X","Y","Z"];
 575
 576           /* Two random ints between 0 and 35 */
 577           const i1 = Math.floor(Math.random() * 36);
 578           const i2 = Math.floor(Math.random() * 36);
 579           const d1 = bucket[i1];
 580           const d2 = bucket[i2];
 581           ct.textContent = d1 + d2;
 582         }
 583       }
 584
 585
 586       /**
 587        * Center the security code within its container.
 588        *
 589        * Some codes like "II" and "WW" can take up wildly different
 590        * amounts of horizonetal space, but they should always be
 591        * centered inside their little red box. This turns out to be
 592        * harder than it sounds because we can only find the width of
 593        * the code in browser coordinates, whereas its "x" coordinate
 594        * is in SVG coordinates. Anyway, we do it.
 595        */
 596       function center_code() {
 597         /* Center the security code inside its red box */
 598         const ct = document.getElementById("codetext");
 599         const bg = document.getElementById("codebg");
 600
 601         /* First, find the center of the red box */
 602         const r1 = bg.getBoundingClientRect();
 603         const c1 = r1.left + (r1.width / 2);
 604
 605         /* Now the center of the code text */
 606         const r2 = ct.getBoundingClientRect();
 607         const c2 = r2.left + (r2.width / 2);
 608
 609         /* What do we add to c2 to make it equal to c1? */
 610         const hdelta = c1 - c2;
 611
 612         /* We've measured everything so far in "client rect"
 613          * coordinates, because that's the only available measurement
 614          * we have for the width of the <text> element. But when we
 615          * reposition that <text> element, it will be by adjusting its
 616          * "x" attribute, and that attribute uses a different coordinate
 617          * system than the client rect does. Specifically, "x" refers to
 618          * an offset within the SVG's coordinate system, and the client
 619          * rect coordinates are pixels on-screen. To convert between the
 620          * two, we can take the "width" attribute of the background
 621          * element and compare it to the width of the background
 622          * element's client rect. Since the size of the background is
 623          * fixed, this should give us a multiplier that turns client rect
 624          * distances (what we have) into SVG distances (what we want) */
 625         const client_to_svg = parseFloat(bg.getAttribute("width"))/r1.width;
 626
 627         /* Convert hdelta from client rect to SVG coordinates */
 628         const svg_hdelta = hdelta * client_to_svg;
 629
 630         /* Since this <text> element has an "x" attribute it's easier for
 631          * us to shift that than it is to mess with the "left" style. */
 632         ct.setAttribute("x", parseFloat(ct.getAttribute("x")) + svg_hdelta);
 633       }
 634
 635       /**
 636        * Set the ticket's expiration date and time.
 637        *
 638        * BaltimoreLink and MARC Train tickets expire after 90 minutes;
 639        * while Commuter Bus tickets expire after 10 minutes.
 640        */
 641       function set_ticket_expiry() {
 642         /* There are two parameters, time and date, that we store in one
 643          * underlying "date" variable. */
 644         const date = new Date();
 645
 646         /* BaltimoreLink and MARC Train */
 647         let minutes = 90;
 648         const params = new URLSearchParams(document.location.search);
 649         if (params.get("servicename") === "Commuter Bus") {
 650           /* Commuter bus tickets are only valid for ten minutes */
 651           minutes = 10;
 652         }
 653
 654         /* We use the low-level get/setTime to change the number of
 655          * milliseconds since the epoch that this date represents
 656          * Obviously correct, and avoids all suspicious corner cases
 657          * for a few more decades. */
 658         date.setTime(date.getTime() + (minutes*60*1000));
 659
 660         tt = document.getElementById("tickettime");
 661         tt.textContent = date.toLocaleTimeString();
 662
 663         const td = document.getElementById("ticketdate");
 664         const dateopts = {
 665           day: "2-digit",
 666           month: "2-digit",
 667           year: "2-digit"
 668         };
 669         td.textContent = date.toLocaleDateString("en-US", dateopts);
 670       }
 671
 672
 673       /**
 674        * Swap the day/night sky colors.
 675        *
 676        * We use CSS classes to keep track of the current state because
 677        * it's a tiny bit cleaner than a global variable, but for some
 678        * reason we can't use those same classes to actually change the
 679        * color. (The classes, change, but the color doesn't.) Rather
 680        * than waste time trying to explain this, we just set the "fill"
 681        * attribute ourselves whenever we swap classes.
 682        */
 683       function swap_day_night() {
 684         const sky = document.getElementById("sky");
 685
 686         if (sky.getAttribute("class") === "night") {
 687           sky.setAttribute("fill", "#efb02f");
 688           sky.setAttribute("class", "day");
 689         }
 690         else {
 691           /* Put this case second so that the first time the
 692            * screen is tapped (when there are no classes on
 693            * the sky element) the color still changes. */
 694           sky.setAttribute("fill", "#143b66");
 695           sky.setAttribute("class", "night");
 696         }
 697       }
 698
 699
 700       /**
 701        * Compute the zone (string) for the given origin/destination pair.
 702        *
 703        * If we don't know it or if you chose in invalid pair (destination
 704        * not on the same line as your origin?) then null is returned.
 705        */
 706       function compute_marc_zone(src, dest) {
 707
 708         /* Sorted on the first component, then the second */
 709         const zone_map = {
 710           BAL_BWE: 2,
 711           BAL_BWI: 1,
 712           BAL_SEB: 3,
 713           BAL_WAS: 4,
 714           BAL_WBL: 1,
 715           BCA_CPK: 3,
 716           BCA_WAS: 4,
 717           BWE_BWI: 1,
 718           BWE_SEB: 1,
 719           BWE_WAS: 2,
 720           BWE_WBL: 2,
 721           BWI_WAS: 3,
 722           BWI_WBL: 1
 723         };
 724
 725         /* Forward direction key for zone_map */
 726         const fwd = src + "_" +  dest;
 727
 728         /* Reverse direction key for zone_map. The zone_map only
 729          * has them listed in one direction, so we check both
 730          * directions here. */
 731         const rev = dest + "_" +  src;
 732
 733         /* The default. Obviously wrong for when we don't
 734          * have the necessary data. */
 735         let zone = -1;
 736
 737         if (zone_map[fwd]) {
 738           zone = zone_map[fwd];
 739         }
 740         else if (zone_map[rev]) {
 741           zone = zone_map[rev];
 742         }
 743
 744         /* Convert the number to a string */
 745         switch (zone) {
 746           case 1:
 747             return "One Zone";
 748           case 2:
 749             return "Two Zone";
 750           case 3:
 751             return "Three Zone";
 752           case 4:
 753             return "Four Zone";
 754           default:
 755             return null;
 756         }
 757       }
 758
 759
 760       /**
 761        * Compute and set the zone.
 762        *
 763        * We can be given a zone in two ways. First, on Commuter Bus
 764        * tickets, it is given explicitly via the querystring. But
 765        * It can also be specified implicitly via the origin and
 766        * destination on a MARC Train ticket. Here we try both and
 767        * then call set_zone() with the result if something worked.
 768        */
 769       function compute_and_set_zone() {
 770         const params = new URLSearchParams(document.location.search);
 771         const src = params.get("origin");
 772         const dest = params.get("destination");
 773
 774         if (src && dest) {
 775           /* MARC Train. We can assume that compute_marc_zone() doesn't
 776            * return null because that's part of our form validation. */
 777           const zone = compute_marc_zone(src, dest);
 778           set_zone(zone);
 779         }
 780         else if (params.get("zone")) {
 781           /* Commuter Bus */
 782           set_zone(params.get("zone"));
 783         }
 784       }
 785
 786
 787       /**
 788        * Set the origin and destination for the MARC Train if they
 789        * were provided, and unhide them if so.
 790        */
 791       function set_marc_origin_destination() {
 792         const params = new URLSearchParams(document.location.search);
 793         if (!params.get("origin") || !params.get("destination")) {
 794           return;
 795         }
 796
 797         const src = params.get("origin");
 798         const dest = params.get("destination");
 799
 800         /* origindest contains both the origin and destination */
 801         const origindest = document.getElementById("origindest");
 802
 803         const origin = document.getElementById("origin");
 804         const destination = document.getElementById("destination");
 805
 806         origin.textContent = params.get("origin");
 807         destination.textContent = params.get("destination");
 808
 809         origindest.style.display = "block"; /* hidden by default */
 810       }
 811
 812
 813       /**
 814        * Hide the menu and display the ticket. This is what happens
 815        * when you submit the form.
 816        */
 817       function go() {
 818         /* To create our "window" onto the scene, we're going to slide the
 819          * SVG off the left-hand side of the screen, and we don't want
 820          * scroll bars to appear. */
 821         document.body.style.overflow = "hidden";
 822         document.body.style.margin = "0";
 823         document.body.style.padding = "0";
 824
 825         const svg = document.querySelector("svg");
 826         const menu = document.getElementById("menu");
 827         svg.style.display = "initial";
 828         menu.style.display = "none";
 829       }
 830
 831       /**
 832        * Determine if the user agent is mobile Firefox.
 833        */
 834       function ua_is_mobile_ff() {
 835         const ua = navigator.userAgent.toLowerCase();
 836         return (ua.includes("firefox") && ua.includes("mobile"));
 837       }
 838
 839       /**
 840        * Validate the MARC form's origin/destination.
 841        *
 842        * We don't want the user to be able to choose a pair of stops that
 843        * aren't actually connected by the same MARC line. If we don't have
 844        * zone information for the (origin,destination) pair, that indicates
 845        * that it's probably not a valid choice; otherwise I would have
 846        * filled in the information from the CharmPass app already.
 847        *
 848        * All browsers except mobile Firefox let us call setCustomValidity()
 849        * to provide an error message that is displayed if the user tries
 850        * to submit invalid choices. But amazingly, mobile Firefox does not:
 851        *
 852        *   https://bugzilla.mozilla.org/show_bug.cgi?id=1510450
 853        *
 854        * Instead we have to work around it (in that one browser) by
 855        * showing/hiding a paragraph that we fill with the errors.
 856        */
 857       function validate_origin_destination(event) {
 858         const origins = document.getElementsByName("origin");
 859         const destinations = document.getElementsByName("destination");
 860         const mfe = document.getElementById("marc-form-errors");
 861         const marcsubmit = document.getElementById("marc-submit");
 862
 863         if (ua_is_mobile_ff()) {
 864           /* Even though this is only for one browser, empty paragraphs
 865            * are handled inconsistently and should be avoided as a rule.
 866            * So, we make it say "OK" before we hide it. */
 867           mfe.textContent = "OK";
 868           mfe.style.visibility = "hidden";
 869           marcsubmit.disabled = false;
 870         }
 871
 872         let src = null;
 873         let dest = null;
 874         origins.forEach((x) => { if (x.checked) src = x; })
 875         destinations.forEach((x) => {
 876           if (x.checked) dest = x;
 877
 878           /* clear all errors before possibly setting one */
 879           x.setCustomValidity('');
 880         })
 881
 882         if (src.value === dest.value) {
 883           let err = "Origin and destination are the same";
 884           dest.setCustomValidity(err);
 885
 886           if (ua_is_mobile_ff()) {
 887             mfe.textContent = err;
 888             mfe.style.visibility = "visible";
 889             marcsubmit.disabled = true;
 890           }
 891         }
 892         else if (compute_marc_zone(src.value, dest.value) === null) {
 893           let err = "Origin and destination are on different lines";
 894           dest.setCustomValidity(err);
 895
 896           if (ua_is_mobile_ff()) {
 897             mfe.textContent = err;
 898             mfe.style.visibility = "visible";
 899             marcsubmit.disabled = true;
 900           }
 901         }
 902       }
 903
 904       /*****************************************************/
 905       /* Add event handlers for all of the functions above */
 906       /*****************************************************/
 907
 908       const params = new URLSearchParams(document.location.search);
 909       if (params.get("go")) {
 910         /* First unhide the SVG (swap it with the form) */
 911         window.addEventListener("load", go);
 912
 913         /* Center the ticket once when the page has loaded */
 914         window.addEventListener("load", center_ticket);
 915
 916         /* Re-center the ticket when the window is resized */
 917         window.addEventListener("resize", center_ticket);
 918
 919         /* Set the service identifier when the page has loaded */
 920         window.addEventListener("load", set_service_id);
 921
 922         /* Set the service name when the page has loaded */
 923         window.addEventListener("load", set_service_name);
 924
 925         /* Resize the ticket background if necessary */
 926         window.addEventListener("load", resize_ticket);
 927
 928         /* Set the security code text when the page has loaded */
 929         window.addEventListener("load", set_code);
 930
 931         /* Center the security code text when the page has loaded; in
 932          * particular, after we set the code. */
 933         window.addEventListener("load", center_code);
 934
 935         /* Set the ticket expiration date/time upon page load */
 936         window.addEventListener("load", set_ticket_expiry);
 937
 938         /* Set the MARC Train origin and destination, if applicable */
 939         window.addEventListener("load", set_marc_origin_destination);
 940
 941         /* Compute and set the zone, if applicable */
 942         window.addEventListener("load", compute_and_set_zone);
 943
 944         /* Swap colors when the screen is tapped */
 945         document.body.addEventListener("click", swap_day_night);
 946       }
 947       else {
 948         /* If we haven't submitted the form yet, set up change handlers
 949          * for the origin/destination radio buttons that validate that
 950          * the origin and destination are on the same line. */
 951         document.getElementsByName("origin").forEach(
 952          (x) => x.addEventListener("change", validate_origin_destination)
 953         );
 954         document.getElementsByName("destination").forEach(
 955          (x) => x.addEventListener("change", validate_origin_destination)
 956         );
 957
 958         /* Also do it when the page loads, because firefox likes to
 959          * remember your selection even after the page reloads. */
 960         window.addEventListener("load", validate_origin_destination);
 961
 962         /* Finally, we have to babysit mobile Firefox, who doesn't
 963          * support HTML5 form validation going into 2024. Turn on
 964          * the little form errors paragraph so we can toggle its
 965          * visibility (and make it display the error) when the user
 966          * makes an invalid selection. */
 967         window.addEventListener("load", () => {
 968           if (ua_is_mobile_ff()) {
 969             const mfe = document.getElementById("marc-form-errors");
 970             mfe.style.display = "block";
 971           }
 972         });
 973       }
 974
 975     </script>
 976   </body>
 977 </html>