DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (c68fe15a81fc)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

"use strict";

var EXPORTED_SYMBOLS = ["UrlbarView"];

const { XPCOMUtils } = ChromeUtils.import(
  "resource://gre/modules/XPCOMUtils.jsm"
);
XPCOMUtils.defineLazyModuleGetters(this, {
  UrlbarPrefs: "resource:///modules/UrlbarPrefs.jsm",
  UrlbarTokenizer: "resource:///modules/UrlbarTokenizer.jsm",
  UrlbarUtils: "resource:///modules/UrlbarUtils.jsm",
});

// Stale rows are removed on a timer with this timeout.  Tests can override this
// by setting UrlbarView.removeStaleRowsTimeout.
const DEFAULT_REMOVE_STALE_ROWS_TIMEOUT = 400;

const getBoundsWithoutFlushing = element =>
  element.ownerGlobal.windowUtils.getBoundsWithoutFlushing(element);

// Used to get a unique id to use for row elements, it wraps at 9999, that
// should be plenty for our needs.
let gUniqueIdSerial = 1;
function getUniqueId(prefix) {
  return prefix + (gUniqueIdSerial++ % 9999);
}

/**
 * Receives and displays address bar autocomplete results.
 */
class UrlbarView {
  /**
   * @param {UrlbarInput} input
   *   The UrlbarInput instance belonging to this UrlbarView instance.
   */
  constructor(input) {
    this.input = input;
    this.panel = input.panel;
    this.controller = input.controller;
    this.document = this.panel.ownerDocument;
    this.window = this.document.defaultView;

    this._mainContainer = this.panel.querySelector(".urlbarView-body-inner");
    this._rows = this.panel.querySelector(".urlbarView-results");

    this._rows.addEventListener("mousedown", this);
    this._rows.addEventListener("mouseup", this);

    // For the horizontal fade-out effect, set the overflow attribute on result
    // rows when they overflow.
    this._rows.addEventListener("overflow", this);
    this._rows.addEventListener("underflow", this);

    this.controller.setView(this);
    this.controller.addQueryListener(this);
    // This is used by autoOpen to avoid flickering results when reopening
    // previously abandoned searches.
    this._queryContextCache = new QueryContextCache(5);
  }

  get oneOffSearchButtons() {
    if (!this._oneOffSearchButtons) {
      this._oneOffSearchButtons = new this.window.SearchOneOffs(
        this.panel.querySelector(".search-one-offs")
      );
      this._oneOffSearchButtons.addEventListener(
        "SelectedOneOffButtonChanged",
        this
      );
    }
    return this._oneOffSearchButtons;
  }

  /**
   * @returns {boolean}
   *   Whether the panel is open.
   */
  get isOpen() {
    return this.input.hasAttribute("open");
  }

  get allowEmptySelection() {
    return !(
      this._queryContext &&
      this._queryContext.results[0] &&
      this._queryContext.results[0].heuristic
    );
  }

  get selectedRowIndex() {
    if (!this.isOpen) {
      return -1;
    }

    let selectedRow = this._getSelectedRow();

    if (!selectedRow) {
      return -1;
    }

    return selectedRow.result.rowIndex;
  }

  set selectedRowIndex(val) {
    if (!this.isOpen) {
      throw new Error(
        "UrlbarView: Cannot select an item if the view isn't open."
      );
    }

    if (val < 0) {
      this._selectElement(null);
      return val;
    }

    let items = Array.from(this._rows.children).filter(r =>
      this._isElementVisible(r)
    );
    if (val >= items.length) {
      throw new Error(`UrlbarView: Index ${val} is out of bounds.`);
    }
    this._selectElement(items[val]);
    return val;
  }

  get selectedElementIndex() {
    if (!this.isOpen || !this._selectedElement) {
      return -1;
    }

    return this._selectedElement.elementIndex;
  }

  set selectedElementIndex(val) {
    if (!this.isOpen) {
      throw new Error(
        "UrlbarView: Cannot select an item if the view isn't open."
      );
    }

    if (val < 0) {
      this._selectElement(null);
      return val;
    }

    let selectableElement = this._getFirstSelectableElement();
    while (selectableElement && selectableElement.elementIndex != val) {
      selectableElement = this._getNextSelectableElement(selectableElement);
    }

    if (!selectableElement) {
      throw new Error(`UrlbarView: Index ${val} is out of bounds.`);
    }

    this._selectElement(selectableElement);
    return val;
  }

  /**
   * @returns {UrlbarResult}
   *   The currently selected result.
   */
  get selectedResult() {
    if (!this.isOpen) {
      return null;
    }

    let selectedRow = this._getSelectedRow();

    if (!selectedRow) {
      return null;
    }

    return selectedRow.result;
  }

  /**
   * @returns {Element}
   *   The currently selected element.
   */
  get selectedElement() {
    if (!this.isOpen) {
      return null;
    }

    return this._selectedElement;
  }

  /**
   * @returns {number}
   *   The number of visible results in the view.  Note that this may be larger
   *   than the number of results in the current query context since the view
   *   may be showing stale results.
   */
  get visibleRowCount() {
    let sum = 0;
    for (let row of this._rows.children) {
      sum += Number(this._isElementVisible(row));
    }
    return sum;
  }

  /**
   * @returns {number}
   *   The number of selectable elements in the view.
   */
  get visibleElementCount() {
    let sum = 0;
    let element = this._getFirstSelectableElement();
    while (element) {
      if (this._isElementVisible(element)) {
        sum++;
      }
      element = this._getNextSelectableElement(element);
    }
    return sum;
  }

  /**
   * Returns the result of the row containing the given element, or the result
   * of the element if it itself is a row.
   *
   * @param {Element} element
   *   An element in the view.
   * @returns {UrlbarResult}
   *   The result of the element's row.
   */
  getResultFromElement(element) {
    if (!this.isOpen) {
      return null;
    }

    let row = this._getRowFromElement(element);

    if (!row) {
      return null;
    }

    return row.result;
  }

  /**
   * Returns the element closest to the given element that can be
   * selected/picked.  If the element itself can be selected, it's returned.  If
   * there is no such element, null is returned.
   *
   * @param {Element} element
   *   An element in the view.
   * @returns {Element}
   *   The closest element that can be picked including the element itself, or
   *   null if there is no such element.
   */
  getClosestSelectableElement(element) {
    let result = this.getResultFromElement(element);
    if (result && result.type == UrlbarUtils.RESULT_TYPE.TIP) {
      if (
        element.classList.contains("urlbarView-tip-button") ||
        element.classList.contains("urlbarView-tip-help")
      ) {
        return element;
      }
      return null;
    }
    return element.closest(".urlbarView-row");
  }

  /**
   * Moves the view selection forward or backward.
   *
   * @param {number} amount
   *   The number of steps to move.
   * @param {boolean} options.reverse
   *   Set to true to select the previous item. By default the next item
   *   will be selected.
   */
  selectBy(amount, { reverse = false } = {}) {
    if (!this.isOpen) {
      throw new Error(
        "UrlbarView: Cannot select an item if the view isn't open."
      );
    }

    // Freeze results as the user is interacting with them.
    this.controller.cancelQuery();

    let selectedElement = this._selectedElement;

    // We cache the first and last rows since they will not change while
    // selectBy is running.
    let firstSelectableElement = this._getFirstSelectableElement();
    // _getLastSelectableElement will not return an element that is over
    // maxResults and thus may be hidden and not selectable.
    let lastSelectableElement = this._getLastSelectableElement();

    if (!selectedElement) {
      this._selectElement(
        reverse ? lastSelectableElement : firstSelectableElement
      );
      return;
    }
    let endReached = reverse
      ? selectedElement == firstSelectableElement
      : selectedElement == lastSelectableElement;
    if (endReached) {
      if (this.allowEmptySelection) {
        selectedElement = null;
      } else {
        selectedElement = reverse
          ? lastSelectableElement
          : firstSelectableElement;
      }
      this._selectElement(selectedElement);
      return;
    }

    while (amount-- > 0) {
      let next = reverse
        ? this._getPreviousSelectableElement(selectedElement)
        : this._getNextSelectableElement(selectedElement);
      if (!next) {
        break;
      }
      if (!this._isElementVisible(next)) {
        continue;
      }
      selectedElement = next;
    }
    this._selectElement(selectedElement);
  }

  removeAccessibleFocus() {
    this._setAccessibleFocus(null);
  }

  clear() {
    this._rows.textContent = "";
  }

  /**
   * Closes the view, cancelling the query if necessary.
   * @param {boolean} [elementPicked]
   *   True if the view is being closed because a result was picked.
   */
  close(elementPicked = false) {
    this.controller.cancelQuery();

    if (!this.isOpen) {
      return;
    }

    this.removeAccessibleFocus();
    this.input.inputField.setAttribute("aria-expanded", "false");

    this.input.removeAttribute("open");
    this.input.endLayoutExtend();

    // Search Tips can open the view without the Urlbar being focused. If the
    // tip is ignored (e.g. the page content is clicked or the window loses
    // focus) we should discard the telemetry event created when the view was
    // opened.
    if (!this.input.focused && !elementPicked) {
      this.controller.engagementEvent.discard();
      this.controller.engagementEvent.record(null, {});
    }

    this.window.removeEventListener("resize", this);
    this.window.removeEventListener("blur", this);

    this.controller.notify(this.controller.NOTIFICATIONS.VIEW_CLOSE);
  }

  /**
   * This can be used to open the view automatically as a consequence of
   * specific user actions. For Top Sites searches (without a search string)
   * the view is opened only for mouse or keyboard interactions.
   * If the user abandoned a search (there is a search string) the view is
   * reopened, and we try to use cached results to reduce flickering, then a new
   * query is started to refresh results.
   * @param {Event} queryOptions Options to use when starting a new query. The
   *        event property is mandatory for proper telemetry tracking.
   * @returns {boolean} Whether the view was opened.
   */
  autoOpen(queryOptions = {}) {
    if (this._pickSearchTipIfPresent(queryOptions.event)) {
      return false;
    }

    if (!queryOptions.event) {
      return false;
    }

    if (
      !this.input.value ||
      this.input.getAttribute("pageproxystate") == "valid"
    ) {
      if (
        // Do not show Top Sites in private windows.
        !this.input.isPrivate &&
        !this.isOpen &&
        ["mousedown", "command"].includes(queryOptions.event.type)
      ) {
        this.input.startQuery(queryOptions);
        return true;
      }
      return false;
    }

    // Reopen abandoned searches only if the input is focused.
    if (!this.input.focused) {
      return false;
    }

    // Tab switch is the only case where we requery if the view is open, because
    // switching tabs doesn't necessarily close the view.
    if (this.isOpen && queryOptions.event.type != "tabswitch") {
      return false;
    }

    if (
      this._rows.firstElementChild &&
      this._queryContext.searchString == this.input.value
    ) {
      // We can reuse the current results.
      queryOptions.allowAutofill = this._queryContext.allowAutofill;
    } else {
      // To reduce results flickering, try to reuse a cached UrlbarQueryContext.
      let cachedQueryContext = this._queryContextCache.get(this.input.value);
      if (cachedQueryContext) {
        this.onQueryResults(cachedQueryContext);
      }
    }

    this.controller.engagementEvent.discard();
    queryOptions.searchString = this.input.value;
    queryOptions.autofillIgnoresSelection = true;
    queryOptions.event.interactionType = "returned";

    if (
      this._queryContext &&
      this._queryContext.results &&
      this._queryContext.results.length
    ) {
      this._openPanel();
    }

    // If we had cached results, this will just refresh them, avoiding results
    // flicker, otherwise there may be some noise.
    this.input.startQuery(queryOptions);
    return true;
  }

  // UrlbarController listener methods.
  onQueryStarted(queryContext) {
    this._queryWasCancelled = false;
    this._queryUpdatedResults = false;
    this._startRemoveStaleRowsTimer();
  }

  onQueryCancelled(queryContext) {
    this._queryWasCancelled = true;
    this._cancelRemoveStaleRowsTimer();
  }

  onQueryFinished(queryContext) {
    this._cancelRemoveStaleRowsTimer();
    if (!this._queryWasCancelled) {
      // If the query has not been canceled and returned some results, remove
      // stale rows immediately. If no results were returned, just clear and
      // close the view.
      if (this._queryUpdatedResults) {
        this._removeStaleRows();
      } else {
        this.clear();
        this.close();
      }
    }
  }

  onQueryResults(queryContext) {
    this._queryContextCache.put(queryContext);
    this._queryContext = queryContext;

    if (!this.isOpen) {
      this.clear();
    }
    this._queryUpdatedResults = true;
    this._updateResults(queryContext);

    let firstResult = queryContext.results[0];

    if (queryContext.lastResultCount == 0) {
      // Clear the selection when we get a new set of results.
      this._selectElement(null, {
        updateInput: false,
      });

      // Hide the one-off search buttons if the search string is empty, or
      // starts with a potential @ search alias or the search restriction
      // character.
      let trimmedValue = queryContext.searchString.trim();
      this._enableOrDisableOneOffSearches(
        trimmedValue &&
          trimmedValue[0] != "@" &&
          (trimmedValue[0] != UrlbarTokenizer.RESTRICT.SEARCH ||
            trimmedValue.length != 1)
      );

      // Notify the input, so it can make adjustments based on the first result.
      this.input.onFirstResult(firstResult);
    }

    if (
      firstResult.heuristic &&
      !this.selectedElement &&
      !this.oneOffSearchButtons.selectedButton
    ) {
      // Select the heuristic result.  The heuristic may not be the first result
      // added, which is why we do this check here when each result is added and
      // not above.
      this._selectElement(this._getFirstSelectableElement(), {
        updateInput: false,
        setAccessibleFocus: this.controller._userSelectionBehavior == "arrow",
      });
    }

    this._openPanel();

    if (firstResult.heuristic) {
      // The heuristic result may be a search alias result, so apply formatting
      // if necessary.  Conversely, the heuristic result of the previous query
      // may have been an alias, so remove formatting if necessary.
      this.input.formatValue();
    }
  }

  /**
   * Handles removing a result from the view when it is removed from the query,
   * and attempts to select the new result on the same row.
   *
   * This assumes that the result rows are in index order.
   *
   * @param {number} index The index of the result that has been removed.
   */
  onQueryResultRemoved(index) {
    let rowToRemove = this._rows.children[index];
    rowToRemove.remove();

    this._updateIndices();

    if (rowToRemove != this._getSelectedRow()) {
      return;
    }

    // Select the row at the same index, if possible.
    let newSelectionIndex = index;
    if (index >= this._queryContext.results.length) {
      newSelectionIndex = this._queryContext.results.length - 1;
    }
    if (newSelectionIndex >= 0) {
      this.selectedRowIndex = newSelectionIndex;
    }
  }

  /**
   * Passes DOM events for the view to the _on_<event type> methods.
   * @param {Event} event
   *   DOM event from the <view>.
   */
  handleEvent(event) {
    let methodName = "_on_" + event.type;
    if (methodName in this) {
      this[methodName](event);
    } else {
      throw new Error("Unrecognized UrlbarView event: " + event.type);
    }
  }

  /**
   * This is called when a one-off is clicked and when "search in new tab"
   * is selected from a one-off context menu.
   * @param {Event} event
   * @param {nsISearchEngine} engine
   * @param {string} where
   * @param {object} params
   */
  handleOneOffSearch(event, engine, where, params) {
    this.input.handleCommand(event, where, params);
  }

  // Private methods below.

  _createElement(name) {
    return this.document.createElementNS("http://www.w3.org/1999/xhtml", name);
  }

  _openPanel() {
    if (this.isOpen) {
      return;
    }
    this.controller.userSelectionBehavior = "none";

    this.panel.removeAttribute("actionoverride");

    this._enableOrDisableRowWrap();

    this.input.inputField.setAttribute("aria-expanded", "true");

    this.input.setAttribute("open", "true");
    this.input.startLayoutExtend();

    this.window.addEventListener("resize", this);
    this.window.addEventListener("blur", this);

    this.controller.notify(this.controller.NOTIFICATIONS.VIEW_OPEN);
  }

  /**
   * Whether a result is a search suggestion.
   * @param {UrlbarResult} result The result to examine.
   * @returns {boolean} Whether the result is a search suggestion.
   */
  _resultIsSearchSuggestion(result) {
    return Boolean(
      result &&
        result.type == UrlbarUtils.RESULT_TYPE.SEARCH &&
        result.payload.suggestion
    );
  }

  /**
   * Checks whether the given row index can be update to the result we want
   * to apply. This is used in _updateResults to avoid flickering of results, by
   * reusing existing rows.
   * @param {number} rowIndex Index of the row to examine.
   * @param {UrlbarResult} result The result we'd like to apply.
   * @param {number} firstSearchSuggestionIndex Index of the first search suggestion.
   * @param {number} lastSearchSuggestionIndex Index of the last search suggestion.
   * @returns {boolean} Whether the row can be updated to this result.
   */
  _rowCanUpdateToResult(
    rowIndex,
    result,
    firstSearchSuggestionIndex,
    lastSearchSuggestionIndex
  ) {
    // The heuristic result must always be current, thus it's always compatible.
    if (result.heuristic) {
      return true;
    }
    let row = this._rows.children[rowIndex];
    let resultIsSearchSuggestion = this._resultIsSearchSuggestion(result);
    // If the row is same type, just update it.
    if (
      resultIsSearchSuggestion == this._resultIsSearchSuggestion(row.result)
    ) {
      return true;
    }
    // If the row has a different type, update it if we are in a compatible
    // index range.
    // In practice we don't want to overwrite a search suggestion with a non
    // search suggestion, but we allow the opposite.
    return resultIsSearchSuggestion && rowIndex >= firstSearchSuggestionIndex;
  }

  _updateResults(queryContext) {
    // TODO: For now this just compares search suggestions to the rest, in the
    // future we should make it support any type of result. Or, even better,
    // results should be grouped, thus we can directly update groups.

    // Find where are existing search suggestions.
    let firstSearchSuggestionIndex = -1;
    let lastSearchSuggestionIndex = -1;
    for (let i = 0; i < this._rows.children.length; ++i) {
      let row = this._rows.children[i];
      // Mark every row as stale, _updateRow will unmark them later.
      row.setAttribute("stale", "true");
      // Skip any row that isn't a search suggestion, or is non-visible because
      // over maxResults.
      if (
        row.result.heuristic ||
        i >= queryContext.maxResults ||
        !this._resultIsSearchSuggestion(row.result)
      ) {
        continue;
      }
      if (firstSearchSuggestionIndex == -1) {
        firstSearchSuggestionIndex = i;
      }
      lastSearchSuggestionIndex = i;
    }

    // Walk rows and find an insertion index for results. To avoid flicker, we
    // skip rows until we find one compatible with the result we want to apply.
    // If we couldn't find a compatible range, we'll just update.
    let results = queryContext.results;
    let resultIndex = 0;
    // We can have more rows than the visible ones.
    for (
      let rowIndex = 0;
      rowIndex < this._rows.children.length && resultIndex < results.length;
      ++rowIndex
    ) {
      let row = this._rows.children[rowIndex];
      let result = results[resultIndex];
      if (
        this._rowCanUpdateToResult(
          rowIndex,
          result,
          firstSearchSuggestionIndex,
          lastSearchSuggestionIndex
        )
      ) {
        this._updateRow(row, result);
        resultIndex++;
      }
    }
    // Add remaining results, if we have fewer rows than results.
    for (; resultIndex < results.length; ++resultIndex) {
      let row = this._createRow();
      this._updateRow(row, results[resultIndex]);
      // Due to stale rows, we may have more rows than maxResults, thus we must
      // hide them, and we'll revert this when stale rows are removed.
      if (this._rows.children.length >= queryContext.maxResults) {
        this._setRowVisibility(row, false);
      }
      this._rows.appendChild(row);
    }

    this._updateIndices();
  }

  _createRow() {
    let item = this._createElement("div");
    item.className = "urlbarView-row";
    item.setAttribute("role", "option");
    item._elements = new Map();
    return item;
  }

  _createRowContent(item) {
    // The url is the only element that can wrap, thus all the other elements
    // are child of noWrap.
    let noWrap = this._createElement("span");
    noWrap.className = "urlbarView-no-wrap";
    item._content.appendChild(noWrap);

    let favicon = this._createElement("img");
    favicon.className = "urlbarView-favicon";
    noWrap.appendChild(favicon);
    item._elements.set("favicon", favicon);

    let typeIcon = this._createElement("span");
    typeIcon.className = "urlbarView-type-icon";
    noWrap.appendChild(typeIcon);

    let tailPrefix = this._createElement("span");
    tailPrefix.className = "urlbarView-tail-prefix";
    noWrap.appendChild(tailPrefix);
    item._elements.set("tailPrefix", tailPrefix);
    // tailPrefix holds text only for alignment purposes so it should never be
    // read to screen readers.
    tailPrefix.toggleAttribute("aria-hidden", true);

    let tailPrefixStr = this._createElement("span");
    tailPrefixStr.className = "urlbarView-tail-prefix-string";
    tailPrefix.appendChild(tailPrefixStr);
    item._elements.set("tailPrefixStr", tailPrefixStr);

    let tailPrefixChar = this._createElement("span");
    tailPrefixChar.className = "urlbarView-tail-prefix-char";
    tailPrefix.appendChild(tailPrefixChar);
    item._elements.set("tailPrefixChar", tailPrefixChar);

    let title = this._createElement("span");
    title.className = "urlbarView-title";
    noWrap.appendChild(title);
    item._elements.set("title", title);

    let tagsContainer = this._createElement("span");
    tagsContainer.className = "urlbarView-tags";
    noWrap.appendChild(tagsContainer);
    item._elements.set("tagsContainer", tagsContainer);

    let titleSeparator = this._createElement("span");
    titleSeparator.className = "urlbarView-title-separator";
    noWrap.appendChild(titleSeparator);
    item._elements.set("titleSeparator", titleSeparator);

    let action = this._createElement("span");
    action.className = "urlbarView-action";
    noWrap.appendChild(action);
    item._elements.set("action", action);

    let url = this._createElement("span");
    url.className = "urlbarView-url";
    item._content.appendChild(url);
    item._elements.set("url", url);
  }

  _createRowContentForTip(item) {
    // We use role="group" so screen readers will read the group's label when a
    // button inside it gets focus. (Screen readers don't do this for
    // role="option".) We set aria-labelledby for the group in _updateIndices.
    item._content.setAttribute("role", "group");

    let favicon = this._createElement("img");
    favicon.className = "urlbarView-favicon";
    favicon.setAttribute("data-l10n-id", "urlbar-tip-icon-description");
    item._content.appendChild(favicon);
    item._elements.set("favicon", favicon);

    let title = this._createElement("span");
    title.className = "urlbarView-title";
    item._content.appendChild(title);
    item._elements.set("title", title);

    let buttonSpacer = this._createElement("span");
    buttonSpacer.className = "urlbarView-tip-button-spacer";
    item._content.appendChild(buttonSpacer);

    let tipButton = this._createElement("span");
    tipButton.className = "urlbarView-tip-button";
    tipButton.setAttribute("role", "button");
    item._content.appendChild(tipButton);
    item._elements.set("tipButton", tipButton);

    let helpIcon = this._createElement("span");
    helpIcon.className = "urlbarView-tip-help";
    helpIcon.setAttribute("role", "button");
    helpIcon.setAttribute("data-l10n-id", "urlbar-tip-help-icon");
    item._elements.set("helpButton", helpIcon);
    item._content.appendChild(helpIcon);

    // Due to role=button, the button and help icon can sometimes become
    // focused.  We want to prevent that because the input should always be
    // focused instead.  (This happens when input.search("", { focus: false })
    // is called, a tip is the first result but not heuristic, and the user tabs
    // the into the button from the navbar buttons.  The input is skipped and
    // the focus goes straight to the tip button.)
    item.addEventListener("focus", () => this.input.focus(), true);
  }

  _updateRow(item, result) {
    let oldResultType = item.result && item.result.type;
    item.result = result;
    item.removeAttribute("stale");
    item.id = getUniqueId("urlbarView-row-");

    let needsNewContent =
      oldResultType === undefined ||
      (oldResultType == UrlbarUtils.RESULT_TYPE.TIP) !=
        (result.type == UrlbarUtils.RESULT_TYPE.TIP);

    if (needsNewContent) {
      if (item._content) {
        item._content.remove();
        item._elements.clear();
      }
      item._content = this._createElement("span");
      item._content.className = "urlbarView-row-inner";
      item.appendChild(item._content);
      if (item.result.type == UrlbarUtils.RESULT_TYPE.TIP) {
        this._createRowContentForTip(item);
      } else {
        this._createRowContent(item);
      }
    }

    if (
      result.type == UrlbarUtils.RESULT_TYPE.SEARCH &&
      !result.payload.keywordOffer &&
      !result.payload.inPrivateWindow
    ) {
      item.setAttribute("type", "search");
    } else if (result.type == UrlbarUtils.RESULT_TYPE.REMOTE_TAB) {
      item.setAttribute("type", "remotetab");
    } else if (result.type == UrlbarUtils.RESULT_TYPE.TAB_SWITCH) {
      item.setAttribute("type", "switchtab");
    } else if (result.type == UrlbarUtils.RESULT_TYPE.TIP) {
      item.setAttribute("type", "tip");
      this._updateRowForTip(item, result);
      return;
    } else if (result.source == UrlbarUtils.RESULT_SOURCE.BOOKMARKS) {
      item.setAttribute("type", "bookmark");
    } else {
      item.removeAttribute("type");
    }

    let favicon = item._elements.get("favicon");
    if (
      result.type == UrlbarUtils.RESULT_TYPE.SEARCH ||
      result.type == UrlbarUtils.RESULT_TYPE.KEYWORD
    ) {
      favicon.src = this._iconForSearchResult(result);
    } else {
      favicon.src = result.payload.icon || UrlbarUtils.ICON.DEFAULT;
    }

    if (result.payload.isPinned) {
      item.toggleAttribute("pinned", true);
    } else {
      item.removeAttribute("pinned");
    }

    let title = item._elements.get("title");
    this._addTextContentWithHighlights(
      title,
      result.title,
      result.titleHighlights
    );

    if (result.payload.tail && result.payload.tailOffsetIndex >= 0) {
      this._fillTailSuggestionPrefix(item, result);
      title.setAttribute("aria-label", result.payload.suggestion);
      item.toggleAttribute("tail-suggestion", true);
    } else {
      item.removeAttribute("tail-suggestion");
      title.removeAttribute("aria-label");
    }

    title._tooltip = result.title;
    if (title.hasAttribute("overflow")) {
      title.setAttribute("title", title._tooltip);
    }

    let tagsContainer = item._elements.get("tagsContainer");
    tagsContainer.textContent = "";
    if (result.payload.tags && result.payload.tags.length) {
      tagsContainer.append(
        ...result.payload.tags.map((tag, i) => {
          const element = this._createElement("span");
          element.className = "urlbarView-tag";
          this._addTextContentWithHighlights(
            element,
            tag,
            result.payloadHighlights.tags[i]
          );
          return element;
        })
      );
    }

    let action = "";
    let isVisitAction = false;
    let setURL = false;
    switch (result.type) {
      case UrlbarUtils.RESULT_TYPE.TAB_SWITCH:
        action = UrlbarUtils.strings.GetStringFromName("switchToTab2");
        setURL = true;
        break;
      case UrlbarUtils.RESULT_TYPE.REMOTE_TAB:
        action = result.payload.device;
        setURL = true;
        break;
      case UrlbarUtils.RESULT_TYPE.SEARCH:
        if (result.payload.inPrivateWindow) {
          if (result.payload.isPrivateEngine) {
            action = UrlbarUtils.strings.formatStringFromName(
              "searchInPrivateWindowWithEngine",
              [result.payload.engine]
            );
          } else {
            action = UrlbarUtils.strings.GetStringFromName(
              "searchInPrivateWindow"
            );
          }
        } else {
          action = UrlbarUtils.strings.formatStringFromName(
            "searchWithEngine",
            [result.payload.engine]
          );
        }
        break;
      case UrlbarUtils.RESULT_TYPE.KEYWORD:
        isVisitAction = result.payload.input.trim() == result.payload.keyword;
        break;
      case UrlbarUtils.RESULT_TYPE.OMNIBOX:
        action = result.payload.content;
        break;
      default:
        if (result.heuristic) {
          isVisitAction = true;
        } else {
          setURL = true;
        }
        break;
    }

    let url = item._elements.get("url");
    if (setURL) {
      item.setAttribute("has-url", "true");
      this._addTextContentWithHighlights(
        url,
        result.payload.displayUrl,
        result.payloadHighlights.displayUrl || []
      );
      url._tooltip = result.payload.displayUrl;
    } else {
      item.removeAttribute("has-url");
      url.textContent = "";
      url._tooltip = "";
    }
    if (url.hasAttribute("overflow")) {
      url.setAttribute("title", url._tooltip);
    }

    if (isVisitAction) {
      action = UrlbarUtils.strings.GetStringFromName("visit");
      title.setAttribute("isurl", "true");
    } else {
      title.removeAttribute("isurl");
    }
    item._elements.get("action").textContent = action;

    if (!title.hasAttribute("isurl")) {
      title.setAttribute("dir", "auto");
    } else {
      title.removeAttribute("dir");
    }

    item._elements.get("titleSeparator").hidden = !action && !setURL;
  }

  _iconForSearchResult(result, engineOverride = null) {
    return (
      (result.source == UrlbarUtils.RESULT_SOURCE.HISTORY &&
        UrlbarUtils.ICON.HISTORY) ||
      (engineOverride &&
        engineOverride.iconURI &&
        engineOverride.iconURI.spec) ||
      result.payload.icon ||
      UrlbarUtils.ICON.SEARCH_GLASS
    );
  }

  _updateRowForTip(item, result) {
    let favicon = item._elements.get("favicon");
    favicon.src = result.payload.icon || UrlbarUtils.ICON.TIP;
    favicon.id = item.id + "-icon";

    let title = item._elements.get("title");
    title.id = item.id + "-title";
    // Add-ons will provide text, rather than l10n ids.
    if (result.payload.textData) {
      this.document.l10n.setAttributes(
        title,
        result.payload.textData.id,
        result.payload.textData.args
      );
    } else {
      title.textContent = result.payload.text;
    }

    item._content.setAttribute("aria-labelledby", `${favicon.id} ${title.id}`);

    let tipButton = item._elements.get("tipButton");
    tipButton.id = item.id + "-tip-button";
    // Add-ons will provide buttonText, rather than l10n ids.
    if (result.payload.buttonTextData) {
      this.document.l10n.setAttributes(
        tipButton,
        result.payload.buttonTextData.id,
        result.payload.buttonTextData.args
      );
    } else {
      tipButton.textContent = result.payload.buttonText;
    }

    let helpIcon = item._elements.get("helpButton");
    helpIcon.id = item.id + "-tip-help";
    helpIcon.style.display = result.payload.helpUrl ? "" : "none";

    if (result.providerName == "UrlbarProviderSearchTips") {
      // For a11y, we treat search tips as alerts.  We use A11yUtils.announce
      // instead of role="alert" because role="alert" will only fire an alert
      // event when the alert (or something inside it) is the root of an
      // insertion.  In this case, the entire tip result gets inserted into the
      // a11y tree as a single insertion, so no alert event would be fired.
      this.window.A11yUtils.announce(result.payload.textData);
    }
  }

  _updateIndices() {
    for (let i = 0; i < this._rows.children.length; i++) {
      let item = this._rows.children[i];
      item.result.rowIndex = i;
    }
    let selectableElement = this._getFirstSelectableElement();
    let uiIndex = 0;
    while (selectableElement) {
      selectableElement.elementIndex = uiIndex++;
      selectableElement = this._getNextSelectableElement(selectableElement);
    }
  }

  _setRowVisibility(row, visible) {
    row.style.display = visible ? "" : "none";
    if (!visible && row.result.type != UrlbarUtils.RESULT_TYPE.TIP) {
      // Reset the overflow state of elements that can overflow in case their
      // content changes while they're hidden. When making the row visible
      // again, we'll get new overflow events if needed.
      this._setElementOverflowing(row._elements.get("title"), false);
      this._setElementOverflowing(row._elements.get("url"), false);
    }
  }

  /**
   * Returns true if a row or a descendant in the view is visible.
   *
   * @param {Element} element
   *   A row in the view or a descendant of the row.
   * @returns {boolean}
   *   True if `element` or `element`'s ancestor row is visible in the view.
   */
  _isElementVisible(element) {
    if (!element.classList.contains("urlbarView-row")) {
      element = element.closest(".urlbarView-row");
    }

    if (!element) {
      return false;
    }

    return element.style.display != "none";
  }

  _removeStaleRows() {
    let row = this._rows.lastElementChild;
    while (row) {
      let next = row.previousElementSibling;
      if (row.hasAttribute("stale")) {
        row.remove();
      } else {
        this._setRowVisibility(row, true);
      }
      row = next;
    }
    this._updateIndices();
  }

  _startRemoveStaleRowsTimer() {
    this._removeStaleRowsTimer = this.window.setTimeout(() => {
      this._removeStaleRowsTimer = null;
      this._removeStaleRows();
    }, UrlbarView.removeStaleRowsTimeout);
  }

  _cancelRemoveStaleRowsTimer() {
    if (this._removeStaleRowsTimer) {
      this.window.clearTimeout(this._removeStaleRowsTimer);
      this._removeStaleRowsTimer = null;
    }
  }

  _selectElement(item, { updateInput = true, setAccessibleFocus = true } = {}) {
    if (this._selectedElement) {
      this._selectedElement.toggleAttribute("selected", false);
      this._selectedElement.removeAttribute("aria-selected");
    }
    if (item) {
      item.toggleAttribute("selected", true);
      item.setAttribute("aria-selected", "true");
    }
    this._setAccessibleFocus(setAccessibleFocus && item);
    this._selectedElement = item;

    if (updateInput) {
      this.input.setValueFromResult(item?.result);
    }
  }

  /**
   * Returns the first selectable element in the view.
   *
   * @returns {Element} The first selectable element in the view.
   */
  _getFirstSelectableElement() {
    let firstElementChild = this._rows.firstElementChild;
    if (
      firstElementChild &&
      firstElementChild.result &&
      firstElementChild.result.type == UrlbarUtils.RESULT_TYPE.TIP
    ) {
      firstElementChild = firstElementChild._elements.get("tipButton");
    }
    return firstElementChild;
  }

  /**
   * Returns the last selectable element in the view.
   *
   * @returns {Element} The last selectable element in the view.
   */
  _getLastSelectableElement() {
    let lastElementChild = this._rows.lastElementChild;

    // We are only interested in visible elements.
    while (lastElementChild && !this._isElementVisible(lastElementChild)) {
      lastElementChild = this._getPreviousSelectableElement(lastElementChild);
    }

    if (
      lastElementChild.result &&
      lastElementChild.result.type == UrlbarUtils.RESULT_TYPE.TIP
    ) {
      lastElementChild = lastElementChild._elements.get("helpButton");
      if (lastElementChild.style.display == "none") {
        lastElementChild = this._getPreviousSelectableElement(lastElementChild);
      }
    }

    return lastElementChild;
  }

  /**
   * Returns the next selectable element after the parameter `element`.
   * @param {Element} element A selectable element in the view.
   * @returns {Element} The next selectable element after the parameter `element`.
   */
  _getNextSelectableElement(element) {
    let next;
    if (element.classList.contains("urlbarView-tip-button")) {
      next = element.closest(".urlbarView-row")._elements.get("helpButton");
      if (next.style.display == "none") {
        next = this._getNextSelectableElement(next);
      }
    } else if (element.classList.contains("urlbarView-tip-help")) {
      next = element.closest(".urlbarView-row").nextElementSibling;
    } else {
      next = element.nextElementSibling;
    }

    if (!next) {
      return null;
    }

    if (next.result && next.result.type == UrlbarUtils.RESULT_TYPE.TIP) {
      next = next._elements.get("tipButton");
    }

    return next;
  }

  /**
   * Returns the previous selectable element before the parameter `element`.
   * @param {Element} element A selectable element in the view.
   * @returns {Element} The previous selectable element before the parameter `element`.
   */
  _getPreviousSelectableElement(element) {
    let previous;
    if (element.classList.contains("urlbarView-tip-button")) {
      previous = element.closest(".urlbarView-row").previousElementSibling;
    } else if (element.classList.contains("urlbarView-tip-help")) {
      previous = element.closest(".urlbarView-row")._elements.get("tipButton");
    } else {
      previous = element.previousElementSibling;
    }

    if (!previous) {
      return null;
    }

    if (
      previous.result &&
      previous.result.type == UrlbarUtils.RESULT_TYPE.TIP
    ) {
      previous = previous._elements.get("helpButton");
      if (previous.style.display == "none") {
        previous = this._getPreviousSelectableElement(previous);
      }
    }

    return previous;
  }

  /**
   * Returns the currently selected row. Useful when this._selectedElement may be a
   * non-row element, such as a descendant element of RESULT_TYPE.TIP.
   *
   * @returns {Element}
   *   The currently selected row, or ancestor row of the currently selected item.
   *
   */
  _getSelectedRow() {
    if (!this.isOpen || !this._selectedElement) {
      return null;
    }
    let selected = this._selectedElement;

    if (!selected.classList.contains("urlbarView-row")) {
      // selected may be an element in a result group, like RESULT_TYPE.TIP.
      selected = selected.closest(".urlbarView-row");
    }

    return selected;
  }

  /**
   * @param {Element} element
   *   An element that is potentially a row or descendant of a row.
   * @returns {Element}
   *   The row containing `element`, or `element` itself if it is a row.
   */
  _getRowFromElement(element) {
    if (!this.isOpen || !element) {
      return null;
    }

    if (!element.classList.contains("urlbarView-row")) {
      element = element.closest(".urlbarView-row");
    }

    return element;
  }

  _setAccessibleFocus(item) {
    if (item) {
      this.input.inputField.setAttribute("aria-activedescendant", item.id);
    } else {
      this.input.inputField.removeAttribute("aria-activedescendant");
    }
  }

  /**
   * Adds text content to a node, placing substrings that should be highlighted
   * inside <em> nodes.
   *
   * @param {Node} parentNode
   *   The text content will be added to this node.
   * @param {string} textContent
   *   The text content to give the node.
   * @param {array} highlights
   *   The matches to highlight in the text.
   */
  _addTextContentWithHighlights(parentNode, textContent, highlights) {
    parentNode.textContent = "";
    if (!textContent) {
      return;
    }
    highlights = (highlights || []).concat([[textContent.length, 0]]);
    let index = 0;
    for (let [highlightIndex, highlightLength] of highlights) {
      if (highlightIndex - index > 0) {
        parentNode.appendChild(
          this.document.createTextNode(
            textContent.substring(index, highlightIndex)
          )
        );
      }
      if (highlightLength > 0) {
        let strong = this._createElement("strong");
        strong.textContent = textContent.substring(
          highlightIndex,
          highlightIndex + highlightLength
        );
        parentNode.appendChild(strong);
      }
      index = highlightIndex + highlightLength;
    }
  }

  /**
   * Adds markup for a tail suggestion prefix to a row.
   * @param {Node} item
   *   The node for the result row.
   * @param {UrlbarResult} result
   *   A UrlbarResult representing a tail suggestion.
   */
  _fillTailSuggestionPrefix(item, result) {
    let tailPrefixStrNode = item._elements.get("tailPrefixStr");
    let tailPrefixStr = result.payload.suggestion.substring(
      0,
      result.payload.tailOffsetIndex
    );
    tailPrefixStrNode.textContent = tailPrefixStr;

    let tailPrefixCharNode = item._elements.get("tailPrefixChar");
    tailPrefixCharNode.textContent = result.payload.tailPrefix;
  }

  _enableOrDisableOneOffSearches(enable = true) {
    if (enable) {
      this.oneOffSearchButtons.telemetryOrigin = "urlbar";
      this.oneOffSearchButtons.style.display = "";
      this.oneOffSearchButtons.textbox = this.input.inputField;
      this.oneOffSearchButtons.view = this;
    } else {
      this.oneOffSearchButtons.telemetryOrigin = null;
      this.oneOffSearchButtons.style.display = "none";
      this.oneOffSearchButtons.textbox = null;
      this.oneOffSearchButtons.view = null;
    }
  }

  _enableOrDisableRowWrap() {
    if (getBoundsWithoutFlushing(this.input.textbox).width < 650) {
      this._rows.setAttribute("wrap", "true");
    } else {
      this._rows.removeAttribute("wrap");
    }
  }

  _setElementOverflowing(element, overflowing) {
    element.toggleAttribute("overflow", overflowing);
    if (overflowing) {
      element.setAttribute("title", element._tooltip);
    } else {
      element.removeAttribute("title");
    }
  }

  /**
   * If the view is open and showing a single search tip, this method picks it
   * and closes the view.  This counts as an engagement, so this method should
   * only be called due to user interaction.
   *
   * @param {event} event
   *   The user-initiated event for the interaction.  Should not be null.
   * @returns {boolean}
   *   True if this method picked a tip, false otherwise.
   */
  _pickSearchTipIfPresent(event) {
    if (
      !this.isOpen ||
      !this._queryContext ||
      this._queryContext.results.length != 1
    ) {
      return false;
    }
    let result = this._queryContext.results[0];
    if (result.type != UrlbarUtils.RESULT_TYPE.TIP) {
      return false;
    }
    let tipButton = this._rows.firstElementChild.querySelector(
      ".urlbarView-tip-button"
    );
    if (!tipButton) {
      throw new Error("Expected a tip button");
    }
    this.input.pickElement(tipButton, event);
    return true;
  }

  // Event handlers below.

  _on_SelectedOneOffButtonChanged() {
    if (!this.isOpen || !this._queryContext) {
      return;
    }

    // Update all search suggestion results to use the newly selected engine, or
    // if no engine is selected, revert to their original engines.
    let engine =
      this.oneOffSearchButtons.selectedButton &&
      this.oneOffSearchButtons.selectedButton.engine;

    for (let item of this._rows.children) {
      let result = item.result;
      if (
        result.type != UrlbarUtils.RESULT_TYPE.SEARCH ||
        (!result.heuristic &&
          (!result.payload.suggestion || result.payload.isSearchHistory) &&
          (!result.payload.inPrivateWindow || result.payload.isPrivateEngine))
      ) {
        continue;
      }
      if (engine) {
        if (!result.payload.originalEngine) {
          result.payload.originalEngine = result.payload.engine;
        }
        result.payload.engine = engine.name;
      } else if (result.payload.originalEngine) {
        result.payload.engine = result.payload.originalEngine;
        delete result.payload.originalEngine;
      }
      // If a one-off button is the only selection, force the heuristic result
      // to show its action text, so the engine name is visible.
      if (result.heuristic && engine && !this.selectedElement) {
        item.setAttribute("show-action-text", "true");
      } else {
        item.removeAttribute("show-action-text");
      }
      if (!result.payload.inPrivateWindow) {
        let action = item.querySelector(".urlbarView-action");
        action.textContent = UrlbarUtils.strings.formatStringFromName(
          "searchWithEngine",
          [(engine && engine.name) || result.payload.engine]
        );
      }
      // If we just changed the engine from the original engine and it had an
      // icon, then make sure the result now uses the new engine's icon or
      // failing that the default icon.  If we changed it back to the original
      // engine, go back to the original or default icon.
      let favicon = item.querySelector(".urlbarView-favicon");
      if (engine && result.payload.icon) {
        favicon.src =
          (engine.iconURI && engine.iconURI.spec) ||
          UrlbarUtils.ICON.SEARCH_GLASS;
      } else if (!engine) {
        favicon.src = result.payload.icon || UrlbarUtils.ICON.SEARCH_GLASS;
      }
      favicon.src = this._iconForSearchResult(result, engine);
    }
  }

  _on_blur(event) {
    // If the view is open without the input being focused, it will not close
    // automatically when the window loses focus. We might be in this state
    // after a Search Tip is shown on an engine homepage.
    if (!UrlbarPrefs.get("ui.popup.disable_autohide")) {
      this.close();
    }
  }

  _on_mousedown(event) {
    if (event.button == 2) {
      // Ignore right clicks.
      return;
    }
    let element = this.getClosestSelectableElement(event.target);
    if (!element) {
      // Ignore clicks on elements that can't be selected/picked.
      return;
    }
    this._selectElement(element, { updateInput: false });
    this.controller.speculativeConnect(
      this.selectedResult,
      this._queryContext,
      "mousedown"
    );
  }

  _on_mouseup(event) {
    if (event.button == 2) {
      // Ignore right clicks.
      return;
    }
    let element = this.getClosestSelectableElement(event.target);
    if (!element) {
      // Ignore clicks on elements that can't be selected/picked.
      return;
    }
    this.input.pickElement(element, event);
  }

  _on_overflow(event) {
    if (
      event.detail == 1 &&
      (event.target.classList.contains("urlbarView-url") ||
        event.target.classList.contains("urlbarView-title"))
    ) {
      this._setElementOverflowing(event.target, true);
    }
  }

  _on_underflow(event) {
    if (
      event.detail == 1 &&
      (event.target.classList.contains("urlbarView-url") ||
        event.target.classList.contains("urlbarView-title"))
    ) {
      this._setElementOverflowing(event.target, false);
    }
  }

  _on_resize() {
    this._enableOrDisableRowWrap();
  }
}

UrlbarView.removeStaleRowsTimeout = DEFAULT_REMOVE_STALE_ROWS_TIMEOUT;

/**
 * Implements a QueryContext cache, working as a circular buffer, when a new
 * entry is added at the top, the last item is remove from the bottom.
 */
class QueryContextCache {
  /**
   * Constructor.
   * @param {number} size The number of entries to keep in the cache.
   */
  constructor(size) {
    this.size = size;
    this._cache = [];
  }

  /**
   * Adds a new entry to the cache.
   * @param {UrlbarQueryContext} queryContext The UrlbarQueryContext to add.
   * @note QueryContexts without a searchString or without results are ignored
   *       and not added.
   */
  put(queryContext) {
    let searchString = queryContext.searchString;
    if (!searchString || !queryContext.results.length) {
      return;
    }

    let index = this._cache.findIndex(e => e.searchString == searchString);
    if (index != -1) {
      if (this._cache[index] == queryContext) {
        return;
      }
      this._cache.splice(index, 1);
    }
    if (this._cache.unshift(queryContext) > this.size) {
      this._cache.length = this.size;
    }
  }

  get(searchString) {
    return this._cache.find(e => e.searchString == searchString);
  }
}