modules/hints.js

   1 /**
   2  * (C) Copyright 2007-2008 Jeremy Maitin-Shepard
   3  * (C) Copyright 2009-2010 John J. Foerch
   4  *
   5  * Portions of this file are derived from Vimperator,
   6  * (C) Copyright 2006-2007 Martin Stubenschrott.
   7  *
   8  * Use, modification, and distribution are subject to the terms specified in the
   9  * COPYING file.
  10 **/
  11
  12 define_variable("active_img_hint_background_color", "#88FF00",
  13     "Color for the active image hint background.");
  14
  15 define_variable("img_hint_background_color", "yellow",
  16     "Color for inactive image hint backgrounds.");
  17
  18 define_variable("active_hint_background_color", "#88FF00",
  19     "Color for the active hint background.");
  20
  21 define_variable("hint_background_color", "yellow",
  22     "Color for the inactive hint.");
  23
  24
  25 define_variable("hint_digits", null,
  26     "Null or a string of the digits to use as the counting base "+
  27     "for hint numbers, starting with the digit that represents zero "+
  28     "and ascending.  If null, base 10 will be used with the normal "+
  29     "hindu-arabic numerals.");
  30
  31
  32 /**
  33  * hints_enumerate is a generator of natural numbers in the base defined
  34  * by hint_digits.
  35  */
  36 function hints_enumerate () {
  37     var base = hint_digits.length;
  38     var n = [1];
  39     var p = 1;
  40     while (true) {
  41         yield n.map(function (x) hint_digits[x]).join("");
  42         var i = p-1;
  43         n[i]++;
  44         while (n[i] >= base && i > 0) {
  45             n[i] = 0;
  46             n[--i]++;
  47         }
  48         if (n[0] >= base) {
  49             n[0] = 0;
  50             n.unshift(1);
  51             p++;
  52         }
  53     }
  54 }
  55
  56 /**
  57  * hints_parse converts a string that represents a natural number to an
  58  * int.  When hint_digits is non-null, it defines the base for conversion.
  59  */
  60 function hints_parse (str) {
  61     if (hint_digits) {
  62         var base = hint_digits.length;
  63         var n = 0;
  64         for (var i = 0, p = str.length - 1; p >= 0; i++, p--) {
  65             n += hint_digits.indexOf(str[i]) * Math.pow(base, p);
  66         }
  67         return n;
  68     } else
  69         return parseInt(str);
  70 }
  71
  72 /**
  73  * Register hints style sheet
  74  */
  75 const hints_stylesheet = "chrome://conkeror-gui/content/hints.css";
  76 register_user_stylesheet(hints_stylesheet);
  77
  78
  79 function hints_simple_text_match (text, pattern) {
  80     var pos = text.indexOf(pattern);
  81     if (pos == -1)
  82         return false;
  83     return [pos, pos + pattern.length];
  84 }
  85
  86 define_variable('hints_text_match', hints_simple_text_match,
  87     "A function which takes a string and a pattern (another string) "+
  88     "and returns an array of [start, end] indices if the pattern was "+
  89     "found in the string, or false if it was not.");
  90
  91
  92 /**
  93  *   In the hints interaction, a node can be selected either by typing
  94  * the number of its associated hint, or by typing substrings of the
  95  * text content of the node.  In the case of selecting by text
  96  * content, multiple substrings can be given by separating them with
  97  * spaces.
  98  */
  99 function hint_manager (window, xpath_expr, focused_frame, focused_element) {
 100     this.window = window;
 101     this.hints = [];
 102     this.valid_hints = [];
 103     this.xpath_expr = xpath_expr;
 104     this.focused_frame = focused_frame;
 105     this.focused_element = focused_element;
 106     this.last_selected_hint = null;
 107
 108     // Generate
 109     this.generate_hints();
 110 }
 111 hint_manager.prototype = {
 112     constructor: hint_manager,
 113     current_hint_string: "",
 114     current_hint_number: -1,
 115
 116     /**
 117      * Create an initially hidden hint span element absolutely
 118      * positioned over each element that matches
 119      * hint_xpath_expression.  This is done recursively for all frames
 120      * and iframes.  Information about the resulting hints are also
 121      * stored in the hints array.
 122      */
 123     generate_hints: function () {
 124         var topwin = this.window;
 125         var top_height = topwin.innerHeight;
 126         var top_width = topwin.innerWidth;
 127         var hints = this.hints;
 128         var xpath_expr = this.xpath_expr;
 129         var focused_frame_hint = null, focused_element_hint = null;
 130         var focused_frame = this.focused_frame;
 131         var focused_element = this.focused_element;
 132
 133         function helper (window, offsetX, offsetY) {
 134             var win_height = window.height;
 135             var win_width = window.width;
 136
 137             // Bounds
 138             var minX = offsetX < 0 ? -offsetX : 0;
 139             var minY = offsetY < 0 ? -offsetY : 0;
 140             var maxX = offsetX + win_width > top_width ? top_width - offsetX : top_width;
 141             var maxY = offsetY + win_height > top_height ? top_height - offsetY : top_height;
 142
 143             var scrollX = window.scrollX;
 144             var scrollY = window.scrollY;
 145
 146             var doc = window.document;
 147             if (! doc.documentElement)
 148                 return;
 149             var res = doc.evaluate(xpath_expr, doc, xpath_lookup_namespace,
 150                                    Ci.nsIDOMXPathResult.UNORDERED_NODE_SNAPSHOT_TYPE,
 151                                    null /* existing results */);
 152
 153             var base_node = doc.createElementNS(XHTML_NS, "span");
 154             base_node.className = "__conkeror_hint";
 155
 156             var fragment = doc.createDocumentFragment();
 157             var rect, elem, text, node, show_text;
 158             for (var j = 0; j < res.snapshotLength; j++) {
 159                 elem = res.snapshotItem(j);
 160                 rect = elem.getBoundingClientRect();
 161                 if (elem instanceof Ci.nsIDOMHTMLAreaElement) {
 162                     rect = { top: rect.top,
 163                              left: rect.left,
 164                              bottom: rect.bottom,
 165                              right: rect.right };
 166                     try {
 167                         var coords = elem.getAttribute("coords")
 168                             .match(/^\D*(-?\d+)\D+(-?\d+)/);
 169                         if (coords.length == 3) {
 170                             rect.left += parseInt(coords[1]);
 171                             rect.top += parseInt(coords[2]);
 172                         }
 173                     } catch (e) {}
 174                 }
 175                 if (!rect || rect.left > maxX || rect.right < minX || rect.top > maxY || rect.bottom < minY)
 176                     continue;
 177                 let style = topwin.getComputedStyle(elem, "");
 178                 if (style.display == "none" || style.visibility == "hidden")
 179                     continue;
 180                 if (! (elem instanceof Ci.nsIDOMHTMLAreaElement))
 181                     rect = elem.getClientRects()[0];
 182                 if (!rect)
 183                     continue;
 184                 var nchildren = elem.childNodes.length;
 185                 if (elem instanceof Ci.nsIDOMHTMLAnchorElement &&
 186                     rect.width == 0 && rect.height == 0)
 187                 {
 188                     for (var c = 0; c < nchildren; ++c) {
 189                         var cc = elem.childNodes.item(c);
 190                         if (cc.getBoundingClientRect) {
 191                             rect = cc.getBoundingClientRect();
 192                             break;
 193                         }
 194                     }
 195                 }
 196                 show_text = false;
 197                 if (elem instanceof Ci.nsIDOMHTMLInputElement || elem instanceof Ci.nsIDOMHTMLTextAreaElement)
 198                     text = elem.value;
 199                 else if (elem instanceof Ci.nsIDOMHTMLSelectElement) {
 200                     if (elem.selectedIndex >= 0)
 201                         text = elem.item(elem.selectedIndex).text;
 202                     else
 203                         text = "";
 204                 } else if (elem instanceof Ci.nsIDOMHTMLFrameElement) {
 205                     text = elem.name ? elem.name : "";
 206                 } else if (/^\s*$/.test(elem.textContent) &&
 207                            nchildren == 1 &&
 208                            elem.childNodes.item(0) instanceof Ci.nsIDOMHTMLImageElement) {
 209                     text = elem.childNodes.item(0).alt;
 210                     show_text = true;
 211                 } else
 212                     text = elem.textContent;
 213
 214                 node = base_node.cloneNode(true);
 215                 node.style.left = (rect.left + scrollX) + "px";
 216                 node.style.top = (rect.top + scrollY) + "px";
 217                 fragment.appendChild(node);
 218
 219                 let hint = { text: text,
 220                              ltext: text.toLowerCase(),
 221                              elem: elem,
 222                              hint: node,
 223                              img_hint: null,
 224                              visible: false,
 225                              show_text: show_text };
 226                 if (elem.style) {
 227                     hint.saved_color = elem.style.color;
 228                     hint.saved_bgcolor = elem.style.backgroundColor;
 229                 }
 230                 hints.push(hint);
 231
 232                 if (elem == focused_element)
 233                     focused_element_hint = hint;
 234                 else if ((elem instanceof Ci.nsIDOMHTMLFrameElement ||
 235                           elem instanceof Ci.nsIDOMHTMLIFrameElement) &&
 236                          elem.contentWindow == focused_frame)
 237                     focused_frame_hint = hint;
 238             }
 239             doc.documentElement.appendChild(fragment);
 240
 241             /* Recurse into any IFRAME or FRAME elements */
 242             var frametag = "frame";
 243             while (true) {
 244                 var frames = doc.getElementsByTagName(frametag);
 245                 for (var i = 0, nframes = frames.length; i < nframes; ++i) {
 246                     elem = frames[i];
 247                     rect = elem.getBoundingClientRect();
 248                     if (!rect || rect.left > maxX || rect.right < minX || rect.top > maxY || rect.bottom < minY)
 249                         continue;
 250                     helper(elem.contentWindow, offsetX + rect.left, offsetY + rect.top);
 251                 }
 252                 if (frametag == "frame") frametag = "iframe"; else break;
 253             }
 254         }
 255         helper(topwin, 0, 0);
 256         this.last_selected_hint = focused_element_hint || focused_frame_hint;
 257     },
 258
 259     /* Updates valid_hints and also re-numbers and re-displays all hints. */
 260     update_valid_hints: function () {
 261         this.valid_hints = [];
 262         var cur_number = 1;
 263         if (hint_digits)
 264             var number_generator = hints_enumerate();
 265         var active_number = this.current_hint_number;
 266         var tokens = this.current_hint_string.split(" ");
 267         var case_sensitive = (this.current_hint_string !=
 268                               this.current_hint_string.toLowerCase());
 269         var rect, text, img_hint, doc, scrollX, scrollY;
 270     outer:
 271         for (var i = 0, h; (h = this.hints[i]); ++i) {
 272             if (case_sensitive)
 273                 text = h.text;
 274             else
 275                 text = h.ltext;
 276             for (var j = 0, ntokens = tokens.length; j < ntokens; ++j) {
 277                 if (! hints_text_match(text, tokens[j])) {
 278                     if (h.visible) {
 279                         h.visible = false;
 280                         h.hint.style.display = "none";
 281                         if (h.img_hint)
 282                             h.img_hint.style.display = "none";
 283                         if (h.saved_color != null) {
 284                             h.elem.style.backgroundColor = h.saved_bgcolor;
 285                             h.elem.style.color = h.saved_color;
 286                         }
 287                     }
 288                     continue outer;
 289                 }
 290             }
 291
 292             h.visible = true;
 293
 294             if (h == this.last_selected_hint && active_number == -1)
 295                 this.current_hint_number = active_number = cur_number;
 296
 297             var img_elem = null;
 298
 299             if (text == "" && h.elem.firstChild &&
 300                 h.elem.firstChild instanceof Ci.nsIDOMHTMLImageElement)
 301                 img_elem = h.elem.firstChild;
 302             else if (h.elem instanceof Ci.nsIDOMHTMLImageElement)
 303                 img_elem = h.elem;
 304
 305             if (img_elem) {
 306                 if (!h.img_hint) {
 307                     rect = img_elem.getBoundingClientRect();
 308                     if (rect) {
 309                         doc = h.elem.ownerDocument;
 310                         scrollX = doc.defaultView.scrollX;
 311                         scrollY = doc.defaultView.scrollY;
 312                         img_hint = doc.createElementNS(XHTML_NS, "span");
 313                         img_hint.className = "__conkeror_img_hint";
 314                         img_hint.style.left = (rect.left + scrollX) + "px";
 315                         img_hint.style.top = (rect.top + scrollY) + "px";
 316                         img_hint.style.width = (rect.right - rect.left) + "px";
 317                         img_hint.style.height = (rect.bottom - rect.top) + "px";
 318                         h.img_hint = img_hint;
 319                         doc.documentElement.appendChild(img_hint);
 320                     } else
 321                         img_elem = null;
 322                 }
 323                 if (img_elem) {
 324                     var bgcolor = (active_number == cur_number) ?
 325                         active_img_hint_background_color : img_hint_background_color;
 326                     h.img_hint.style.backgroundColor = bgcolor;
 327                     h.img_hint.style.display = "inline";
 328                 }
 329             }
 330
 331             if (!h.img_hint && h.elem.style)
 332                 h.elem.style.backgroundColor = (active_number == cur_number) ?
 333                     active_hint_background_color : hint_background_color;
 334
 335             if (h.elem.style)
 336                 h.elem.style.color = "black";
 337
 338             var label = "";
 339             if (hint_digits)
 340                 label = number_generator.next();
 341             else
 342                 label += cur_number;
 343             if (h.elem instanceof Ci.nsIDOMHTMLFrameElement) {
 344                 label +=  " " + text;
 345             } else if (h.show_text && !/^\s*$/.test(text)) {
 346                 let substrs = [[0,4]];
 347                 for (j = 0; j < ntokens; ++j) {
 348                     let m = hints_text_match(text, tokens[j]);
 349                     if (m == false) continue;
 350                     splice_range(substrs, m[0], m[1] + 2);
 351                 }
 352                 label += " " + substrs.map(function (x) {
 353                     return text.substring(x[0],Math.min(x[1], text.length));
 354                 }).join("..") + "..";
 355             }
 356             h.hint.textContent = label;
 357             h.hint.style.display = "inline";
 358             this.valid_hints.push(h);
 359             cur_number++;
 360         }
 361
 362         if (active_number == -1)
 363             this.select_hint(1);
 364     },
 365
 366     select_hint: function (index) {
 367         var old_index = this.current_hint_number;
 368         if (index == old_index)
 369             return;
 370         var vh = this.valid_hints;
 371         var vl = this.valid_hints.length;
 372         if (old_index >= 1 && old_index <= vl) {
 373             var h = vh[old_index - 1];
 374             if (h.img_hint)
 375                 h.img_hint.style.backgroundColor = img_hint_background_color;
 376             if (h.elem.style)
 377                 h.elem.style.backgroundColor = hint_background_color;
 378         }
 379         this.current_hint_number = index;
 380         this.last_selected_hint = null;
 381         if (index >= 1 && index <= vl) {
 382             h = vh[index - 1];
 383             if (h.img_hint)
 384                 h.img_hint.style.backgroundColor = active_img_hint_background_color;
 385             if (h.elem.style)
 386                 h.elem.style.backgroundColor = active_hint_background_color;
 387             this.last_selected_hint = h;
 388         }
 389     },
 390
 391     hide_hints: function () {
 392         for (var i = 0, h; h = this.hints[i]; ++i) {
 393             if (h.visible) {
 394                 h.visible = false;
 395                 if (h.saved_color != null) {
 396                     h.elem.style.color = h.saved_color;
 397                     h.elem.style.backgroundColor = h.saved_bgcolor;
 398                 }
 399                 if (h.img_hint)
 400                     h.img_hint.style.display = "none";
 401                 h.hint.style.display = "none";
 402             }
 403         }
 404     },
 405
 406     remove: function () {
 407         for (var i = 0, h; h = this.hints[i]; ++i) {
 408             if (h.visible && h.saved_color != null) {
 409                 h.elem.style.color = h.saved_color;
 410                 h.elem.style.backgroundColor = h.saved_bgcolor;
 411             }
 412             if (h.img_hint)
 413                 h.img_hint.parentNode.removeChild(h.img_hint);
 414             h.hint.parentNode.removeChild(h.hint);
 415         }
 416         this.hints = [];
 417         this.valid_hints = [];
 418     }
 419 };
 420
 421 /**
 422  * Display the URL and other information for the currently selected node.
 423  */
 424 function hints_minibuffer_annotation (hints, window) {
 425     this.hints = hints;
 426     this.input = window.minibuffer.input_element;
 427 }
 428 hints_minibuffer_annotation.prototype = {
 429     constructor: hints_minibuffer_annotation,
 430
 431     update: function () {
 432         var s = [];
 433         if (this.hints.manager && this.hints.manager.last_selected_hint) {
 434             var elem = this.hints.manager.last_selected_hint.elem;
 435             if (elem.hasAttribute("onmousedown") ||
 436                 elem.hasAttribute("onclick"))
 437             {
 438                 s.push("[script]");
 439             }
 440             var tag = elem.localName.toLowerCase();
 441             if ((tag == "input" || tag == "button") &&
 442                 elem.type == "submit" && elem.form && elem.form.action)
 443             {
 444                 s.push((elem.form.method || "GET").toUpperCase() + ":" +
 445                        elem.form.action);
 446             } else {
 447                 try {
 448                     var spec = load_spec(elem);
 449                     var uri = load_spec_uri_string(spec);
 450                     if (uri)
 451                         s.push(uri);
 452                 } catch (e) {}
 453             }
 454         }
 455         this.input.annotation = s.join(" ");
 456     },
 457
 458     load: function () {
 459         this.input.annotate = true;
 460         this.update();
 461     },
 462
 463     unload: function () {
 464         this.input.annotate = false;
 465     }
 466 };
 467
 468 define_global_mode("hints_minibuffer_annotation_mode",
 469     function enable () {
 470         minibuffer_annotation_mode.register(hints_minibuffer_annotation_mode);
 471     },
 472     function disable () {
 473         minibuffer_annotation_mode.unregister(hints_minibuffer_annotation_mode);
 474     },
 475     $doc = "Display the URL associated with the currently selected hint in "+
 476            "a minibuffer annotation.\nThis mode is most useful when "+
 477            "hints_auto_exit_delay is long or disabled.");
 478
 479 hints_minibuffer_annotation_mode(true);
 480
 481 /**
 482  * keyword arguments:
 483  *
 484  * $prompt
 485  * $callback
 486  * $abort_callback
 487  */
 488 define_keywords("$keymap", "$auto", "$hint_xpath_expression", "$multiple");
 489 function hints_minibuffer_state (minibuffer, continuation, buffer) {
 490     keywords(arguments, $keymap = hint_keymap, $auto);
 491     basic_minibuffer_state.call(this, minibuffer, $prompt = arguments.$prompt,
 492                                 $keymap = arguments.$keymap);
 493     if (hints_minibuffer_annotation_mode_enabled)
 494         this.hints_minibuffer_annotation = new hints_minibuffer_annotation(this, buffer.window);
 495     this.original_prompt = arguments.$prompt;
 496     this.continuation = continuation;
 497     this.auto_exit = arguments.$auto ? true : false;
 498     this.xpath_expr = arguments.$hint_xpath_expression;
 499     this.auto_exit_timer_ID = null;
 500     this.multiple = arguments.$multiple;
 501     this.focused_element = buffer.focused_element;
 502     this.focused_frame = buffer.focused_frame;
 503 }
 504 hints_minibuffer_state.prototype = {
 505     constructor: hints_minibuffer_state,
 506     __proto__: basic_minibuffer_state.prototype,
 507     manager: null,
 508     typed_string: "",
 509     typed_number: "",
 510     load: function () {
 511         basic_minibuffer_state.prototype.load.call(this);
 512         if (!this.manager) {
 513             var buf = this.minibuffer.window.buffers.current;
 514             this.manager = new hint_manager(buf.top_frame, this.xpath_expr,
 515                                             this.focused_frame, this.focused_element);
 516         }
 517         this.manager.update_valid_hints();
 518         if (this.hints_minibuffer_annotation)
 519             this.hints_minibuffer_annotation.load();
 520     },
 521     clear_auto_exit_timer: function () {
 522         var window = this.minibuffer.window;
 523         if (this.auto_exit_timer_ID != null) {
 524             window.clearTimeout(this.auto_exit_timer_ID);
 525             this.auto_exit_timer_ID = null;
 526         }
 527     },
 528     unload: function () {
 529         this.clear_auto_exit_timer();
 530         this.manager.hide_hints();
 531         if (this.hints_minibuffer_annotation)
 532             this.hints_minibuffer_annotation.unload();
 533         basic_minibuffer_state.prototype.unload.call(this);
 534     },
 535     destroy: function () {
 536         this.clear_auto_exit_timer();
 537         this.manager.remove();
 538         if (this.hints_minibuffer_annotation)
 539             this.hints_minibuffer_annotation.unload();
 540         basic_minibuffer_state.prototype.destroy.call(this);
 541     },
 542     update_minibuffer: function (m) {
 543         if (this.typed_number.length > 0)
 544             m.prompt = this.original_prompt + " #" + this.typed_number;
 545         else
 546             m.prompt = this.original_prompt;
 547         if (this.hints_minibuffer_annotation)
 548             this.hints_minibuffer_annotation.update();
 549     },
 550
 551     handle_auto_exit: function (ambiguous) {
 552         var window = this.minibuffer.window;
 553         var num = this.manager.current_hint_number;
 554         if (!this.auto_exit)
 555             return;
 556         let s = this;
 557         let delay = ambiguous ? hints_ambiguous_auto_exit_delay : hints_auto_exit_delay;
 558         if (delay > 0)
 559             this.auto_exit_timer_ID = window.setTimeout(function () { hints_exit(window, s); },
 560                                                         delay);
 561     },
 562
 563     handle_input: function (m) {
 564         this.clear_auto_exit_timer();
 565         this.typed_number = "";
 566         this.typed_string = m._input_text;
 567         this.manager.current_hint_string = this.typed_string;
 568         this.manager.current_hint_number = -1;
 569         this.manager.update_valid_hints();
 570         if (this.manager.valid_hints.length == 1)
 571             this.handle_auto_exit(false /* unambiguous */);
 572         else if (this.manager.valid_hints.length > 1)
 573         this.handle_auto_exit(true /* ambiguous */);
 574         this.update_minibuffer(m);
 575     }
 576 };
 577
 578 define_variable("hints_auto_exit_delay", 0,
 579     "Delay (in milliseconds) after the most recent key stroke before a "+
 580     "sole matching element is automatically selected.  When zero, "+
 581     "automatic selection is disabled.  A value of 500 is a good "+
 582     "starting point for an average-speed typist.");
 583
 584 define_variable("hints_ambiguous_auto_exit_delay", 0,
 585     "Delay (in milliseconds) after the most recent key stroke before the "+
 586     "first of an ambiguous match is automatically selected.  If this is "+
 587     "set to 0, automatic selection in ambiguous matches is disabled.");
 588
 589
 590 define_key_match_predicate("match_hint_digit", "hint digit",
 591     function (e) {
 592         if (e.type != "keypress")
 593             return false;
 594         if (e.charCode == 48) //0 is special
 595             return true;
 596         if (hint_digits) {
 597             if (hint_digits.indexOf(String.fromCharCode(e.charCode)) > -1)
 598                 return true;
 599         } else if (e.charCode >= 49 && e.charCode <= 57)
 600             return true;
 601         return false;
 602     });
 603
 604 interactive("hints-handle-number",
 605     "This is the handler for numeric keys in hinting mode.  Normally, "+
 606     "that means '1' through '9' and '0', but the numeric base (and digits) "+
 607     "can be configured via the user variable 'hint_digits'.  No matter "+
 608     "what numeric base is in effect, the character '0' is special, and "+
 609     "will always be treated as a number 0, translated into the current "+
 610     "base if necessary.",
 611     function (I) {
 612         let s = I.minibuffer.check_state(hints_minibuffer_state);
 613         s.clear_auto_exit_timer();
 614         var ch = String.fromCharCode(I.event.charCode);
 615         if (hint_digits && ch == "0")
 616             ch = hint_digits[0];
 617         var auto_exit_ambiguous = null; // null -> no auto exit; false -> not ambiguous; true -> ambiguous
 618         s.typed_number += ch;
 619         s.manager.select_hint(hints_parse(s.typed_number));
 620         var num = s.manager.current_hint_number;
 621         if (num > 0 && num <= s.manager.valid_hints.length)
 622             auto_exit_ambiguous = num * 10 > s.manager.valid_hints.length ? false : true;
 623         else if (num == 0) {
 624             if (!s.multiple) {
 625                 hints_exit(I.window, s);
 626                 return;
 627             }
 628             auto_exit_ambiguous = false;
 629         }
 630         if (auto_exit_ambiguous !== null)
 631             s.handle_auto_exit(auto_exit_ambiguous);
 632         s.update_minibuffer(I.minibuffer);
 633     });
 634
 635 function hints_backspace (window, s) {
 636     let m = window.minibuffer;
 637     s.clear_auto_exit_timer();
 638     var l = s.typed_number.length;
 639     if (l > 0) {
 640         s.typed_number = s.typed_number.substring(0, --l);
 641         var num = l > 0 ? hints_parse(s.typed_number) : 1;
 642         s.manager.select_hint(num);
 643     } else if (s.typed_string.length > 0) {
 644         call_builtin_command(window, 'cmd_deleteCharBackward');
 645         s.typed_string = m._input_text;
 646         //m._set_selection();
 647         s.manager.current_hint_string = s.typed_string;
 648         s.manager.current_hint_number = -1;
 649         s.manager.update_valid_hints();
 650     }
 651     s.update_minibuffer(m);
 652 }
 653 interactive("hints-backspace", null,
 654     function (I) {
 655         hints_backspace(I.window, I.minibuffer.check_state(hints_minibuffer_state));
 656     });
 657
 658 function hints_next (window, s, count) {
 659     s.clear_auto_exit_timer();
 660     s.typed_number = "";
 661     var cur = s.manager.current_hint_number - 1;
 662     var vh = s.manager.valid_hints;
 663     var vl = s.manager.valid_hints.length;
 664     if (vl > 0) {
 665         cur = (cur + count) % vl;
 666         if (cur < 0)
 667             cur += vl;
 668         s.manager.select_hint(cur + 1);
 669     }
 670     s.update_minibuffer(window.minibuffer);
 671 }
 672 interactive("hints-next", null,
 673     function (I) {
 674         hints_next(I.window, I.minibuffer.check_state(hints_minibuffer_state), I.p);
 675     });
 676
 677 interactive("hints-previous", null,
 678     function (I) {
 679         hints_next(I.window, I.minibuffer.check_state(hints_minibuffer_state), -I.p);
 680     });
 681
 682 function hints_exit (window, s) {
 683     var cur = s.manager.current_hint_number;
 684     var elem = null;
 685     if (cur > 0 && cur <= s.manager.valid_hints.length)
 686         elem = s.manager.valid_hints[cur - 1].elem;
 687     else if (cur == 0)
 688         elem = window.buffers.current.top_frame;
 689     if (elem !== null) {
 690         var c = s.continuation;
 691         delete s.continuation;
 692         window.minibuffer.pop_state();
 693         if (c)
 694             c(elem);
 695     }
 696 }
 697
 698 interactive("hints-exit", null,
 699     function (I) {
 700         hints_exit(I.window, I.minibuffer.check_state(hints_minibuffer_state));
 701     });
 702
 703 interactive("hints-quote-next", null,
 704     function (I) {
 705         I.overlay_keymap = hint_quote_next_keymap;
 706     },
 707     $prefix);
 708
 709
 710 define_keywords("$buffer");
 711 minibuffer.prototype.read_hinted_element = function () {
 712     keywords(arguments);
 713     var buf = arguments.$buffer;
 714     var s = new hints_minibuffer_state(this, (yield CONTINUATION), buf, forward_keywords(arguments));
 715     this.push_state(s);
 716     var result = yield SUSPEND;
 717     yield co_return(result);
 718 };
 719
 720 provide("hints");