matitaB/matita/matitaweb.js

   1 var locked;
   2 var unlocked;
   3 var workarea;
   4 var scriptcell;
   5 var goalcell;
   6 var goals;
   7 var goalview;
   8 var filename;
   9 var logarea;
  10 var advanceButton;
  11 var retractButton;
  12 var cursorButton;
  13 var bottomButton;
  14 var dialogBox;
  15 var dialogTitle;
  16 var dialogContent;
  17 var metasenv = "";
  18 var lockedbackup = "";
  19
  20 function initialize()
  21 {
  22   if (readCookie("session") == null) {
  23     window.location = "/login.html"
  24   } else {
  25     locked = document.getElementById("locked");
  26     unlocked = document.getElementById("unlocked");
  27     workarea = document.getElementById("workarea");
  28     scriptcell = document.getElementById("scriptcell");
  29     goalcell = document.getElementById("goalcell");
  30     goals = document.getElementById("goals");
  31     goalview = document.getElementById("goalview");
  32     filename = document.getElementById("filename");
  33     logarea = document.getElementById("logarea");
  34     advanceButton = document.getElementById("advance");
  35     retractButton = document.getElementById("retract");
  36     cursorButton = document.getElementById("cursor");
  37     bottomButton = document.getElementById("bottom");
  38     dialogBox = document.getElementById("dialogBox");
  39     dialogTitle = document.getElementById("dialogTitle");
  40     dialogContent = document.getElementById("dialogContent");
  41
  42     // hide sequent view at start
  43     hideSequent();
  44
  45     // initialize keyboard events in the unlocked script
  46     init_keyboard(unlocked);
  47   }
  48 }
  49
  50 function init_keyboard(target)
  51 {
  52     if (target.addEventListener)
  53     {
  54 //       target.addEventListener("keydown",keydown,false);
  55        target.addEventListener("keypress",keypress,false);
  56 //       target.addEventListener("keyup",keyup,false);
  57 //       target.addEventListener("textInput",textinput,false);
  58     }
  59     else if (target.attachEvent)
  60     {
  61 //       target.attachEvent("onkeydown", keydown);
  62        target.attachEvent("onkeypress", keypress);
  63 //       target.attachEvent("onkeyup", keyup);
  64 //       target.attachEvent("ontextInput", textinput);
  65     }
  66     else
  67     {
  68 //       target.onkeydown= keydown;
  69        target.onkeypress= keypress;
  70 //       target.onkeyup= keyup;
  71 //       target.ontextinput= textinput;   // probably doesn't work
  72     }
  73
  74 }
  75
  76 function keyval(n)
  77 {
  78     if (n == null) return 'undefined';
  79     var s= '' + n;
  80     if (n >= 32 && n < 127) s+= ' (' + String.fromCharCode(n) + ')';
  81     while (s.length < 9) s+= ' ';
  82     return s;
  83 }
  84
  85 function string_of_key(n)
  86 {
  87     if (n == null) return 'undefined';
  88     return String.fromCharCode(n);
  89 }
  90
  91 function pressmesg(w,e)
  92 {
  93    debug(w + '  keyCode=' + keyval(e.keyCode) +
  94                  ' which=' + keyval(e.which) +
  95                  ' charCode=' + keyval(e.charCode) +
  96                  '\n          shiftKey='+e.shiftKey
  97               + ' ctrlKey='+e.ctrlKey
  98               + ' altKey='+e.altKey
  99               + ' metaKey='+e.metaKey);
 100 }
 101
 102 function suppressdefault(e,flag)
 103 {
 104    if (flag)
 105    {
 106        if (e.preventDefault) e.preventDefault();
 107        if (e.stopPropagation) e.stopPropagation();
 108    }
 109    return !flag;
 110 }
 111
 112 function restoreSelection(adjust) {
 113     unlocked.focus();
 114     if (savedRange != null) {
 115         if (window.getSelection)//non IE and there is already a selection
 116         {
 117             var s = window.getSelection();
 118             if (s.rangeCount > 0)
 119                 s.removeAllRanges();
 120             range = document.createRange();
 121             range.setStart(savedsc,savedso + adjust);
 122             range.collapse(true);
 123             s.addRange(range);
 124         }
 125         else
 126             if (document.createRange)//non IE and no selection
 127             {
 128                 window.getSelection().addRange(savedRange);
 129             }
 130             else
 131                 if (document.selection)//IE
 132                 {
 133                     savedRange.select();
 134                 }
 135     }
 136 }
 137
 138 function lookup_tex(texmacro)
 139 {
 140   texmacro = texmacro.substring(1);
 141   return unescape(macro2utf8[texmacro]);
 142 }
 143
 144 function keypress(e)
 145 {
 146    if (!e) e= event;
 147    pressmesg('keypress',e);
 148    var s = string_of_key(e.charCode);
 149    if (s == " ") {
 150         j = getCursorPos();
 151         i = unlocked.innerHTML.lastIndexOf('\\',j);
 152         if (i >= 0) {
 153           match = unlocked.innerHTML.substring(i,j);
 154           pre = unlocked.innerHTML.substring(0,i);
 155           post = unlocked.innerHTML.substring(j);
 156
 157           sym = lookup_tex(match);
 158           if (typeof sym != "undefined") {
 159              len1 = unlocked.innerText.length;
 160              unlocked.innerHTML = pre + sym + post;
 161              len2 = unlocked.innerText.length;
 162              restoreSelection(len2 - len1);
 163              return suppressdefault(e,true);
 164           }
 165           else {
 166              // restoreSelection(0);
 167              return suppressdefault(e,false);
 168           }
 169         }
 170         else return suppressdefault(e,false);
 171    } else {
 172         return suppressdefault(e,false);
 173    }
 174 }
 175
 176 function debug(txt)
 177 {
 178         // internet explorer (v.9) doesn't work with innerHTML
 179         // but google chrome's innerText is, in a sense, "write only"
 180         // what should we do?
 181         // logarea.innerText = txt + "\n" + logarea.innerText;
 182         logarea.innerHTML = txt + "\n" + logarea.innerHTML;
 183 }
 184
 185 function listhd(l)
 186 {
 187         ar = l.split("#");
 188         debug("hd of '" + l + "' = '" + ar[0] + "'");
 189         return (ar[0]);
 190 }
 191
 192 function listtl(l)
 193 {
 194         i = l.indexOf("#");
 195         tl = l.substr(i+1);
 196         debug("tl of '" + l + "' = '" + tl + "'");
 197         return (tl);
 198 }
 199
 200 function listcons(x,l)
 201 {
 202         debug("cons '" + x + "' on '" + l + "'");
 203         return (x + "#" + l);
 204 }
 205
 206 function listnil()
 207 {
 208         return ("");
 209 }
 210
 211 function is_nil(l)
 212 {
 213         return (l == "");
 214 }
 215
 216 function fold_left (f,acc,l)
 217 {
 218         if (is_nil(l))
 219            { debug("'" + l + "' is fold end");
 220            return (acc); }
 221         else
 222            { debug("'" + l + "' is fold cons");
 223              return(fold_left (f,f(acc,(listhd(l))),listtl(l))); }
 224 }
 225
 226 function listiter (f,l)
 227 {
 228         if (is_nil(l))
 229         { debug("'" + l + "' is nil");
 230            return;
 231         }
 232         else
 233         {
 234            debug("'" + l + "' is not nil");
 235            f(listhd(l));
 236            listiter(f,listtl(l));
 237         }
 238 }
 239
 240 function listmap (f,l)
 241 {
 242         debug("listmap on " + l);
 243         if (is_nil(l))
 244            { debug("returning listnil");
 245              return(listnil());
 246            }
 247         else
 248            { debug("cons f(hd) map(f,tl)");
 249              return(f(listhd(l)) + "#" + listmap(f,listtl(l)));
 250            }
 251 }
 252
 253 var statements = listnil();
 254
 255 var goalarray;
 256 var metalist = listnil();
 257
 258 function pairmap (f,p)
 259 {
 260   debug("pairmap of '" + p + "'");
 261   ar = p.split("|");
 262   return (f(ar[0],ar[1]));
 263 }
 264
 265 function tripletmap (f,p)
 266 {
 267   debug("tripletmap of '" + p + "'");
 268   ar = p.split("|");
 269   return (f(ar[0],ar[1],ar[2]));
 270 }
 271
 272 function fst (p)
 273 {
 274   debug("fst");
 275   return (pairmap (function (a,b) { return (a); }, p));
 276 }
 277
 278 function p13 (p)
 279 {
 280   debug("p13");
 281   return (tripletmap (function (a,b,c) { return (a); }, p));
 282 }
 283
 284 function p23 (p)
 285 {
 286   debug("p23");
 287   return (tripletmap (function (a,b,c) { return (b); }, p));
 288 }
 289
 290 function p33 (p)
 291 {
 292   debug("f33");
 293   return (tripletmap (function (a,b,c) { return (c); }, p));
 294 }
 295
 296 function populate_goalarray(menv)
 297 {
 298   debug("metasenv.length = " + menv.length);
 299   if (menv.length == 0) {
 300       try {
 301           hideSequent();
 302       } catch (err) { };
 303   } else {
 304       showSequent();
 305       goalarray = new Array();
 306       metalist = listnil();
 307       var tmp_goallist = "";
 308       for (i = 0; i < menv.length; i++) {
 309         metano = menv[i].getAttribute("number");
 310         metaname = menv[i].childNodes[0].childNodes[0].data;
 311         goal = menv[i].childNodes[1].childNodes[0].data;
 312         debug ("found meta n. " + metano);
 313         debug ("found goal\nBEGIN" + goal + "\nEND");
 314         goalarray[metano] = goal;
 315         tmp_goallist = " <A href=\"javascript:switch_goal(" + metano + ")\">" + metaname + "</A>" + tmp_goallist;
 316         metalist = listcons(metano,metalist);
 317         debug ("goalarray[\"" + metano + "\"] = " + goalarray[metano]);
 318       }
 319       goals.innerHTML = tmp_goallist;
 320       debug("new metalist is '" + metalist + "'");
 321       if (is_nil(metalist)) {
 322         switch_goal();
 323       }
 324       else {
 325         switch_goal(listhd(metalist));
 326       }
 327   }
 328 }
 329
 330 function switch_goal(meta)
 331 {
 332   if (typeof meta == "undefined") {
 333     goalview.innerHTML = "";
 334   }
 335   else {
 336     debug("switch_goal " + meta + "\n" + goalarray[meta]);
 337     goalview.innerHTML = "<B>Goal ?" + meta + ":</B>\n\n" + goalarray[meta];
 338   }
 339 }
 340
 341 // the following is used to avoid escaping unicode, which results in
 342 // the server being unable to unescape the string
 343 String.prototype.sescape = function() {
 344         var patt1 = /%/gi;
 345         var patt2 = /=/gi;
 346         var patt3 = /&/gi;
 347         var patt4 = /\+/gi;
 348         var result = this;
 349         result = result.replace(patt1,"%25");
 350         result = result.replace(patt2,"%3D");
 351         result = result.replace(patt3,"%26");
 352         result = result.replace(patt4,"%2B");
 353         return (result);
 354 }
 355
 356 String.prototype.html_to_matita = function()
 357 {
 358         var patt1 = /<br(\/|)>/gi;
 359         var patt2 = /</gi
 360         var patt3 = />/gi
 361         var patt4 = /&lt;/gi;
 362         var patt5 = /&gt;/gi;
 363         var result = this;
 364         result = result.replace(patt1,"\n");
 365         result = result.replace(patt2,"\005");
 366         result = result.replace(patt3,"\006");
 367         result = result.replace(patt4,"<");
 368         result = result.replace(patt5,">");
 369         return (unescape(result));
 370 }
 371
 372 String.prototype.matita_to_html = function()
 373 {
 374         var patt1 = /</gi
 375         var patt2 = />/gi
 376         var patt3 = /\005/gi;
 377         var patt4 = /\006/gi;
 378         var result = this;
 379         result = result.replace(patt1,"&lt;");
 380         result = result.replace(patt2,"&gt;");
 381         result = result.replace(patt3,"<");
 382         result = result.replace(patt4,">");
 383         return (unescape(result));
 384 }
 385
 386 function pause()
 387 {
 388         advanceButton.disabled = true;
 389         retractButton.disabled = true;
 390         cursorButton.disabled = true;
 391         bottomButton.disabled = true;
 392 }
 393
 394 function resume()
 395 {
 396         advanceButton.disabled = false;
 397         retractButton.disabled = false;
 398         cursorButton.disabled = false;
 399         bottomButton.disabled = false;
 400 }
 401
 402 function is_defined(x)
 403 {
 404         return (typeof x != "undefined");
 405 }
 406
 407 /* servicename: name of the service being called
 408  * reqbody: text of the request
 409  * processResponse: processes the server response
 410  *     (takes the response text in input, undefined in case of error)
 411  */
 412 function callServer(servicename,processResponse,reqbody)
 413 {
 414         var req = null;
 415         // pause();
 416         if (window.XMLHttpRequest)
 417         {
 418                 req = new XMLHttpRequest();
 419         }
 420         else if (window.ActiveXObject)
 421         {
 422                 try {
 423                                 req = new ActiveXObject("Msxml2.XMLHTTP");
 424                 } catch (e)
 425                 {
 426                         try {
 427                                 req = new ActiveXObject("Microsoft.XMLHTTP");
 428                                 } catch (e) {}
 429                 }
 430         }
 431         req.onreadystatechange = function()
 432         {
 433
 434                 rs = req.readyState;
 435
 436                 if(rs == 4)
 437                 {
 438                         stat = req.status;
 439                         stxt = req.statusText;
 440                         if(stat == 200)
 441                         {
 442                           debug(req.responseText);
 443                           if (window.DOMParser) {
 444                             parser=new DOMParser();
 445                             xmlDoc=parser.parseFromString(req.responseText,"text/xml");
 446                           }
 447                           else // Internet Explorer
 448                           {
 449                             xmlDoc=new ActiveXObject("Microsoft.XMLDOM");
 450                             xmlDoc.async="false";
 451                             xmlDoc.loadXML(req.responseText);
 452                           }
 453                           processResponse(xmlDoc);
 454                         } else {
 455                           processResponse();
 456                         }
 457                 }
 458         };
 459         req.open("POST", servicename); // + escape(unlocked.innerHTML), true);
 460         req.setRequestHeader("Content-type","application/x-www-form-urlencoded");
 461         if (reqbody) {
 462                 req.send(reqbody);
 463         } else {
 464                 req.send();
 465         }
 466
 467 }
 468
 469 function advanceForm1()
 470 {
 471         processor = function(xml) {
 472                 if (is_defined(xml)) {
 473                         // debug("advance: received response\nBEGIN\n" + req.responseText + "\nEND");
 474                         parsed = xml.getElementsByTagName("parsed")[0];
 475                         len = parseInt(parsed.getAttribute("length"));
 476                         // len0 = unlocked.innerHTML.length;
 477                         unescaped = unlocked.innerHTML.html_to_matita();
 478                         parsedtxt = parsed.childNodes[0].nodeValue;
 479                         //parsedtxt = unescaped.substr(0,len);
 480                         unparsedtxt = unescaped.substr(len);
 481                         lockedbackup += parsedtxt;
 482                         locked.innerHTML = lockedbackup;
 483                         unlocked.innerHTML = unparsedtxt.matita_to_html();
 484                         // len1 = unlocked.innerHTML.length;
 485                         // len2 = len0 - len1;
 486                         len2 = parsedtxt.length;
 487                         metasenv = xml.getElementsByTagName("meta");
 488                         populate_goalarray(metasenv);
 489                         statements = listcons(len2,statements);
 490                         unlocked.scrollIntoView(true);
 491                 } else {
 492                         debug("advance failed");
 493                 }
 494                 resume();
 495         };
 496         pause();
 497         callServer("advance",processor,"body=" + (unlocked.innerHTML.html_to_matita()).sescape());
 498
 499 }
 500
 501 function gotoBottom()
 502 {
 503         processor = function(xml) {
 504                 if (is_defined(xml)) {
 505                         // debug("goto bottom: received response\nBEGIN\n" + req.responseText + "\nEND");
 506                         parsed = xml.getElementsByTagName("parsed")[0];
 507                         len = parseInt(parsed.getAttribute("length"));
 508                         if (len > 0) {
 509                           // len0 = unlocked.innerHTML.length;
 510                           unescaped = unlocked.innerHTML.html_to_matita();
 511                           parsedtxt = parsed.childNodes[0].nodeValue;
 512                           //parsedtxt = unescaped.substr(0,len);
 513                           unparsedtxt = unescaped.substr(len);
 514                           lockedbackup += parsedtxt;
 515                           locked.innerHTML = lockedbackup; //.matita_to_html();
 516                           unlocked.innerHTML = unparsedtxt.matita_to_html();
 517                           // len1 = unlocked.innerHTML.length;
 518                           len2 = parsedtxt.length;
 519                           metasenv = xml.getElementsByTagName("meta");
 520                           populate_goalarray(metasenv);
 521                           if (len2 > 0)
 522                             statements = listcons(len2,statements);
 523                           unlocked.scrollIntoView(true);
 524                         }
 525                 } else {
 526                         debug("goto bottom failed");
 527                 }
 528                 resume();
 529         };
 530         pause();
 531         callServer("bottom",processor,"body=" + (unlocked.innerHTML.html_to_matita()).sescape());
 532
 533 }
 534
 535
 536 function gotoPos(offset)
 537 {
 538         if (!is_defined(offset)) {
 539                 offset = getCursorPos();
 540         }
 541         processor = function(xml) {
 542                 if (is_defined(xml)) {
 543                         parsed = xml.getElementsByTagName("parsed")[0];
 544                         len = parseInt(parsed.getAttribute("length"));
 545                         // len0 = unlocked.innerHTML.length;
 546                         unescaped = unlocked.innerHTML.html_to_matita();
 547                         parsedtxt = parsed.childNodes[0].nodeValue;
 548                         //parsedtxt = unescaped.substr(0,len);
 549                         unparsedtxt = unescaped.substr(len);
 550                         lockedbackup += parsedtxt;
 551                         locked.innerHTML = lockedbackup; //.matita_to_html();
 552                         unlocked.innerHTML = unparsedtxt.matita_to_html();
 553                         // len1 = unlocked.innerHTML.length;
 554                         len2 = parsedtxt.length;
 555                         metasenv = xml.getElementsByTagName("meta");
 556                         // populate_goalarray(metasenv);
 557                         statements = listcons(len2,statements);
 558                         unlocked.scrollIntoView(true);
 559                         // la populate non andrebbe fatta a ogni passo
 560                         if (offset <= len) {
 561                                 populate_goalarray(metasenv);
 562                                 resume();
 563                         } else {
 564                                 gotoPos(offset - len);
 565                         }
 566                 } else {
 567                         unlocked.scrollIntoView(true);
 568                         populate_goalarray(metasenv);
 569                         resume();
 570                 }
 571         }
 572         pause();
 573         callServer("advance",processor,"body=" + (unlocked.innerHTML.html_to_matita()).sescape());
 574 }
 575
 576 function retract()
 577 {
 578         processor = function(xml) {
 579                 if (typeof xml != "undefined") {
 580                         // debug("advance: received response\nBEGIN\n" + req.responseText + "\nEND");
 581                         statementlen = parseInt(listhd(statements));
 582                         statements = listtl(statements);
 583                         /*
 584                         lockedlen = locked.innerHTML.length - statementlen;
 585                         statement = locked.innerHTML.substr(lockedlen, statementlen);
 586                         locked.innerHTML = locked.innerHTML.substr(0,lockedlen);
 587                         unlocked.innerHTML = statement + unlocked.innerHTML;
 588                         */
 589                         lockedlen = lockedbackup.length - statementlen;
 590                         statement = lockedbackup.substr(lockedlen, statementlen);
 591                         lockedbackup = lockedbackup.substr(0,lockedlen);
 592                         locked.innerHTML = lockedbackup;
 593                         unlocked.innerHTML = statement + unlocked.innerHTML;
 594                         metasenv = xml.getElementsByTagName("meta");
 595                         populate_goalarray(metasenv);
 596                         unlocked.scrollIntoView(true);
 597                 } else {
 598                         debug("retract failed");
 599                 }
 600                 resume();
 601         };
 602         debug("retract 1");
 603         pause();
 604         callServer("retract",processor);
 605         debug("retract 2");
 606 }
 607
 608 function openFile()
 609 {
 610         processor = function(xml)
 611         {
 612                 if (is_defined(xml)) {
 613                         lockedbackup = "";
 614                         locked.innerHTML = lockedbackup;
 615                         unlocked.innerHTML = xml.documentElement.textContent;
 616                 } else {
 617                         debug("file open failed");
 618                 }
 619         };
 620         callServer("open",processor,"file=" + escape(filename.value));
 621 }
 622
 623 function retrieveFile(thefile)
 624 {
 625         processor = function(xml)
 626         {
 627                 if (is_defined(xml)) {
 628                         lockedbackup = ""
 629                         locked.innerHTML = lockedbackup;
 630                         // code originally used in google chrome (problems with mozilla)
 631                         // debug(xml.getElementsByTagName("file")[0].childNodes[0].nodeValue);
 632                         // unlocked.innerHTML = xml.getElementsByTagName("file")[0].childNodes[0].nodeValue;
 633                         debug(xml.childNodes[0].textContent);
 634                         unlocked.innerHTML = xml.childNodes[0].textContent;
 635
 636                 } else {
 637                         debug("file open failed");
 638                 }
 639         };
 640         dialogBox.style.display = "none";
 641         current_fname = thefile;
 642         callServer("open",processor,"file=" + escape(thefile));
 643 }
 644
 645 function showLibrary()
 646 {
 647         var req = null;
 648         // pause();
 649         if (window.XMLHttpRequest)
 650         {
 651                 req = new XMLHttpRequest();
 652         }
 653         else if (window.ActiveXObject)
 654         {
 655                 try {
 656                                 req = new ActiveXObject("Msxml2.XMLHTTP");
 657                 } catch (e)
 658                 {
 659                         try {
 660                                 req = new ActiveXObject("Microsoft.XMLHTTP");
 661                                 } catch (e) {}
 662                 }
 663         }
 664         req.onreadystatechange = function()
 665         {
 666
 667                 rs = req.readyState;
 668
 669                 if(rs == 4)
 670                 {
 671                         stat = req.status;
 672                         stxt = req.statusText;
 673                         if(stat == 200)
 674                         {
 675                           debug(req.responseText);
 676                           showDialog("<H2>Library</H2>",req.responseText);
 677                         }
 678                 }
 679         };
 680         req.open("POST", "viewlib"); // + escape(unlocked.innerHTML), true);
 681         req.setRequestHeader("Content-type","application/x-www-form-urlencoded");
 682         req.send();
 683
 684 }
 685
 686 function saveFile()
 687 {
 688         processor = function(xml) {
 689                 if (is_defined(xml)) {
 690                         debug("file saved!");
 691                 } else {
 692                         debug("save file failed");
 693                 }
 694                 resume();
 695         };
 696         if (is_defined(current_fname)) {
 697           pause();
 698           callServer("save",processor,"file=" + escape(current_fname) +
 699                                     "&locked=" + (locked.innerHTML.html_to_matita()).sescape() +
 700                                     "&unlocked=" + (unlocked.innerHTML.html_to_matita()).sescape());
 701         }
 702         else { debug("no file selected"); }
 703 }
 704
 705 function commitAll()
 706 {
 707         processor = function(xml) {
 708                 if (is_defined(xml)) {
 709                         debug("commit succeeded(?)");
 710                 } else {
 711                         debug("commit failed!");
 712                 }
 713                 resume();
 714         };
 715         pause();
 716         callServer("commit",processor);
 717 }
 718
 719 var goalcell;
 720
 721 function hideSequent() {
 722   goalcell.parentNode.removeChild(goalcell);
 723   scriptcell.setAttribute("colspan","2");
 724 }
 725
 726 function showSequent() {
 727   scriptcell.setAttribute("colspan","1");
 728   workarea.appendChild(goalcell);
 729 }
 730
 731 function showDialog(title,content) {
 732   dialogTitle.innerHTML = title;
 733   dialogContent.innerHTML = content;
 734   dialogBox.style.display = "block";
 735 }
 736
 737 function removeElement(id) {
 738   var element = document.getElementById(id);
 739   element.parentNode.removeChild(element);
 740 }
 741
 742 var savedsc;
 743 var savedso;
 744
 745 function getCursorPos() {
 746   var cursorPos;
 747   if (window.getSelection) {
 748     var selObj = window.getSelection();
 749     savedRange = selObj.getRangeAt(0);
 750     savedsc = savedRange.startContainer;
 751     savedso = savedRange.startOffset;
 752     //cursorPos =  findNode(selObj.anchorNode.parentNode.childNodes, selObj.anchorNode) + selObj.anchorOffset;
 753     cursorPos =  findNode(unlocked.childNodes, selObj.anchorNode,0) + selObj.anchorOffset;
 754     /* FIXME the following works wrong in Opera when the document is longer than 32767 chars */
 755     return(cursorPos);
 756   }
 757   else if (document.selection) {
 758     savedRange = document.selection.createRange();
 759     var bookmark = savedRange.getBookmark();
 760     /* FIXME the following works wrong when the document is longer than 65535 chars */
 761     cursorPos = bookmark.charCodeAt(2) - 11; /* Undocumented function [3] */
 762     return(cursorPos);
 763   }
 764 }
 765
 766 function findNode(list, node, acc) {
 767   for (var i = 0; i < list.length; i++) {
 768     if (list[i] == node) {
 769    //   debug("success " + i);
 770       return acc;
 771     }
 772     if (list[i].hasChildNodes()) {
 773        try {
 774    //      debug("recursion on node " + i);
 775          return (findNode(list[i].childNodes,node,acc))
 776        }
 777        catch (e) { /* debug("recursion failed"); */ }
 778     }
 779     sandbox = document.getElementById("sandbox");
 780     dup = list[i].cloneNode(true);
 781     sandbox.appendChild(dup);
 782 //    debug("fail " + i + ": " + sandbox.innerHTML);
 783     acc += sandbox.innerHTML.length;
 784     sandbox.removeChild(dup);
 785   }
 786   throw "not found";
 787 }
 788
 789 function test () {
 790   debug("cursor test: " + unlocked.innerHTML.substr(0,getCursorPos()));
 791 }
 792
 793 function readCookie(name) {
 794         var nameEQ = name + "=";
 795         var ca = document.cookie.split(';');
 796         for(var i=0;i < ca.length;i++) {
 797                 var c = ca[i];
 798                 while (c.charAt(0)==' ') c = c.substring(1,c.length);
 799                 if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
 800         }
 801         return null;
 802 }
 803
 804 function delete_cookie ( cookie_name )
 805 {
 806   var cookie_date = new Date();  // current date & time
 807   cookie_date.setTime ( cookie_date.getTime() - 1 );
 808   document.cookie = cookie_name += "=; expires=" + cookie_date.toGMTString();
 809 }
 810
 811 function delete_session()
 812 {
 813         delete_cookie("session");
 814 }