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Annotation of loncom/html/adm/LC_math_editor/src/ui.js, revision 1.1

1.1     ! damieng     1: /*
        !             2: 
        !             3: Copyright (C) 2014  Michigan State University Board of Trustees
        !             4: 
        !             5: The JavaScript code in this page is free software: you can
        !             6: redistribute it and/or modify it under the terms of the GNU
        !             7: General Public License (GNU GPL) as published by the Free Software
        !             8: Foundation, either version 3 of the License, or (at your option)
        !             9: any later version.  The code is distributed WITHOUT ANY WARRANTY;
        !            10: without even the implied warranty of MERCHANTABILITY or FITNESS
        !            11: FOR A PARTICULAR PURPOSE.  See the GNU GPL for more details.
        !            12: 
        !            13: As additional permission under GNU GPL version 3 section 7, you
        !            14: may distribute non-source (e.g., minimized or compacted) forms of
        !            15: that code without the copy of the GNU GPL normally required by
        !            16: section 4, provided you include this license notice and a URL
        !            17: through which recipients can access the Corresponding Source.
        !            18: 
        !            19: */
        !            20: 
        !            21: "use strict";
        !            22: 
        !            23: var handleChange = function(math_object) {
        !            24:     // math_object has 3 fields: ta, output_node, oldtxt
        !            25:     // we need to pass this object instead of the values because oldtxt will change
        !            26:     var ta, output_node, txt, parser, output, root, test1, test2;
        !            27:     ta = math_object.ta;
        !            28:     output_node = math_object.output_node;
        !            29:     txt = ta.value;
        !            30:     
        !            31:     // automatically add brackets to something like "1;2;3", for LON-CAPA:
        !            32:     // NOTE: this is ugly and sometimes adds brackets to error messages
        !            33:     test1 = '';
        !            34:     test2 = txt;
        !            35:     while (test2 != test1) {
        !            36:       test1 = test2;
        !            37:       test2 = test1.replace(/\[[^\[\]]*\]/g, '');
        !            38:     }
        !            39:     if (test2.split("[").length == test2.split("]").length) {
        !            40:       test1 = '';
        !            41:       while (test2 != test1) {
        !            42:         test1 = test2;
        !            43:         test2 = test1.replace(/\([^\(\)]*\)/g, '');
        !            44:       }
        !            45:       if (test2.split("(").length == test2.split(")").length) {
        !            46:         if (test2.indexOf(Definitions.ARG_SEPARATOR) != -1) {
        !            47:           txt = '['+txt+']';
        !            48:         }
        !            49:       }
        !            50:     }
        !            51:     
        !            52:     if (txt != math_object.oldtxt) {
        !            53:         math_object.oldtxt = txt;
        !            54:         while (output_node.firstChild != null)
        !            55:             output_node.removeChild(output_node.firstChild);
        !            56:         output_node.removeAttribute("title");
        !            57:         if (txt != "") {
        !            58:             parser = math_object.parser;
        !            59:             try {
        !            60:                 root = parser.parse(txt);
        !            61:                 if (root != null) {
        !            62:                     var math = document.createElement("math");
        !            63:                     math.setAttribute("display", "block");
        !            64:                     math.appendChild(root.toMathML());
        !            65:                     output_node.appendChild(math);
        !            66:                     MathJax.Hub.Queue(["Typeset", MathJax.Hub, output_node]);
        !            67:                 }
        !            68:             } catch (e) {
        !            69:                 output = "error: " + e;
        !            70:                 output_node.setAttribute("title", output);
        !            71:                 if (e instanceof ParseException) {
        !            72:                     output_node.appendChild(document.createTextNode(txt.substring(0, e.from)));
        !            73:                     var span = document.createElement('span');
        !            74:                     span.appendChild(document.createTextNode(txt.substring(e.from, e.to + 1)));
        !            75:                     span.className = 'math-error';
        !            76:                     output_node.appendChild(span);
        !            77:                     if (e.to < txt.length - 1) {
        !            78:                         output_node.appendChild(document.createTextNode(txt.substring(e.to + 1)));
        !            79:                     }
        !            80:                 } else {
        !            81:                     var tn = document.createTextNode(output);
        !            82:                     output_node.appendChild(tn);
        !            83:                 }
        !            84:             }
        !            85:         }
        !            86:     }
        !            87: }
        !            88: 
        !            89: var init_done = false;
        !            90: 
        !            91: /*
        !            92:   Looks for elements with the "math" class, and
        !            93:   adds a preview div afterward which is updated automatically.
        !            94: */
        !            95: var initEditors = function() {
        !            96:     if (init_done)
        !            97:         return;
        !            98:     init_done = true;
        !            99:     var math_objects = [];
        !           100:     var math_inputs = document.getElementsByClassName('math');
        !           101:     for (var i=0; i<math_inputs.length; i++) {
        !           102:         var ta = math_inputs[i];
        !           103:         if (ta.nodeName == "TEXTAREA" || ta.nodeName == "INPUT") {
        !           104:             var output_node = document.createElement("span");
        !           105:             output_node.setAttribute("style", "display:none");
        !           106:             if (ta.nextSibling)
        !           107:                 ta.parentNode.insertBefore(output_node, ta.nextSibling);
        !           108:             else
        !           109:                 ta.parentNode.appendChild(output_node);
        !           110:             var hideNode = function(node) {
        !           111:                 return function(e) { node.setAttribute("style", "display:none"); };
        !           112:             };
        !           113:             var showNode = function(node) {
        !           114:                 return function(e) { node.setAttribute("style", "display: inline-block; background-color: #FFFFE0"); };
        !           115:             };
        !           116:             ta.addEventListener("blur", hideNode(output_node), false);
        !           117:             ta.addEventListener("focus", showNode(output_node), false);
        !           118:             var implicit_operators = (ta.getAttribute("data-implicit_operators") === "true");
        !           119:             var unit_mode = (ta.getAttribute("data-unit_mode") === "true");
        !           120:             var constants = ta.getAttribute("data-constants");
        !           121:             if (constants)
        !           122:                 constants = constants.split(/[\s,]+/);
        !           123:             var oldtxt = "";
        !           124:             math_objects[i] = {
        !           125:                 "ta": ta,
        !           126:                 "output_node": output_node,
        !           127:                 "oldtxt": oldtxt,
        !           128:                 "parser": new Parser(implicit_operators, unit_mode, constants)
        !           129:             };
        !           130:             var changeObjectN = function(n) {
        !           131:                 return function(e) {
        !           132:                   var obj = math_objects[n];
        !           133:                   if (document.activeElement == obj.ta) {
        !           134:                     // this is useful if there is data in the field with the page default focus
        !           135:                     // (there might not be a focus event for the active element)
        !           136:                     obj.output_node.setAttribute("style", "display: inline-block; background-color: #FFFFE0");
        !           137:                   }
        !           138:                   handleChange(obj);
        !           139:                 };
        !           140:             };
        !           141:             var startChange = changeObjectN(i);
        !           142:             if (ta.value != oldtxt)
        !           143:                 startChange(); // process non-empty fields even though they are not visible yet
        !           144:             ta.addEventListener('change', startChange, false);
        !           145:             ta.addEventListener('keyup', startChange, false);
        !           146:         }
        !           147:     }
        !           148: }
        !           149: