      1 /*
      2     Copyright 2008-2025
      3         Matthias Ehmann,
      4         Carsten Miller,
      5         Alfred Wassermann
      6
      7     This file is part of JSXGraph.
      8
      9     JSXGraph is free software dual licensed under the GNU LGPL or MIT License.
     10
     11     You can redistribute it and/or modify it under the terms of the
     12
     13       * GNU Lesser General Public License as published by
     14         the Free Software Foundation, either version 3 of the License, or
     15         (at your option) any later version
     16       OR
     17       * MIT License: https://github.com/jsxgraph/jsxgraph/blob/master/LICENSE.MIT
     18
     19     JSXGraph is distributed in the hope that it will be useful,
     20     but WITHOUT ANY WARRANTY; without even the implied warranty of
     21     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     22     GNU Lesser General Public License for more details.
     23
     24     You should have received a copy of the GNU Lesser General Public License and
     25     the MIT License along with JSXGraph. If not, see <https://www.gnu.org/licenses/>
     26     and <https://opensource.org/licenses/MIT/>.
     27  */
     28
     29 /*global JXG: true, define: true*/
     30 /*jslint nomen: true, plusplus: true*/
     31
     32 /**
     33  * @fileoverview Implementation of smart labels..
     34  */
     35
     36 import JXG from "../jxg.js";
     37 import Const from "../base/constants.js";
     38 import Type from "../utils/type.js";
     39
     40 /**
     41  * @class Customized text elements for displaying measurements of JSXGraph elements,
     42  * Examples are length of a
     43  * segment, perimeter or area of a circle or polygon (including polygonal chain),
     44  * slope of a line, value of an angle, and coordinates of a point.
     45  * <p>
     46  * If additionally a text, or a function is supplied and the content is not the empty string,
     47  * that text is displayed instead of the measurement.
     48  * <p>
     49  * Smartlabels use custom made CSS layouts defined in jsxgraph.css. Therefore, the inclusion of the file jsxgraph.css is mandatory or
     50  * the CSS classes have to be replaced by other classes.
     51  * <p>
     52  * The default attributes for smartlabels are defined for each type of measured element in the following sub-objects.
     53  * This is a deviation from the usual JSXGraph attribute usage.
     54  * <ul>
     55  *  <li> <tt>JXG.Options.smartlabelangle</tt> for smartlabels of angle objects
     56  *  <li> <tt>JXG.Options.smartlabelcircle</tt> for smartlabels of circle objects
     57  *  <li> <tt>JXG.Options.smartlabelline</tt> for smartlabels of line objects
     58  *  <li> <tt>JXG.Options.smartlabelpoint</tt> for smartlabels of point objects.
     59  *  <li> <tt>JXG.Options.smartlabelpolygon</tt> for smartlabels of polygon objects.
     60  * </ul>
     61  *
     62  *
     63  * @pseudo
     64  * @name Smartlabel
     65  * @augments JXG.Text
     66  * @constructor
     67  * @type JXG.Text
     68  * @throws {Error} If the element cannot be constructed with the given parent objects an exception is thrown.
     69  * @param {JXG.GeometryElement} Parent parent object: point, line, circle, polygon, angle.
     70  * @param {String|Function} Txt Optional text. In case, this content is not the empty string,
     71  *  the measurement is overwritten by this text.
     72  *
     73  * @example
     74  * var p1 = board.create('point', [3, 4], {showInfobox: false, withLabel: false});
     75  * board.create('smartlabel', [p1], {digits: 1, unit: 'm', dir: 'col', useMathJax: false});
     76  *
     77  * </pre><div id="JXG30cd1f9e-7e78-48f3-91a2-9abd466a754f" class="jxgbox" style="width: 300px; height: 300px;"></div>
     78  * <script type="text/javascript">
     79  *     (function() {
     80  *         var board = JXG.JSXGraph.initBoard('JXG30cd1f9e-7e78-48f3-91a2-9abd466a754f',
     81  *             {boundingbox: [-8, 8, 8,-8], axis: true, showcopyright: false, shownavigation: false});
     82  *     var p1 = board.create('point', [3, 4], {showInfobox: false, withLabel: false});
     83  *     board.create('smartlabel', [p1], {digits: 1, unit: 'cm', dir: 'col', useMathJax: false});
     84  *
     85  *     })();
     86  *
     87  * </script><pre>
     88  *
     89  * @example
     90  * var s1 = board.create('line', [[-7, 2], [6, -6]], {point1: {visible:true}, point2: {visible:true}});
     91  * board.create('smartlabel', [s1], {unit: 'm', measure: 'length', prefix: 'L = ', useMathJax: false});
     92  * board.create('smartlabel', [s1], {unit: 'm',  measure: 'slope', prefix: 'Δ = ', useMathJax: false});
     93  *
     94  *
     95  * </pre><div id="JXGfb4423dc-ee3a-4122-a186-82123019a835" class="jxgbox" style="width: 300px; height: 300px;"></div>
     96  * <script type="text/javascript">
     97  *     (function() {
     98  *         var board = JXG.JSXGraph.initBoard('JXGfb4423dc-ee3a-4122-a186-82123019a835',
     99  *             {boundingbox: [-8, 8, 8,-8], axis: true, showcopyright: false, shownavigation: false});
    100  *     var s1 = board.create('line', [[-7, 2], [6, -6]], {point1: {visible:true}, point2: {visible:true}});
    101  *     board.create('smartlabel', [s1], {unit: 'm', measure: 'length', prefix: 'L = ', useMathJax: false});
    102  *     board.create('smartlabel', [s1], {unit: 'm',  measure: 'slope', prefix: 'Δ = ', useMathJax: false});
    103  *
    104  *
    105  *     })();
    106  *
    107  * </script><pre>
    108  *
    109  * @example
    110  * var c1 = board.create('circle', [[0, 1], [4, 1]], {point2: {visible: true}});
    111  * board.create('smartlabel', [c1], {unit: 'm', measure: 'perimeter', prefix: 'U = ', useMathJax: false});
    112  * board.create('smartlabel', [c1], {unit: 'm', measure: 'area', prefix: 'A = ', useMathJax: false});
    113  * board.create('smartlabel', [c1], {unit: 'm', measure: 'radius', prefix: 'R = ', useMathJax: false});
    114  *
    115  *
    116  * </pre><div id="JXG763c4700-8273-4eb7-9ed9-1dc6c2c52e93" class="jxgbox" style="width: 300px; height: 300px;"></div>
    117  * <script type="text/javascript">
    118  *     (function() {
    119  *         var board = JXG.JSXGraph.initBoard('JXG763c4700-8273-4eb7-9ed9-1dc6c2c52e93',
    120  *             {boundingbox: [-8, 8, 8,-8], axis: true, showcopyright: false, shownavigation: false});
    121  *     var c1 = board.create('circle', [[0, 1], [4, 1]], {point2: {visible: true}});
    122  *     board.create('smartlabel', [c1], {unit: 'm', measure: 'perimeter', prefix: 'U = ', useMathJax: false});
    123  *     board.create('smartlabel', [c1], {unit: 'm', measure: 'area', prefix: 'A = ', useMathJax: false});
    124  *     board.create('smartlabel', [c1], {unit: 'm', measure: 'radius', prefix: 'R = ', useMathJax: false});
    125  *
    126  *
    127  *     })();
    128  *
    129  * </script><pre>
    130  *
    131  * @example
    132  * var p2 = board.create('polygon', [[-6, -5], [7, -7], [-4, 3]], {});
    133  * board.create('smartlabel', [p2], {
    134  *     unit: 'm',
    135  *     measure: 'area',
    136  *     prefix: 'A = ',
    137  *     cssClass: 'smart-label-pure smart-label-polygon',
    138  *     highlightCssClass: 'smart-label-pure smart-label-polygon',
    139  *     useMathJax: false
    140  * });
    141  * board.create('smartlabel', [p2, () => 'X: ' + p2.vertices[0].X().toFixed(1)], {
    142  *     measure: 'perimeter',
    143  *     cssClass: 'smart-label-outline smart-label-polygon',
    144  *     highlightCssClass: 'smart-label-outline smart-label-polygon',
    145  *     useMathJax: false
    146  * });
    147  *
    148  * </pre><div id="JXG376425ac-b4e5-41f2-979c-6ff32a01e9c8" class="jxgbox" style="width: 300px; height: 300px;"></div>
    149  * <script type="text/javascript">
    150  *     (function() {
    151  *         var board = JXG.JSXGraph.initBoard('JXG376425ac-b4e5-41f2-979c-6ff32a01e9c8',
    152  *             {boundingbox: [-8, 8, 8,-8], axis: true, showcopyright: false, shownavigation: false});
    153  *     var p2 = board.create('polygon', [[-6, -5], [7, -7], [-4, 3]], {});
    154  *     board.create('smartlabel', [p2], {
    155  *         unit: 'm',
    156  *         measure: 'area',
    157  *         prefix: 'A = ',
    158  *         cssClass: 'smart-label-pure smart-label-polygon',
    159  *         highlightCssClass: 'smart-label-pure smart-label-polygon',
    160  *         useMathJax: false
    161  *     });
    162  *     board.create('smartlabel', [p2, () => 'X: ' + p2.vertices[0].X().toFixed(1)], {
    163  *         measure: 'perimeter',
    164  *         cssClass: 'smart-label-outline smart-label-polygon',
    165  *         highlightCssClass: 'smart-label-outline smart-label-polygon',
    166  *         useMathJax: false
    167  *     });
    168  *
    169  *     })();
    170  *
    171  * </script><pre>
    172  *
    173  * @example
    174  * var a1 = board.create('angle', [[1, -1], [1, 2], [1, 5]], {name: 'β', withLabel: false});
    175  * var sma = board.create('smartlabel', [a1], {digits: 1, prefix: a1.name + '=', unit: '°', useMathJax: false});
    176  *
    177  * </pre><div id="JXG48d6d1ae-e04a-45f4-a743-273976712c0b" class="jxgbox" style="width: 300px; height: 300px;"></div>
    178  * <script type="text/javascript">
    179  *     (function() {
    180  *         var board = JXG.JSXGraph.initBoard('JXG48d6d1ae-e04a-45f4-a743-273976712c0b',
    181  *             {boundingbox: [-8, 8, 8,-8], axis: true, showcopyright: false, shownavigation: false});
    182  *     var a1 = board.create('angle', [[1, -1], [1, 2], [1, 5]], {name: 'β', withLabel: false});
    183  *     var sma = board.create('smartlabel', [a1], {digits: 1, prefix: a1.name + '=', unit: '°', useMathJax: false});
    184  *
    185  *     })();
    186  *
    187  * </script><pre>
    188  *
    189  */
    190 JXG.createSmartLabel = function (board, parents, attributes) {
    191     var el, attr,
    192         p, user_supplied_text,
    193         getTextFun, txt_fun;
    194
    195     if (parents.length === 0 || (
    196         [Const.OBJECT_CLASS_POINT, Const.OBJECT_CLASS_LINE,Const.OBJECT_CLASS_CIRCLE].indexOf(parents[0].elementClass) < 0 &&
    197         [Const.OBJECT_TYPE_POLYGON, Const.OBJECT_TYPE_ANGLE].indexOf(parents[0].type) < 0
    198         )
    199     ) {
    200         throw new Error(
    201             "JSXGraph: Can't create smartlabel with parent types " +
    202                 "'" + typeof parents[0] + "', " +
    203                 "'" + typeof parents[1] + "'."
    204         );
    205     }
    206
    207     p = parents[0];
    208     user_supplied_text = parents[1] || '';
    209
    210     if (p.elementClass === Const.OBJECT_CLASS_POINT) {
    211         attr = Type.copyAttributes(attributes, board.options, 'smartlabelpoint');
    212
    213     } else if (p.elementClass === Const.OBJECT_CLASS_LINE) {
    214         attr = Type.copyAttributes(attributes, board.options, 'smartlabelline');
    215         /**
    216          * @class
    217          * @ignore
    218          */
    219         attr.rotate = function () { return Math.atan(p.getSlope()) * 180 / Math.PI; };
    220         /**
    221          * @class
    222          * @ignore
    223          */
    224         attr.visible = function () { return (p.L() < 1.5) ? false : true; };
    225
    226     } else if (p.elementClass === Const.OBJECT_CLASS_CIRCLE) {
    227         attr = Type.copyAttributes(attributes, board.options, 'smartlabelcircle');
    228         /**
    229          * @class
    230          * @ignore
    231          */
    232         attr.visible = function () { return (p.Radius() < 1.5) ? false : true; };
    233
    234     } else if (p.type === Const.OBJECT_TYPE_POLYGON) {
    235         attr = Type.copyAttributes(attributes, board.options, 'smartlabelpolygon');
    236     } else if (p.type === Const.OBJECT_TYPE_ANGLE) {
    237         attr = Type.copyAttributes(attributes, board.options, 'smartlabelangle');
    238         /**
    239          * @class
    240          * @ignore
    241          */
    242         attr.rotate = function () {
    243             var c1 = p.center.coords.usrCoords,
    244                 c2 = p.getLabelAnchor().usrCoords,
    245                 v = Math.atan2(c2[2] - c1[2], c2[1] - c1[1]) * 180 / Math.PI;
    246             return (v > 90 && v < 270) ? v + 180 : v;
    247         };
    248         /**
    249          * @class
    250          * @ignore
    251          */
    252         attr.anchorX = function () {
    253             var c1 = p.center.coords.usrCoords,
    254                 c2 = p.getLabelAnchor().usrCoords,
    255                 v = Math.atan2(c2[2] - c1[2], c2[1] - c1[1]) * 180 / Math.PI;
    256             return (v > 90 && v < 270) ? 'right' : 'left';
    257         };
    258     }
    259
    260     getTextFun = function (el, p, elType, mType) {
    261         var measure;
    262         switch (mType) {
    263             case 'length':
    264                 /**
    265                  * @ignore
    266                  */
    267                 measure = function () { return p.L(); };
    268                 break;
    269             case 'slope':
    270                 /**
    271                  * @ignore
    272                  */
    273                 measure = function () { return p.Slope(); };
    274                 break;
    275             case 'area':
    276                 /**
    277                  * @ignore
    278                  */
    279                 measure = function () { return p.Area(); };
    280                 break;
    281             case 'radius':
    282                 /**
    283                  * @ignore
    284                  */
    285                 measure = function () { return p.Radius(); };
    286                 break;
    287             case 'perimeter':
    288                 /**
    289                  * @ignore
    290                  */
    291                 measure = function () { return p.Perimeter(); };
    292                 break;
    293             case 'rad':
    294                 /**
    295                  * @ignore
    296                  */
    297                 measure = function () { return p.Value(); };
    298                 break;
    299             case 'deg':
    300                 /**
    301                  * @ignore
    302                  */
    303                 measure = function () { return p.Value() * 180 / Math.PI; };
    304                 break;
    305             default:
    306                 /**
    307                  * @ignore
    308                  */
    309                 measure = function () { return 0.0; };
    310         }
    311
    312         return function () {
    313             var str = '',
    314                 val,
    315                 txt = Type.evaluate(user_supplied_text),
    316                 digits = el.evalVisProp('digits'),
    317                 u = el.evalVisProp('unit'),
    318                 pre = el.evalVisProp('prefix'),
    319                 suf = el.evalVisProp('suffix'),
    320                 mj = el.evalVisProp('usemathjax') || el.evalVisProp('usekatex');
    321
    322             if (txt === '') {
    323                 if (el.useLocale()) {
    324                     val = el.formatNumberLocale(measure(), digits);
    325                 } else {
    326                     val = Type.toFixed(measure(), digits);
    327                 }
    328                 if (mj) {
    329                     str = ['\\(', pre, val, '\\,', u, suf, '\\)'].join('');
    330                 } else {
    331                     str = [pre, val, u, suf].join('');
    332                 }
    333             } else {
    334                 str = txt;
    335             }
    336             return str;
    337         };
    338     };
    339
    340     if (p.elementClass === Const.OBJECT_CLASS_POINT) {
    341         el = board.create('text', [
    342             function () { return p.X(); },
    343             function () { return p.Y(); },
    344             ''
    345         ], attr);
    346
    347         txt_fun = function () {
    348             var str = '',
    349                 txt = Type.evaluate(user_supplied_text),
    350                 digits = el.evalVisProp('digits'),
    351                 u = el.evalVisProp('unit'),
    352                 pre = el.evalVisProp('prefix'),
    353                 suf = el.evalVisProp('suffix'),
    354                 dir = el.evalVisProp('dir'),
    355                 mj = el.evalVisProp('usemathjax') || el.evalVisProp('usekatex'),
    356                 x, y;
    357
    358             if (el.useLocale()) {
    359                 x = el.formatNumberLocale(p.X(), digits);
    360                 y = el.formatNumberLocale(p.Y(), digits);
    361             } else {
    362                 x = Type.toFixed(p.X(), digits);
    363                 y = Type.toFixed(p.Y(), digits);
    364             }
    365
    366             if (txt === '') {
    367                 if (dir === 'row') {
    368                     if (mj) {
    369                         str = ['\\(', pre, x, '\\,', u, ' / ', y, '\\,', u, suf, '\\)'].join('');
    370                     } else {
    371                         str = [pre, x, ' ', u, ' / ', y, ' ', u, suf].join('');
    372                     }
    373                 } else if (dir.indexOf('col') === 0) { // Starts with 'col'
    374                     if (mj) {
    375                         str = ['\\(', pre, '\\left(\\array{', x, '\\,', u, '\\\\ ', y, '\\,', u, '}\\right)', suf, '\\)'].join('');
    376                     } else {
    377                         str = [pre, x, ' ', u, '<br/>', y, ' ', u, suf].join('');
    378                     }
    379                 }
    380             } else {
    381                 str = txt;
    382             }
    383             return str;
    384         };
    385
    386     } else if (p.elementClass === Const.OBJECT_CLASS_LINE) {
    387
    388         if (attr.measure === 'length') {
    389             el = board.create('text', [
    390                 function () { return (p.point1.X() + p.point2.X()) * 0.5; },
    391                 function () { return (p.point1.Y() + p.point2.Y()) * 0.5; },
    392                 ''
    393             ], attr);
    394             txt_fun = getTextFun(el, p, 'line', 'length');
    395
    396         } else if (attr.measure === 'slope') {
    397             el = board.create('text', [
    398                 function () { return (p.point1.X() * 0.25 + p.point2.X() * 0.75); },
    399                 function () { return (p.point1.Y() * 0.25 + p.point2.Y() * 0.75); },
    400                 ''
    401             ], attr);
    402             txt_fun = getTextFun(el, p, 'line', 'slope');
    403         }
    404
    405     } else if (p.elementClass === Const.OBJECT_CLASS_CIRCLE) {
    406         if (attr.measure === 'radius') {
    407             el = board.create('text', [
    408                 function () { return p.center.X() + p.Radius() * 0.5; },
    409                 function () { return p.center.Y(); },
    410                 ''
    411             ], attr);
    412             txt_fun = getTextFun(el, p, 'circle', 'radius');
    413
    414         } else if (attr.measure === 'area') {
    415             el = board.create('text', [
    416                 function () { return p.center.X(); },
    417                 function () { return p.center.Y() + p.Radius() * 0.5; },
    418                 ''
    419             ], attr);
    420             txt_fun = getTextFun(el, p, 'circle', 'area');
    421
    422         } else if (attr.measure === 'circumference' || attr.measure === 'perimeter') {
    423             el = board.create('text', [
    424                 function () { return p.getLabelAnchor(); },
    425                 ''
    426             ], attr);
    427             txt_fun = getTextFun(el, p, 'circle', 'perimeter');
    428
    429         }
    430     } else if (p.type === Const.OBJECT_TYPE_POLYGON) {
    431         if (attr.measure === 'area') {
    432             el = board.create('text', [
    433                 function () { return p.getTextAnchor(); },
    434                 ''
    435             ], attr);
    436             txt_fun = getTextFun(el, p, 'polygon', 'area');
    437
    438         } else if (attr.measure === 'perimeter') {
    439             el = board.create('text', [
    440                 function () {
    441                     var last = p.borders.length - 1;
    442                     if (last >= 0) {
    443                         return [
    444                             (p.borders[last].point1.X() + p.borders[last].point2.X()) * 0.5,
    445                             (p.borders[last].point1.Y() + p.borders[last].point2.Y()) * 0.5
    446                         ];
    447                     } else {
    448                         return p.getTextAnchor();
    449                     }
    450                 },
    451                 ''
    452             ], attr);
    453             txt_fun = getTextFun(el, p, 'polygon', 'perimeter');
    454         }
    455
    456     } else if (p.type === Const.OBJECT_TYPE_ANGLE) {
    457         el = board.create('text', [
    458             function () {
    459                 return p.getLabelAnchor();
    460             },
    461             ''
    462         ], attr);
    463         txt_fun = getTextFun(el, p, 'angle', attr.measure);
    464     }
    465
    466     if (Type.exists(el)) {
    467         el.setText(txt_fun);
    468         p.addChild(el);
    469         el.setParents([p]);
    470     }
    471
    472     return el;
    473 };
    474
    475 JXG.registerElement("smartlabel", JXG.createSmartLabel);
    476