JSXGraph
JSXGraph share

Share

Adding JSXGraph events
Show plain example
QR code 
<iframe 
    src="http://jsxgraph.uni-bayreuth.de/share/iframe/adding-jsxgraph-events" 
    style="border: 1px solid black; overflow: hidden; width: 550px; aspect-ratio: 55 / 65;" 
    name="JSXGraph example: Adding JSXGraph events" 
    allowfullscreen
></iframe>
This code has to 
<p id="myOutput"> </p>

<div id="board-0-wrapper" class="jxgbox-wrapper " style="width: 100%; ">
   <div id="board-0" class="jxgbox" style="aspect-ratio: 1 / 1; width: 100%;" data-ar="1 / 1"></div>
</div>

<script type = "text/javascript"> 
    /*
    This example is licensed under a 
    Creative Commons Attribution 4.0 International License.
    https://creativecommons.org/licenses/by/4.0/
    
    Please note you have to mention 
    The Center of Mobile Learning with Digital Technology
    in the credits.
    */
    
    const BOARDID = 'board-0';

    const board = JXG.JSXGraph.initBoard(BOARDID, {
        boundingbox: [-4, 4, 4, -4],
        keepaspectratio: true
    });
    
    var p = board.create('point', [1, 1], {
        size: 5,
        fixed: true
    });
    p.on('over', (e) => {
        document.getElementById('myOutput').innerHTML = "Point " + p.name;
    });
    
    p.on('out', (e) => {
        document.getElementById('myOutput').innerHTML = ' ';
    });
    
    var p2 = board.create('point', [-1, 1], {
        size: 5
    });
    p2.on('over', function(e) {
        document.getElementById('myOutput').innerHTML = "Point " + this.name;
    });
    p2.on('out', function(e) {
        document.getElementById('myOutput').innerHTML = ' ';
    });
 </script> 
/*
This example is licensed under a 
Creative Commons Attribution 4.0 International License.
https://creativecommons.org/licenses/by/4.0/

Please note you have to mention 
The Center of Mobile Learning with Digital Technology
in the credits.
*/

const BOARDID = 'your_div_id'; // Insert your id here!

const board = JXG.JSXGraph.initBoard(BOARDID, {
    boundingbox: [-4, 4, 4, -4],
    keepaspectratio: true
});

var p = board.create('point', [1, 1], {
    size: 5,
    fixed: true
});
p.on('over', (e) => {
    document.getElementById('myOutput').innerHTML = "Point " + p.name;
});

p.on('out', (e) => {
    document.getElementById('myOutput').innerHTML = ' ';
});

var p2 = board.create('point', [-1, 1], {
    size: 5
});
p2.on('over', function(e) {
    document.getElementById('myOutput').innerHTML = "Point " + this.name;
});
p2.on('out', function(e) {
    document.getElementById('myOutput').innerHTML = ' ';
});

Adding JSXGraph events

Technical
It is possible to supply user-defined defined functions for certain events. The user-defined functions are called additionally to the default JSXGraph events. For the events `down` and `up` the user-supplied event handlers are called before the default JSXGraph event handler. For the event `update` the user-supplied handler is called after the default JSXGraph event handler which is an update of the board. A user-supplied event handler can be defined by the method `on`: ~~~ var p = board.create('point',[1,1]); p.on('update', function(e) { /* do something ... */); ~~~ The possible events are listed in the API docs for [elements, see Event Summary](https://jsxgraph.org/docs/symbols/JXG.GeometryElement.html) and [board, see Event Summary](https://jsxgraph.org/docs/symbols/JXG.Board.html). As of version 1.5.0, it is only possible to access the element via *this* if the event listener is supplied as regular JavaScript function and not as *arrow function*.

 

<p id="myOutput"> </p>
// Define the id of your board in BOARDID

const board = JXG.JSXGraph.initBoard(BOARDID, {
    boundingbox: [-4, 4, 4, -4],
    keepaspectratio: true
});

var p = board.create('point', [1, 1], {
    size: 5,
    fixed: true
});
p.on('over', (e) => {
    document.getElementById('myOutput').innerHTML = "Point " + p.name;
});

p.on('out', (e) => {
    document.getElementById('myOutput').innerHTML = ' ';
});

var p2 = board.create('point', [-1, 1], {
    size: 5
});
p2.on('over', function(e) {
    document.getElementById('myOutput').innerHTML = "Point " + this.name;
});
p2.on('out', function(e) {
    document.getElementById('myOutput').innerHTML = ' ';
});

license

This example is licensed under a Creative Commons Attribution 4.0 International License.
Please note you have to mention The Center of Mobile Learning with Digital Technology in the credits.