reveal-js-base-theme/plugin/math/mathjax/test/sample-dynamic-2.html

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<!DOCTYPE html>
<html>
<head>
<title>Dynamic Preview of Textarea with MathJax Content</title>
<!-- Copyright (c) 2012-2013 The MathJax Consortium -->
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<script type="text/x-mathjax-config">
MathJax.Hub.Config({
showProcessingMessages: false,
tex2jax: { inlineMath: [['$','$'],['\\(','\\)']] }
});
</script>
<script type="text/javascript" src="../MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
<script>
var Preview = {
delay: 150, // delay after keystroke before updating
preview: null, // filled in by Init below
buffer: null, // filled in by Init below
timeout: null, // store setTimout id
mjRunning: false, // true when MathJax is processing
oldText: null, // used to check if an update is needed
//
// Get the preview and buffer DIV's
//
Init: function () {
this.preview = document.getElementById("MathPreview");
this.buffer = document.getElementById("MathBuffer");
},
//
// Switch the buffer and preview, and display the right one.
// (We use visibility:hidden rather than display:none since
// the results of running MathJax are more accurate that way.)
//
SwapBuffers: function () {
var buffer = this.preview, preview = this.buffer;
this.buffer = buffer; this.preview = preview;
buffer.style.visibility = "hidden"; buffer.style.position = "absolute";
preview.style.position = ""; preview.style.visibility = "";
},
//
// This gets called when a key is pressed in the textarea.
// We check if there is already a pending update and clear it if so.
// Then set up an update to occur after a small delay (so if more keys
// are pressed, the update won't occur until after there has been
// a pause in the typing).
// The callback function is set up below, after the Preview object is set up.
//
Update: function () {
if (this.timeout) {clearTimeout(this.timeout)}
this.timeout = setTimeout(this.callback,this.delay);
},
//
// Creates the preview and runs MathJax on it.
// If MathJax is already trying to render the code, return
// If the text hasn't changed, return
// Otherwise, indicate that MathJax is running, and start the
// typesetting. After it is done, call PreviewDone.
//
CreatePreview: function () {
Preview.timeout = null;
if (this.mjRunning) return;
var text = document.getElementById("MathInput").value;
if (text === this.oldtext) return;
this.buffer.innerHTML = this.oldtext = text;
this.mjRunning = true;
MathJax.Hub.Queue(
["Typeset",MathJax.Hub,this.buffer],
["PreviewDone",this]
);
},
//
// Indicate that MathJax is no longer running,
// and swap the buffers to show the results.
//
PreviewDone: function () {
this.mjRunning = false;
this.SwapBuffers();
}
};
//
// Cache a callback to the CreatePreview action
//
Preview.callback = MathJax.Callback(["CreatePreview",Preview]);
Preview.callback.autoReset = true; // make sure it can run more than once
</script>
</head>
<body>
Type text in the box below:<br/>
<textarea id="MathInput" cols="60" rows="10" onkeyup="Preview.Update()" style="margin-top:5px">
</textarea>
<br/><br/>
Preview is shown here:
<div id="MathPreview" style="border:1px solid; padding: 3px; width:50%; margin-top:5px"></div>
<div id="MathBuffer" style="border:1px solid; padding: 3px; width:50%; margin-top:5px;
visibility:hidden; position:absolute; top:0; left: 0"><div>
<script>
Preview.Init();
</script>
</body>
</html>