I was trying to figure out a way to detect when the user typing in the editor has paused / stopped. The documentation of CKEditor and Stackoverflow do not have my answer, fortunately I was able to come up with a simple solution!

I first started with the basics – I played with a simple <textarea />  without CKEditor and the code bellow worked for me:

Type in the text box. it will time out and run the function when you stop for the time alotted.
<textarea id="editor"></textarea>

var timer = null;
$('#editor').keydown(function(){
       clearTimeout(timer); 
       timer = setTimeout(doStuff, 1000)
});

function doStuff() {
    alert('do stuff');
}

And next –  I applied the code above to a CKEditor instance.

CKEditor doesn’t have keyup  or keydown  events, but what they have is key

So I did the following using closures and it worked for me!

var timer = null;
CKEDITOR.instances['#editor'].on('key', function(){ 
	clearTimeout(timer); 
	timer = setTimeout(doStuff.bind(textarea, $('#editor')), 1000)
});

function doStuff(textarea) {
    alert(textarea.val());
}