On Text Highlight Event?

Question

I'm curious if anyone knows how I would trigger a function to run if/once the user finishes selecting text on the web page? I would like the user to be able to select text, and after a short delay(or immediately, at this point it doesn't matter much) an overlay button appears near the text that the user can then click and I go back and run more of my code that is based on the selection. This is for a Firefox extension.

A similar example that I can think of would be like in IE where you can select text and then it brings up the "web accelerators". I'm 99% sure I know how I would actually overlay the button, and get the position of the selected text, but I have no idea how to check to see if there is anything selected, without doing some sort of infinite loop, which just seems like a terrible idea.

EDIT:

//In my overlay.js with the rest of my sidebar code
isTextSelected: function () {   
        var myText = cqsearch.getSelectedText();
        var sidebar = document.getElementById("sidebar");
        var sidebarDoc = sidebar.contentDocument || document;

        var curHighlightedDiv = sidebarDoc.getElementById("testDiv");
        curHighlightedDiv.innerHTML = "Current text selection:" + myText;
    }
};

//In my on firefox load function I added this
document.onmouseup = cqsearch.isTextSelected;

So this is what I have come up with using Robert's suggestion, and it took me some time getting everything in the right spot, but it works great! Now on to position my button.

Answer 1

There isn't any onhighlightext or anything like that, but a solution would be to bind onmouseup to check if any text is selected if this isn't in a input/textarea.

Edit

Here's an implementation example for you. I only tested this in Chrome/Firefox/IE7. This works in inputs as well.

http://jsfiddle.net/qY7gE/

Code from JSFiddle:

var t = '';
function gText(e) {
    t = (document.all) ? document.selection.createRange().text : document.getSelection();

    document.getElementById('input').value = t;
}

document.onmouseup = gText;
if (!document.all) document.captureEvents(Event.MOUSEUP);

<input type='text' id='input' />
In software, a stack overflow occurs when too much memory is used on the call stack. The call stack contains a limited amount of memory, often determined at the start of the program. The size of the call stack depends on many factors, including the programming language, machine architecture, multi-threading, and amount of available memory. When too much memory is used on the call stack the stack is said to overflow, typically resulting in a program crash.[1] This class of software bug is usually caused by one of two types of programming errors.[2]