You can't do this with plain vanilla HTML, so JSF can't do much for you here as well.
Your best bet is using JavaScript for this. Here's an SSCCE, copy'n'paste'n'run it.
<!doctype html>
<html lang="en">
<head>
<title>SO question 2310734</title>
<script>
window.onload = function() {
var labels = document.getElementsByTagName('label');
for (var i = 0; i < labels.length; i++) {
disableSelection(labels[i]);
}
};
function disableSelection(element) {
if (typeof element.onselectstart != 'undefined') {
element.onselectstart = function() { return false; };
} else if (typeof element.style.MozUserSelect != 'undefined') {
element.style.MozUserSelect = 'none';
} else {
element.onmousedown = function() { return false; };
}
}
</script>
</head>
<body>
<label>Try to select this</label>
</body>
</html>
If you're already using jQuery, then here's another example which adds a new function disableSelection()
to jQuery so that you can use it anywhere in your jQuery code:
<!doctype html>
<html lang="en">
<head>
<title>SO question 2310734 with jQuery</title>
<script src="http://code.jquery.com/jquery-latest.min.js"></script>
<script>
$.fn.extend({
disableSelection: function() {
this.each(function() {
if (typeof this.onselectstart != 'undefined') {
this.onselectstart = function() { return false; };
} else if (typeof this.style.MozUserSelect != 'undefined') {
this.style.MozUserSelect = 'none';
} else {
this.onmousedown = function() { return false; };
}
});
}
});
$(document).ready(function() {
$('label').disableSelection();
});
</script>
</head>
<body>
<label>Try to select this</label>
</body>
</html>