Determine if an HTML element's content overflows

Question

Can I use JavaScript to check (irrespective of scrollbars) if an HTML element has overflowed its content? For example, a long div with small, fixed size, the overflow proper

Answer 1

This is a javascript solution (with Mootools) that will reduce the font size to fit the bounds of elHeader.

while (elHeader.clientWidth < elHeader.scrollWidth || elHeader.clientHeight < elHeader.scrollHeight) {
  var f = parseInt(elHeader.getStyle('font-size'), 10);
  f--;
  elHeader.setStyle('font-size', f + 'px');
}

The CSS of elHeader:

    width:100%;
    font-size:40px;
    line-height:36px;
    font-family:Arial;
    text-align:center;
    max-height:36px;
    overflow:hidden;

Note the wrapper of elHeader sets the width of elHeader.