Dynamic font-resizing for fixed width element that corresponds with another div

Question

I'm looking for a solution that will automatically re-size some text in a fixed width div to fit.

The only tricky thing is that on some of them, I need the both of the font sizes to match the smallest size (to ensure that both of the elements are always the same size.) I was thinking this could be achieved by giving them the same class name or something to indicate correlation.

Thanks!

Answer 1

So, given a bunch of inputs and outputs:

<div class="inputs">
    <input type="text" value="John Smith">
    <input type="text" value="Jane Doe">
</div>

<ul class="outputs">
    <li></li>
    <li></li>
</ul>

Use this function to bind the outputs to the inputs:

function sync( inputs, outputs ) {
    var max_width, max_size, curr_size;

    function curr_max_width() {
        return Math.max.apply( null, $( outputs ).map( function () {
            return $( this ).width();
        }).get() );
    }

    outputs = $( outputs ).wrapInner( '<span />' ).children().get();
    max_width = $( outputs ).parent().width();
    max_size = parseInt( $( outputs ).css( 'font-size' ), 10 );

    $( inputs ).bind( 'keyup change', function ( e ) {      
        $( outputs ).text( function ( i ) {
            return $( inputs ).eq( i ).val();
        });

        curr_size = 0;        
        do {
            curr_size += 1;
            $( outputs ).css({ 'font-size': curr_size + 'px' });
        } while ( curr_max_width() < max_width && curr_size < max_size );

        $( outputs ).css({ 'font-size': ( curr_size - 1 ) + 'px' });
    }).triggerHandler( 'change' );
}

Usage:

var inputs = $( 'input:text', '.inputs' ).get();
var outputs = $( 'li', '.outputs' ).get();

sync( inputs, outputs );

Live demo: http://jsfiddle.net/HF4W4/18/

So, the sync function expects an array of <input> elements as the first argument and an array of block elements as the second argument. Notice that the output elements should have white-space: nowrap set. The sync function inner-wraps the output elements in <span> elements, so that it can read the width of the content.