使用jQuery检测容器溢出？

$.fn.hasOverflow = function() {
    var $this = $(this);
    var $children = $this.find('*');
    var len = $children.length;

    if (len) {
        var maxWidth = 0;
        var maxHeight = 0
        $children.map(function(){
            maxWidth = Math.max(maxWidth,$(this).outerWidth(true));
            maxHeight = Math.max(maxHeight,$(this).outerHeight(true));
        });

        return maxWidth > $this.width() || maxHeight > $this.height();
    }

    return false;
};

例：

var $content = $('#content').children().wrapAll('<div>');
while($content.hasOverflow()){
    var size = parseFloat($content.css('font-size'),10);
    size -= 1;
    $content.css('font-size',size + 'px');
}