How can I get this fieldset border to wrap tightly around it's contents

Question

I have a form with dynamically added fields (varying sizes). I would like to put a number of form fields in a fieldset, and have the fieldset border just large enough to contain all the fields.

Here is an (ugly) example that shows the issue:

var win = new Ext.Window({
    xtype: 'form',
    layout: 'form',
    height: 200,
    width: 500,
    title: 'Testing',
    items: [{
        xtype: 'fieldset',
        layout: 'hbox',
        autoHeight:true,
        autoWidth: false,
        title: 'Fieldset',
        defaults: {
            border: false,
            layout: 'form',
            labelAlign: 'top',
            labelSeparator: ''
        },
        items: [{
            items: new Ext.form.TextField({
                fieldLabel: 'Col1',
                name: 'col1',
                value: 'nothing',
            })
        }, {
            items: new Ext.form.TextField({
                fieldLabel: 'Col2',
                name: 'col2',
                value: 'something'
            })
        }]
    }, 
        new Ext.form.TextField({
            fieldLabel: 'Col3',
            name: 'col3',
            value: 'anything'
        })
    ]
}).show();

This is what it looks like:

I will not know the width of the contained fields beforehand, so I can't specify a width.

Thanks for any suggestions.

Answer 1

Ok, works by changing some fieldset properties:
layout to 'table',
autoWidth to true,
adding a cls with 'float:left', (putting this in style doesn't seem to help)
and adding a dummy element to clear the float:
{ xtype: 'component', style: 'clear:both' }

It now shows as desired!