Thank you so much for this submission; I'm finding that it's very powerful and well thought out. I was wondering if someone could help me, though. I'm trying to create my own file chooser so that I'm able to add some check boxes to it. I've got that part down, but I'm not sure how to correctly create my own file filter, add callbacks to the 'Open' and 'Cancel' push buttons, and add icons to the buttons to the right of the directory selection drop down menu. I've tried setting the 'ActionPerformedCallback' property, but for some reason the callback function is only called when I click the 'Cancel' button.