SystemFileChooser: Add custom components (like file format options) below the file browser #1077
Description
I don't know the possibility and the complexity of implementation the feature proposed but let's discuss it anyway :)
Our app has some save/export dialogs in which file format can be customized. We used to use JFileChooser as a JComponent that can be added in a custom JDialog with some custom elements below it. Is it possible to add some (maybe AWT) components into SystemFileChooser? LibreOffice Calc save dialog is an example. It is not desired practice to show format dialog after file selection dialog (or hide format options to app preferences).
This feature also depends on #1065, because the user selected file format/extension is needed to change format options enabled.
P.S. Thank you for the SystemFileChooser, it is a very desirable feature.