Problems with FileOpenItem

[Mauro Cavalcanti]

Dear ALL,

I just started using guidata, which is really great. However, when
attempting to put two fields of FileOpenItem class in a tabbed dialog (that
is, a DataSetGroup) I found two annoying problems, as follows:

1) When I attempt to close the dialog by clicking the OK button *without*
filling the fields with filenames, I am presented with a message
complaining that "highlighted fields" must not be empty, even if none is
shown because I have initialized the FileOpenItem fields with null strings
(but they appear highlighted if I initialize them with blank strings).
Anyway, perusing the source code and the documentation could not find just
how to control this behaviour, which I want to turn off.

2) The icons in the buttons of the FileOpenItem fields are shown as Qt
default icons, but I want to have my own icons displayed.

What seems more strange is that when I run the all_features.py demo
program, the icons in the FileOpenItem field are show as different icons,
even if I execute a copy of the script in a different directory from the
guidata installation.

I attach my (humble) code to this message and hope someone can help me on
these issues.

Thanks in advance for any assistance you can provide!