Filedialog "sandbox"

[sancelot]

Hi,
I have following questions regarding filedialog :

1/ Is there a way to lock filedialog access to a particular location (like a sandbox, user can not access parents directories)

2/ I need a rich filedialog UI interface (on linux system)
At time of writing I don't know which way to go for filedialog :
a/ Define a desktop theme that the filedialog will use ?
b/ override qml filedialog icons ?

Regards,
Steph