Function openable 

pub fn openable(uri: &str) -> bool

Whether the system may be asked to open an address read from a file (someone else’s task or event, a note): the web, mail, a phone, a map, a file on this computer. Not a share of another computer (“file://host/…”, which Windows reaches with your credentials), nor a scheme that starts a program (“ms-msdt:”, “search-ms:”): those are shown, not opened. The window should ask it too before Qt.openUrlExternally.