next-read-file-uses-dialog-p

next-read-file-uses-dialog-p is a built-in function in `C source code'.

(next-read-file-uses-dialog-p)

Return t if a call to `read-file-name' will use a dialog.
The return value is only relevant for a call to `read-file-name' that happens
before any other event (mouse or keypress) is handled.