Hi, On Mon, Dec 09, 2002 at 11:39:50PM +0100, Oliver Rauch wrote: > > SANE_Status sane_message_callback (SANE_String_Const text); > > > > Only one function. We don't need multiple open messages boxes, do we? > > For more than one function, we would need multiple callbacks. > > > > For a graphical interface: > > - Open a window, print the text, add a cancel button. > > - If the window is already open, change the text. (10/9/8... if someone > > likes countdowns) > > - If text == 0, close the window > > > > For a command-line interface > > - print the message(s) > > - If text == 0, do nothing > > Keep in mind that a frontend can open multiple backends/scanners > and so a frontend must be able to handle multiple backend messages. > I suggest to keep the **window field, this makes it much easier for > a frontend to handle it.
Depends when the callback pointer is transmitted to the backend. If it's done in sane_open, the frontend knows for which handle it is. And that's a good idea anyway because the user probably wants to know about which of his scanners the message is talking. > > | this has to be done with a callback, eg.: > > | sane_frontend_dialog_display(**window, text, ok_text, cancel_text, > > | backend_dialog_callback_function) sane_frontend_dialog_close(window) > > > > That would be a callback of a callback... > > I do not need a selection "ok", "cancel" but someone asked for it. I don't even know how to implement the "simple" callback over the network. For a double callback, oh well. I don't want to think about it :-) Bye, Henning
