Selecting multiple files / directories is not actually implemented.

[TheNeikos]

A bug I ran into just now:

I currently have:

    let dialog_options = FileDialogOptions::new()
        .select_directories()
        .multi_selection();

    let window = WindowDesc::new(build_schauglas)
        .menu(MenuDesc::new(LocalizedString::new("menubar")).append(
            MenuDesc::new(LocalizedString::new("file").with_placeholder("File")).append(
                MenuItem::new(
                    LocalizedString::new("open").with_placeholder("Open"),
                    Command::new(SHOW_OPEN_PANEL, dialog_options),
                ),
            ),
        ));

And in my delegate, I am simply printing out whatever command gets in:

      -> bool {
        debug!("Cmd: {:?}", cmd);
        if let Some(file_info) = cmd.get(OPEN_FILE) {
            return true;
        }

        false
    }

this gives me the following outputs:

• When selecting a single directory: Cmd: Command { symbol: "druid-builtin.open-file-path", payload: Any }
• When selecting multiple:

Info:

• Windows 10
• Druid 0.6

[luleyleo]

Now this one is interesting.

It seems like the options for selecting multiple files / directories were added in #616, yet they have never been implemented.
Enabling multi_selection does set the flag for the dialog, but does not handle the result correctly (It just expects a single file).
On Windows it apparently returns nothing, on GTK it just returns the uppermost selected file, not sure what the effect on macOS is.

To make this work we would also have to change OPEN_FILE to take a Vec<FileInfo> as payload and change WindowHandle::open_file_sync to return Vec<FileInfo>.

[cmyr]

Huh yea this is an oversight. Agree with @Finnerale about the required API changes.

[raphlinus]

Since we want get rid of the sync call to deal with #1068, maybe we can roll up both API changes at the same time.

[cmyr]

I also think we might want to unify file opening to use whatever API we end up with for modals alerts; see #1039.

[atlanticaccent]

Hi, it'd be great if this were to be implemented for Windows too.

I do think it should be called out in the FileDialogOption docs that this is not implemented on Windows yet.