• Michael Weghorn's avatar
    FileChooser: Return selected filter · 8922d260
    Michael Weghorn authored and Jan Grulich's avatar Jan Grulich committed
    This implements handling the 'current_filter' return
    value which returns the filter that was selected in the
    file chooser and was added to 'xdg-desktop-portal'
    and thus the FileChooser API in commit [1].
    
    Keep a mapping between the user-visible names
    (for name filters) or MIME types (for MIME type
    filters) to the actual filters in order to retrieve
    the actual filter to return after running the file dialog.
    
    Since multiple name filters can use the same filter string,
    those aren't necessarily unique, so use the user-visible
    names rather than just the filter string to avoid
    potential name clashes and be able to retrieve the correct
    filter again in the end.
    
    Mapping back to an actual filter does not necessarily
    work in all cases, e.g. if a manual filter string was
    entered in the file widget. No 'current_filter' is
    returned in that case.
    
    This commit moves the extraction of the filters to a
    separate method to avoid code duplication.
    
    Handling 'current_filter' is e.g. needed to make gtk's
    'gtk_file_chooser_get_filter' function work for the portal
    use case. The filter returned by 'gtk_file_chooser_get_filter'
    (not just the file extension) is used e.g. by Firefox and
    Thunderbird to determine what file format to save a file in,
    s. Mozilla bug [2] and gtk issue [3] for more details.
    
    This way, this commit makes that scenario work for the
    KF5 native file chooser as well (with 'GTK_USE_PORTAL=1'
    set and 'xdg-desktop-portal-kde' in use).
    
    Note: For the case of a gtk program, like the Firefox use case,
    this depends on the gtk commits [4] and and [5] in addition
    to xdg-desktop-portal commit [1] to actually work as expected.
    
    [1] https://github.com/flatpak/xdg-desktop-portal/commit/35fca7fae881bdaba1bebccf7775eba84407a488
    [2] https://bugzilla.mozilla.org/show_bug.cgi?id=1517074
    [3] https://gitlab.gnome.org/GNOME/gtk/-/issues/1820
    [4] https://gitlab.gnome.org/GNOME/gtk/-/commit/baddc90c26f65a0867aa6b4073e1a6b689d87136
    [5] https://gitlab.gnome.org/GNOME/gtk/-/commit/d59b28d5f4e2c4ff4cb51df0a39d94c7df7fee96
    8922d260
filechooser.cpp 20 KB