[simple-scan] Restrict image file filter to supported image formats.

[Robert Ancell <rancell src gnome org>]

commit 1b3c99bc73b7ae490268f8a6974f026c588c191c
Author: Stéphane Fillion <stphanef3724 gmail com>
Date:   Thu Apr 27 12:26:50 2017 -0400

    Restrict image file filter to supported image formats.
    
    Old image file filter displayed many file with image formats supported by
    Gdk.Pixbuf but unsupported by Simple-Scan. By example, it showed bmp images.
    Selecting such file didn't have the expected result of saving in bmp format but
    replaced the bmp image by a jpeg one. The new behaviour is to only display files
    simple-scan support.

 src/ui.vala |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/src/ui.vala b/src/ui.vala
index 2265a13..29b2169 100644
--- a/src/ui.vala
+++ b/src/ui.vala
@@ -532,9 +532,10 @@ public class UserInterface : Gtk.ApplicationWindow
 
         /* Filter to only show images by default */
         var filter = new Gtk.FileFilter ();
-        filter.set_filter_name (/* Save dialog: Filter name to show only image files */
+        filter.set_filter_name (/* Save dialog: Filter name to show only supported image files */
                                 _("Image Files"));
-        filter.add_pixbuf_formats ();
+        filter.add_mime_type ("image/jpeg");
+        filter.add_mime_type ("image/png");
         filter.add_mime_type ("application/pdf");
         save_dialog.add_filter (filter);
         filter = new Gtk.FileFilter ();