pixbuf-thumbnailer: Use a mime-type-specific loader when possible

This allows to fully use the capabilities of the specific pixbuf loader
for the considered mime type according to the installed optional
libraries. This is especially necessary to load some SVG or HEIF
thumbnails.

On the other hand, if this specific loader doesn't work properly, it may
be even more noticeable. This is the case for libopenraw, for which a
dedicated plugin using another API has fortunately been implemented. So
we just have to prioritize it in `tumbler.rc`.

Fixes #20, #32, #36, see !18 for more details.

Co-authored-by: @Krifa75 (Gitlab ID)

1 files changed, 8 insertions, 2 deletions

diff --git a/plugins/pixbuf-thumbnailer/pixbuf-thumbnailer.c b/plugins/pixbuf-thumbnailer/pixbuf-thumbnailer.c
index df00f99..e7f1820 100644
--- a/plugins/pixbuf-thumbnailer/pixbuf-thumbnailer.c
+++ b/plugins/pixbuf-thumbnailer/pixbuf-thumbnailer.c
@@ -138,6 +138,7 @@ pixbuf_thumbnailer_size_prepared (GdkPixbufLoader  *loader,
 static GdkPixbuf *
 pixbuf_thumbnailer_new_from_stream (GInputStream      *stream,
                                     TumblerThumbnail  *thumbnail,
+                                    const gchar       *mime_type,
                                     GCancellable      *cancellable,
                                     GError           **error)
 {
@@ -152,8 +153,12 @@ pixbuf_thumbnailer_new_from_stream (GInputStream      *stream,
   g_return_val_if_fail (G_IS_INPUT_STREAM (stream), NULL);
   g_return_val_if_fail (error == NULL || *error == NULL, NULL);
 
-  /* prepare the loader */
-  loader = gdk_pixbuf_loader_new ();
+  /* try to use a pixbuf loader specific to the mime type, falling back on the
+   * generic loader in case of error */
+  loader = gdk_pixbuf_loader_new_with_mime_type (mime_type, NULL);
+  if (loader == NULL)
+    loader = gdk_pixbuf_loader_new ();
+
   g_signal_connect (loader, "size-prepared",
       G_CALLBACK (pixbuf_thumbnailer_size_prepared), thumbnail);
 
@@ -257,6 +262,7 @@ pixbuf_thumbnailer_create (TumblerAbstractThumbnailer *thumbnailer,
    * gdk_pixbuf_new_from_file_at_scale(), but without increasing the
    * pixbuf size. */
   pixbuf = pixbuf_thumbnailer_new_from_stream (G_INPUT_STREAM (stream), thumbnail,
+                                               tumbler_file_info_get_mime_type (info),
                                                cancellable, &error);
 
   g_object_unref (stream);