[gimp] pdb, libgimp: add gimp_load_procedure_set_thumbnail_loader()

[Michael Natterer <mitch src gnome org>]

commit fc065f8addf4ea637acfec6a42250dec2674efe0
Author: Michael Natterer <mitch gimp org>
Date:   Sun Aug 11 14:27:41 2019 +0200

    pdb, libgimp: add gimp_load_procedure_set_thumbnail_loader()
    
    and move the old API to gimplegacy.[ch]

 libgimp/gimp.def            |  2 ++
 libgimp/gimpfileops_pdb.c   |  6 +++---
 libgimp/gimpfileops_pdb.h   |  2 +-
 libgimp/gimplegacy.c        | 27 ++++++++++++++++++++++++
 libgimp/gimplegacy.h        |  2 ++
 libgimp/gimploadprocedure.c | 50 +++++++++++++++++++++++++++++++++++++++++++++
 libgimp/gimploadprocedure.h | 28 ++++++++++++++-----------
 pdb/groups/fileops.pdb      |  2 ++
 8 files changed, 103 insertions(+), 16 deletions(-)
---
diff --git a/libgimp/gimp.def b/libgimp/gimp.def
index 114bc07b8a..657eb5862b 100644
--- a/libgimp/gimp.def
+++ b/libgimp/gimp.def
@@ -569,9 +569,11 @@ EXPORTS
        gimp_layer_set_opacity
        gimp_layer_set_show_mask
        gimp_load_procedure_get_handles_raw
+       gimp_load_procedure_get_thumbnail_loader
        gimp_load_procedure_get_type
        gimp_load_procedure_new
        gimp_load_procedure_set_handles_raw
+       gimp_load_procedure_set_thumbnail_loader
        gimp_main
        gimp_main_legacy
        gimp_message
diff --git a/libgimp/gimpfileops_pdb.c b/libgimp/gimpfileops_pdb.c
index 23cc4b1cc2..dcd7affb3c 100644
--- a/libgimp/gimpfileops_pdb.c
+++ b/libgimp/gimpfileops_pdb.c
@@ -616,7 +616,7 @@ _gimp_register_file_handler_raw (const gchar *procedure_name)
 }
 
 /**
- * gimp_register_thumbnail_loader:
+ * _gimp_register_thumbnail_loader:
  * @load_proc: The name of the procedure the thumbnail loader with.
  * @thumb_proc: The name of the thumbnail load procedure.
  *
@@ -634,8 +634,8 @@ _gimp_register_file_handler_raw (const gchar *procedure_name)
  * Since: 2.2
  **/
 gboolean
-gimp_register_thumbnail_loader (const gchar *load_proc,
-                                const gchar *thumb_proc)
+_gimp_register_thumbnail_loader (const gchar *load_proc,
+                                 const gchar *thumb_proc)
 {
   GimpPDB        *pdb = gimp_get_pdb ();
   GimpValueArray *args;
diff --git a/libgimp/gimpfileops_pdb.h b/libgimp/gimpfileops_pdb.h
index 54be19cbc2..572f5c2ded 100644
--- a/libgimp/gimpfileops_pdb.h
+++ b/libgimp/gimpfileops_pdb.h
@@ -65,7 +65,7 @@ G_GNUC_INTERNAL gboolean _gimp_register_file_handler_mime     (const gchar *proc
                                                                const gchar *mime_types);
 G_GNUC_INTERNAL gboolean _gimp_register_file_handler_uri      (const gchar *procedure_name);
 G_GNUC_INTERNAL gboolean _gimp_register_file_handler_raw      (const gchar *procedure_name);
-gboolean                 gimp_register_thumbnail_loader       (const gchar *load_proc,
+G_GNUC_INTERNAL gboolean _gimp_register_thumbnail_loader      (const gchar *load_proc,
                                                                const gchar *thumb_proc);
 
 
diff --git a/libgimp/gimplegacy.c b/libgimp/gimplegacy.c
index 1af0d02810..efcee94b4c 100644
--- a/libgimp/gimplegacy.c
+++ b/libgimp/gimplegacy.c
@@ -1396,6 +1396,33 @@ gimp_register_file_handler_raw (const gchar *procedure_name)
   return _gimp_register_file_handler_raw (procedure_name);
 }
 
+/**
+ * gimp_register_thumbnail_loader:
+ * @load_proc: The name of the procedure the thumbnail loader with.
+ * @thumb_proc: The name of the thumbnail load procedure.
+ *
+ * Associates a thumbnail loader with a file load procedure.
+ *
+ * Some file formats allow for embedded thumbnails, other file formats
+ * contain a scalable image or provide the image data in different
+ * resolutions. A file plug-in for such a format may register a special
+ * procedure that allows GIMP to load a thumbnail preview of the image.
+ * This procedure is then associated with the standard load procedure
+ * using this function.
+ *
+ * Returns: TRUE on success.
+ *
+ * Since: 2.2
+ **/
+gboolean
+gimp_register_thumbnail_loader (const gchar *load_proc,
+                                const gchar *thumb_proc)
+{
+  ASSERT_NO_PLUG_IN_EXISTS (G_STRFUNC);
+
+  return _gimp_register_thumbnail_loader (load_proc, thumb_proc);
+}
+
 /**
  * gimp_pdb_temp_name:
  *
diff --git a/libgimp/gimplegacy.h b/libgimp/gimplegacy.h
index 44af8b9918..4c5e20b748 100644
--- a/libgimp/gimplegacy.h
+++ b/libgimp/gimplegacy.h
@@ -328,6 +328,8 @@ gboolean   gimp_register_file_handler_mime     (const gchar *procedure_name,
                                                 const gchar *mime_types);
 gboolean   gimp_register_file_handler_uri      (const gchar *procedure_name);
 gboolean   gimp_register_file_handler_raw      (const gchar *procedure_name);
+gboolean   gimp_register_thumbnail_loader      (const gchar *load_proc,
+                                                const gchar *thumb_proc);
 
 /* pdb stuff that should now be done using GimpPDB
  */
diff --git a/libgimp/gimploadprocedure.c b/libgimp/gimploadprocedure.c
index 918fb38abc..76e2e5b9b8 100644
--- a/libgimp/gimploadprocedure.c
+++ b/libgimp/gimploadprocedure.c
@@ -34,6 +34,7 @@ struct _GimpLoadProcedurePrivate
   GDestroyNotify  run_data_destroy;
 
   gboolean        handles_raw;
+  gchar          *thumbnail_proc;
 };
 
 
@@ -111,6 +112,8 @@ gimp_load_procedure_finalize (GObject *object)
   if (procedure->priv->run_data_destroy)
     procedure->priv->run_data_destroy (procedure->priv->run_data);
 
+  g_clear_pointer (&procedure->priv->thumbnail_proc, g_free);
+
   G_OBJECT_CLASS (parent_class)->finalize (object);
 }
 
@@ -153,6 +156,10 @@ gimp_load_procedure_install (GimpProcedure *procedure)
 
   if (load_proc->priv->handles_raw)
     _gimp_register_file_handler_raw (gimp_procedure_get_name (procedure));
+
+  if (load_proc->priv->thumbnail_proc)
+    _gimp_register_thumbnail_loader (gimp_procedure_get_name (procedure),
+                                     load_proc->priv->thumbnail_proc);
 }
 
 static GimpValueArray *
@@ -260,3 +267,46 @@ gimp_load_procedure_get_handles_raw (GimpLoadProcedure *procedure)
 
   return procedure->priv->handles_raw;
 }
+
+/**
+ * gimp_load_procedure_set_thumbnail_loader:
+ * @procedure:      A #GimpLoadProcedure.
+ * @thumbnail_proc: The name of the thumbnail load procedure.
+ *
+ * Associates a thumbnail loader with a file load procedure.
+ *
+ * Some file formats allow for embedded thumbnails, other file formats
+ * contain a scalable image or provide the image data in different
+ * resolutions. A file plug-in for such a format may register a
+ * special procedure that allows GIMP to load a thumbnail preview of
+ * the image. This procedure is then associated with the standard
+ * load procedure using this function.
+ *
+ * Since: 3.0
+ **/
+void
+gimp_load_procedure_set_thumbnail_loader (GimpLoadProcedure *procedure,
+                                          const gchar       *thumbnail_proc)
+{
+  g_return_if_fail (GIMP_IS_LOAD_PROCEDURE (procedure));
+
+  g_free (procedure->priv->thumbnail_proc);
+  procedure->priv->thumbnail_proc = g_strdup (thumbnail_proc);
+}
+
+/**
+ * gimp_load_procedure_get_thumbnail_loader:
+ * @procedure: A #GimpLoadProcedure.
+ *
+ * Returns: The procedure's thumbnail loader procedure as set with
+ *          gimp_load_procedure_set_thumbnail_procedure().
+ *
+ * Since: 3.0
+ **/
+const gchar *
+gimp_load_procedure_get_thumbnail_loader (GimpLoadProcedure *procedure)
+{
+  g_return_val_if_fail (GIMP_IS_LOAD_PROCEDURE (procedure), NULL);
+
+  return procedure->priv->thumbnail_proc;
+}
diff --git a/libgimp/gimploadprocedure.h b/libgimp/gimploadprocedure.h
index 1b77e03908..4011fbe6a3 100644
--- a/libgimp/gimploadprocedure.h
+++ b/libgimp/gimploadprocedure.h
@@ -76,18 +76,22 @@ struct _GimpLoadProcedureClass
 };
 
 
-GType           gimp_load_procedure_get_type        (void) G_GNUC_CONST;
-
-GimpProcedure * gimp_load_procedure_new             (GimpPlugIn        *plug_in,
-                                                     const gchar       *name,
-                                                     GimpPDBProcType    proc_type,
-                                                     GimpLoadFunc       run_func,
-                                                     gpointer           run_data,
-                                                     GDestroyNotify     run_data_destroy);
-
-void            gimp_load_procedure_set_handles_raw (GimpLoadProcedure *procedure,
-                                                     gboolean           handles_raw);
-gboolean        gimp_load_procedure_get_handles_raw (GimpLoadProcedure *procedure);
+GType           gimp_load_procedure_get_type             (void) G_GNUC_CONST;
+
+GimpProcedure * gimp_load_procedure_new                  (GimpPlugIn        *plug_in,
+                                                          const gchar       *name,
+                                                          GimpPDBProcType    proc_type,
+                                                          GimpLoadFunc       run_func,
+                                                          gpointer           run_data,
+                                                          GDestroyNotify     run_data_destroy);
+
+void            gimp_load_procedure_set_handles_raw      (GimpLoadProcedure *procedure,
+                                                          gboolean           handles_raw);
+gboolean        gimp_load_procedure_get_handles_raw      (GimpLoadProcedure *procedure);
+
+void            gimp_load_procedure_set_thumbnail_loader (GimpLoadProcedure *procedure,
+                                                          const gchar       *thumbnail_proc);
+const gchar   * gimp_load_procedure_get_thumbnail_loader (GimpLoadProcedure *procedure);
 
 
 G_END_DECLS
diff --git a/pdb/groups/fileops.pdb b/pdb/groups/fileops.pdb
index a9df8419ea..75e205644e 100644
--- a/pdb/groups/fileops.pdb
+++ b/pdb/groups/fileops.pdb
@@ -712,6 +712,8 @@ HELP
 
     &neo_pdb_misc('2004', '2.2');
 
+    $lib_private = 1;
+
     @inargs = (
         { name => 'load_proc', type => 'string', non_empty => 1,
           desc => "The name of the procedure the thumbnail loader with." },