[gegl] operations: add metadata property to gegl:load and gegl:save

[Øyvind "pippin" Kolås <ok src gnome org>]

commit 385f1ab0ec19dceb5c0e438721cd2e3ae2f8a977
Author: Øyvind Kolås <pippin gimp org>
Date:   Fri May 8 13:43:51 2020 +0200

    operations: add metadata property to gegl:load and gegl:save
    
    This exposes a GeglMetaDataStore property on these wrapper ops, iff the
    load handler or saver supports meta data it also gets set on the format
    specific handler.

 operations/common/save.c |  8 ++++++++
 operations/core/load.c   | 12 +++++++++++-
 2 files changed, 19 insertions(+), 1 deletion(-)
---
diff --git a/operations/common/save.c b/operations/common/save.c
index 4780c8fa9..da9653a1d 100644
--- a/operations/common/save.c
+++ b/operations/common/save.c
@@ -18,12 +18,15 @@
 
 #include "config.h"
 #include <glib/gi18n-lib.h>
+#include <gegl-metadata.h>
 
 
 #ifdef GEGL_PROPERTIES
 
 property_file_path (path, _("File"), "")
     description(_("Path of file to save."))
+property_object (metadata, _("Metadata"), GEGL_TYPE_METADATA)
+    description (_("Object providing image metadata"))
 
 #else
 
@@ -82,6 +85,11 @@ gegl_save_set_saver (GeglOperation *operation)
                      "operation", handler,
                      "path",      o->path,
                      NULL);
+
+      if (o->metadata &&
+          gegl_operation_find_property (handler, "metadata") != NULL)
+        gegl_node_set (self->save, "metadata", o->metadata, NULL);
+
     }
   else
     {
diff --git a/operations/core/load.c b/operations/core/load.c
index 47d02ba7b..095e05c53 100644
--- a/operations/core/load.c
+++ b/operations/core/load.c
@@ -18,6 +18,7 @@
 
 #include "config.h"
 #include <glib/gi18n-lib.h>
+#include <gegl-metadata.h>
 
 #ifdef G_OS_WIN32
 #define realpath(a,b) _fullpath(b,a,_MAX_PATH)
@@ -29,6 +30,8 @@ property_file_path (path, _("File"), "")
     description (_("Path of file to load."))
 property_uri (uri, _("URI"), "")
     description (_("URI of file to load."))
+property_object (metadata, _("Metadata"), GEGL_TYPE_METADATA)
+    description (_("Object to supply image metadata"))
 
 #else
 
@@ -79,6 +82,7 @@ static void
 do_setup (GeglOperation *operation, const gchar *path, const gchar *uri)
 {
   GeglOp  *self = GEGL_OP (operation);
+  GeglProperties *o = GEGL_PROPERTIES (operation);
   const gchar *handler = NULL;
   gchar *content_type = NULL, *filename = NULL, *message;
   gboolean load_from_uri, uncertain;
@@ -256,6 +260,11 @@ do_setup (GeglOperation *operation, const gchar *path, const gchar *uri)
     }
 
   gegl_node_set (self->load, "operation", handler, NULL);
+
+  if (o->metadata &&
+      gegl_operation_find_property (handler, "metadata") != NULL)
+    gegl_node_set (self->load, "metadata", o->metadata, NULL);
+
   if (load_from_uri == TRUE)
     gegl_node_set (self->load, "uri", uri, NULL);
   else
@@ -332,6 +341,7 @@ my_set_property (GObject      *gobject,
 
   gchar *old_path = g_strdup (o->path);
   gchar *old_uri = g_strdup (o->uri);
+  void  *old_metadata = o->metadata;
 
   gboolean props_changed;
 
@@ -339,7 +349,7 @@ my_set_property (GObject      *gobject,
    * storing and reffing/unreffing of the input properties
    */
   set_property (gobject, property_id, value, pspec);
-  props_changed = g_strcmp0 (o->path, old_path) || g_strcmp0 (o->uri, old_uri);
+  props_changed = g_strcmp0 (o->path, old_path) || g_strcmp0 (o->uri, old_uri) || (old_metadata != 
o->metadata);
 
   if (self->load && props_changed)
     do_setup (operation, o->path, o->uri);