[gegl] graph: add GeglCallbackVisitor

[N/A <ell src gnome org>]

commit b1458e0d1e211ffbc885e916ec723f90b17d9c90
Author: Ell <ell_se yahoo com>
Date:   Thu Nov 9 14:36:52 2017 -0500

    graph: add GeglCallbackVisitor
    
    Add GeglCallbackVisitor -- a GeglVisitor subclass, taking a custom
    callback, and using it to visit the nodes.  Useful for traversing
    the graph without the fuss of defining a dedicated GObject.

 gegl/graph/Makefile.am             |    2 +
 gegl/graph/gegl-callback-visitor.c |   73 ++++++++++++++++++++++++++++++++++++
 gegl/graph/gegl-callback-visitor.h |   63 +++++++++++++++++++++++++++++++
 3 files changed, 138 insertions(+), 0 deletions(-)
---
diff --git a/gegl/graph/Makefile.am b/gegl/graph/Makefile.am
index 9cbfc2b..9992065 100644
--- a/gegl/graph/Makefile.am
+++ b/gegl/graph/Makefile.am
@@ -28,6 +28,7 @@ libgraph_la_SOURCES = \
        gegl-node.c             \
        gegl-pad.c              \
        gegl-visitor.c          \
+       gegl-callback-visitor.c \
        gegl-visitable.c        \
        \
        gegl-connection.h       \
@@ -35,6 +36,7 @@ libgraph_la_SOURCES = \
        gegl-node-private.h     \
        gegl-pad.h              \
        gegl-visitor.h          \
+       gegl-callback-visitor.h \
        gegl-visitable.h
 
 #libgraph_la_SOURCES = $(libgraph_sources) $(libgraph_public_HEADERS)
diff --git a/gegl/graph/gegl-callback-visitor.c b/gegl/graph/gegl-callback-visitor.c
new file mode 100644
index 0000000..c8ab737
--- /dev/null
+++ b/gegl/graph/gegl-callback-visitor.c
@@ -0,0 +1,73 @@
+/* This file is part of GEGL
+ *
+ * GEGL is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * GEGL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GEGL; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2017 Ell
+ */
+
+#include "config.h"
+
+#include <glib-object.h>
+
+#include "gegl.h"
+#include "gegl-types-internal.h"
+#include "gegl-callback-visitor.h"
+
+
+static void       gegl_callback_visitor_class_init (GeglCallbackVisitorClass *klass);
+static void       gegl_callback_visitor_init       (GeglCallbackVisitor      *self);
+static gboolean   gegl_callback_visitor_visit_node (GeglVisitor              *visitor,
+                                                    GeglNode                 *node);
+
+
+G_DEFINE_TYPE (GeglCallbackVisitor, gegl_callback_visitor, GEGL_TYPE_VISITOR)
+
+
+static void
+gegl_callback_visitor_class_init (GeglCallbackVisitorClass *klass)
+{
+  GeglVisitorClass *visitor_class = GEGL_VISITOR_CLASS (klass);
+
+  visitor_class->visit_node = gegl_callback_visitor_visit_node;
+}
+
+static void
+gegl_callback_visitor_init (GeglCallbackVisitor *self)
+{
+}
+
+static gboolean
+gegl_callback_visitor_visit_node (GeglVisitor *visitor,
+                                  GeglNode    *node)
+{
+  GeglCallbackVisitor *self = GEGL_CALLBACK_VISITOR (visitor);
+
+  return self->callback (node, self->data);
+}
+
+GeglVisitor *
+gegl_callback_visitor_new (GeglCallbackVisitorCallback callback,
+                           gpointer                    data)
+{
+  GeglCallbackVisitor *self;
+
+  g_return_val_if_fail (callback != NULL, NULL);
+
+  self = g_object_new (GEGL_TYPE_CALLBACK_VISITOR, NULL);
+
+  self->callback = callback;
+  self->data     = data;
+
+  return GEGL_VISITOR (self);
+}
diff --git a/gegl/graph/gegl-callback-visitor.h b/gegl/graph/gegl-callback-visitor.h
new file mode 100644
index 0000000..32c9cc5
--- /dev/null
+++ b/gegl/graph/gegl-callback-visitor.h
@@ -0,0 +1,63 @@
+/* This file is part of GEGL
+ *
+ * GEGL is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * GEGL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GEGL; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2017 Ell
+ */
+
+#ifndef __GEGL_CALLBACK_VISITOR_H__
+#define __GEGL_CALLBACK_VISITOR_H__
+
+#include "gegl-visitor.h"
+
+G_BEGIN_DECLS
+
+
+#define GEGL_TYPE_CALLBACK_VISITOR            (gegl_callback_visitor_get_type ())
+#define GEGL_CALLBACK_VISITOR(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), 
GEGL_TYPE_CALLBACK_VISITOR, GeglCallbackVisitor))
+#define GEGL_CALLBACK_VISITOR_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass),  
GEGL_TYPE_CALLBACK_VISITOR, GeglCallbackVisitorClass))
+#define GEGL_IS_CALLBACK_VISITOR(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), 
GEGL_TYPE_CALLBACK_VISITOR))
+#define GEGL_IS_CALLBACK_VISITOR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass),  
GEGL_TYPE_CALLBACK_VISITOR))
+#define GEGL_CALLBACK_VISITOR_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj),  
GEGL_TYPE_CALLBACK_VISITOR, GeglCallbackVisitorClass))
+
+
+typedef gboolean (* GeglCallbackVisitorCallback) (GeglNode *node,
+                                                  gpointer  data);
+
+
+typedef struct _GeglCallbackVisitor      GeglCallbackVisitor;
+typedef struct _GeglCallbackVisitorClass GeglCallbackVisitorClass;
+
+struct _GeglCallbackVisitor
+{
+  GeglVisitor                  parent_instance;
+
+  GeglCallbackVisitorCallback  callback;
+  gpointer                     data;
+};
+
+struct _GeglCallbackVisitorClass
+{
+  GeglVisitorClass  parent_class;
+};
+
+
+GType         gegl_callback_visitor_get_type (void) G_GNUC_CONST;
+
+GeglVisitor * gegl_callback_visitor_new      (GeglCallbackVisitorCallback callback,
+                                              gpointer                    data);
+
+G_END_DECLS
+
+#endif /* __GEGL_CALLBACK_VISITOR_H__ */