/* gstreamermm - a C++ wrapper for gstreamer
 *
 * Copyright 2008 The gstreamermm Development Team
 *
 * This library 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 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <gstreamermm/pad.h>
#include <gstreamermm/caps.h>
#include <gstreamermm/buffer.h>

_PINCLUDE(gstreamermm/private/element_p.h)

namespace Gst
{

const Glib::ustring BaseTransform::SINK_NAME = GST_BASE_TRANSFORM_SINK_NAME;
const Glib::ustring BaseTransform::SRC_NAME = GST_BASE_TRANSFORM_SRC_NAME;

GstFlowReturn BaseTransform_Class::prepare_output_buffer_vfunc_callback(GstBaseTransform* self, GstBuffer* input, GstBuffer** buffer)
{
  Glib::ObjectBase *const obj_base = static_cast<Glib::ObjectBase*>(
      Glib::ObjectBase::_get_current_wrapper((GObject*)self));

  // Non-gtkmmproc-generated custom classes implicitly call the default
  // Glib::ObjectBase constructor, which sets is_derived_. But gtkmmproc-
  // generated classes can use this optimisation, which avoids the unnecessary
  // parameter conversions if there is no possibility of the virtual function
  // being overridden:
  if(obj_base && obj_base->is_derived_())
  {
    CppObjectType *const obj = dynamic_cast<CppObjectType* const>(obj_base);
    if(obj) // This can be NULL during destruction.
    {
      try // Trap C++ exceptions which would normally be lost because this is a C callback.
      {
        Glib::RefPtr<Gst::Buffer> cpp_buffer;
        // Call the virtual member method, which derived classes might override.
        const GstFlowReturn result =
          static_cast<GstFlowReturn>(obj->prepare_output_buffer_vfunc(
          Glib::wrap(input, true), cpp_buffer));
          *buffer = cpp_buffer ? cpp_buffer->gobj_copy() : 0;
        return result;
      }
      catch(...)
      {
        Glib::exception_handlers_invoke();
      }
    }
  }
  
  BaseClassType *const base = static_cast<BaseClassType*>(
      g_type_class_peek_parent(G_OBJECT_GET_CLASS(self)) // Get the parent class of the object class (The original underlying C class).
  );

  // Call the original underlying C function:
  if(base && base->prepare_output_buffer)
    return (*base->prepare_output_buffer)(self, input, buffer);


  typedef GstFlowReturn RType;
  return RType();
}
FlowReturn Gst::BaseTransform::prepare_output_buffer_vfunc(const Glib::RefPtr<Gst::Buffer>& input, Glib::RefPtr<Gst::Buffer>& buffer)
{
  BaseClassType *const base = static_cast<BaseClassType*>(
      g_type_class_peek_parent(G_OBJECT_GET_CLASS(gobject_)) // Get the parent class of the object class (The original underlying C class).
  );

  if(base && base->prepare_output_buffer)
  {
    GstBuffer* gst_buffer;
    const Gst::FlowReturn result =
      static_cast<Gst::FlowReturn>((*base->prepare_output_buffer)(gobj(),
      Glib::unwrap(input), &gst_buffer));
    buffer = Glib::wrap(gst_buffer, false); // Don't take copy because callback returns a newly created copy.
    return result;
  }

  typedef FlowReturn RType;
  return RType();
}

} //namespace Gst
