text: 
  //
  // This source file is part of appleseed.
  // Visit http://appleseedhq.net/ for additional information and resources.
  //
  // This software is released under the MIT license.
  //
  // Copyright (c) 2010-2013 Francois Beaune, Jupiter Jazz Limited
  // Copyright (c) 2014-2017 Francois Beaune, The appleseedhq Organization
  //
  // Permission is hereby granted, free of charge, to any person obtaining a copy
  // of this software and associated documentation files (the "Software"), to deal
  // in the Software without restriction, including without limitation the rights
  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  // copies of the Software, and to permit persons to whom the Software is
  // furnished to do so, subject to the following conditions:
  //
  // The above copyright notice and this permission notice shall be included in
  // all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  // THE SOFTWARE.
  //
  
  // Interface header.
  #include "qttilecallback.h"
  
  // appleseed.studio headers.
  #include "mainwindow/rendering/renderwidget.h"
  
  // Qt headers.
  #include <QObject>
  #include <Qt>
  
  // Standard headers.
  #include <cassert>
  #include <cstddef>
  
  // Forward declarations.
  namespace renderer  { class Frame; }
  
  using namespace foundation;
  using namespace renderer;
  
  namespace appleseed {
  namespace studio {
  
  namespace
  {
      class QtTileCallback
        : public QObject
        , public TileCallbackBase
      {
          Q_OBJECT
  
        public:
          explicit QtTileCallback(RenderWidget* render_widget)
            : m_render_widget(render_widget)
          {
              connect(
                  this, SIGNAL(signal_update()),
                  m_render_widget, SLOT(update()),
                  Qt::QueuedConnection);
          }
  
          void release() override
          {
              delete this;
          }
  
          void on_tile_begin(
              const Frame*    frame,
              const size_t    tile_x,
              const size_t    tile_y) override
          {
              assert(m_render_widget);
              m_render_widget->highlight_tile(*frame, tile_x, tile_y);
              emit signal_update();
          }
  
          void on_tile_end(
              const Frame*    frame,
              const size_t    tile_x,
              const size_t    tile_y) override
          {
              assert(m_render_widget);
              m_render_widget->blit_tile(*frame, tile_x, tile_y);
              emit signal_update();
          }
  
          void on_progressive_frame_end(
              const Frame*    frame) override
          {
              assert(m_render_widget);
              m_render_widget->blit_frame(*frame);
              emit signal_update();
          }
  
        signals:
          void signal_update();
  
        private:
          RenderWidget* m_render_widget;
      };
  }
  
  
  //
  // QtTileCallbackFactory class implementation.
  //
  
  QtTileCallbackFactory::QtTileCallbackFactory(RenderWidget* render_widget)
    : m_render_widget(render_widget)
  {
  }
  
  void QtTileCallbackFactory::release()
  {
      delete this;
  }
  
  ITileCallback* QtTileCallbackFactory::create()
  {
      return new QtTileCallback(m_render_widget);
  }
  
  }   // namespace studio
  }   // namespace appleseed
  
  #include "mainwindow/rendering/moc_cpp_qttilecallback.cxx"
  