text: 
  //
  // This source file is part of appleseed.
  // Visit https://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) 2014-2018 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.
  //
  
  #pragma once
  
  // appleseed.studio headers.
  #include "mainwindow/project/entityeditorcontext.h"
  #include "mainwindow/project/itemregistry.h"
  #include "mainwindow/project/projectbuilder.h"
  
  // appleseed.foundation headers.
  #include "foundation/core/concepts/noncopyable.h"
  #include "foundation/utility/uid.h"
  
  // Qt headers.
  #include <QList>
  #include <QObject>
  #include <QShortcut>
  
  // Standard headers.
  #include <memory>
  
  // Forward declarations.
  namespace appleseed { namespace studio { class AttributeEditor; } }
  namespace appleseed { namespace studio { class ItemBase; } }
  namespace appleseed { namespace studio { class ProjectManager; } }
  namespace appleseed { namespace studio { class RenderingManager; } }
  namespace renderer  { class ParamArray; }
  namespace renderer  { class Project; }
  class QMenu;
  class QPoint;
  class QString;
  class QTreeWidget;
  class QTreeWidgetItem;
  
  namespace appleseed {
  namespace studio {
  
  class ProjectExplorer
    : public QObject
    , public foundation::NonCopyable
  {
      Q_OBJECT
  
    public:
      ProjectExplorer(
          QTreeWidget*            tree_widget,
          AttributeEditor*        attribute_editor,
          renderer::Project&      project,
          ProjectManager&         project_manager,
          RenderingManager&       rendering_manager,
          renderer::ParamArray&   settings);
  
      ~ProjectExplorer() override;
  
      void filter_items(const QString& pattern) const;
  
      void clear_selection() const;
      ItemBase* select_entity(const foundation::UniqueID uid) const;
  
    signals:
      void signal_project_modified() const;
      void signal_frame_modified() const;
  
    private:
      QTreeWidget*                m_tree_widget;
      AttributeEditor*            m_attribute_editor;
      ProjectBuilder              m_project_builder;
      ItemRegistry                m_item_registry;
      EntityEditorContext         m_editor_context;
      std::unique_ptr<QShortcut>  m_delete_shortcut;
  
      QMenu* build_single_item_context_menu(QTreeWidgetItem* item) const;
      QMenu* build_multiple_items_context_menu(const QList<QTreeWidgetItem*>& item_widgets) const;
  
    private slots:
      void slot_context_menu(const QPoint& point);
      void slot_item_selection_changed();
      void slot_edit_item(QTreeWidgetItem* item, int column);
      void slot_delete_items();
  };
  
  }   // namespace studio
  }   // namespace appleseed
  