text: //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~//
  // Copyright (c) 2015-2019, Lawrence Livermore National Security, LLC.
  //
  // Produced at the Lawrence Livermore National Laboratory
  //
  // LLNL-CODE-716457
  //
  // All rights reserved.
  //
  // This file is part of Ascent.
  //
  // For details, see: http://ascent.readthedocs.io/.
  //
  // Please also read ascent/LICENSE
  //
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are met:
  //
  // * Redistributions of source code must retain the above copyright notice,
  //   this list of conditions and the disclaimer below.
  //
  // * Redistributions in binary form must reproduce the above copyright notice,
  //   this list of conditions and the disclaimer (as noted below) in the
  //   documentation and/or other materials provided with the distribution.
  //
  // * Neither the name of the LLNS/LLNL nor the names of its contributors may
  //   be used to endorse or promote products derived from this software without
  //   specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  // ARE DISCLAIMED. IN NO EVENT SHALL LAWRENCE LIVERMORE NATIONAL SECURITY,
  // LLC, THE U.S. DEPARTMENT OF ENERGY OR CONTRIBUTORS BE LIABLE FOR ANY
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  //
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~//
  
  //-----------------------------------------------------------------------------
  ///
  /// file: ascent_web_interface.hpp
  ///
  //-----------------------------------------------------------------------------
  #ifndef ASCENT_WEB_INTERFACE_HPP
  #define ASCENT_WEB_INTERFACE_HPP
  
  #include <string>
  
  #include <conduit.hpp>
  #include <conduit_relay.hpp>
  #include <ascent_config.h>
  
  //-----------------------------------------------------------------------------
  // -- begin ascent:: --
  //-----------------------------------------------------------------------------
  namespace ascent
  {
  
  //-----------------------------------------------------------------------------
  /// -- Returns path to root directory for web client resources --
  /// Source path:     src/ascent/web_clients
  /// Installed path:  {install_prefix}/share/ascent/web_clients
  //-----------------------------------------------------------------------------
  std::string web_client_root_directory();
  
  class WebInterface
  {
  public:
  
       WebInterface();
      ~WebInterface();
  
      // Note: Set methods must be called before first call
      // to Push methods.
  
      // if set, Ascent's web resources (html, js files, etc) are
      // are copied to and server at the given path
      // if not set, they are served out of web_client_root_directory()
  
      void                            SetDocumentRoot(const std::string &path);
      void                            SetPoll(int ms_poll);
      void                            SetTimeout(int ms_timeout);
  
      void                            Enable();
  
      void                            PushMessage(const conduit::Node &msg);
      void                            PushRenders(const conduit::Node &renders);
  
  private:
  #ifdef ASCENT_WEBSERVER_ENABLED
      conduit::relay::web::WebSocket *Connection();
  
      void                            EncodeImage(const std::string &png_file_path,
                                                  conduit::Node &out);
      bool                            m_enabled;
      conduit::relay::web::WebServer  m_server;
      int                             m_ms_poll;
      int                             m_ms_timeout;
      std::string                     m_doc_root;
  #endif
  };
  
  
  //-----------------------------------------------------------------------------
  };
  //-----------------------------------------------------------------------------
  // -- end ascent:: --
  //-----------------------------------------------------------------------------
  
  #endif
  //-----------------------------------------------------------------------------
  // -- end header ifdef guard
  //-----------------------------------------------------------------------------
  
  
  