new_contents: # Copyright (c) 2018, CNRS-LAAS
  # All rights reserved.
  #
  # 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 following disclaimer.
  #
  #  * Redistributions in binary form must reproduce the above copyright notice,
  #    this list of conditions and the following disclaimer in the documentation
  #    and/or other materials provided with the distribution.
  #
  # 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 THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  # SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  import subprocess
  import abc
  
  
  class NoUI:
      def message_dialog(self, message: str):
          pass
  
      def warning_dialog(self, message: str):
          pass
  
      def error_dialog(self, message: str):
          pass
  
      def question_dialog(self, message: str) -> bool:
          """Always returns True"""
          return True
  
  
  class ZenityUI(NoUI):
      def message_dialog(self, message: str):
          """Show a dialog window with a 'message' next an image 'type'"""
          subprocess.run(["zenity", "--info",
                          "--text={}".format(message)])
  
      def warning_dialog(self, message: str):
          """Show a dialog window with a 'message' next an image 'type'"""
          subprocess.run(["zenity", "--warning",
                          "--text={}".format(message)])
  
      def error_dialog(self, message: str):
          """Show a dialog window with a 'message' next an image 'type'"""
          subprocess.run(["zenity", "--error",
                          "--text={}".format(message)])
  
      def question_dialog(self, message: str) -> bool:
          """Show a dialog window with a 'message' next an image 'type'"""
          if subprocess.run(["zenity", "--question",
                             "--text={}".format(message)]).returncode == 0:
              return True
          else:
              return False
  
  
subject: Add Zenity-based user interface for SuperSAOP