code: def add_history(self, filename, color_scheme, font, wrap):
          
          filename = encoding.to_unicode_from_fs(filename)
          if filename in self.filenames:
              return
          editor = codeeditor.CodeEditor(self)
          if osp.splitext(filename)[1] == '.py':
              language = 'py'
          else:
              language = 'bat'
          editor.setup_editor(linenumbers=False,
                              language=language,
                              scrollflagarea=False,
                              show_class_func_dropdown=False)
          editor.focus_changed.connect(lambda: self.focus_changed.emit())
          editor.setReadOnly(True)
  
          editor.set_font(font, color_scheme)
          editor.toggle_wrap_mode(wrap)
  
          text, _ = encoding.read(filename)
          editor.set_text(text)
          editor.set_cursor_position('eof')
  
          self.editors.append(editor)
          self.filenames.append(filename)
          index = self.tabwidget.addTab(editor, osp.basename(filename))
          self.find_widget.set_editor(editor)
          self.tabwidget.setTabToolTip(index, filename)
          self.tabwidget.setCurrentIndex(index)
docs: Add new history tab.
  
          Args:
              filename (str): file to be loaded in a new tab.