code: def apply_settings(self):
          
          qapp = QApplication.instance()
          # Set 'gtk+' as the default theme in Gtk-based desktops
          # Fixes Issue 2036
          if is_gtk_desktop() and ('GTK+' in QStyleFactory.keys()):
              try:
                  qapp.setStyle('gtk+')
              except:
                  pass
          else:
              style_name = CONF.get('appearance', 'windows_style',
                                    self.default_style)
              style = QStyleFactory.create(style_name)
              if style is not None:
                  style.setProperty('name', style_name)
                  qapp.setStyle(style)
  
          default = self.DOCKOPTIONS
          if CONF.get('main', 'vertical_tabs'):
              default = default|QMainWindow.VerticalTabs
          if CONF.get('main', 'animated_docks'):
              default = default|QMainWindow.AnimatedDocks
          self.setDockOptions(default)
  
          self.apply_panes_settings()
          self.apply_statusbar_settings()
  
          if CONF.get('main', 'use_custom_cursor_blinking'):
              qapp.setCursorFlashTime(CONF.get('main', 'custom_cursor_blinking'))
          else:
              qapp.setCursorFlashTime(self.CURSORBLINK_OSDEFAULT)
docs: Apply settings changed in 'Preferences' dialog box