code: def add_to_screen(self, screen_width, screen):
          
          for lineno, fields in enumerate(self.line_fields):
              for left, field in self.compute_positions(screen_width, fields):
                  logger.debug(
                      "Adding field %s to screen %s at x=%d->%d, y=%d",
                      field, screen.ref, left, left + field.width - 1, 1 + lineno,
                  )
  
                  self.widgets[field] = field.add_to_screen(screen, left, 1 + lineno)
                  self.register_hooks(field)
docs: Add the pattern to a screen.
  
          Also fills self.widgets.
  
          Args:
              screen_width (int): the width of the screen
              screen (lcdprod.Screen): the screen to fill.