Visual map items may each be constructed and placed in position using logic defined by a map view component corresponding to each visual item, where that logic may depend on one or more values populated into parameter of the map view component. The engaging ring has first teeth defined in an outer periphery thereof and a pawl is movably received in a side hole in the head. In addition, the wireless drawing command receiving unit transmits drawing command throttle data back to the wireless drawing command transmitting unit to throttle transmission of drawing commands that are sent by the drawing command transmitting unit.