how to modify google maps navigator control style

i search through the google maps api reference, but they provide no met开发者_运维问答hod or property for creating a new type of navigation control. i wonder how to create navigator control like image below.

1. First disable the defaultUI
2. Add your custom control in the map like that
3. Catch zoom events from the map(zoom_changed event) and notify your control and vice versa(map.setZoom())