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.

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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())