The GearContext interface extends PortalContext. Its getGearMode method provides access to the gear mode. The GearContext also provides access to the community, display mode, page, and portal made available by the PortalContext.
Each gear renders in a particular GearContext. You can access the current GearContext from a gear by accessing the GEARSERVLETREQUEST attribute, part of the HttpServletRequest. To create your own GearContext you can use the GearContextImpl class
