Nissan: Parse distance button from steering wheel (#31766)

selfdrive/car/nissan/carstate.py

@@ -20,9 +20,15 @@ class CarState(CarStateBase):
     self.steeringTorqueSamples = deque(TORQUE_SAMPLES*[0], TORQUE_SAMPLES)
     self.shifter_values = can_define.dv["GEARBOX"]["GEAR_SHIFTER"]
 
+    self.prev_distance_button = 0
+    self.distance_button = 0
+
   def update(self, cp, cp_adas, cp_cam):
     ret = car.CarState.new_message()
 
+    self.prev_distance_button = self.distance_button
+    self.distance_button = cp.vl["CRUISE_THROTTLE"]["FOLLOW_DISTANCE_BUTTON"]
+
     if self.CP.carFingerprint in (CAR.ROGUE, CAR.XTRAIL, CAR.ALTIMA):
       ret.gas = cp.vl["GAS_PEDAL"]["GAS_PEDAL"]
     elif self.CP.carFingerprint in (CAR.LEAF, CAR.LEAF_IC):

selfdrive/car/nissan/interface.py

@@ -1,9 +1,11 @@
 from cereal import car
 from panda import Panda
-from openpilot.selfdrive.car import get_safety_config
+from openpilot.selfdrive.car import create_button_events, get_safety_config
 from openpilot.selfdrive.car.interfaces import CarInterfaceBase
 from openpilot.selfdrive.car.nissan.values import CAR
 
+ButtonType = car.CarState.ButtonEvent.Type
+
 
 class CarInterface(CarInterfaceBase):
 
@@ -30,6 +32,8 @@ class CarInterface(CarInterfaceBase):
   def _update(self, c):
     ret = self.CS.update(self.cp, self.cp_adas, self.cp_cam)
 
+    ret.buttonEvents = create_button_events(self.CS.distance_button, self.CS.prev_distance_button, {1: ButtonType.gapAdjustCruise})
+
     events = self.create_common_events(ret, extra_gears=[car.CarState.GearShifter.brake])
 
     if self.CS.lkas_enabled: