ArduPlane: add and use HAL_BUTTON_ENABLE

ArduPlane/ArduPlane.cpp

@@ -102,7 +102,9 @@ const AP_Scheduler::Task Plane::scheduler_tasks[] = {
     SCHED_TASK(avoidance_adsb_update,  10,    100),
 #endif
     SCHED_TASK_CLASS(RC_Channels,       (RC_Channels*)&plane.g2.rc_channels, read_aux_all,           10,    200),
+#if HAL_BUTTON_ENABLED
     SCHED_TASK_CLASS(AP_Button, &plane.button, update, 5, 100),
+#endif
 #if STATS_ENABLED == ENABLED
     SCHED_TASK_CLASS(AP_Stats, &plane.g2.stats, update, 1, 100),
 #endif

ArduPlane/Parameters.cpp

@@ -1033,9 +1033,11 @@ const AP_Param::Info Plane::var_info[] = {
  */
 const AP_Param::GroupInfo ParametersG2::var_info[] = {
 
+#if HAL_BUTTON_ENABLED
     // @Group: BTN_
     // @Path: ../libraries/AP_Button/AP_Button.cpp
     AP_SUBGROUPPTR(button_ptr, "BTN_", 1, ParametersG2, AP_Button),
+#endif
 
     // @Group: ICE_
     // @Path: ../libraries/AP_ICEngine/AP_ICEngine.cpp
@@ -1262,7 +1264,9 @@ ParametersG2::ParametersG2(void) :
 #if HAL_SOARING_ENABLED
     ,soaring_controller(plane.TECS_controller, plane.aparm)
 #endif
+#if HAL_BUTTON_ENABLED
     ,button_ptr(&plane.button)
+#endif
 {
     AP_Param::setup_object_defaults(this, var_info);
 }

ArduPlane/Parameters.h

@@ -489,7 +489,9 @@ public:
     static const struct AP_Param::GroupInfo var_info[];
 
     // button reporting library
+#if HAL_BUTTON_ENABLED
     AP_Button *button_ptr;
+#endif
 
 #if STATS_ENABLED == ENABLED
     // vehicle statistics