homing: Create QueryEndstops class from gcode

Create the QueryEndstops in the gcode handler instead of in the
kinematic classes.  This simplifies the gcode handler as it can
directly register its response callback.

Also, store the stepper name in the stepper class.  Also, propagate
the print_time of the query request to the mcu_endstop class.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/homing.py

@@ -65,31 +65,36 @@ class Homing:
         del self.endstops[:]
         return False
 
+# Helper code for querying and reporting the status of the endstops
 class QueryEndstops:
-    def __init__(self, names, steppers):
+    def __init__(self, print_time, respond_cb):
+        self.print_time = print_time
+        self.respond_cb = respond_cb
         self.endstops = []
         self.busy = []
-        for name, stepper in zip(names, steppers):
-            es = stepper.query_endstop()
+    def set_steppers(self, steppers):
+        for stepper in steppers:
+            es = stepper.query_endstop(self.print_time)
             if es is None:
                 continue
-            self.endstops.append((name, es))
+            self.endstops.append((stepper.name, es))
             self.busy.append(es)
     def check_busy(self, eventtime):
+        # Check if all endstop queries have been received
         while self.busy:
             busy = self.busy[0].check_busy(eventtime)
             if busy:
                 return True
             self.busy.pop(0)
-        return False
-    def get_msg(self):
+        # All responses received - report status
         msgs = []
         for name, es in self.endstops:
             msg = "open"
             if es.get_last_triggered():
                 msg = "TRIGGERED"
             msgs.append("%s:%s" % (name, msg))
-        return " ".join(msgs)
+        self.respond_cb(" ".join(msgs))
+        return False
 
 class EndstopError(Exception):
     def __init__(self, pos, msg="Move out of range"):