Add named getters to check "state" of motor (#310)

See #297

Author: ddemidov

ev3dev/core.py

@@ -845,6 +845,40 @@ def reset(self, **kwargs):
         self.command = self.COMMAND_RESET
 
 
+# ~autogen
+# ~autogen motor_states classes.motor>currentClass
+
+    @property
+    def is_running(self):
+        """Power is being sent to the motor.
+        """
+        return self.STATE_RUNNING in self.state
+
+    @property
+    def is_ramping(self):
+        """The motor is ramping up or down and has not yet reached a constant output level.
+        """
+        return self.STATE_RAMPING in self.state
+
+    @property
+    def is_holding(self):
+        """The motor is not turning, but rather attempting to hold a fixed position.
+        """
+        return self.STATE_HOLDING in self.state
+
+    @property
+    def is_overloaded(self):
+        """The motor is turning, but cannot reach its `speed_sp`.
+        """
+        return self.STATE_OVERLOADED in self.state
+
+    @property
+    def is_stalled(self):
+        """The motor is not turning when it should be.
+        """
+        return self.STATE_STALLED in self.state
+
+
 # ~autogen
 
     def wait(self, cond, timeout=None):

templates/motor_states.liquid

@@ -0,0 +1,13 @@
+{% assign class_name = currentClass.friendlyName | camel_case | capitalize %}{%
+for prop in currentClass.propertyValues %}{%
+    if prop.propertyName == "State" %}{%
+        for state in prop.values %}
+    @property
+    def is_{{ state.name }}(self):
+        """{%
+        for line in state.description %}{{line}}
+        {% endfor %}"""
+        return self.STATE_{{ state.name | upcase }} in self.state
+{% endfor %}{%
+endif %}{%
+endfor %}