constraint: auto label constraint object with type name

assembly.py

@@ -1027,12 +1027,10 @@ class AsmConstraint(AsmGroup):
             constraints = sel.Assembly.Proxy.getConstraintGroup()
             cstr = constraints.Document.addObject("App::FeaturePython",
                     name,AsmConstraint(constraints),None,True)
-            proxy = ViewProviderAsmConstraint(cstr.ViewObject)
-            logger.debug('cstr viewobject {},{},{},{}'.format(
-                id(proxy),id(cstr.ViewObject.Proxy),
-                id(proxy.ViewObject),id(cstr.ViewObject)))
+            ViewProviderAsmConstraint(cstr.ViewObject)
             constraints.setLink({-1:cstr})
             Constraint.setTypeID(cstr,typeid)
+            cstr.Label = Constraint.getTypeName(cstr)
 
         try:
             for e in sel.Elements:

constraint.py

@@ -398,8 +398,13 @@ class Constraint(ProxyType):
     def onChanged(mcs,obj,prop):
         if prop == mcs._disabled:
             obj.ViewObject.signalChangeIcon()
-            return
-        return super(Constraint,mcs).onChanged(obj,prop)
+        if super(Constraint,mcs).onChanged(obj,prop):
+            try:
+                if obj.Name==obj.Label or \
+                   mcs.getType(utils.getLabel(obj)):
+                    obj.Label = mcs.getTypeName(obj)
+            except Exception as e:
+                logger.debug('auto constraint label failed: {}'.format(e))
 
     @classmethod
     def isDisabled(mcs,obj):

utils.py

@@ -521,3 +521,13 @@ def edge2VertexIndex(obj,name,retInteger=False):
     if retInteger:
         return idx-1,idx2-1
     return 'Vertex{}'.format(idx),'Vertex{}'.format(idx2)
+
+def getLabel(obj):
+    '''Return object's label without trailing index'''
+    label = obj.Label
+    for i,c in enumerate(reversed(label)):
+        if not c.isdigit():
+            if i:
+                label = label[:-i]
+            break
+    return label