Changed parent of ETS

jhavl · jhavl · commit 73aaef51c5b9 · 2020-09-21T15:23:20.000+10:00
diff --git a/roboticstoolbox/backend/urdf/urdf.py b/roboticstoolbox/backend/urdf/urdf.py
@@ -1718,15 +1718,15 @@ def __init__(self, name, links, joints=None,
             for j in range(len(elinks)):
                 if i != j:
                     if self.joints[i].parent == self.joints[j].child:
-                        elinks[i]._parent.append(elinks[j])
+                        elinks[i]._parent = elinks[j]
                         found = True
 
             if not found:
                 link = self._link_map[self.joints[i].parent]
                 base_link = rp.ELink(
                         rp.ET(),
                         name=link.name)
-                elinks[i]._parent.append(base_link)
+                elinks[i]._parent = base_link
                 try:
                     for visual in link.visuals:
                         base_link.geometry.append(visual.geometry.ob)
diff --git a/roboticstoolbox/robot/ELink.py b/roboticstoolbox/robot/ELink.py
@@ -75,13 +75,12 @@ def __init__(
         self._name = name
 
         if isinstance(parent, ELink):
-            parent = [parent]
+            pass
         elif parent is None:
-            parent = []
-        elif not isinstance(parent, list):
+            pass
+        elif isinstance(parent, list):
             raise TypeError(
-                'The parent link must be of type ELink'
-                ' or list of Elink')
+                'Only one parent link can be present')
 
         self._parent = parent
         self._child = []
@@ -118,6 +117,9 @@ def __init__(
         self.Tc = Tc
         self.G = G
 
+    def __repr__(self):
+        return self.name
+
     @property
     def collision(self):
         return self._collision
diff --git a/roboticstoolbox/robot/ETS.py b/roboticstoolbox/robot/ETS.py
@@ -74,6 +74,7 @@ def __init__(
             raise TypeError('The links must be stored in a list.')
 
         self._ets = []
+        self._elinks = {}
         self._n = 0
         self._M = 0
         self._q_idx = []
@@ -82,6 +83,7 @@ def __init__(
         for link in elinks:
             if isinstance(link, ELink):
                 self._M += 1
+                self._elinks[link.name] = link
             else:
                 raise TypeError("Input can be only ELink")
 
@@ -90,11 +92,12 @@ def __init__(
         self.root = []
         self.end = []
         for link in elinks:
-            for li in link.parent:
-                li._child.append(link)
-
-            if len(link.parent) == 0:
+            if link.parent is None:
                 self.root.append(link)
+            else:
+                link.parent._child.append(link)
+
+
 
         # Find the bottom of the tree
         for link in elinks:
@@ -336,6 +339,10 @@ def qlim(self):
 
         return v
 
+    @property
+    def elinks(self):
+        return self._elinks
+
     @property
     def base_link(self):
         return self._base_link
@@ -570,7 +577,7 @@ def fkine_all(self, q=None):
             else:
                 t = self.ets[i].A()
 
-            self.ets[i]._fk = self.ets[i].parent[0]._fk * t
+            self.ets[i]._fk = self.ets[i].parent._fk * t
 
             # Update the collision objects transform as well
             for col in self.ets[i].collision:
