Add position and rotation propagation - (Task #5)

Add a simple solution in json_product_child to propagate values from
parent to children and also test this behavior.

The current method results in children only having an absolute position
(and rotation) instead of a relative one to their parent. This should be
reconsidered with usability and the export functionality in mind.

---
Task #5: Implement Import Functionality

VirtualSatelliteCAD/json_io/products/json_product.py

@@ -129,6 +129,8 @@ def _set_freecad_position_and_rotation(self, active_document):
 
         product_part = active_document.app_active_document.getObjectsByLabel(product_part_name)[0]
 
+        # TODO: check if the same bug as below applies
+        # TODO: Add testcases in test_product
         # First translate than rotate around X, Y and Z
         vector_translation = active_document.app.Vector(self.pos_x, self.pos_y, self.pos_z)
         vector_rotation_zero = active_document.app.Rotation(VECTOR_ZERO, 0)
@@ -195,7 +197,7 @@ def is_part_reference(self):
 
         return has_part_uuid and has_part_name
 
-    def hasEqualValues(self, other):
+    def has_equal_values(self, other):
         """
         Compares values with another AJsonProduct
         """

VirtualSatelliteCAD/json_io/products/json_product_assembly.py

@@ -70,6 +70,7 @@ class without implementation. Additionally this method starts parsing
         self.children = []
         for json_object_child in json_object_children:
             json_product_child = JsonProductChild().parse_from_json(json_object_child)
+            json_product_child.propagate_pos_and_rot_from_parent(self)
             self.children.append(json_product_child)
 
         # Don't hand back an assembly if there are no children

VirtualSatelliteCAD/json_io/products/json_product_child.py

@@ -54,6 +54,7 @@ def parse_from_json(self, json_object):
             for json_object_child in json_object_children:
 
                 json_product_child = JsonProductChild().parse_from_json(json_object_child)
+                json_product_child.propagate_pos_and_rot_from_parent(self)
                 self.children.append(json_product_child)
 
         return self
@@ -70,3 +71,25 @@ def write_to_freecad(self, active_document):
         if self.has_children:
             for child in self.children:
                 child.write_to_freecad(active_document)
+
+    def propagate_pos_and_rot_from_parent(self, parent):
+        """
+        TODO:
+        This function propagates position and rotation parameters from the parent:
+        Doing this the pos and rot of an object become absolute not relative, which could result
+        in overhead when parsing back.
+        The question occurs how we handle this problems:
+        - Does a product hold its relative and absolute position?
+        - if yes how do we keep them in sync
+        - ideal would be to only show relative positions to the FreeCAD user and compute them
+         to absolute positions internally
+        - is that possible with freecad? it seems to only accept absolute positions and no inheritance
+        - constraints???
+        """
+        self.pos_x += parent.pos_x
+        self.pos_y += parent.pos_y
+        self.pos_z += parent.pos_z
+
+        self.rot_x += parent.rot_x
+        self.rot_y += parent.rot_y
+        self.rot_z += parent.rot_z

VirtualSatelliteCAD/test/json_io/test_json_importer.py

@@ -324,7 +324,9 @@ def test_full_import(self):
                     product_object = active_document.app_active_document.getObjectsByLabel(subchild.get_unique_name())
                     self.assertIsNotNone(product_object, "Found an object under the given part name")
 
-        # TODO: Check: Should it propagate coordinate values from parent to child or is there a bug in virsat export?
+                    # Check propagation
+                    # poz_z of -500 should be propagated from "BeamStructure"
+                    self.assertEqual(subchild.pos_z, 500.0, "Z position got propagated correctly")
 
     def test_full_import_again(self):
         """
@@ -363,7 +365,11 @@ def test_full_import_again(self):
 
         for i, child1 in enumerate(json_product.children):
             child2 = json_product2.children[i]
-            child1.hasEqualValues(child2)
+            child1.has_equal_values(child2)
 
     def test_full_import_again_with_changes(self):
+        """
+        If two files with the same name get imported all elements of the second file should overwrite the elements of the first file,
+        but elements existing in the first file (but not in the second file) won't be changed
+        """
         pass