fix can_create in editor list (and some refactoring)

src/c3nav/editor/utils.py

@@ -0,0 +1,45 @@
+class DefaultEditUtils:
+    def __init__(self, request):
+        self.request = request
+
+    @property
+    def can_access_child_base_mapdata(self):
+        return self.request.user_permissions.can_access_base_mapdata
+
+    @property
+    def can_create(self):
+        return self.can_access_child_base_mapdata
+
+    @property
+    def _geometry_url(self):
+        return None
+
+    @property
+    def geometry_url(self):
+        return self._geometry_url if self.can_access_child_base_mapdata else None
+
+
+class LevelChildEditUtils(DefaultEditUtils):
+    def __init__(self, level, request):
+        super().__init__(request)
+        self.level = level
+
+    @property
+    def _geometry_url(self):
+        return '/api/editor/geometries/?level=' + str(self.level.primary_level_pk)
+
+
+class SpaceChildEditUtils(DefaultEditUtils):
+    def __init__(self, space, request):
+        super().__init__(request)
+        self.space = space
+
+    @property
+    def can_access_child_base_mapdata(self):
+        return (self.request.user_permissions.can_access_base_mapdata or
+                self.space.base_mapdata_accessible or
+                self.space.pk in self.request.user_space_access)
+
+    @property
+    def _geometry_url(self):
+        return '/api/editor/geometries/?space='+str(self.space.pk)