Do not include ndarray data in BufferGeometry repr

There was an tendency for the numpy array data to unreasonably pad the
notebook size. This change prevents that.

Author: vidartf

pythreejs/core/BufferGeometry.py

@@ -1,7 +1,7 @@
 
 from ipywidgets import register, widget_serialization
-from traitlets import validate, TraitError
-from ipydatawidgets import NDArrayWidget
+from traitlets import validate, TraitError, Undefined
+from ipydatawidgets import NDArrayWidget, get_union_array
 
 from .BufferGeometry_autogen import BufferGeometry as BufferGeometryBase
 
@@ -30,3 +30,43 @@ def validate(self, proposal):
                 raise TraitError('Index attribute must be a flat array. Consider using array.ravel().')
 
         return value
+
+
+    def _gen_repr_from_keys(self, keys):
+        # Hide data in repr to avoid overly large datasets
+        # Replace with uuids of buffer attributes
+        class_name = self.__class__.__name__
+        signature_parts = [
+            '%s=%r' % (key, getattr(self, key))
+            for key in keys if key not in ('attributes', 'morphAttributes')
+        ]
+        for name in ('attributes', 'morphAttributes'):
+            if not _dict_is_default(self, name):
+                signature_parts.append('%s=%s' % (name, _attr_dict_repr(getattr(self, name))))
+        return '%s(%s)' % (class_name, ', '.join(signature_parts))
+
+
+def _dict_is_default(ht, name):
+    value = getattr(ht, name)
+    return (
+        getattr(ht.__class__, name).default_value == Undefined and
+        (value is None or len(value) == 0)
+    )
+
+def _attr_value_repr(v):
+    array = get_union_array(v.array)
+    # Return full repr if array size is small:
+    if array.size < 50:
+        return repr(v)
+    # Otherwise, return a summary:
+    return '<%s shape=%r, dtype=%s>' % (v.__class__.__name__, array.shape, array.dtype)
+
+def _attr_dict_repr(d):
+    parts = []
+    for key, value in d.items():
+        if isinstance(value, tuple):
+            value_parts = [_attr_value_repr(v) for v in value]
+        else:
+            value_parts = [_attr_value_repr(value)]
+        parts.append('%r: %s' % (key, ', '.join(value_parts)))
+    return '{%s}' % (', '.join(parts),)