@Override
  public void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter) {
    super.onTextChanged(text, start, lengthBefore, lengthAfter);
    // The text changed, so we might not have a DraweeSpanStringBuilder any more
    // (or a different one). Since all setText methods in TextView are final, we cannot directly
    // hook into the setText calls to handle this in a cleaner way.
    detachCurrentDraweeSpanStringBuilder();
  }
Detaches the currently attached DraweeSpanStringBuilder (if there is one) so that this view can
be used as a normal text view instead.
drawee-span/src/main/java/com/facebook/drawee/span/SimpleDraweeSpanTextView.java