/// <summary>
/// Must be called once when the view is created.
/// </summary>
public void RegisterSelectionHelper()
{
view.CreateObject(SELECTION_OBJECT);
view.SetObjectCallback(SELECTION_OBJECT, SELECTION_TEXT_CALLBACK, OnTextSelectionChanged);
view.SetObjectCallback(SELECTION_OBJECT, SELECTION_HTML_CALLBACK, OnHTMLSelectionChanged);
isRegistered = true;
}