I've added an answer to a similar (kind of...) problem in this post https://community.st.com/s/question/0D50X0000AFpwBx/can-you-call-a-method-on-view-from-a-custom-container.Hope it helps
Hi, not sure this answers your question fuly, but might suggest other way. Actually I have a similar issue....I also have a base Container that is placed in all my views and thi container has some elements that I must draw on top of all other element...