I have a background thread working on collecting data, once that's ready, I want to send out a global notification such that all the views can get it. That's easily achievable logically. But visually, I want the user, while on any view of the app, got notified as well so he can prompted to take some action - e.g., ignore or reload - once see the prompt.
Now the question is - what'll the best design for this prompt? a popup dialog definitely serves the purpose, but it's annoying of it pops up frequently; a top down notification or a bottom up notification is better - but can I do that globally? and I have a TabBar at the bottom, so the top down might be better, will overlay the navigation bar be a good idea for that purpose?
any other suggestions?