Design Pattern For UI Control and Provider to Call Control's Events [closed]

Question

I have a UI control that uses a provider class to implement the actual logic of a complex task. So the control delegates to the provider to do some work. But the provider needs to work with the control too; it needs to fire some events on the control.

I was looking for a good design pattern of how the two could work together, but wasn't sure of any. I didn't want the provider to directly invoke events on the control. I thought about methods on the control that it could call, but I don't know that I quite like that either.

Any ideas, thoughts? What is a good design pattern that the provider can use to fire a notification through the control? Each event may also need to pass custom parameters too.