I have started learning of custom transition animation with using UIViewControllerAnimatedTransitioning protocol. And mostly all videos I've found on youtube are based on the flow when we have new ViewController presented with circle animation or similar to it.
I have problems with implementation my way of transitions. Mostly, what I need, is similar to the facebook app and how they open full-screen image viewer.
So, lets say we have VC1 and VC2. On VC1 we call action to present VC2. And on both VCs we have the same UI element. In my case that is UIImageView. Like you click on imageView on VC1 and it opens detail page for some object with its image at the top. And I want to have animation, that should look like image from VC1 is changing frame to the final frame of image from VC2, and then other content (like labels, buttons, etc) on detail page should appear.
But I've faced with some problems during training.
1. First of all, I don't understand the idea of containerView of transitionContext. But as I see, it is something like a middle-state view between between transitions. Is that correct? But that works strange
to me, since even backgroundColor property not working for containerView.
2. I don't understand what exactly I need to animate during transition, and what should be the structure of the containerView subViews. In my example, when presenting VC2, I need, as I understand, to kinda hide all its subViews. Then animate imageView from VC1 to the frame of imageView from VC2, and then make visible all subViews again. So, in this case imageView should be added to containerView? If so, then should it be the actual imageView from VC1, or that is fully new copy of imageView, with the same frame/image, that is just temporarily used during transitions...
It will be helpful to link me to examples/tutorial/code with similar animation
