I'm trying to make a transition animation in iOS where a view or view controller appears to expand to fill the whole screen, then contract back to its former position when done. I'm not sure what this type of transition is officially called, but you can see an example in the YouTube app for iPad. When you tap one of the search result thumbnails on the grid, it expands from the thumbnail, then contracts back into the thumbnail when you return to the search.
I'm interested in two aspects of this:
How would you make this effect when transitioning between one view and another? In other words, if view A takes up some area of the screen, how would you transition it to view B which takes up the whole screen, and vice versa?
How would you transition to a modal view this way? In other words, if UIViewController C is currently showing and contains view D which takes up part of the screen, how do you make it look like view D is turning into UIViewController E which is presented modally on top of C?
Edit: I'm adding a bounty to see if that gets this question more love.
Edit: I've got some source code that does this, and Anomie's idea works like a charm, with a few refinements. I had first tried animating the modal controller's view (E), but it didn't produce the effect of feeling like you're zooming into the screen, because it wasn't expanding all the stuff around the thumbnail view in (C). So then I tried animating the original controller's view (C), but the redrawing of it made for a jerky animation, and things like background textures did not zoom properly. So what I wound up doing is taking an image of the the original view controller (C) and zooming that inside the modal view (E). This method is substantially more complex than my original one, but it does look nice! I think it's how iOS must do its internal transitions as well. Anyway, here's the code, which I