Question

I have an MVC application with a single model and several views (something like skins). I want the user to be able to switch the views and I can’t get it working with interface orientation. The most simple approach looks like this:

- (void) switchToADifferentView: (UIView*) newView {
    // self is a descendant of UIViewController
    self.view = newView;
}

This does not work because the incoming view does not get rotated according to current orientation (until the next orientation change, test case). Is there a way to force the orientation on a view? It looks like the system is trying really hard to keep the interface controls for itself. (Or is it as simple as setting the right transform by hand?)

I figured I’d better not switch the views directly and switch controllers instead. This makes sense, as it makes the initial code simpler. But how do I switch controllers that have no “navigation relation” between them? I guess I could use presentModalViewController:, but that seems like a hack. Same goes for navigation controller. If I exchange the controllers by hand, I get the wrong orientation again:

- (void) switchToAController: (id) incoming {
    [currentController.view removeFromSuperview];
    [window addSubview:incoming.view]; // does not respect current orientation
}

Now how the heck do I simply exchange the current controller for another one? Again, the controllers are something like “skins” operating above a shared model, so it really makes no sense to pretend that skin A is a “modal” dialog above skin B or that they’re a part of a navigation stack.

Answer 1

In the end I went with a “trampoline” approach. Each “skin” is a separate controller and there is a special root controller that presents the skins as modal controllers. When the skin wants to switch to a different one, it sets a flag indicating the desired next skin and dismisses itself. The root controller wakes up (viewWillAppear), notices the flag and displays the next skin.

This solution has two main advantages: 1] The controller code stays simple, as each controller displays one and only view, no view switching. 2] There is no need to hack the orientation code, because view orientation inside modally displayed controllers is handled transparently by the system.