toggle view with UINavigationController - iphone

Question

I have a navigation controller and a button located on the right of the navigation bar that is called toggle. When ever I press the button I basically want to toggle between a table view and a map view. How can I do this?
Can this be done by pushing and popping from the navigation stack back and forth?

Answer 1

Ok... what you want can be done using navigationControllers and such.
You just need to make a method in both viewControllers, and in the viewDidLoad of each put this:
[self.navigationItem setRightBarButtonItem:[[[UIBarButtonItem alloc] initWithTitle:#"Toggle" style:UIBarButtonItemStylePlain target:self action:#selector(toggleView:)] autorelease]];
then you want this method in the first view you get to (lets say its the list view):
-(void)toggleView:(id)selector {
MapViewController *mapViewController = [[MapViewController alloc] initWithNibName:nil bundle:nil];
[self.navigationController pushViewController:mapViewController animated:NO]; // this pushes a view onto the stack
/* or you could use this:
[self presentModalViewController:mapViewController animated:YES];
// which slides the view up over the current view */
[mapViewController release];
}
then in the mapview:
- (void)toggleView:(id)selector {
[self.navigationController popViewControllerAnimated:YES]; // this pops back a view
/* or you went for the second option above:
[self dismissModalViewControllerAnimated:YES];
// which slides the view back down. */
}

Answer 2

I am doing this same thing in one of my apps, except with a segmented control. In my case, the map and the table were logically on the same hierarchical level, so using the navigation controller didn't make sense.
Basically, I instantiate both the table view and the map view when the user is at that point in the app. When I receive a button press event, I just move one view in front of the other (bringSubviewToFront). The events from both of these views (map and table) push the next view onto the controller. To make sure that the back button on the navigation controller makes sense, I just toggle the navigationItem title in the RootViewController. So, if they want to toggle the map:
[self.view bringSubviewToFront:self.map_view.view];
UIBarButtonItem *backButton =
[[UIBarButtonItem alloc] initWithTitle:#"Map" style:
UIBarButtonItemStylePlain target:nil action:nil];
self.navigationItem.backBarButtonItem = backButton;
etc...
Since I ran into some memory problems, I also have some code that will trash the map and reset the back button title if I get a memory warning, and the toggle button delegate method will check to see if the map needs to be re-instantiated before shuffling the views. I like this better than instantiating and releasing the map every time it's toggled. Generally retaining the map has much more fluid performance, and it allows the user's state for the map to persist (as long as we don't hit the memory limit).
Hope this helps.