BradB132

-(float)percentForPinch:(UIPinchGestureRecognizer*)pinch
{
	return (pinch.scale - 1.0f)/2.0f;//denominator is just a fudge factor to get the 'feel' right
}

-(void)handlePinch:(UIPinchGestureRecognizer*)pinch
{
	switch (pinch.state)
	{
		case UIGestureRecognizerStateBegan:

BradB132

- (void)viewDidLoad
{
    [super viewDidLoad];
	
    self.pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinch:)];
    [self.view addGestureRecognizer:_pinch];

    self.transition = [[UIPercentDrivenInteractiveTransition alloc] init];

    self.navigationController.delegate = self;

BradB132

@property (nonatomic, strong) UIPercentDrivenInteractiveTransition* transition;
@property (nonatomic, strong) UIPinchGestureRecognizer* pinch;

BradB132

- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext
{
	UIViewController* toController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
	UIViewController* fromController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
	UIView* container = [transitionContext containerView];
	
	//get rects that represent the top and bottom halves of the screen
	CGSize viewSize = fromController.view.bounds.size;
	CGRect topFrame = CGRectMake(0, 0, viewSize.width, viewSize.height/2);
	CGRect bottomFrame = CGRectMake(0, viewSize.height/2, viewSize.width, viewSize.height/2);

BradB132

- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext
{
	UIViewController* toController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
	UIViewController* fromController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
	UIView* container = [transitionContext containerView];
	
	//get rects that represent the top and bottom halves of the screen
	CGSize viewSize = fromController.view.bounds.size;
	CGRect topFrame = CGRectMake(0, 0, viewSize.width, viewSize.height/2);
	CGRect bottomFrame = CGRectMake(0, viewSize.height/2, viewSize.width, viewSize.height/2);

BradB132

#pragma mark - UINavigationControllerDelegate

- (id <UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController
                                   animationControllerForOperation:(UINavigationControllerOperation)operation
                                                fromViewController:(UIViewController *)fromVC
                                                  toViewController:(UIViewController *)toVC
{
	switch(operation)
	{
		case UINavigationControllerOperationPush:

BradB132

#define kTransitionDuration 0.35

// ...

#pragma mark - UIViewControllerAnimatedTransitioning

- (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext
{
	return kTransitionDuration;
}

BradB132

#pragma mark - UINavigationControllerDelegate

- (id <UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController
                                   animationControllerForOperation:(UINavigationControllerOperation)operation
                                                fromViewController:(UIViewController *)fromVC
                                                  toViewController:(UIViewController *)toVC
{
	return [[TTFadeAnimator alloc] init];
}

BradB132

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.navigationController.delegate = self;
}

BradB132

func application(application: UIApplication, _: [NSObject: AnyObject]?) -> Bool {
    //we don't care about launch options
    return true
}