[iOS] Class for view controller transitioning

TransitionController

@import Foundation;
@import UIKit;

@interface FIQTransitionDismissalController : NSObject <UIViewControllerAnimatedTransitioning>

@end

//------------------

#import "FIQTransitionDismissalController.h"

@implementation FIQTransitionDismissalController

- (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext
{
    UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    
    [UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{
        fromViewController.view.alpha = 0.0f;
    } completion:^(BOOL finished) {
        [transitionContext completeTransition:![transitionContext transitionWasCancelled]];
    }];
}

- (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext
{
    return 0.5f;
}

@end