#import "DropdownMenuSegue.h"

#import "DropdownMenuController.h"

@implementation DropdownMenuSegue

- (void) perform {

DropdownMenuController *containerViewController = (DropdownMenuController *) self.sourceViewController;

UIViewController *nextViewController = (UIViewController *) self.destinationViewController;

UIViewController *currentViewController = (UIViewController *) containerViewController.currentViewController;

// Add nextViewController as child of container view controller.

[containerViewController addChildViewController:nextViewController];

// Tell current View controller that it will be removed.

[currentViewController willMoveToParentViewController:nil];

// Set the frame of the next view controller to equal the outgoing (current) view controller

nextViewController.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

nextViewController.view.frame = currentViewController.view.frame;

nextViewController.view.translatesAutoresizingMaskIntoConstraints = YES;

// Make the transition with a very short Cross disolve animation

[containerViewController transitionFromViewController:currentViewController

toViewController:nextViewController

duration:0.1f

options:UIViewAnimationOptionTransitionCrossDissolve

animations:^{

}

completion:^(BOOL finished) {

containerViewController.currentViewController = nextViewController;

[currentViewController removeFromParentViewController];

[nextViewController didMoveToParentViewController:containerViewController];

}];

}