Emulate UINavigationController with views

gistfile1.m

#import "NSMutableArray+Stack.h"
#define SHOW_ANIMATION_DURATON 0.5f

@property (nonatomic, strong) NSMutableArray *viewStack;

-(void)pushView:(UIView *)view
{
    UIView *anterior = [self.viewStack peek];
    [self.viewStack push:view];
    
    
    UIView *fatherView = self.view;
    
    CGRect f = fatherView.bounds;
    f.origin.x = f.size.width;
    [fatherView addSubview:view];
    [view setFrame:f];
    [fatherView bringSubviewToFront:view];
    
    CGRect f2 = anterior.frame;
    f2.origin.x = -f2.size.width;
    
    f.origin.x = 0.0f;
    
    UINavigationItem *navigation = self.navigationItem;
    
    //Animation
    [UIView  animateWithDuration:SHOW_ANIMATION_DURATON delay:0.0f options:UIViewAnimationOptionAllowUserInteraction
                      animations:^{
                          [view setFrame:f];
                          [anterior setFrame:f2];
                          
                      }
                      completion:^(BOOL finished){
                          [anterior setHidden:YES];
                          
                          if([self.viewStack count]==2)
                          {
                              UIBarButtonItem *izq;
                              izq = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"btn_back"] title:@"Back" target:self action:@selector(popView)];
                              [navigation setLeftBarButtonItem:izq];

                          }
                      }
     ];
    
    

}

-(void)popView
{
    
    if ([self.viewStack count]>1)
    {
        UIView *view = [self.viewStack pop];
        UIView *anterior = [self.viewStack peek];
        
        UIView *fatherView = self.view;
        
        CGRect f = fatherView.bounds;
        f.origin.x = -f.size.width;
        [anterior setHidden:NO];
        [anterior setFrame:f];
        f.origin.x = 0;
        
        CGRect f2 = f;
        f2.origin.x = f2.size.width;
        
        //Animation
        [UIView  animateWithDuration:SHOW_ANIMATION_DURATON delay:0.0f options:UIViewAnimationOptionAllowUserInteraction
                          animations:^{
                              [anterior setFrame:f];
                              [view setFrame:f2];
                              
                          }
                          completion:^(BOOL finished){
                              [view removeFromSuperview];
                              
                              
                              if ([self.viewStack count]==1)
                              {
                                  self.navigationItem.leftBarButtonItem = nil;
                              }
                          }
         ];
    }
    else
    {
        self.navigationItem.leftBarButtonItem = nil;
        
    }
    
}