Handle UIButton in Child View Controller of Container View Controller

Question

I am working on creating custom Container ViewController class and am able to create 5 sub viewcontrollers and able to move from one child view controller to other child using the following API:

transitionFromViewController:fromViewController
        toViewController:toViewController
            duration:1.0
             options:0
          animations:^{
                              }
          completion:^(BOOL finished) {
                          }];

Child view controllers are occupying part of Parent View Controller. Each time when user swipe I am making previous controller goes off and present controller comes on displayable area.

Now I have buttons on child viewcontrollers and when i click on them I am not getting events or trigger to the Action method of Child View Controller. But Parent View Controller is getting callbacks for its buttons even currently childview is getting displayed. Adding the code snippet below (though it is little bigger, this will help you to analyze if I am doing any mistake).

Parent ViewController:

- (void) handleSwipeGestureLeft:(UISwipeGestureRecognizer *)gesture
{
    if (showPopupValue) {
        return;
    }

    NSInteger index = [arrayOfChildVCs indexOfObject:selectedViewController];
    index = MIN(index+1, [arrayOfChildVCs count]-1);

    UIViewController *newSubViewController = [arrayOfChildVCs objectAtIndex:index];


    endFrame.origin.x = -1024;

    startOfNewVCFrame.origin.x = 1024;

    [self transitionFromViewController:selectedViewController toViewController:newSubViewController];
    selectedViewController = newSubViewController;

}
- (void) handleSwipeGestureRight:(UISwipeGestureRecognizer *)gesture
{
    if (showPopupValue) {
        return;
    }

    NSInteger index = [arrayOfChildVCs indexOfObject:selectedViewController];
    index = MAX(index-1, 0);

    UIViewController *newSubViewController = [arrayOfChildVCs objectAtIndex:index];

    endFrame.origin.x = 1024;

    startOfNewVCFrame.origin.x = -1024;

    [self transitionFromViewController:selectedViewController toViewController:newSubViewController]; 
    selectedViewController = newSubViewController;

}

- (void) populateChildVCList
{


    if (self.currentactivity == EPI_Normal) 
    {
        arrayOfImageNames = [[NSArray alloc]initWithObjects:@"AD_Initiate_SPI_Normal.jpg", @"AD_Initiate_CPI_Normal.jpg", @"AD_Initiate_EAC_Normal.jpg", @"AD_Initiate_PV_Normal.jpg", @"AD_Initiate_EV_Normal.jpg", nil];
    }
    else 
    {
        arrayOfImageNames = [[NSArray alloc]initWithObjects:@"AD_Initiate_SPI_Trigger.jpg", @"AD_Initiate_CPI_Trigger.jpg", @"AD_Initiate_EAC_Trigger.jpg", @"AD_Initiate_PV_Trigger.jpg", @"AD_Initiate_EV_Trigger.jpg", nil];
        isTriggerOn = YES;
    }


    arrayOfChildVCs = [[NSMutableArray alloc] init];

    [arrayOfChildVCs addObject:[[PopupDummyViewController alloc]initWithNibName:@"PopupDummyViewController" bundle:nil]]; // Note: Add one dummy VC to initiate swap

    for (int vcIndex = 0; vcIndex < [arrayOfImageNames count]; vcIndex++) 
    {
        PiSLAComplianceViewController *childPopupController = [[PiSLAComplianceViewController alloc]initWithNibName:@"PiSLAComplianceViewController" bundle:nil];

        childPopupController.popUpImageName = [arrayOfImageNames objectAtIndex:vcIndex];
        childPopupController.imageIndex = vcIndex;
        childPopupController.isTriggerOn = isTriggerOn;

        [arrayOfChildVCs addObject:childPopupController];
    }

    selectedViewController = [arrayOfChildVCs objectAtIndex:0];
    selectedViewController.view.frame = CGRectMake(0, 100, 100, 511); // Took the imageview coordinates
    // Add the dummy view controller to Container View Initially
    [self addChildViewController:selectedViewController];

    [self.view addSubview:selectedViewController.view];

    // notify it that move is done
    [selectedViewController didMoveToParentViewController:self];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.

    [super viewDidLoad];

    UISwipeGestureRecognizer *swipeGestureRecognizerRight = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeGestureRight:)];
    [swipeGestureRecognizerRight setDirection:UISwipeGestureRecognizerDirectionRight];
    [ self.view addGestureRecognizer:swipeGestureRecognizerRight];

    UISwipeGestureRecognizer *swipeGestureRecognizerLeft = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeGestureLeft:)];
    [swipeGestureRecognizerLeft setDirection:UISwipeGestureRecognizerDirectionLeft];
    [ self.view addGestureRecognizer:swipeGestureRecognizerLeft];

    endFrame = deliverableimageview.frame;
    startOfNewVCFrame = deliverableimageview.frame;

    [self populateChildVCList]; // To Create list of child view controllers and loads one invisible dummy view controller to be ready for swiping

}

- (void)transitionFromViewController:(UIViewController *)fromViewController toViewController:(UIViewController *)toViewController
{
    if (fromViewController == toViewController)
    {
        // cannot transition to same
        return;
    }

    // animation setup


    toViewController.view.frame = startOfNewVCFrame;

    // notify
    [fromViewController willMoveToParentViewController:nil];
    [self addChildViewController:toViewController];

    // transition
    [self transitionFromViewController:fromViewController
                      toViewController:toViewController
                              duration:1.0
                               options:0
                            animations:^{
                                toViewController.view.frame = fromViewController.view.frame;
                                fromViewController.view.frame = endFrame;
                            }
                            completion:^(BOOL finished) {
                                [toViewController didMoveToParentViewController:self];
                                [fromViewController removeFromParentViewController];

                            }];



}