Implementing Thumbs Down Navigation Controller with Scrollable Views

In this article, we will explore a common problem in iOS development: creating a thumbs down navigation controller that scrolls its left and right views from the root view controller. This is a fundamental concept in building complex navigation-based user interfaces.

A UINavigationController is a part of the UIKit framework that provides a way to manage a stack of view controllers, allowing users to navigate between them. It also handles the animation of pushing and popping view controllers from its stack. In our case, we want to create a navigation controller with two views: one on the left and one on the right.

To start, let’s create a basic UINavigationController instance and add a LeftSideControllerView as its root view controller:

// Create the left side controller view
LeftSideControllerView *firstVC = [[LeftSideControllerView alloc] init];

// Create the navigation controller with the left side controller view
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:firstVC];

Adding a Center View Controller

Next, we want to add a center view controller that will serve as the root view controller for our navigation controller. This view controller should not have any animations when pushing it onto the navigation stack:

// Create the center view controller
SecondViewController *secondVC = [[SecondViewController alloc] init];

// Push the second view controller onto the navigation stack without animation
[[self navigationController] pushViewController:secondVC animated:NO];

Now that we have our basic layout in place, let’s implement the thumbs down navigation functionality. We want to allow users to scroll from one end of the navigation controller to the other.

To achieve this, we’ll create a custom UIScrollView subclass and add it as a subview to our left side view controller. The right side view controller will also have its own UIScrollView instance.

// Create a custom UIScrollView subclass for the left side view controller
class LeftSideScrollView: UIScrollView {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Add a scrollable content view
        let scrollView = UIView(frame: CGRect(x: 0, y: 0, width: self.bounds.size.width, height: self.bounds.size.height))
        self.addSubview(scrollView)
        
        // Set the scroll content size
        scrollView.contentSize = CGSize(width: 100, height: 200) // replace with your desired content size
    }
}

// Create a custom UIScrollView subclass for the right side view controller
class RightSideScrollView: UIScrollView {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Add a scrollable content view
        let scrollView = UIView(frame: CGRect(x: 0, y: 0, width: self.bounds.size.width, height: self.bounds.size.height))
        self.addSubview(scrollView)
        
        // Set the scroll content size
        scrollView.contentSize = CGSize(width: 100, height: 200) // replace with your desired content size
    }
}

Now that we have our custom UIScrollView subclasses, let’s integrate them into our navigation controller. We’ll add a gesture recognizer to our left side view controller and another one to our right side view controller. When these gestures are detected, we’ll scroll our respective UIScrollViews.

// Implement the gestures for the left side view controller
override func viewDidLoad() {
    super.viewDidLoad()
    
    // Add a pan gesture recognizer to the view controller
    let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(handlePanGesture))
    panGestureRecognizer.minimumNumberOfTouches = 1
    panGestureRecognizer.maximumNumberOfTouches = 2
    
    self.view.addGestureRecognizer(panGestureRecognizer)
}

@objc func handlePanGesture(_ panGestureRecognizer: UIPanGestureRecognizer) {
    // Get the translation values from the gesture recognizer
    let translation = panGestureRecognizer.translation(in: view)
    
    // Scroll the scroll view based on the translation values
    leftSideScrollView.scrollToX(x: translation.x, dy: translation.y)
}

// Implement the gestures for the right side view controller
override func viewDidLoad() {
    super.viewDidLoad()
    
    // Add a pan gesture recognizer to the view controller
    let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(handlePanGesture))
    panGestureRecognizer.minimumNumberOfTouches = 1
    panGestureRecognizer.maximumNumberOfTouches = 2
    
    self.view.addGestureRecognizer(panGestureRecognizer)
}

@objc func handlePanGesture(_ panGestureRecognizer: UIPanGestureRecognizer) {
    // Get the translation values from the gesture recognizer
    let translation = panGestureRecognizer.translation(in: view)
    
    // Scroll the scroll view based on the translation values
    rightSideScrollView.scrollToX(x: translation.x, dy: translation.y)
}

Conclusion

In this article, we explored how to implement a thumbs down navigation controller with scrollable views using UINavigationController, UIScrollView, and custom gesture recognizers. By following these steps, you can create a complex user interface that scrolls smoothly from one end of the navigation controller to the other.

Example Use Cases

Creating a social media app with a navigation bar that slides between different content sections.
Building an e-commerce website with a product catalog and customer reviews section that can be scrolled horizontally.
Developing a news app with articles and comments that need to be displayed in a scrolling layout.

Last modified on 2023-11-18

Implementing Thumbs Down Navigation Controller with Scrollable Views

Understanding Navigation Controllers

Creating the Navigation Controller

Adding a Center View Controller

Implementing Thumbs Down Navigation with Scrollable Views

Integrating the Scroll Views into the Navigation Controller

Conclusion

Example Use Cases