How to tell if UIViewController"s view is visible

How to Tell if UIViewController's View is Visible 👀

So you have a tab bar application with multiple views, and you're wondering if there's a way to determine whether a specific UIViewController is currently visible. 🤔 Don't worry, you've come to the right place! In this blog post, we'll explore various techniques to solve this common problem. Let's dive in! 💪

The Challenge: Identifying UIViewController Visibility

The challenge is to find a way to know if a specific UIViewController is currently visible from within the UIViewController itself. This is particularly useful when you want to perform certain actions or updates only when the view is on screen. 📱

🧠 Thinking Through the Solutions

We can approach this problem in different ways, depending on the desired outcome and the structure of your app. Let's consider a few possible scenarios:

Scenario 1: Check if the UIViewController's view is currently the frontmost view in the window hierarchy

Sometimes, you might want to know if a particular UIViewController is the one actively displayed to the user. To achieve this, we can use the UIWindow class's rootViewController property and compare it with the current UIViewController. Here's an example of how you can do this:

if let rootViewController = UIApplication.shared.windows.first?.rootViewController {
    if rootViewController == self {
        // The view controller is currently visible
    } else {
        // The view controller is not currently visible
    }
}

Scenario 2: Check if the UIViewController's view is currently visible on screen

In some cases, you may want to check if a specific UIViewController's view is currently visible on the screen. You can achieve this by determining whether the view's window property is not nil and if the view intersects with the window's bounds. Here's an example:

if let window = view.window, view.bounds.intersects(window.bounds) {
    // The view controller is currently visible
} else {
    // The view controller is not currently visible
}

🚀 Solution Implemented! What's Next?

Now that you have an understanding of how to check if a UIViewController's view is visible, you can implement the solution that best suits your app's needs. Remember to consider the intended outcome and tailor the approach accordingly. 🛠️

👥 Engage with Us!

We hope this guide has helped you understand how to determine the visibility of a UIViewController's view like a pro. If you have any questions or suggestions, feel free to leave a comment down below. ⬇️ We would love to hear from you! Let's keep the conversation going. 💬

Happy coding! 🎉