LNPopupController

LNPopupController is a UIKit framework that allows you to present view controllers as popups, mimicking the behavior of Apple Music or Podcasts mini-players.

Key characteristics:

• It is implemented as a category over UIViewController.
• It allows a view controller to present a popup bar docked to a specific view (e.g., a tab bar or toolbar).
• It handles safe area insets automatically during presentation and dismissal.
• Popup bar information is driven by LNPopupItem objects.
• For SwiftUI projects, use the LNPopupUI library instead.

In this default mode, the UIViewController representing the content manages its own LNPopupItem. This is the simplest implementation and does not support paging between items. The popup bar automatically updates whenever the content controller's popupItem is modified.

To use this mode:

1. Create a UIViewController.
2. Configure its popupItem properties (title, subtitle, progress, etc.).
3. Call presentPopupBar(with:animated:completion:) on your container controller.

class PopupContentViewController: UIViewController {
  init() {
    // ...
    
    popupItem.title = "Hello Title"
    popupItem.subtitle = "And a Subtitle!"
    popupItem.progress = 0.34
    popupItem.barButtonItems = [/* ... */]
  }
}

func presentPopupBar() {
  let contentVC = PopupContentViewController()
  tabBarController?.presentPopupBar(with: contentVC)
}

To use the framework in your Swift source files, import the module:

import LNPopupController

The framework supports smooth transitions between the popup bar's image and an image in the content view.

Automatic Discovery: If you include an LNPopupImageView in your popup content view hierarchy, the system will automatically attempt to use it as the transition target/source. Ensure there is only one such instance in the hierarchy.

Manual Implementation: For advanced scenarios, implement viewForPopupTransition(from:to:) in your popup content controller to return the specific view to be used for the transition. The returned view must be part of the content controller's view hierarchy and should ideally implement the LNPopupTransitionView protocol.

You can add LNPopupController to your project using Swift Package Manager (SPM).

Via Xcode UI

1. Click File → Add Package Dependencies….
2. Enter https://github.com/LeoNatan/LNPopupController.
3. Select your desired version.

Via Package.swift

Add the package to your Package.swift file:

.package(url: "https://github.com/LeoNatan/LNPopupController.git", from: "4.0.0")

And add the dependency to your target:

.target(name: "MyExampleApp", dependencies: ["LNPopupController"]),

Starting with iOS 26, minimization is supported for UITabBarController containers. Enable it by setting the tabBarMinimizeBehavior property.

You can listen for environment changes (like the bar minimizing) by registering for LNPopupBar.EnvironmentTrait trait changes in your content controller.

// Enable minimization
self.tabBarController?.tabBarMinimizeBehavior = .onScrollDown

// Listen for changes
registerForTraitChanges([LNPopupBar.EnvironmentTrait.self]) { (self: Self, previousTraitCollection) in
  self.popupItem.barButtonItems?.last?.isHidden = self.traitCollection.popupBarEnvironment == .inline
}

To create a completely custom bar design, subclass LNPopupCustomBarViewController.

1. Build your view hierarchy and set preferredContentSize to the desired bar height.
2. Optionally override wantsDefaultTapGestureRecognizer, wantsDefaultPanGestureRecognizer, or wantsDefaultHighlightGestureRecognizer to disable default behaviors.
3. Implement popupItemDidUpdate() (calling super) to respond to item updates.
4. Assign an instance of your subclass to the customBarViewController property of the popup bar object. This sets the bar style to .custom.

Do not manually set isHidden = true on a tab bar or toolbar, as this is explicitly discouraged by Apple and not supported by the framework, leading to undefined behavior. Instead, use the standard Apple APIs which are fully supported by LNPopupController:

• UINavigationController.setToolbarHidden(_:animated:)
• UITabBarController.setTabBarHidden(_:animated:)