lynnswap/floatingaccessorykit

Requirements

• iOS 18.0+
• iPhone only
• Swift 6.2

Usage

import FloatingAccessoryKit
import UIKit

final class MainTabBarController: UITabBarController {
    override func viewDidLoad() {
        super.viewDidLoad()

        let button = UIButton(type: .system)
        button.setImage(UIImage(systemName: "plus"), for: .normal)
        button.widthAnchor.constraint(equalTo: button.heightAnchor).isActive = true

        floatingAccessoryController.setContentView(
            button,
            position: .trailing,
            animated: false
        )
    }
}

Content Updates

Layout-driven content-size changes are measured automatically. If you change a view's intrinsic size, bounds, constraints, or subview hierarchy explicitly, perform the changes through the accessory controller:

floatingAccessoryController.performContentUpdate {
    button.setTitle("Updated", for: .normal)
    button.invalidateIntrinsicContentSize()
}

performContentUpdate runs the mutations and remeasurement in one UIKit update transaction. The default update animates with UIKit timing and respects Reduce Motion. Pass animated: false when the change should be applied immediately. The content view remains installed, and its position and visibility are preserved.

Accessory Background

The view passed to setContentView is foreground content. Do not add your own capsule or material background.

On iOS 26+, FloatingAccessoryKit uses the native UITabAccessory presentation without adding another background. On iOS 18, FloatingAccessoryKit adds a matching overlay background around the content.

Tab Bar Minimization

On iOS 26+, use UIKit's tabBarMinimizeBehavior when you want the tab bar to minimize while scrolling.

On iOS 18, toggle the tab bar through floatingAccessoryController.setTabBarHidden(_:animated:). FloatingAccessoryKit then updates the accessory and the tab bar from the same coordination boundary. When the tab bar is hidden, tapping or long-pressing the empty area where the tab bar was shown restores it.

if #available(iOS 26.0, *) {
    tabBarMinimizeBehavior = .onScrollDown
}

For iOS 18, implement your own scroll policy, then call floatingAccessoryController.setTabBarHidden(_:animated:) when that policy decides to hide or show the tab bar.

func scrollViewDidScroll(_ scrollView: UIScrollView) {
    guard #unavailable(iOS 26.0) else {
        return
    }

    floatingAccessoryController.setTabBarHidden(
        shouldHideTabBar,
        animated: true
    )
}

Migration

v0.3.0

These notes apply when upgrading from v0.2.x or earlier to v0.3.0.

• Replace TabBarAccessoryController(tabBarController:) with the controller owned by the host:

``swift let accessoryController = tabBarController.floatingAccessoryController ``

• Replace setContent(_:position:animated:) with the operation that matches the change:

``swift accessoryController.setContentView(view, position: .trailing, animated: true) accessoryController.setPosition(.center, animated: true) accessoryController.setHidden(true, animated: true) accessoryController.removeContent(animated: true) ``

• position and isHidden now remain unchanged when content is removed. Installing content without a position also preserves the current position.
• Replace resubmitting the same view for measurement with a content update transaction:

``swift accessoryController.performContentUpdate { view.invalidateIntrinsicContentSize() } ``

Put every explicit layout-affecting mutation in the closure. Layout-driven changes are still measured automatically. The transaction animates by default with UIKit timing and respects Reduce Motion.

• removeContent(animated:) detaches the consumer view before returning. Any remaining removal animation uses a snapshot.
• On iOS 18, replace direct calls to UITabBarController.setTabBarHidden(:animated:) with floatingAccessoryController.setTabBarHidden(:animated:) so the overlay is updated in the same operation.

Package Metadata

Repository: lynnswap/floatingaccessorykit

Default branch: main

README: README.md