Show/Hide UITabBar

UITabBarController+HideTabBar.swift

import UIKit

extension UITabBarController {
	/// Extends the size of the `UITabBarController` view frame, pushing the tab bar controller off screen.
	/// - Parameters:
	///   - hidden: Hide or Show the `UITabBar`
	///   - animated: Animate the change
	func setTabBarHidden(_ hidden: Bool, animated: Bool) {
		guard let vc = selectedViewController else { return }
		guard tabBarHidden != hidden else { return }
		
		let frame = self.tabBar.frame
		let height = frame.size.height
		let offsetY = hidden ? height : -height

		UIViewPropertyAnimator(duration: animated ? 0.3 : 0, curve: .easeOut) {
			self.tabBar.frame = self.tabBar.frame.offsetBy(dx: 0, dy: offsetY)
			self.selectedViewController?.view.frame = CGRect(
				x: 0,
				y: 0,
				width: vc.view.frame.width,
				height: vc.view.frame.height + offsetY
			)
			
			self.view.setNeedsDisplay()
			self.view.layoutIfNeeded()
		}
		.startAnimation()
	}
	
	/// Is the tab bar currently off the screen.
	private var tabBarHidden: Bool {
		tabBar.frame.origin.y >= UIScreen.main.bounds.height
	}
}