Action Tab Bar SwiftUI Block

Four tabs float in one capsule at the foot of the screen, and a round create button in the accent stands apart beside it, the way iOS 26 apps set a primary action off from their tabs. Each tab is a symbol over its label; the selected one sits on a quiet pill that slides between tabs and turns to its fill variant in textPrimary, and a badge count sits on the symbol. Tapping the selected tab again calls onReselect, where the app scrolls that tab to its top. The create button opens a short menu of quick actions on a raised card just above the bar, while a scrim dims the content behind it and the plus turns to a cross. Picking an action closes the menu and runs your closure: the button shows a spinner while it runs and a checkmark after work that took a moment, and a thrown error shows its message on a small card above the bar. Tapping the scrim, another tab or the button again closes the menu. With one action the button runs it directly; with none it is hidden. Tabs keep their content alive once visited, as TabView does.

Notes

• ActionTabBar(selection:items:actions:createLabel:onAction:onReselect:content:) is generic over your own tab type (any Hashable & Sendable value, usually an enum). content builds the screen for a tab.
• A tab bar is the root of a screen, so this block owns its container rather than being a section: it lays your content out full size, floats the bar over its foot with safeAreaInset(edge: .bottom) so your scroll views end above it, and draws the scrim over the content only. Put a NavigationStack inside each tab's content, not around the bar.
• ActionTabBarItem(_:title:symbol:badge:) (also ActionTabBar.Item) is a tab: your value, its label, an outline SF Symbol and an optional count. Over 99 reads "99+"; nil or 0 hides it. Two to four tabs fit the capsule; the create button sits after them.
• ActionTabBarAction(id:title:detail:symbol:) (also ActionTabBar.Action) is a menu row: a symbol, a title and an optional line under it. ActionTabBarAction.samples is the Example's menu.
• onAction is async throws. Present a composer and return, and the button settles at once; run longer work (an upload, a scan) in it and the button shows progress, then a checkmark. A thrown error's errorDescription (or "New task didn't finish. Try again.") shows above the bar for a few seconds with a close button; CancellationError returns the button to rest quietly.
• onReselect receives the tab tapped while already selected. The Example keeps a counter per tab and scrolls to the top with ScrollViewReader when it changes.
• Haptics: selection when the tab changes, success when an action finishes after a moment, error when one fails.
• VoiceOver reads each tab with its badge ("Inbox, 3 new") and the selected trait; the create button is "Create" with a hint, and reports In progress and Done. The open menu is modal and closes with the escape gesture. The bar keeps its size up to xLarge text; at accessibility sizes the labels step aside and a long press shows the system's large content viewer, as system tab bars do. Menu rows wrap their text, and their symbols step aside at accessibility sizes.
• Reduce Motion turns the menu's rise and the button's states into short fades.
• ActionTabBarExample at the end of ActionTabBar.swift is a planner's root: Today, Inbox with three unread, Projects and Profile, and a menu with New task, New note, Scan document (which takes a moment and confirms) and New event. Pass wrapsInNavigationStack: false when each tab already sits in a stack you own.

Theming

• Reads SPTheme from @Environment(\.spTheme) and requires the design-system item.
• The capsule is color.surface with a separator hairline and the e2 shadow, and the selected tab's pill is fill. Tab labels are type.caption at medium weight; symbols and labels are textPrimary when selected and textSecondary otherwise. Badges are textPrimary capsules with surface figures.
• The create button is the block's one accent: a circle of accent with an accentOn symbol, on the e2 shadow.
• The menu is surfaceElevated at radius.lg with a separator hairline, rows of type.body titles and type.footnote lines in textSecondary, symbols in textSecondary, and inset hairlines. A pressed row shows fill. The menu lifts on the e3 shadow. The scrim is .ultraThinMaterial with black over it at 12% (35% in dark mode), so the screen softens rather than greying flat.
• The failure card is surfaceElevated at radius.md, with its symbol in danger and the message in type.subhead.
• The menu rises with motion.standard; the pill slides and states cross-fade with motion.snappy.