Riffle

A minimal keyboard window switcher for the windows of the current app. Menu-bar-only, no Dock icon, ~500 lines of Swift, zero dependencies.

Features

• Hold ⌥, tap ⇥ — cycle through every window of the frontmost app as a title list
• Includes minimized windows and windows on other Spaces (via the Accessibility API)
• Windows ordered front-to-back (most recently used first)
• Panel auto-sizes to the longest title and centers on the screen under your mouse
• Mouse support: hover to select, click to focus
• Optional Stay Open to Search (menu bar toggle): a quick ⌥⇥ tap leaves the panel up so you can type to filter the list

Keys

Search mode

With Stay Open to Search enabled (menu bar → toggle), tapping ⌥⇥ and letting ⌥ go within 250 ms leaves the panel up with a search field instead of committing. Keep ⌥ held down past that and the switcher stays classic: cycle with ⇥, release ⌥ to focus the highlighted window.

The panel still never takes key focus — keystrokes are read from the event tap and swallowed, so nothing leaks into the app underneath. A click anywhere else, or any ⌘/⌃ shortcut, dismisses it.

Build & install

Requires macOS 13+ and Xcode command line tools.

./build.sh              # builds build/Riffle.app
open build/Riffle.app   # or copy to /Applications first

build.sh signs with the first available codesigning identity. This matters: macOS ties the Accessibility grant to the code signature, and ad-hoc signatures change on every build — a certificate keeps the grant stable across rebuilds.

Permissions

Accessibility (required) — global ⌥⇥ capture, window enumeration, and window raising. Prompted on first launch; grant in System Settings → Privacy & Security → Accessibility. No Screen Recording permission needed.

Architecture

main.swift ─▶ AppDelegate ─▶ KeyboardHook (CGEventTap: ⌥⇥ intercept)
                   │               │
                   ▼               ▼
             status item       Switcher (session state, frontmost-app scope)
                                ├─▶ WindowDiscovery (AX windows + CG z-order)
                                ├─▶ SwitcherPanel (non-activating NSPanel)
                                │      └─▶ SwitcherView (SwiftUI title list)
                                └─▶ WindowFocus (AX unminimize/raise + activate)

Notable implementation details:

• A CGEventTap swallows ⌥⇥ before it reaches the focused app.
• Window ↔ AX matching uses the private _AXUIElementGetWindow; z-order comes from CGWindowListCopyWindowInfo.
• The panel is a borderless .nonactivatingPanel — it never steals focus.

Limitations

• Switches within the current app only (that's the point); no across-app mode
• Shortcuts are not configurable; no thumbnails

License

MIT