Snappy

A macOS window manager inspired by Divvy.

Open a floating panel, drag across a grid to define any region, and snap the frontmost window into place instantly.

Features

• Floating panel — Opens on launch and via the menu bar; shows the target app's icon and name
• Grid drag selection — Drag across a 6×4 grid to define any region, then release to snap
• Local shortcuts — Assign key combos that fire while the panel is open (no system-wide conflicts)
• Optional global hotkey — Optionally bind a global key combo to open the panel
• Menu bar app — Runs in the background with no Dock icon
• Liquid Glass UI — Built for macOS 26
• Launch at Login — Toggle from Settings

Requirements

• macOS 26.0+
• Apple Silicon or Intel

Building & Installing

Prerequisites

• Xcode 26+
• xcodegen

brew install xcodegen

Install to ~/Applications (default)

git clone https://github.com/katsuma/snappy.git
cd snappy
make install

Install to /Applications (system-wide)

make install-system   # prompts for sudo password

Both commands build the app, copy it to the target directory, register it with LaunchServices, and launch it. Running from ~/Applications or /Applications is required for Accessibility permissions and Launch at Login to work correctly.

Uninstall

make clean

Removes the app from both ~/Applications and /Applications, and resets Accessibility permissions.

First-time Setup

1. Launch the app — a menu bar icon appears and the panel opens automatically
2. Click the menu bar icon → Settings…
3. General tab → click Open System Settings…
4. Enable Snappy under Privacy & Security → Accessibility
5. The status in Settings updates to "Access granted" within a few seconds

Usage

Snapping a window

1. The panel opens automatically when Snappy launches, or click the menu bar icon → Show Panel
2. The panel displays the frontmost app's icon and name as the target
3. Drag across the grid to define the region — release to snap the window
4. Press Esc or click ✕ to dismiss without snapping

Adding a shortcut

1. Click Settings… → Shortcuts tab → New
2. Enter a name (e.g. Left Half)
3. Drag across the small grid to select the target region
4. Click the key recorder and press your desired key combo (e.g. ⌘←)

Using a shortcut

Open the panel, then press the configured key combo — the target window snaps to the assigned region and the panel closes.

Shortcuts are local to the panel and are not registered system-wide, so they never conflict with other apps' shortcuts.

Optional global hotkey

To open the panel with a global key combo:

1. Settings… → General tab → enable Use global shortcut to open panel
2. Click the key recorder and press your desired combo

Architecture

Snappy/
├── App/
│   ├── SnappyApp.swift          # @main entry point
│   └── AppDelegate.swift        # Menu bar, panel lifecycle, settings window
├── Models/
│   ├── Shortcut.swift           # Shortcut data model (name + region + key combo)
│   ├── GridRegion.swift         # Grid region (6×4)
│   └── KeyCombo.swift           # Key code + Carbon modifier flags
├── Services/
│   ├── SnapPanelManager.swift   # Panel window lifecycle, target app tracking
│   ├── HotkeyManager.swift      # Optional global hotkey via Carbon RegisterEventHotKey
│   ├── WindowMover.swift        # Window move/resize via AXUIElement
│   ├── ShortcutStore.swift      # JSON persistence (~/Library/Application Support/Snappy/)
│   └── PanelSettings.swift      # Panel hotkey settings (UserDefaults)
└── Views/
    ├── SnapPanelView.swift       # Floating panel (target app header + grid)
    ├── PreferencesView.swift     # Settings window (General + Shortcuts tabs)
    ├── GeneralView.swift         # Accessibility, login item, panel hotkey
    ├── ShortcutsView.swift       # Shortcut list
    ├── ShortcutRowView.swift     # Per-shortcut editor row
    ├── GridPickerView.swift      # 6×4 grid picker (Canvas + DragGesture)
    └── KeyRecorderView.swift     # Key capture (NSViewRepresentable)

Notable implementation details:

• The panel captures NSWorkspace.frontmostApplication and kAXFocusedWindowAttribute before activating Snappy, so the correct target window is always acquired. When Snappy is already frontmost (e.g. via menu bar click), it falls back to the last observed non-Snappy app tracked via NSWorkspace.didActivateApplicationNotification.
• Local shortcuts use NSEvent.addLocalMonitorForEvents installed while the panel is visible — they are never registered as global hotkeys.
• The optional global hotkey uses Carbon's RegisterEventHotKey + InstallEventHandler. Self is recovered inside the C callback via Unmanaged.
• Window manipulation uses AXUIElement. Coordinates require a flip: NSScreen uses a bottom-left origin while AX uses the top-left of the primary display.
• App Sandbox is disabled — required for both AXUIElement and Carbon hotkeys.

Development Notes

Accessibility permissions are tied to the app's install path and code signature. Always use make install rather than running directly from Xcode's DerivedData — otherwise the app icon won't appear in System Settings and permissions won't stick.

If permissions get out of sync after a rebuild:

make clean && make install

License

MIT