Swift Script to Focus macOS Windows

Swift Script to Focus macOS Windows | Generated by AI

Home 2026.05

Here’s how it works, step by step:

1. Listing all Ghostty windows

I wrote a Swift script that uses macOS’s CGWindowListCopyWindowInfo API from CoreGraphics. This is the same API that Activity Monitor uses to list windows. It returns metadata for every on-screen window — owner name, window title, position, size, and a unique CGWindowID.

swift -e '
import Cocoa
import CoreGraphics
// CGWindowListCopyWindowInfo enumerates all on-screen windows
// Filter by owner name == "ghostty"
// Extract: window ID, title, position, size
'

No special permissions needed — this is a read-only public API.

2. Focusing a specific window by ID

This is the harder part. The compiled script lives at /tmp/focus_window. It does:

Step 1: Look up the target window's bounds (x, y, width, height)
        using CGWindowListCopyWindowInfo filtered by window ID

Step 2: Activate the Ghostty app via NSRunningApplication.activate()
        (brings the app to front, but only the last-focused window)

Step 3: Calculate the center point of the target window

Step 4: Convert coordinates — CGWindowList returns "top-left origin"
        coordinates, but CGEvent uses Quartz coordinates (bottom-left origin).
        So: quartzY = screenHeight - clickY

Step 5: Post synthetic mouse events via CGEvent:
        - mouseMoved to the center
        - leftMouseDown
        - leftMouseUp
        This "clicks" the target window, which tells macOS to focus it.

Limitations:

CGEvent.post(tap: .cghidEventTap) injects events at the HID level. It works, but it’s a synthetic click — it will interact with whatever is at that screen position. If a popup or overlay is in the way, it gets clicked instead.
If you grant Accessibility permissions to the process running this (Terminal or Hermes), I could use AppleScript via System Events (tell process "ghostty" to set frontmost to true, perform action "AXRaise" of window N), which is more precise — no synthetic clicks, just an accessibility command to raise a specific window.
The Swift script needs to be compiled once (swiftc), which I did in /tmp. It’s ephemeral — survives until reboot.

What’s on disk:

File	Purpose
`/tmp/focus_window.swift`	Source — lists window bounds, activates app, clicks center
`/tmp/focus_window`	Compiled binary (macOS arm64)
`/tmp/raise_window.swift`	Simpler variant — just activates app, no click

If you want this to be more robust, I could:

Install cliclick (brew install cliclick) — a tiny CLI for synthetic mouse/keyboard events, simpler than compiling Swift
Grant accessibility access so I can use AppleScript for clean window raising without clicks

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