NeoFrame (nf)

August 3, 2026 · View on GitHub

A minimal on-screen overlay that creates a transparent, always‑on‑top window which lets normal mouse and keyboard input pass through. An always‑visible toolbar window lets you pick a color and draw on the screen or erase; Esc or Done returns control to the desktop. A command window (the Cmd button) offers basic commands (e.g., clear, exit). The UI is built with minigui.

Status: early prototype. Released for macOS (signed, notarized universal app), Windows, and Linux.

NeoFrame

Features

  • Transparent, click‑through overlay window (stays above all apps).
  • Always‑visible, draggable toolbar window for tool and color selection.
  • Freehand drawing with an 18‑swatch color palette (including a transparent swatch) and an eraser, plus a Clear button that wipes the canvas.
  • In‑app command window (clear/cls, help, exit/quit/q).
  • Skips taskbar / dock and uses a window class/name for X11 when available.
  • Auto-detects monitor size on startup.

Build

Requirements:

  • Go 1.26+.
  • No C toolchain on any platform: Ebitengine v2.10+ talks to the OS through purego, so CGO_ENABLED=0 builds natively everywhere (no Xcode, MinGW, or X11 dev libraries).
  • Module deps are managed via go.mod: Ebitengine v2.10 plus the sibling package minigui (UI toolkit), which brings native along for the system clipboard in its text fields.

Quick build:

# Using the Makefile (produces ./nf)
make build

# Or directly:
CGO_ENABLED=0 go build -trimpath -ldflags "-s -w" -o nf .

Release

release.sh (run on a macOS host, from a clean worktree on a Git tag) builds a signed, notarized macOS universal .app (amd64 + arm64 via lipo, hardened runtime, stapled) plus the Windows (amd64/arm64) and Linux (amd64 + arm64, gzipped) binaries, all CGo‑free, then creates the GitHub release. The ci workflow tests on Linux and compile‑checks the macOS/Windows cross‑builds on every push and pull request targeting trunk.

Requires APPLE_DEVELOPER_ID (a Developer ID Application certificate) and APPLE_NOTARY_PROFILE (notarytool credentials stored in Keychain). The macOS app is an accessory overlay (LSUIElement), so it has no Dock icon.

Run

./nf

Behavior:

  • The overlay starts transparent and on top of other windows, with a small always‑visible toolbar window in the top‑left; the rest of the screen stays click‑through, so you keep using the desktop.
  • Pick a color (or Draw / Erase) to start drawing; Done or Esc releases the tools and hands control back to the desktop. Clicking the active Draw/Erase toggle also releases it, and Clear wipes the canvas.
  • The toolbar windows are draggable by their title bar.
  • The Cmd button opens a command window with a text field and a Run button (Enter also submits): clear/cls, help, exit/quit/q.

Notes & Limitations

  • Click‑through and transparency depend on platform window APIs; exact behavior may vary between OS versions and, on Linux, between window managers.
  • High‑DPI setups are expected to work; edge cases may still exist.
  • Multi‑monitor setups are not supported yet; the overlay appears on the primary display or on the monitor used to start the app.

License

BSD 3‑Clause. See LICENSE.

References

More of my projects

  • minigui: a tiny immediate-mode GUI for Ebitengine.
  • kutta: a 2D wind tunnel; watch air misbehave around an airfoil.
  • neko: the classic desktop cat chasing your pointer, in Go.
  • native: cgo-free Go bindings for OS APIs: clipboard, mmap, keep-awake, and friends.

More at github.com/crgimenes and crg.eti.br.