Helm UI GTK4

Modern C++/GTK4 cockpit helm UI starter project for a 10 inch sailboat touchscreen.

This repository implements the starter phases of the plan:

• Phase 0: visual baseline, module boundaries, safety hierarchy, and architecture notes.
• Phase 1: compilable GTK4/gtkmm shell skeleton with dummy telemetry, scalable Cairo icons, screen modules, and the 4x PNG concept images stored as reference assets.
• Phase 2/3 overlays: telemetry store hardening and compact live NMEA 0183 TCP input.
• Phase 4 overlay: first usable cockpit screens for Home, Nav, Sail, Anchor, AIS, Systems, and Alarms.

The 4x PNG files in assets/reference/ are visual references only. The running UI is drawn with GTK widgets and scalable Cairo primitives; no icons are cropped from the PNGs.

Current screens

The current shell includes these primary modules:

• Home
• Nav
• Sail / Wind
• Anchor
• AIS
• Systems
• Alarms

Bilge and Windlass modules are also compiled and available through the module registry for Systems integration and future direct navigation.

The center area behaves as an app viewport. The top/bottom bars and side sensor tiles stay persistent while the active module changes.

Dependencies

Linux:

sudo apt update
sudo apt install -y build-essential cmake ninja-build pkg-config libgtkmm-4.0-dev

Windows/MSYS2 UCRT64:

pacman -S --needed \
  mingw-w64-ucrt-x86_64-toolchain \
  mingw-w64-ucrt-x86_64-cmake \
  mingw-w64-ucrt-x86_64-ninja \
  mingw-w64-ucrt-x86_64-pkgconf \
  mingw-w64-ucrt-x86_64-gtkmm-4.0

Build

Linux:

cmake --preset linux-debug
cmake --build --preset linux-debug
./build/linux-debug/helm-ui

Windows/MSYS2 UCRT64 shell:

cmake --preset windows-msys2-ucrt64-debug
cmake --build --preset windows-msys2-ucrt64-debug
./build/windows-ucrt64-debug/helm-ui.exe

Tests

The first test target validates the compact NMEA 0183 tokenizer/parser foundation.

ctest --preset linux-debug

Design rules

• Keep the cockpit shell stable and persistent.
• Launch sub-apps only inside the center viewport.
• Keep sensor readings in a central telemetry snapshot with timestamps.
• Do not parse NMEA in UI widgets.
• Do not render from non-GTK threads.
• Do not use a header/class per NMEA 0183 sentence.
• Do not crop icons from concept PNGs; recreate icons as scalable vector/Cairo drawing.
• Windlass controls must be locked by default and press-and-hold only.
• Music/messages, when added later, must never hide safety alarms.

Repository layout

assets/reference/   4x PNG concept references
assets/themes/      theme reference data
docs/               Phase 0 design docs
src/app/            GTK application/window
src/shell/          persistent cockpit frame
src/modules/        center viewport sub-apps
src/telemetry/      latest readings and timestamps
src/graphics/       theme and scalable icons
src/nmea/           compact NMEA tokenizer/parser

Live NMEA 0183 TCP input

Dummy telemetry is still the default:

./helm-ui

To read a TCP NMEA 0183 stream:

./helm-ui --source tcp-nmea0183://127.0.0.1:10110

Also supported:

./helm-ui --source=tcp-nmea0183://127.0.0.1:10110
./helm-ui --nmea-tcp=127.0.0.1:10110
HELM_UI_NMEA_SOURCE=tcp-nmea0183://127.0.0.1:10110 ./helm-ui

The NMEA design is intentionally compact: one tokenizer, one parser entry point, and private helpers in src/nmea/Nmea0183.cpp. There are no message-type decoder headers.

See docs/PHASE2_PHASE3.md and docs/PHASE4.md for details.