Enpreview

Enpreview is a desktop companion for Barco Event Master operators. It talks to the frame over the JSON-RPC API on port 9999, feeding tally and destination state into a configurable Electron + Svelte interface so you always know what is live, on preview, or listening.

Download

Download the latest version for Mac, Windows, and Linux

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Project links

• docs/ contains API experiments and response captures under response_objects/ for reference.
• Releases are built with Electron Builder scripts in package.json.

Issue tracking

• File bugs or feature ideas through your team's normal workflow (this repository ships without Git metadata by default).

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Key features

• JSON-RPC polling of Event Master destinations and layer content.
• Visual tally indicators for program, preview, and listened destinations.
• Electron shell with draggable windows for overlay-style monitoring.
• Carbon Components Svelte UI with themeable widgets.

Architecture notes

• src/main/classes/backendService.cjs boots an Express server (default port 6788) that receives Event Master subscription callbacks and relays them to renderer windows.
• src/main/classes/RequestController.cjs issues HTTP POST requests to http://<frame>:9999 for methods such as listPresets, listContent, and subscribe.
• response_objects/ captures real Event Master responses for reference when iterating on parsing logic.

Getting started

npm install
npm run dev        # launches Vite/Svelte and Electron together

The dev script starts two processes via concurrently: the Svelte frontend (npm run dev:svelte) and the Electron host (npm run dev:electron). When developing UI-only changes you can run npm run dev:svelte on its own.

Building

npm run build          # builds Svelte + Electron bundles
npm run dist           # packages desktop binaries with electron-builder

Artifacts are written to dist/ and build/ depending on the target platform. See electron-builder.json for platform-specific configuration.

Release Workflow

This project uses a hybrid release workflow:

• Windows builds are handled by GitHub Actions.
• Mac & Linux builds are handled locally on your machine.
• All artifacts are uploaded to the same GitHub Release.

Prerequisites

1. Create a Personal Access Token (Classic) on GitHub with repo scope.
2. Add it to a .env file in the project root:

   GH_TOKEN=ghp_your_token_here

Creating a Release

Run the interactive release script:

npm run release-interactive

This script will:

1. Prompt you for the version bump (patch, minor, major).
2. Update package.json, commit, and tag the release.
3. Push the tag to GitHub (triggering the Windows build Action).
4. Build and upload Mac & Linux artifacts from your local machine.

Troubleshooting

• Response samples in response_objects/ illustrate the expected payloads from Event Master APIs.
• If tally data stops updating, confirm the backend Express listener is reachable from the frame and that subscriptions (ScreenDestChanged, AuxDestChanged) are posting to it—these trigger refresh calls for listContent and listAuxContent.

License

Enpreview is distributed under the PolyForm Noncommercial License 1.0.0. See LICENSE for full terms.