theia.frontend.preferences in electron-app/package.json has no effect

[timfayz]

Question

Hey! I'm trying to experiment with theia.frontend.preferences namespace in electron-app/package.json. No matter what I change, nothing applies after I rebuild and restart the app. I work from Windows (the same issue happens on Linux). Before each test I delete Theia settings in %USERDATA%\.theia\* and Electron cache in %APPDATA%\IDE_NAME\*.

This question related to the previous one but since the entire preference thing doesn't work, I opened a new discussion. Theia version is 1.72.1.

I'm using a monorepo setup. Here is the content of packages/application-electron/package.json:

{
  "private": true,
  "name": "@ns/application-electron",
  "version": "0.0.1",
  "main": "lib/backend/electron-main.js",
  "dependencies": {
    "@theia/core": "1.72.1",
    "@theia/editor": "1.72.1",
    "@theia/electron": "1.72.1",
    "@theia/filesystem": "1.72.1",
    "@theia/monaco": "1.72.1",
    "@theia/navigator": "1.72.1",
    "@theia/preferences": "1.72.1",
    "@theia/terminal": "1.72.1",
    "@theia/workspace": "1.72.1",
    "@vscode/ripgrep": "1.14.2",
    "@abak/extension-template": "*"
  },
  "devDependencies": {
    "@theia/cli": "1.72.1",
    "electron": "39.8.7",
    "electron-builder": "^26.8.1"
  },
  "scripts": {
    "clean": "theia clean && rimraf lib",
    "clean:settings-win": "rimraf \"%APPDATA%\\IDE\" \"%USERPROFILE%\\.theia\"",
    "clean:settings-linux": "rimraf \"$HOME/.theia/*\" \"$HOME/.config/IDE/*\"",
    "build": "theia build --mode development",
    "rebuild": "theia rebuild:electron --cacheRoot ..",
    "watch": "npm run rebuild && theia build --watch --mode development",
    "start": "theia start",
    "dist-linux": "electron-builder --linux",
    "dist-win": "electron-builder --win --x64"
  },
  "theia": {
    "target": "electron",
    "frontend": {
      "config": {
        "applicationName": "IDE",
        "preferences": {
          "window.titleBarStyle": "native" 
        }
      }
    }
  }
}

Changing window.titleBarStyle only works when I modify the settings inside the Theia app itself (Ctrl+,). What's wrong here?

[github-actions[bot]]

Hi @timfayz, thanks for starting this discussion! 👋

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[ndoschek]

Hi @timfayz!

The path theia.frontend.config.preferences.<key> is correct - those values are picked up by FrontendConfigPreferenceContribution and registered as defaults. So anything you set via Ctrl+, (persisted in ~/.theia/settings.json for the user scrope for example) will always win over them.

A couple of things to double-check:

1. The config is baked into the generated frontend bundle at build time (see frontend-generator.ts - it writes FrontendApplicationConfigProvider.set(...)). So a fresh theia build is required after changing package.json. You can grep the generated gen-frontend/index.js (or whatever the generator emits in your app) for titleBarStyle to confirm your value is actually in the bundle.

2. For window.titleBarStyle on Electron specifically, there's an extra thing to consider: the Electron main process picks the title bar style in this order (getTitleBarStyle):

   • THEIA_ELECTRON_DISABLE_NATIVE_ELEMENTS=1 env var
   • macOS → always native
   • stored windowstate.frame from electron-store (this lives in app.getPath('userData') - on Windows %APPDATA%\<applicationName>\)
   • config.preferences['window.titleBarStyle'] (your package.json default)
   • OS default (custom on Windows, native elsewhere)

   So once a window state has been saved, the stored frame overrides your default. Make sure your cleanup actually deletes the whole %APPDATA%\IDE\ folder (note: in your script %APPDATA%\IDE not IDE_NAME - your applicationName is IDE) before launching again.

If after a theia build + full wipe of %USERPROFILE%\.theia and %APPDATA%\IDE the value still has no effect, please share the generated bundle snippet containing FrontendApplicationConfigProvider.set(...), that will tell us whether the config made it into the build at all.