# Focus
A quick GNOME extension for apply transparency to inactive windows.
## Settings
Open Focus from the GNOME Extensions app to configure opacity, inactive-window effects, special focus windows,
and exclusions.
### Special Focus Windows
Use the **Special Focus Windows** preferences page to add or remove windows that should use the special focused
opacity while active.
### Excluded Windows
Use the **Excluded Windows** preferences page to add or remove exact criteria. A window is excluded when a criterion exactly matches any of:
- its `WM_CLASS`
- its `WM_CLASS` instance
- its full window title
Both lists use exact, case-sensitive matches against a window's `WM_CLASS`, `WM_CLASS` instance, or full title. On
X11, `xprop WM_CLASS` can show the class and instance; GNOME Shell's Looking Glass can help inspect windows on
Wayland. Blank entries are not stored, duplicate entries are removed, and changes apply immediately while the
extension is enabled.
## Legacy JSON Lists
Existing JSON lists remain supported and are merged with the corresponding preferences. Focus reads them from
`~/.config/focus@scaryrawr.github.io/`, falling back to the legacy `~/.config/Focus/` directory when the preferred
directory is absent. Each file must contain a JSON array of strings; invalid files are ignored with a warning in
the GNOME Shell log.
`special_focus.json` adds special focus windows:
```json
["Code", "Code - Insiders"]
```
`ignore_focus.json` adds excluded windows. This example lets Firefox's Picture-in-Picture keep its normal
appearance:
```json
["Toolkit"]
```
## Installing
[GNOME Extensions - Focus](https://extensions.gnome.org/extension/3924/focus/)
## Repo Guide
The build uses [GJS type definitions](https://gjsify.org/), Rolldown, Oxlint, native TypeScript, and Oxfmt.
Building works on non-Linux systems, but local extension installation requires Linux and GNOME Shell.
### Prerequisites
Use Node.js 22 and the pnpm 11 version pinned in `package.json`.
```bash
corepack enable
pnpm install --frozen-lockfile
```
### Quality checks
```bash
pnpm lint
```
### Build
```bash
pnpm build
```
### Packaging for [GNOME Extensions](https://extensions.gnome.org/)
```bash
pnpm build:package
```
### Installing Locally
```bash
pnpm package:install
```