cosmic-ext-app-switcher

A macOS-style horizontal app switcher for the COSMIC desktop on Pop!_OS — replacing the default vertical Super+Tab list with a compact icon strip centered on screen.

Super+Tab switcher overlay	Panel applet — theme & shortcut toggle

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Install

One-line (no Rust required):

curl -fsSL https://raw.githubusercontent.com/j0rdiun/cosmic-ext-app-switcher/main/install.sh | bash

Or build from source:

# Install dependencies (one-time)
sudo apt install libxkbcommon-dev
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y && source ~/.cargo/env

git clone https://github.com/j0rdiun/cosmic-ext-app-switcher
cd cosmic-ext-app-switcher
make install

Changes take effect immediately — no logout required.

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Uninstall

curl -fsSL https://raw.githubusercontent.com/j0rdiun/cosmic-ext-app-switcher/main/uninstall.sh | bash

Or from the project directory:

make uninstall

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Usage

Shortcut	Action
Super+Tab / Alt+Tab	Open switcher / cycle forward
Super+Shift+Tab / Alt+Shift+Tab	Cycle backward
Modifier release	Activate selected window
Escape	Cancel — return to original window
Click icon	Select
Release click	Activate

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Panel applet

Tip: After installing, right-click your COSMIC panel → Edit Panel → Add Applet → search for App Switcher Settings and add it. This gives you a one-click toggle and theme picker directly in your panel.

Add the App Switcher Settings applet to your COSMIC panel for quick access to:

• Super+Tab shortcut toggle — enable or disable without touching the terminal
• Theme picker — Dark, Light, Frosted, or Midnight

Enable / Disable

Via the panel applet toggle, or from the terminal:

make enable         # register as COSMIC window switcher (live reload)
make disable        # remove — restores COSMIC's default switcher
make status         # show current state
make check-compat   # verify COSMIC environment is compatible

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How it works

COSMIC's compositor (cosmic-comp) lets you override the WindowSwitcher action by pointing a config file at any binary. The scripts detect the config path automatically — if COSMIC updates and moves to a new config version, it still works.

Each key press launches the binary fresh. The first invocation creates a layer-shell overlay and binds a Unix socket. Subsequent presses (while the modifier is held) connect to that socket and send a next/prev signal — the running instance advances the selection and re-renders. Releasing the modifier triggers window activation via zcosmic_toplevel_manager_v1.

Wayland protocols used:

• zcosmic_toplevel_info_v1 — enumerate open windows
• zcosmic_toplevel_manager_v1 — activate a window
• zwlr_layer_shell_v1 — overlay surface centered on screen

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Project structure

src/
  main.rs      # entry point: IPC check, then launch app
  app.rs       # libcosmic Application: state machine, socket subscription
  ui.rs        # horizontal icon strip view
  wayland.rs   # background thread: enumerate toplevels, activate window
  icons.rs     # app_id → icon name via .desktop file lookup
scripts/
  find-config.sh   # detects COSMIC shortcuts config path dynamically
  enable.sh        # writes WindowSwitcher entries to COSMIC config
  disable.sh       # removes them
  status.sh        # prints current state
install.sh     # standalone installer (downloads binary, no Rust needed)
uninstall.sh   # standalone uninstaller
.github/
  workflows/
    release.yml    # builds x86_64 + aarch64 binaries on tag push

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Releasing a new version

git tag v0.2.0
git push origin v0.2.0

GitHub Actions will build binaries for x86_64 and aarch64 and publish a release automatically.

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Requirements

• Pop!_OS with COSMIC desktop
• x86_64 or aarch64 architecture

Building from source additionally requires libxkbcommon-dev and Rust.

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License

GPL-3.0-only — see LICENSE