Cheeter

Cheeter is a context-aware cheatsheet overlay daemon for Linux. It runs in the background and, when triggered (default: ctrl + alt + c), detects the currently active application and displays a relevant PDF cheatsheet in an overlay.

Features

• Context-Aware: Automatically detects the active window (via X11 or AT-SPI) to show the correct sheets.
• Overlay UI: Minimalist, borderless window that appears in the center of the screen.
• Fast: Written in C using GLib and GTK+.
• Configurable: Simple text-based configuration and mapping files.
• PDF and PNG Support: Renders cheatsheets directly using Poppler.

Dependencies

To build Cheeter, you need a C compiler and the following development libraries:

• glib-2.0
• gtk+-3.0
• poppler-glib
• at-spi2-core (or at-spi-2.0)
• libx11 (for X11 backend)

Arch Linux:

sudo pacman -S glib2 gtk3 poppler-glib at-spi2-core libx11

Debian/Ubuntu:

sudo apt install libglib2.0-dev libgtk-3-dev libpoppler-glib-dev libatspi-dev libx11-dev

Building

Manual Build

make

This produces cheeter (CLI) and cheeterd (Daemon).

Arch Linux (PKGBUILD)

A PKGBUILD is included for generating an Arch package:

makepkg -si

Installation

You can install the binaries, systemd unit, and desktop entry using:

sudo make install

(Defaults to /usr/local. Use PREFIX=/usr to override).

Enable Autostart

To start the daemon automatically with your user session:

systemctl --user enable --now cheeter.service

Alternatively, the cheeter.desktop file is installed to share/applications and should be visible in your desktop environment's startup settings if configured.

Usage

4. Trigger: Press the hotkey (default Super+/ on X11) to toggle the overlay.
   • You can also toggle via CLI: cheeter toggle.

Controls

Key	Action
n / Right Arrow	Next Page
p / Left Arrow	Previous Page
Escape	Close Overlay

Usage

1. Start the Daemon: Ensure cheeterd is running (manually or via systemd).
2. Add Cheatsheets: Place your cheatsheets in ~/.local/share/cheeter/sheets/.
   • Supported formats: .pdf, .png, .jpg, .jpeg.
   • Example: cp ~/Downloads/vim-cheat.png ~/.local/share/cheeter/sheets/vim.png
3. Mappings: Cheeter tries to resolve sheets automatically.
   • Terminal Detection: Cheeter automatically detects applications running inside your terminal (e.g., vim, nano, python) so you can simply name your sheet vim.pdf or python.png.
   • Explicit Mapping: You can manually map applications in ~/.config/cheeter/mappings.tsv.
     • Format: KEY (tab or space) PATH
     • Example:

       exe:code    /home/user/.local/share/cheeter/sheets/vscode.pdf

Configuration

Configuration is stored in ~/.config/cheeter/config.ini.

[core]
# Supported modifiers: Super, Control, Alt, Shift
hotkey=Super+Slash
debug=false

Backends

• X11: Fully supported. Uses XGrabKey for global hotkeys and _NET_ACTIVE_WINDOW for context detection.
• Wayland: Experimental/Mock support. Requires AT-SPI for context detection. Global hotkeys must be handled via Compositor shortcuts invoking cheeter toggle.

License

MIT