Screenshot

A small, fast region screenshot overlay for Windows (C/Win32/GDI), macOS (Objective-C/Cocoa), and Linux Wayland/COSMIC (C/GTK4 + layer-shell). It darkens the desktop, provides an intuitive selection interface with clipboard integration, and can be launched from the tray, menu bar, or COSMIC panel applet.

Features

• Selection Creation: Left-click and drag to create a selection
• Selection Movement: Drag inside the selection to move it
• Resize Handles: Drag handles to resize (handles flip when crossing sides)
• Clipboard Integration: Copy selection to clipboard with Enter or Cmd+C (macOS) / Ctrl+C (Windows)
• Easy Exit: Cancel/exit with Esc or right-click
• System Tray / Menu Bar: Always accessible via tray icon (Windows) or menu bar (macOS)
• COSMIC Applet: Launch from the COSMIC panel on Linux
• Global Hotkey:
  • Windows: PrintScreen key triggers screenshot overlay instantly
  • macOS: Cmd+Shift+4 triggers screenshot overlay

Usage

Screenshot Interface

Action	Result
Left-click + drag	Create a selection
Drag inside selection	Move the selection
Drag handles	Resize the selection
Enter or Cmd+C (macOS) / Ctrl+C (Windows)	Copy to clipboard and exit
Esc or Right-click	Cancel and exit

System Tray (Windows) / Menu Bar (macOS)

• Left-click icon: Launch screenshot overlay
• Right-click icon (Windows) / Click icon (macOS): Show context menu
  • Take Screenshot: Launch overlay
  • Exit / Quit: Close the application

Global Hotkey

• Windows: PrintScreen (no modifiers needed)
• macOS: Cmd+Shift+4

Building

Windows

Prerequisites

• MSVC (Visual Studio Build Tools) with C++ and Windows SDK
• CMake (latest version)
• Ninja build system

Quick Build

Using the provided CMake presets:

cmake --workflow --preset build

Manual Build

mkdir build
cd build
cmake ..
cmake --build . --config Release

macOS

Prerequisites

• Xcode or Command Line Tools (for clang/Objective-C)
• CMake (latest version)
• macOS 12.3+ (Monterey or later) for ScreenCaptureKit

Build

cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build

The app bundle will be at build/screenshot.app.

First Run

On first launch, macOS will prompt for Screen Recording permission. Grant permission in:

• System Settings > Privacy & Security > Screen Recording

Then restart the app.

Running

open build/screenshot.app

Or double-click screenshot.app in Finder.

Linux (Wayland/COSMIC)

Prerequisites

• CMake
• pkg-config
• GTK4
• gtk4-layer-shell
• wl-clipboard
• An XDG desktop portal screenshot backend such as COSMIC

Build

cmake -B build-linux -DCMAKE_BUILD_TYPE=Release
cmake --build build-linux

Build COSMIC Applet

cargo build --release --manifest-path cosmic-applet/Cargo.toml

Install Locally

install -Dm755 build-linux/screenshot ~/.local/bin/screenshot

For the COSMIC panel applet, also install:

install -Dm755 cosmic-applet/target/release/cosmic-applet-screenshot ~/.local/bin/cosmic-applet-screenshot
install -Dm644 cosmic-applet/data/com.screenshot.CosmicApplet.desktop ~/.local/share/applications/com.screenshot.CosmicApplet.desktop