SmallScreenshot

A screenshot tool for GNUStep on Linux. Capture the full screen or a region, preview, and save as PNG.

Features

• Capture full screen – One click captures the entire screen.
• Capture region – Drag a rectangle on a fullscreen overlay to capture only that area.
• Preview – Captured image is shown in the main window.
• Save as PNG – Save via the Save button or menu (Cmd+S).

Dependencies

• GNUStep (gnustep-gui, gnustep-base)
• SmallStepLib (../SmallStepLib) – app lifecycle, menus, file dialogs
• libX11 – X11 screen capture (Linux)

Build

1. Build SmallStepLib first:

   cd ../SmallStepLib
   make
   sudo make install   # optional; or link from obj/

2. Build SmallScreenshot:

   cd SmallScreenshot
   make

3. Run:

   ./SmallScreenshot.app/SmallScreenshot

   Or from the project root:

   openapp ./SmallScreenshot.app

Usage

• Capture Full Screen – Captures the entire root window (all monitors on X11).
• Capture Region… – The main window hides; a semi-transparent overlay appears. Drag to select a rectangle. Release to capture. Press Escape to cancel.
• Save… – Opens a save dialog (PNG). The preview image is written to the chosen path.

SmallStepLib usage

SmallScreenshot uses SmallStepLib as the starting point:

• SSHostApplication / SSAppDelegate – App entry and lifecycle (no manual NSApplication setup).
• SSMainMenu – Application menu (Capture Full Screen, Capture Region, Save, Quit).
• SSFileDialog – Save dialog for choosing path and filename.
• SSWindowStyle – Window style mask for the main window.
• SSConcurrency – Capture runs on a background thread; UI updates on the main thread.

FOSS libraries

• libX11 – X11 API for XGetImage() on the root window. Used for full-screen and region capture. Converts XImage pixel data (with visual masks) to RGB and builds an NSImage for preview and PNG export.
• GNUStep – NSBitmapImageRep and representationUsingType:NSPNGFileType for writing PNG files.

License

GNU General Public License v3 or later. See LICENSE.