libui-hpp

A header-only C++ wrapper around libui-ng with a fluent widget API.

libui-hpp wraps the C API of libui-ng in namespace ui, using RAII-friendly value types and method chaining for widget and layout setup. The library ships as a single header (include/ui/ui.hpp) and a CMake INTERFACE target named ui.

Features

• Header-only: #include <ui/ui.hpp> and link against libui-ng
• Chainable widget API (Window, Button, Tab, VerticalBox, and more)
• Fluent box composition with chained append() calls
• Cross-platform via libui-ng (Windows, macOS, Linux)

Requirements

• CMake 3.20 or newer
• A C++17 compiler
• Meson and Ninja (used to build libui-ng on first configure)
• Platform dependencies for libui-ng:
  • Windows: MSVC
  • macOS: Xcode command-line tools
  • Linux: GTK 3 development packages (pkg-config, gtk+-3.0)

On the first CMake configure, libui-ng is fetched automatically via FetchContent and built as a static library.

Quick Start

cmake -B build
cmake --build build --config Release

Run the widget gallery example:

# Windows
build\examples\Release\widget-gallery.exe

# Linux / macOS
./build/examples/widget-gallery

To build only the library target without examples:

cmake -B build -DLIBUI_HPP_BUILD_EXAMPLES=OFF

Using in Your Project

Add this repository to your build and link the ui target:

add_subdirectory(path/to/libui-hpp)

add_executable(my_app main.cpp)
target_link_libraries(my_app PRIVATE ui)

#include <ui/ui.hpp>

The ui target exports the include path and links libui-ng and its platform libraries.

Example

A minimal tabbed window in the style of the widget gallery:

#include <cstdio>

#include <ui/ui.hpp>

int main() {
  std::string err;
  if (!ui::Application::init(&err)) {
    fprintf(stderr, "error initializing libui: %s\n", err.c_str());
    return 1;
  }

  ui::Window window = ui::Window::make("Widget Gallery", 480, 320, false);
  window.on_closing(
      [](uiWindow *, void *) {
        ui::Application::quit();
        return 1;
      },
      nullptr);

  ui::Tab tab = ui::Tab::make();
  window.set_child(tab).margined(true);

  tab.append("Basic Controls",
             ui::VerticalBox::make()
                 .append(ui::Button::make("Button"))
                 .append(ui::Label::make("Hello from libui-hpp."))
                 .append(ui::Spinbox::make(0, 100))
                 .padded(true));
  tab.set_margined(0, true);

  window.show();
  ui::Application::run();
  ui::Application::uninit();
  return 0;
}

Examples

This repository includes two demo applications:

Target	Source	Description
widget-gallery	examples/widget_gallery.cpp	Control gallery with tabs, dialogs, and a borderless popup
table-demo	examples/table_demo.cpp	Table widget with custom model and cell types

Build them with the default CMake options (LIBUI_HPP_BUILD_EXAMPLES=ON).

Project Layout

include/ui/ui.hpp   Public header
examples/           Demo applications
cmake/              libui-ng fetch and build helpers
windows/            Windows manifest resources for examples

License

See the libui-ng project for the underlying UI library license. Add a license file here if you plan to distribute this wrapper separately.