MiniUI

A small XML/Lua-driven UI framework aimed at embedded devices, rendered with OpenGL and SDL.

demo.mp4

2026 update: the 2007-era code in this repository was modernized in April 2026 with the help of an AI coding assistant so it builds and runs on current macOS. The change set is limited to what was needed to get the project compiling and linking again — the runtime design, XML/Lua schema, widget system, and demo applications are unchanged from the original.

Summary of modernization changes:

• Replaced the SCons build with a single top-level CMakeLists.txt.
• Swapped the abandoned sdl_image package for a vendored copy of stb_image (used only by OpenGLRenderer/ResourceLoader.cpp).
• SDL 1.2 API is now satisfied by sdl12-compat layered on top of SDL2.
• Patched the vendored luabind 0.7 to compile against Boost 1.89 and C++17 (explicit preprocessor includes, std::auto_ptr → std::unique_ptr, obsolete ADL workarounds removed, boost::placeholders handling, etc.).
• Conditional <OpenGL/gl.h> / <GL/gl.h> includes so the code is portable to macOS's framework path.
• Incidental C++17 cleanups (register keyword, a couple of char* → const char* for strchr).

About this project

MiniUI was my graduate design project for my Master's in Software Engineering at DePaul University. At the time I was working at Motorola, in an R&D group in the mobile devices division, and the project was motivated by the class of problems that showed up there: building rich, themable user interfaces for embedded hardware without dragging in a full desktop UI toolkit.

The goals were:

• Declarative layout. Screens are described in XML so that designers can iterate without touching C++.
• Skinnable. Widget appearance (layout regions, source images, slicing) is separated from per-screen layout via a skin.xml / skin.lua pair.
• Scriptable behaviour. Per-widget logic — animations, hover effects, list selection, etc. — is written in Lua and dispatched from the native widget core through luabind.
• Small, portable runtime. A handful of static libraries (Lua, luabind, an OpenGL renderer, an SDL input layer, and the MiniUI core) link into one binary with no desktop-UI dependencies.

The original write-ups are archived alongside the code:

• docs/MiniUI-thesis.pdf — the full graduate design report (72 pages).
• docs/MiniUI-paper-ctirs08.pdf — "The MiniUI Framework – Moving Towards a Highly Portable, Animated User Interface," a 10-page conference paper submission based on the same work.

Repository layout

Lua/                — vendored Lua 5.1 interpreter
luabind/            — vendored luabind 0.7 (C++ ↔ Lua glue)
include/luabind/    — luabind public headers
MiniUI/             — core library: widgets, animation, XML/XPath,
                      Lua system, UI manager, graphics, event system
OpenGLRenderer/     — OpenGL-backed renderer + image resource loader
SDLInput/           — SDL input manager
src/                — executable entry point, application shell,
                      demo applications (MainMenu, PhoneBook, ImageViewer)
third_party/        — vendored third-party headers (stb_image)
build/              — runtime assets (ui/, test.xml) — the built
                      executable is dropped here at link time

Building

Requires CMake ≥ 3.20, a C++17 compiler, and Homebrew packages sdl12-compat and boost.

brew install cmake sdl12-compat boost
cmake -S . -B cmake-build
cmake --build cmake-build -j

The binary lands in build/miniui, alongside the runtime assets.

Running

cd build && ./miniui

The demo opens with a MainMenu screen; clicking Phonebook or Imageviewer transitions into the corresponding sub-application.

Demo applications

• MainMenu — sliding, fading entry screen showing the two demos.
• PhoneBook — a scrollable contact list with per-entry detail view, demonstrating the SelectableList widget and inter-screen navigation.
• ImageViewer — a fading slideshow with hover-revealed chrome, demonstrating the animation system and image loading.

License

Original project source headers reference the LGPL 2.1+. Third-party components retain their own licenses: Lua (MIT), luabind (MIT), stb_image (public domain / MIT).