FLTK is a small C++ GUI toolkit portable to the MS Windows, Linux, and Mac OSX operating systems. fltk4lua is a binding to this C++ toolkit, which allows you to create GUIs from within Lua scripts.

fltk4lua is available via the LuaRocks package manager. For details about building/installing the module see here.

Although FLTK is a small GUI toolkit, it still has many classes and functions. fltk4lua currently exports more than 50 different userdata types and hundreds of C++ functions. Fortunately the Lua API is very close to the C++ API, so you can use the official FLTK documentation, and look at the Lua examples in the repository, or at the source code. There is also a Getting Started Guide, which builds a simple GUI with fltk4lua and explains every step.

However, here is a list of userdata types/functions/properties that are available in Lua. The format of the listing (especially the function prototypes) is specified here.

• Image (abstract)
• Shared_Image
• Widget (abstract)
• Box
• Button
• Light_Button
• Check_Button
• Repeat_Button
• Return_Button
• Round_Button
• Chart
• Clock_Output
• Clock
• Group
• Browser_ (abstract)
• Browser
• File_Browser
• Check_Browser
• Color_Chooser
• Input_Choice
• Pack
• Scroll
• Spinner
• Tabs
• Tile
• Window
• Wizard
• Input
• File_Input
• Menu (abstract)
• Choice
• Menu_Bar
• Menu_Button
• Progress
• Valuator (abstract)
• Adjuster
• Counter
• Dial
• Roller
• Slider
• Scrollbar
• Value_Slider
• Value_Input
• Value_Output
• additional module functions