1 What is it?
wxHaskell is a portable and native GUI library for Haskell. The goal of the project is to provide an industrial strength GUI library for Haskell, but without the burden of developing (and maintaining) one ourselves.
wxHaskell is therefore built on top of wxWidgets – a comprehensive C++ library that is portable across all major GUI platforms; including GTK, Windows, X11, and MacOS X. Furthermore, it is a mature library (in development since 1992) that supports a wide range of widgets with the native look-and-feel, and it has a very active community (ranked among the top 25 most active projects on sourceforge).
We maintain two branches of wxHaskell.
The 0.13 branch supports wxWidgets 2.8.x, and is the easiest to get working. Many Linux distributions come with packaged wxWidgets 2.8.x, and Windows users can download the pre-built wxPack distribution. This branch is in a maintenance mode, and will not receive significant new development.
The 0.90 branch supports wxWidgets 2.9.x. The downside of choosing this version is that you will likely need to build wxWidgets for yourself, which is slightly time consuming and requires you to have g++ installed on your system. The benefit is that it supports quite a number of new and more modern GUI elements. wxHaskell 0.90 is essential if you want to build for 64bit MacOS X targets (e.g. Lion).
The core interface of wxHaskell was originally derived from the wxEiffel binding. Work on this has been dormant for several years, but the wxHaskell maintainers now support updates to the wxWidgets API themselves - we generally respond to new releases of wxWidgets within a few weeks at most.
There are four key components of wxHaskell from version 0.90 onwards (three in earlier branches).
- wxDirect parses specially written C headers and generates low level Haskell FFI bindings for the exported functions.
- wxc is a C language binding for wxWidgets. It is needed because the Haskell FFI can only bind to C as it does not understand C++ name mangling. Because it is a C language wrapper over wxWidgets, and is generated as a standard dynamic library on all supported platforms, wxc could be used as the basis for a wxWidgets wrapper for any language which supports linking to C (so that would be all of them then). In older versions of wxHaskell, the wxc components were built as a monolithic static library with wxcore.
- wxcore is a set of low-level Haskell bindings to wxc. A large part is generated automatically by wxdirect, with some key abstractions being hand-coded in Haskell. You can program directly to the wxcore interface if you wish (it is sometimes the only way, in fact).
- wx is a set of higher-level wrappers over wxcore. It is intended to make it easier to write reasonably idiomatic Haskell. Most wxHaskell software is about 80% wx and 20% wxcore (at least in my experience).
The C wrapper is, unfortunately, generated by hand, so there is some (mainly tedious boilerplate) work involved in porting a new set of widgets to wxHaskell. Some work has been done into automating this aspect, but we are far from being able to replicate the approach reliably over then entire API as yet.
From the perspective of the user (rather than the developer) about 90% of the core wxWidgets functionality is already supported, excluding more "exotic" widgets like dockable windows. The library supports Windows, GTK (Linux) and MacOS X.
- 2 August 2013
- A github organisation 'wxHaskell' has been created, the maintenance repo (https://github.com/atzedijkstra/wxHaskell) has moved to https://github.com/wxHaskell/wxHaskell. It is the intent to soon release a maintenance update working with wxWidgets 2.9.5 and GHC 7.6.x
- 26 January 2013
- Maintenance is now done on the repository at: https://github.com/atzedijkstra/wxHaskell
- 10 June 2012
- Repository now on GitHub: https://github.com/jodonoghue/wxHaskell
- 13 April 2012
- wxHaskell 0.90 is released. This version supports wxWidgets >= 2.9.x, and includes many new features.
See also Old wxHaskell news
- Using wxHaskell
- Building and installing. Please refer to your platform.
- The developer mailing list (wxhaskell-devel) (archive)
- The wxHaskell users mailing list (wxhaskell-users) (archive)
- wxHaskell repository, as of 2 Aug 2013 replacing the old repo  and temporary maintenance repo  on github
- Daan Leijen: wxHaskell / A Portable and Concise GUI Library for Haskell (pdf)
- Wei Tan: GUI programming with wxHaskell (pdf)
- Assignment 1 part of the course Advanced Functional Programming, by Koen Lindström Claessen and Björn Bringert, a portal like page (html)
- Blog articles about wxHaskell
- Questions about wxHaskell on stackoverflow
- Sander Evers, Peter Achten, and Jan Kuper: A Functional Programming Technique for Forms in GUI (PDF)
- FunctionalForms, a combinator library/domain specific language for wxHaskell which enables a very concise programming style for forms (not maintained since 2005)
- Learning by Example Beginners: a Text Editor
- Learning by Example Intermediate: Custom controls
7 See also
- The reverse dependencies list for wx
- An example of how to implement a basic notepad with wxHaskell
- Reducing linking and startup times
- Modified Paint.hs example to show wxGCDC and graphics path drawing in action.
- The Haskell wikibook GUI chapter
- Can GUI Programming Be Liberated From The IO Monad
- Phooey: a purely functional layer on top of wxHaskell
- GuiTV: GUI-based tangible values & composable interfaces, on TV, Phooey and wxHaskell.
- wxAsteroids: a game demonstrating wxHaskell.
- GeBoP: the General Boardgames Player, offers a set of board games: Ataxx, Bamp, Halma, Hez, Kram, Nim, Reversi, TicTacToe, and Zenix.
- Haskell-BlackBoard: a drawing application for making slideshows and videos, based on wxHaskell and Functional Reactive Programming
- reactive-banana - FRP library with bindings to wxHaskell.
- wxHaskell for the web: a port of a subset of wxHaskell to the web browser.
- wxHaskell Drag and Drop example (Stackoverflow)
- The package binding-wx; binds mutable data and lists to WxHaskell widgets.