Custom Controls

To learn how to work with custom controls it is useful to read:

• Custom Controls in wxHaskell - Part 1
• Custom Controls in wxHaskell - Part 2
• Custom Controls in wxHaskell - Part 3
• Custom Controls in wxHaskell - Part 4
• Custom Controls in wxHaskell - Part 5
• [Custom DIFF Control] (https://hackage.haskell.org/package/WXDiffCtrl)