obj <- < widgetName >New -- How widgets (e.g Windows, Buttons, Grids) are created
set < widget > [ < attributes > ] -- Set attributes as defined as Attr self in widget documentation (e.g. buttonLabel)
on < widget > < event > < IO action > -- Adding an IO action to a widgets Signal self (e.g. buttonActivated)
On many Linux distributions, the Haskell Gtk3 library is available as a package in the systems package manager (e.g.
libghc-gtk in Ubuntu's APT). However, for some developers it might be preferable to use a tool like
stack to manage isolated environments, and have Gtk3 installed via
cabal instead of via an global installation by the systems package manager. For this option,
gtk2hs-buildtools is required. Run
cabal install gtk2hs-buildtools before adding
gtk3 or any other Gtk-based Haskell libraries to your projects
build-depends entry in your cabal file.
This example show how one may create a simple "Hello World" in Gtk3, setting up a window and button widgets. The sample code will also demonstrate how to set different attributes and actions on the widgets.
module Main (Main.main) where import Graphics.UI.Gtk main :: IO () main = do initGUI window <- windowNew on window objectDestroy mainQuit set window [ containerBorderWidth := 10, windowTitle := "Hello World" ] button <- buttonNew set button [ buttonLabel := "Hello World" ] on button buttonActivated $ do putStrLn "A \"clicked\"-handler to say \"destroy\"" widgetDestroy window set window [ containerChild := button ] widgetShowAll window mainGUI -- main loop