Gtk2Hs/Tutorials/Intro

Note: this page is under construction. Feel free to help out!

Introduction

As with any tutorial, certain assumptions are inherent in the code and instructions presented below. In this case the primary assumptions are:

• You are reasonably familiar with Haskell and in particular, writing code using the IO Monad.
• You have successfully installed Gtk2Hs.
• You believe using Glade to design your user interface is a good idea.

Bon chance, mes amis!

"Hello World" with Gtk2Hs

Start with the most basic working hello world app. Then we compile it...

Here's the most basic Gtk2Hs prog:

import Graphics.UI.Gtk

main = do
  initGUI
  window <- windowNew
  widgetShow window
  mainGUI

Compiling "Hello World"

How to compile it with GHC on linux/mac/win32

> ghc --make Hello.hs -o hello

Stepping through "Hello World"

Go through line by line of the hello world code to explain what each one does. It should not mention in too much detail how signals work yet, but note that they will be explained more fully shorty.

Signals

The concept of event driven GUI programming. What GObject signals are (without necessarily mentioning the term GObject yet)

Widget types

The way that the class heiriaharcy is represented in Haskell using type classes. Breif mention of up casting & downcasting. We'll come back to downcasting in the glade section.

Attributes

Show the "set object [ attr := value ]" style syntax. Reccomend it over the more verbose "objectSetAttr object value" style.

Using Glade

We want to encourage people to use Glade to do their widget layout rather than doing it all in code. We can explain manual widget layout as a more advanced topic next.

Redo the hello world program using Glade.

Widget layout

Doing widget layout in code rather than with Glade.

Basic concepts

Brief explanation of basic and general concepts. With references to the API functions whenever possible. (probably in form of examples?).

 - signal
 - event
 - window
 - widget
 - container
 - box
 - layout
 - button
 - label

The idea is to get the user with as general and useful concepts as possible so it makes it easier for him to surf the API since the beginning and write simple code.