2. Basics
Prev |  | Next

## 2. Basics

The central point of `Object I/O` are various kinds of objects (devices) as Windows, Controls, Timers, Menus and Process. Every object has it's own unique Id which may be defined from user or may be automatically generated from the system. Having object Id we may manage it, i.e. change it attributes. For example: we may change the windows's title. The most important attribute of the object is it's local state. It can be data from various types who describe the current state of the object. The object can also receive events. Every time an event is received, a user defined function, named 'handler', is called. The 'handler' takes current local state of the object and the local state of process in which the object exists, and returns the modified states.

Prev |  | Next
The `Object I/O` package: GUI library for Haskell | Home | 3. Usage