I

IDL

Interface Definition Language. You must define CORBA object interfaces in this C++-like language so that the ORB can export the objects.

IIOP

Internet Inter- ORB Protocol. The IP-based protocol that CORBA uses to transfer information over the network.

index

(in a GtkTextBuffer object) The distance between two positions in a text buffer, measured in bytes (not characters ).

inherit

See derive.

inheritance

The feature in object-oriented programming that allows you to derive one class from another.

initializer

A function that initializes a data structure. GType has several initializers: a base class initializer for dynamically allocated class variables and any number of class initializers to set initial values and install properties and signals.

inode

A data structure in a Unix file system that contains details about the file (permissions, access times, data block location, and so on).

instance

An incarnation of a class; that is, the in-memory runtime details of an object.

instance structure

The data structure for instances of a class in GObject.

instantiation

The act of creating an instance of a class, reserving memory and calling the constructor.

interface

In GObject, a collection of methods that apply to a number of classes that are not necessarily derived from the same parent class. Any class that has the required methods is said to implement the interface. The interface system is the GObject substitute for multiple inheritance.

iterator

A data structure that represents a position in another, composite data structure. For example, a tree iterator points to a specific node in a tree. In GTK+, iterators assist in the management of text buffers and tree widgets.