# Package org.eclipse.core.commands.common

package org.eclipse.core.commands.common
Application programming interfaces for common base classes.

## Package Specification

This package provides some common base classes and exceptions that are used in one or more packages elsewhere. Nothing in this package is intended to be directly subclassed, or used. The code here only supports code in other packages.

Related Packages
Package
Description
org.eclipse.core.commands
Application programming interfaces for commands and handlers.
org.eclipse.core.commands.contexts
Application programming interfaces for contexts.
org.eclipse.core.commands.operations
Classes for the creation of undoable operations which can be added to an operations history and later be undone and redone.
org.eclipse.core.commands.util
Classes representing core utilities for the Commands infrastructure.
Class
Description
AbstractBitSetEvent
An event that carries with it two or more boolean values.
AbstractHandleObjectEvent
An event fired from a `NamedHandleObject`.
AbstractNamedHandleEvent
An event fired from a `NamedHandleObject`.
CommandException
Signals that an exception occured within the command architecture.
EventManager
A manager to which listeners can be attached.
HandleObject
An object that can exist in one of two states: defined and undefined.
HandleObjectManager
A manager of `HandleObject` instances.
IIdentifiable
An object that is unique identifiable based on the combination of its class and its identifier.
NamedHandleObject
A handle object that carries with it a name and a description.
NamedHandleObjectComparator
Comparator for instances of `NamedHandleObject` for display to an end user.
NotDefinedException
Signals that an attempt was made to access the properties of an undefined object.