# Package org.eclipse.birt.report.model.api.core

package org.eclipse.birt.report.model.api.core
Represents the fundamental data structures of the user-defined property and the interface of UI listener.

## Package Specification

The core package represents the key data structures of the user-defined property. Other packages build on this class to add, remove, replace a user-defined property. UI can add listener to the design element to accept the notification event sent each time the operation is done, undone or redone.

The key classes in this package include:

- `Listener` is the interface class to accept the notification event sent by all report elements. See the extensive documentation in this class for information about the services common to all report elements.
- `UserPropertyDefn` provides generic access to a user-defined property. The class provides some getter/setters to the name, type, choices, and so on.

Related Packages
Package
Description
org.eclipse.birt.report.model.api
Tool-writer's interface for the BIRT design model (also known as the "Design Engine.")
Class
Description
AttributeEvent
Notification event that says that the attribute of the module is changed.
DisposeEvent
Notification event that says that the module is disposed.
IAccessControl
Represents the visibility level of a module.
IAttributeListener
Receives file name events after one attribute of the report design is changed.
IDesignElement
Interface for all the design elements.
IDisposeListener
Receives dispose events after one report design is disposed.
IModuleModel
The interface for the root element to store the constants.
INameManager
Interface to do all managements about the element names.
IResourceChangeListener
This listener is notified of changes to resources in the resource path.
IStructure
Interface for objects that appear in a property list.
Listener
Receives events about a Design Element.
UserPropertyDefn
Represents a user-defined property.