Inside Macintosh: Cyberdog Programmer's Kit / Part 3 - Cyberdog Reference

Chapter 7 - Classes and Methods

CyberOpenerPartExtension

Superclasses

CyberProgressPartExtension --> CyberExtension --> ODExtension --> ODRefCntObject --> ODObject

Subclasses

CyberNavigatorExtension

CyberOpenerPartExtension defines extra behaviors for a part that is to be used as an opener part.

Description

The CyberOpenerPartExtension class is a part extension that allows a part to be used as an opener part. CyberOpenerPartExtension is an abstract superclass that you must subclass and implement to create your own custom opener part. However, Cyberdog provides a fully implemented opener part; to use this opener part, you do not need to subclass this class.

When a Cyberdog item is opened, the type of data the Cyberdog item references is not always known immediately. In some situations -- for instance, when a user is dragging a Cyberdog item or embedding a Cyberdog item in a document -- OpenDoc needs to create a part immediately, sometimes before the type of the data the Cyberdog item references is known.

An opener part is a temporary part used during the process of opening a Cyberdog item until the Cyberdog display part for the item can be opened. If, during opening, OpenDoc must have a part, the opener part acts as a placeholder in a document until the display part can be created. Once the display part has been created, it is swapped into the embedded frames that contain the opener part.

The opener part is a kind of progress part; you can use it to display status information to the user while the Cyberdog display part is being opened.

The opener part is the editor that OpenDoc binds to data whose kind is kCyberItemKind; hence, if you are developing a Cyberdog item, you should store your Cyberdog items as kind kCyberItemKind. When reading a storage unit that contains a Cyberdog item (kCyberItemKind), the opener part creates the Cyberdog item and calls its Open method. The Cyberdog item must determine the right part kind to bind to itself. If this process is time consuming, the opener part can display status and progress information. Once the right display part is created, either it is opened in its own window or the opener part calls ChangePart to replace itself with display part.

For more information on how the opener part is used during the Cyberdog item opening process, see "Cyberdog Item Opening Process" (page 66).

Methods

This section presents summary descriptions of the CyberOpenerPartExtension methods grouped according to purpose, followed by detailed descriptions.

Initialization and Cleanup

ICyberOpenerPartExtension

Initializes this CyberOpenerPartExtension object.

Getting Opener Part Information

GetDestinationDraft

Retrieves the draft in which this opener part is embedded.

GetWindow

Retrieves the window of this opener part.

Opening a Cyberdog Item

BeginOpening

Informs this opener part that the process of opening a Cyberdog item is asynchronous.

EndOpening

Informs this opener part that the process of opening a Cyberdog item is complete.

OpenFile

Opens a file that contains a Cyberdog item's downloaded content.

OpenPart

Opens a Cyberdog item in the specified part.