Inside Macintosh: More Macintosh Toolbox /

Chapter 7 - Translation Manager

About the Translation Manager

The Translation Manager provides extensive data translation services for Macintosh computers. Macintosh Easy Open uses the Translation Manager to provide four basic services:

• translation of documents opened from the Finder
• automatic translation of documents opened by applications that use the Standard File Package
• batch translation of documents at the desktop level
• automatic translation of data in editions or pasted from the Clipboard

These services allow your application to open documents created by other applications (possibly running on other operating systems) and to import data from other applications with better fidelity than previously possible.

Macintosh Easy Open provides the services that the Finder and the Standard File Package use to implement implicit translation (the conversion of a file or scrap without direct intervention from the application). The Finder needs to know which applications are capable of opening a document, either directly or after the document has been translated to another file format. The Standard File Package needs to know which other file types can be translated to some file type that the application can read. Both the Finder and the Standard File Package then call Macintosh Easy Open to translate a file to another format.

Macintosh Easy Open does not do any translating itself, and it does not have any knowledge of translation data models. Instead, it delegates these functions to translation extensions or to applications with built-in translation capability. Translation extensions and application translation capabilities operate as "black boxes" to Macintosh Easy Open.

A translation extension is responsible for many things, including recognizing and translating files or scraps. A translation extension might be a complete entity, able to recognize and translate all by itself. Other translation extensions might require external files, usually called translators or filters, to perform their work. In either case, the whole is called a translation system.

At system startup (or whenever new translation extensions become available), Macintosh Easy Open catalogs the translation capability of each translation extension and each application, and then invokes each as needed. Macintosh Easy Open can support multiple translation systems.

There are two types of translation systems: file translation systems and scrap translation systems. A file translation system can translate from one file format to another. A scrap translation system can translate buffers in memory. Macintosh Easy Open distinguishes between the two because a file format in memory might differ from the same file format on disk. A single translation system, however, might contain both kinds of translators.

The following four sections describe in greater detail the capabilities of Macintosh Easy Open and its interactions with other pieces of the Macintosh system software.

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Subtopics

Opening Documents From the Finder

Opening Documents Within an Application

Translating Documents on the Desktop

Sharing Data Between Applications