September 94 - Adding QuickDraw GX Printing to QuickDraw Applications

Adding QuickDraw GX Printing to QuickDraw Applications

DAVE HERSEY

Now that QuickDraw GX has been released, you may be wondering what to do with your

older QuickDraw applications. The good news is that by adding a relatively small

percentage of code to your existing applications, you can support all the new features

of the QuickDraw GX printing architecture and still retain full compatibility with

non-QuickDraw GX systems.

Compatibility with the existing application base was a primary concern during

thedevelopment of QuickDraw GX; only the most hardened "print criminals" shouldhave

compatibility problems. Since a pre-QuickDraw GX application should work in both

QuickDraw GX and non-QuickDraw GX environments, you may think that leaving your

code as it stands is good enough. Becoming compatible probably doesn't require any

revisions to your existing software, and the fact that your application will perform

with or without QuickDraw GX sounds like a pretty good deal. Where's the catch?

Here it is: A non-QuickDraw GX application doesn't have access to several key features

of QuickDraw GX, so its users can't take advantage of many of the new printing

features. For example, with QuickDraw GX a user can:

• Redirect print jobs using the new Print dialog.

• Choose page-by-page formatting, so that page 1 prints on US Letter, page

2 prints on #10 envelope, page 3 prints on landscape-oriented US Legal, and

so on, instead of printing the entire document in a single format.

• Work with the new QuickDraw GX printing dialogs (shown in Figure 1)

instead of the dialogs provided for compatibility with non-QuickDraw GX

applications.

• Use features provided by printing extensions. Printing extensions can add

items to the QuickDraw GX printing dialogs, but not to the compatibility

dialogs. (Added items show up as icons in the column on the left side of each

dialog.)

• Print a single copy of a document with the new Print One Copy command.

• Print documents by dragging them to desktop printers.

Page Setup dialog

Custom Page Setup dialog

Print dialog

Figure 1. The new QuickDraw GX printing dialogs

Users are shut out from all these features if they're using a non-QuickDraw GX

application. In this article, you'll see how to increase an application's level of

QuickDraw GX support. I'll take a QuickDraw application and convert it step by step

into an application that fully supports both the QuickDraw and QuickDraw GX printing

architectures. First, we'll consider some definitions and background information.

DIFFERENT LEVELS OF QUICKDRAW GX SUPPORT

To begin, let's define the different levels of QuickDraw GX support (from lowest to

highest) that an application can have:

• QuickDraw GX unaware: The application doesn't implement any

QuickDraw GX code, and QuickDraw GX translates all QuickDraw printing and

Referenced by (3):