Adding Panels to Print Dialog Boxes(IM:XP)

Inside Macintosh: QuickDraw GX Printing Extensions and Drivers /: Chapter 2 - Printing Extensions / Printing Extension Tasks

Adding Panels to Print Dialog Boxes
QuickDraw GX allows applications, extensions, and drivers to add panels to the print dialog boxes. Adding a panel and monitoring the user's selections in the dialog box is described in Inside Macintosh: QuickDraw GX Printing. While the user manipulates
the panel, QuickDraw GX sends event messages (the GXFilterPanelEvent and the GXHandlePanelEvent messages) to your extension. It also sends messages before closing a panel and notifies you whether the user confirmed or canceled the dialog
box. The GXFilterPanelEvent message is described on page 4-86 and the GXHandlePanelEvent message is described on page 4-85 in the chapter
"Printing Messages."
You can add panels for users to control the capabilities that your printing extension provides. For example, the background picture printing extension adds a panel to the expanded Print dialog box that is displayed when the user clicks the More Choices button in the Print dialog box. This panel allows the user to specify which picture file
to use as the background picture on printed pages, as shown in Figure 2-1.
Figure 2-1 The background picture panel displayed in the Print dialog box