Legacy Document

Inside Macintosh: Imaging With QuickDraw /

Chapter 4 - Color QuickDraw / Color QuickDraw Reference

Color QuickDraw Routines / Reporting Data Structure Changes to QuickDraw

GDeviceChanged

If you modify the content of a GDevice record (described in the chapter "Graphics Devices" in this book), use the GDeviceChanged procedure.

PROCEDURE GDeviceChanged (gdh: GDHandle);

DESCRIPTION

The GDeviceChanged procedure notifies Color QuickDraw that your application has changed the GDevice record specified in the gdh parameter.

If your application changes the pmTable field of the PixMap record specified in a GDevice record, your application should call GDeviceChanged. If your application changes the content of the ColorTable record referenced by the PixMap record, it should call GDeviceChanged and CTabChanged as well.

SPECIAL CONSIDERATIONS

The GDeviceChanged procedure may move or purge memory in the application heap. Your application should not call the GDeviceChanged procedure at interrupt time.

Your application should never need to directly modify a GDevice record and use the GDeviceChanged procedure; instead, your application should use the QuickDraw routines described in this book for manipulating the values in a GDevice record.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the GDeviceChanged procedure are

Trap macro	Selector
_QDExtensions	$0004000A