Legacy Document

Inside Macintosh: Imaging With QuickDraw /

Chapter 5 - Graphics Devices / Graphics Devices Reference

Routines for Graphics Devices / Getting the Available Graphics Devices

GetMainDevice

To obtain a handle to the GDevice record for the main screen, use the GetMainDevice function.

FUNCTION GetMainDevice: GDHandle;

DESCRIPTION

The GetMainDevice function returns a handle to the GDevice record that corresponds to the main screen--that is, the one containing the menu bar.

A handle to the main device is kept in the global variable MainDevice.

SPECIAL CONSIDERATIONS

The GetMainDevice function may move or purge memory blocks in the application heap. Your application should not call this function at interrupt time.

SEE ALSO

Listing 5-3 on page 5-9 illustrates the use of this function.