Inside Macintosh: Imaging With QuickDraw /

Chapter 2 - Basic QuickDraw / Basic QuickDraw Reference

Routines / Saving and Restoring Graphics Ports

GetPort

To save the current graphics port (basic or color), you can use the GetPort procedure.

PROCEDURE GetPort (VAR port: GrafPtr); 

port

A pointer to a GrafPort record. If the current graphics port is a color graphics port, GetPort coerces its CGrafPort record into a GrafPort record.

DESCRIPTION

The GetPort procedure returns a pointer to the current graphics port in the port parameter. The current graphics port is also available through the global variable thePort, but you may prefer to use GetPort for better readability of your code. For example, your program could include GetPort(savePort) before setting a new graphics port, followed by SetPort(savePort) to restore the previous port.

SEE ALSO

Listing 2-3 on page 2-16 illustrates how to use GetPort to save the graphics port for the active window and SetPort to make an inactive window the current graphics port; then how to use SetPort again to restore the active window as the current graphics port. The basic graphics port is described on page 2-27. The SetPort procedure is described next.

When your application runs in Color QuickDraw or uses offscreen graphics worlds, it should use the GetGWorld procedure instead of GetPort. The GetGWorld procedure saves the current graphics port for basic and color graphics ports as well as offscreen graphics worlds. See the chapter "Offscreen Graphics Worlds" for more information.