Legacy Document

Inside Macintosh: Imaging With QuickDraw /

Chapter 2 - Basic QuickDraw / Basic QuickDraw Reference

Routines / Saving and Restoring Graphics Ports

SetPort

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

PROCEDURE SetPort (port: GrafPtr); 

port

A pointer to a GrafPort record. Typically, you pass a pointer to a GrafPort record that you previously saved with the GetPort procedure (described in the previous section).

DESCRIPTION

The SetPort procedure sets the current graphics port (pointed to by the global variable thePort) to be that specified by the port parameter. All QuickDraw drawing routines affect the bitmap of, and use the local coordinate system of, the current graphics port. Each graphics port has its own graphics pen and text characteristics, which remain unchanged when the graphics port isn't selected as the current graphics 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 GetPort procedure is described on page 2-39.

When your application runs in Color QuickDraw or uses offscreen graphics worlds, it should use the SetGWorld procedure instead of SetPort. The SetGWorld procedure restores 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.