How To Determine if QuickDraw GX Is Loaded Using SYS Function

The information in this article applies to:

• Microsoft Visual FoxPro for Macintosh, version 3.0b

SUMMARY

This article describes how to determine whether QuickDraw GX is loaded in the Macintosh's operating system by using the new SYS function SYS(1038) in Visual FoxPro for Macintosh. Two other methods to make this determination are also described in the More Information section of this article.

The syntax for the SYS(1038) function is:

   ? SYS(1038)   && To output the result to the current output device
       or
   x=SYS(1038)   && To store the result to a variable named "x"

QuickDraw GX is manufactured by a vendor independent of Microsoft; we make no warranty, implied or otherwise, regarding the performance or reliability of QuickDraw GX.

Macintosh Operating System, version 8, no longer supports QuickDraw GX printer drivers and printing extensions. Therefore, SYS(1038) always returns false (.F.) when used in Visual FoxPro running under OS 8. This is true even if the QuickDraw GX 1.1.6 version provided with OS 8 is installed. For additional information on the changes with QuickDraw GX in OS 8 see the About QuickDraw GX readme file in the Mac OS 8 Read Me folder on the CD-ROM.

MORE INFORMATION

There are at least two other methods you can use to determine if QuickDraw GX is loaded, although neither is as easy as SYS(1038) Two other methods are:

• Use the FILE() function, along with the SYS(2033) function, that will return the name of the System:Extensions folder to check for the existence of the QuickDraw GX Extension:

  ? FILE(SYS(2033,1)+":Quickdraw"+CHR(170)+" GX")

  Note the space between the quote mark and GX" at the end. CHR(170) is the trademark symbol (TM).

• Use the FxGestalt() function in FoxTools.cfm. This method requires the FoxTools.cfm library to be loaded first:

  x="" SET LIBRARY TO HOME()+"Foxtools.cfm" ? FxGestalt("qdgx",@x)

  If QuickDraw GX is installed, a positive integer is returned; otherwise, FXGestalt() returns a negative integer.

  NOTE: The values returned to the second argument of FxGestalt() were not documented at the time this article was written. For more information on the FxGestalt() function, see the Foxtools.hlp file in the "Microsoft Visual FoxPro:Tools" folder.