PA_Get4DWinMacOSGlobals

version 2003

PA_Get4DWinMacOSGlobals → void *

The routine PA_Get4DWinMacOSGlobals returns a pointer to the MacOS global variables data structure maintained by the Windows version of 4th Dimension.

This data structure is defined in the Altura Mac2Win header file "ASIEXTRN.h" below:

typedef struct
{
   short    mg_size;
   short   mg_version;
   short   *mg_SFSaveDisk;
   long   *mg_CurDirStore;
   short    *mg_SFVRefNum;
   GDHandle   *mg_MainDevice;
   GDHandle   *mg_DeviceList;
   GrafPtr   *mg_WMgrPort;
   struct QHdr   *mg_EventQueue;
   short   *mg_MBarHeight;
   short   *mg_MemErr;
   RgnHandle   *mg_GrayRgn;
   WindowPeek   *mg_WindowList;
   GrafPt   *mg_thePort;
   Pattern   *mg_white;
   Pattern   *mg_black;
   Pattern   *mg_gray;
   Pattern   *mg_ltGray;
   Pattern   *mg_dkGray;
   Cursor   *mg_arrow;
   BitMap   *mg_screenBits;
   long   *mg_randSeed;
   ScrapStuff   *mg_ScrapInfo;
   short   *mg_PrintErr;
   long   *mg_Ticks;
   Ptr   *mg_ApplLimit;
   THz   *mg_ApplZone;
   Ptr   *mg_CurrentA5;
   Ptr   *mg_CurStackBase;
   long   *mg_CaretTime;
   WindowPtr   *mg_CurActivate;
   char   *mg_HilightMode;
   GDHandle   *mg_TheGDevice;
   short   *mg_ResErr;
   char   *mg_CrsrNew;
   RGBColor   *mg_HilightRGB;
   char   *mg_MBState;
   Point   *mg_MTemp;
   Point   *mg_Mouse;
   Point   *mg_RawMouse;
   char   *mg_FractEnable;
   WidthTableHandle *mg_WidthTabHandle;
   short   *mg_TheMenu;
   ProcPtr   *mg_ResumeProc;
   short   *mg_SysEvtMask;
   long   *mg_DoubleTime;
   THz   *mg_TheZone;
   Handle   *mg_MenuList;
   short   *mg_MenuFlash;
   short   *mg_TEScrpLength;
   Handle   *mg_TEScrpHandle;
   Boolean   *mg_ResLoad;
   short   *mg_PaintWhite; 
   long     *mg_MenuDisable;
   WindowPtr    *mg_CurDeactive;
   short    *mg_KeyThresh;
   short   *mg_TEScrpHasStyle;
   Handle    *mg_TEScrpStyleHandle;
   Handle   *mg_AppParmHandle;
   short   *mg_AtMenuBottom;
   short   *mg_TopMenuItem;
} MG, *pMG, **hMG

This routine is not available for the Macintosh version of 4th Dimension. If the 4D plug-in calls this routine on Macintosh it simply returns 0L and an error -1 in PA_GetLastError .

Usually the 4D plug-in will access this data structure in order to read the value of Macintosh OS global variables. For example, under the Windows platform, while writing a 4D plug-in using Altura's Mac2Win technology, the 4D plug-in may need to know the value of CurDirStore. To accomplish this, the 4D plug-in calls this routine and reads the field "mg_CurDirStore".

There is no way for 4th Dimension to forbid changing one of these values. If the 4D plug-in does so, it is at its own risk. Changing a value of an OS global variable may have effects and/or side effects different than those which are familiar on a Macintosh platform.

Getting the WindowList under MacOS and Windows + Altura Mac2Win:

   #include "ASIEXTRN.h"
   WindowPtr   w;
   #if VERSIONWIN
   MG *macGlob;
   macGlob =  PA_Get4DWinMacOSGlobals();
   w = (WindowPtr) *macGlob->mg_WindowList;
   #endif
   #if VERSIONMAC
   w = LMGetWindowList();
   #endif
   /* . . . work with the window list . . . */
   

No reference.