GpiQueryRegionBox

This function returns the dimensions of the smallest rectangle able to bound the region.

Syntax

GpiQueryRegionBox(hps, hrgn, prclBound)

Parameters

hps (HPS) - input

Presentation-space handle.

The region must be owned by the device identified by the currently associated device context.

hrgn (HRGN) - input

Region handle.

prclBound (PRECTL) - output

Bounding rectangle.

Returns

lComplexity (LONG) - returns

Complexity of region and error indicators.

RGN_NULL

Null region

RGN_RECT

Rectangular region

RGN_COMPLEX

Complex region

RGN_ERROR

Error.

Errors

Possible returns from WinGetLastError

PMERR_INV_HPS (0x207F)

An invalid presentation-space handle was specified.

PMERR_PS_BUSY (0x20F4)

An attempt was made to access the presentation space from more than one thread simultaneously.

PMERR_INV_HRGN (0x2080)

An invalid region handle was specified.

PMERR_REGION_IS_CLIP_REGION (0x20F8)

An attempt was made to perform a region operation on a region that is selected as a clip region.

PMERR_HRGN_BUSY (0x2034)

An internal region busy error was detected. The region was locked by one thread during an attempt to access it from another thread.

Remarks

If the region is null, the rectangle returned has the left boundary equal to the right, and the top boundary equal to the bottom.

It is invalid if the specified region is currently selected as the clip region (by GpiSetClipRegion).

Example Code

#define INCL_GPIREGIONS /* Or use INCL_GPI, INCL_PM, */
#include <os2.h>

HPS       hps;          /*  Presentation-space handle. */
HRGN      hrgn;         /*  Region handle. */
PRECTL    prclBound;    /*  Bounding rectangle. */
LONG      lComplexity;  /*  Complexity of region and error indicators. */

lComplexity = GpiQueryRegionBox(hps, hrgn,
                prclBound);

In this example we determine the dimensions of the smallest rectangle able to bound the region.

#define INCL_GPIPREGIONS
#include <OS2.H>

LONG lResult;     /* number of elements returned */
HPS hps;          /* Presentation space handle. */
HRGN hrgn;        /* region handle */
RECTL rclBound; /* bounding rectangle */

lResult = GpiQueryRegionBox(hps,
                            (VOID *)hrgn,
                            (PRECTL)&rclBound);