## Presentation Device Driver Reference for OS/2

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### GreQueryTextBox - Syntax

Simulation support:

None. This function is mandatory for all drivers.

Description:

GreQueryTextBox processes a character string as if it were being drawn.

This function must be supported by the presentation driver. GreQueryTextBox is called by the function GpiQueryTextBox, and is used to return a tight bounding box for the currently selected font of a given string relative to the current position.

    #define INCL_GRE_STRINGS

    #include <os2.h>

    HDC        hdc;           /*  Device context handle. */

    LONG       cChars;        /*  Number of bytes in string. */

    PCH        pchString;     /*  Pointer to character string. */

    LONG       cptPosition;   /*  Number of (X, Y) pairs that the Position array can contain. */

    PPOINTL    paptPosition;  /*  Pointer to position array. */

    PVOID      pInstance;     /*  Pointer to instance data. */

    ULONG      lFunction;     /*  High-order WORD=flags; low-order WORD=NGreQueryTextBox. */

    BOOL       rc;            /*  Return Code. */

    rc = GreQueryTextBox(hdc, cChars, pchString,

           cptPosition, paptPosition, pInstance,

           lFunction);