GreSaveScreenBits

GreSaveScreenBits saves a rectangle of screen bits.

Simulation support

This function is mandatory for display drivers. For other drivers, it is simulated by a handling routine in the graphics engine.

Syntax

GreSaveScreenBits(hdc, prclRect, pInstance, lFunction)

Parameters

hdc (HDC) - input

The device context handle.

prclRect (PRECTL) - input

A pointer to a screen rectangle defined in screen coordinates.

pInstance (PVOID) - input

A pointer to instance data.

lFunction (ULONG) - input

High-order WORD=flags; low-order WORD=NGreRestoreScreenBits.

Return Code

rc (ULONG) - returns

Return codes.

On completion, the handling routine must return a handle to the saved bits (hsbBits) or 0 to indicate that the bits were not saved or that an error occurred.

Possible Errors Detected: When an error is detected, the handling routine must call WinSetErrorInfo to post the condition. Error codes for conditions that the handling routine is expected to check include:

• PMERR_DEV_FUNC_NOT_INSTALLED
• PMERR_INV_HDC

Remarks

It is permissible to implement this function by returning 0 to indicate that the bits were not saved and, therefore, must be saved by the calling routine.

This function lets the user-interface routines improve the performance of dialog boxes.

Sample Code

#define INCL_GRE_BITMAPS
#include <os2.h>

HDC       hdc;        /*  The device context handle. */
PRECTL    prclRect;   /*  A pointer to a screen rectangle defined in screen coordinates. */
PVOID     pInstance;  /*  A pointer to instance data. */
ULONG     lFunction;  /*  High-order WORD=flags; low-order WORD=NGreRestoreScreenBits. */
ULONG     rc;         /*  Return codes. */

rc = GreSaveScreenBits(hdc, prclRect, pInstance, lFunction);