GreOpenDC
GreOpenDC creates an output device context (DC). The new device context inherits the current code page of the process that created it.
This function is supported by the graphics engine.
Syntax
GreOpenDC(hdc, ulType, pszToken, cData, pszData, pInstance, lFunction);
Parameters
- hdc (HDC) - input
- Device context handle.
- When ulType is OD_ context compatible with bit maps that are used with this device context. If this is NULL, compatibility with the display is assumed.
- ulType (ULONG) - input
- Type of DC being opened.
- Type of device context:
- OD_QUEUED The DC is for a hardcopy device for which output is to be queued by the spooler.
- OD_DIRECT The DC is for a device for which output is not to be queued by the spooler.
- OD_INFO This is similar to OD_DIRECT except that it is only used to retrieve information such as font metrics. Drawing can be done to a presentation space associated with such a DC but no output medium is updated.
- OD_MEMORY The new DC is a memory DC used to contain a bit map. The hdc parameter identifies the device with which the bit map is to be compatible.
- pszToken (PSZ) - input
- This parameter is ignored by the graphics engine.
- cData (LONG) - input
- Number of elements in the data structure.
- pszData (PDEVOPENDATA) - input
- Pointer to data structure.
- Pointer to DEVOPENDATA structure:
- pszLogAddress
- Pointer to logical address, for example, LPT1Q.
- pszDriverName
- Pointer to presentation driver name, for example, LASERJET.
- pdriv
- Pointer to a DRIVDATA structure:
- cb
- Size in bytes of this structure
- lVersion
- Version number of the data. Version numbers are defined by the presentation driver.
- szDeviceName[32]
- String identifying the device. Valid values are supplied by the presentation driver.
- abGeneralData
- General data defined by the presentation driver. This does not contain pointers as they might not be valid when passed to the driver.
- pszDataType
- Pointer to a data type of the queued file. Supported data types are:
- PM_Q_STD
- PM_Q_RAW
- User-defined data types can also be supported.
- pszComment
- Pointer to a description of the file that can be displayed by the spooler to the user.
- pszQueueProcName
- Pointer to name of queue processor.
- pszQueueProcParams
- Pointer to a string of queue processor parameters.
- pszSpoolerParams
- Pointer to a string of spooler parameters separated by one or more blanks. Valid parameters are:
- FORM=aaa
- Identifies the form name for a print job. Multiple names are separated by commas (aaa,bbb,ccc). If this parameter is not present, the current form is used.
- Form names are defined by the presentation driver. Valid names are those that would be returned from a call to the GreQueryHardcopyCaps handling routine of the driver.
- PRTY=n
- Identifies the priority for the print job. The priority can be any value from 1 - 99 (1 is lowest priority). If this parameter is not present, the priority value defaults to 50.
- pszNetworkParams
- Pointer to a string of networking parameters, which are used only in a network environment. Their nature is defined by the network application.
- pInstance (PVOID) - input
- Pointer to instance data.
- lFunction (ULONG) - input
- High-order WORD=flags; low-order WORD=NGreOpenDC.
Return Code
- rc (HDC) - returns
Return codes.
On completion, the graphics engine returns the handle of the new device context (hdc), or DEV_ERROR if an error occurs.
Possible Errors Detected: When an error is detected, the graphics engine calls WinSetErrorInfo to post the condition. Reasons for failure of this function include:
PMERR_BASE_ERROR PMERR_BITMAP_IS_SELECTED PMERR_COORDINATE_OVERFLOW PMERR_DEV_FUNC_NOT_INSTALLED PMERR_EXCEEDS_MAX_SEG_LENGTH PMERR_HBITMAP_BUSY PMERR_HDC_BUSY PMERR_HUGE_FONTS_NOT_SUPPORTED PMERR_INSUFFICIENT_MEMORY PMERR_INV_BACKGROUND_COL_ATTR PMERR_INV_BACKGROUND_MIX_ATTR PMERR_INV_BITMAP_DIMENSION PMERR_INV_CHAR_DIRECTION_ATTR PMERR_INV_CHAR_MODE_ATTR PMERR_INV_CODEPAGE PMERR_INV_COLOR_ATTR PMERR_INV_COORD_SPACE PMERR_INV_COORDINATE PMERR_INV_DC_DATA PMERR_INV_DC_TYPE PMERR_INV_DRIVER_NAME PMERR_INV_HBITMAP PMERR_INV_HDC PMERR_INV_HRGN PMERR_INV_ID PMERR_INV_IN_AREA PMERR_INV_IN_PATH PMERR_INV_INFO_TABLE PMERR_INV_LENGTH_OR_COUNT PMERR_INV_LINE_TYPE_ATTR PMERR_INV_MIX_ATTR PMERR_INV_PATTERN_REF_PT_ATTR PMERR_INV_PATTERN_SET_ATTR PMERR_INV_PATTERN_SET_FONT PMERR_INV_RECT PMERR_INV_REGION_CONTROL PMERR_INV_SCAN_START
Refer to the "Error Explanations" section in the Presentation Manager Programming Reference for further explanation.
Remarks
Sample Code
#define INCL_GRE_DCS #include <os2.h> HDC hdc; /* Device context handle. */ ULONG ulType; /* Type of DC being opened. */ PSZ pszToken; /* This parameter is ignored by the graphics engine. */ LONG cData; /* Number of elements in the data structure. */ PDEVOPENDATA pszData; /* Pointer to data structure. */ PVOID pInstance; /* Pointer to instance data. */ ULONG lFunction; /* High-order WORD=flags; low-order WORD=NGreOpenDC. */ HDC rc; /* Return codes. */ rc = GreOpenDC(hdc, ulType, pszToken, cData, pszData, pInstance, lFunction);