Find Field Position – Function 31

This function determines the starting position of a field in the Host session presentation space. You can use Find Field Position for either protected or unprotected fields but only in a field-formatted host presentation space.

Prerequisite functions

Connect Presentation Space (function 1)

Function call

WinHLLAPI(FINDFIELDPOSITION,lpbyString,lpwLength,lpwReturnnCode)

Call Parameters

Parameter	Description
Data String	A 2-byte string that must be one of the following: [space][space] This (current) field. T[space] This (current) field. P[space] Previous field (protected or unprotected). N[space] Next field (protected or unprotected). NP Next Protected field. NU Next Unprotected field. PP Previous Protected field. PU Previous Unprotected field.
Data Length	NA (length of 2 is implied).
PS Position	The position in the Host session presentation space where the find starts.

Return parameters

Parameter	Description
0	If Return Code = 28, the field length is zero. If Return Code = 24, the Host session presentation space is unformatted.
>0	Starting position of the requested field.

Return code

Code	Description
WHLLOK	The search string was found.
WHLLNOTCONNECTED	Your Windows HLLAPI application is currently not connected to a session.
WHLLPARAMETERERROR	One or more of the call parameters are invalid.
WHLLPOSITIONERROR	Invalid value specified for PS Position.
WHLLSYSERROR	The function failed due to a system error.
WHLLNOFIELD	The search string was not found, or the Host session presentation space is unformatted.
WHLLZEROLENFIELD	The specified field has a length of zero.

Remarks

Position in the Host session presentation space is determined by starting in the upper left corner of the screen display (row 1, column 1). At the end of each screen display row, the next Host session presentation space position is column 1 of the following screen display row. This process continues until the end of the Host session presentation space (screen display) is reached.

5250 emulators supports a Presentation Space of 24 rows by 80 columns. When an error message from the host or when the operator presses the SysReq key, a 25th row is displayed. When the row 25 is displayed, it is a valid area for this function.