HP NonStop G-Series - Manual (Page 110)

User Hook Library
Extending the Tandem DDE Gateway
8–8 110838 Tandem Computers Incorporated
hMainWnd Window handle of Tandem DDE Gateway main
window.
ulInitializeServiceSerialNumber Number incremented with each
INITIALIZESERVICE command. Starts at zero
when the Tandem DDE Gateway is started.
Rolls over to zero after 4,294,967,295.
lpServiceName Current ServiceName object (from
INITIALIZESERVICE command).
pstructElementData Description of current data element. (See the
“Tandem DDE Gateway Dictionary Structure”
topic.)
cfFormat Clipboard format of lpPokeDataElementValue.
lpPokeDataElementValue Data value being sent with the DDE Poke to be
converted.
lpBufferOffset Address in message buffer for converted data.
pstructErrMsg See “Returning Error Messages” earlier in this
section.
TdmgwHookDdePokePreConvert
This function may be called when your client application does an element-by-element
DDE Poke function.
You must enable the function with TdmgwHookEnableUserHooks function by
returning a value with the TDMGW_HOOK_ENABLE_POKE_PRE_CON bit set.
The TdmgwHookDdePokePreConvert function is called only if there is an automatic
built-in data conversion between the Tandem data representation for the current data
element and the clipboard format cfFormat. If the TdmgwHookIsConvSupported
function is enabled, then it also must return non-zero in the pbSupportedFormat
parameter and zero in the pbConvertWithOnlyHookCode parameter.
The TdmgwHookDdePokePreConvert function is called before the automatic data
conversion is used. You can modify the data sent by your client application before it's
converted. The data is pointed to by the parameter lpPokeDataElementValue and is in
the clipboard format cfFormat.
Prototype
BOOL FAR PASCAL TdmgwHookDdePokePreConvert
(HWND hMainWnd, in
unsigned long ulInitializeServiceSerialNumber, in
LPSTR lpServiceName, in
struct tagDdeDictElementData far * pstructElementData, in
WORD cfFormat, in
void far * lpPokeDataElementValue, in/out
struct tagTdmgwErrorMsg far * pstructErrMsg); out