Interface ITypeInfo question
lazarus / 67-Windows

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440bx · 2025-06-28 05:42

Hello,

In activex.pp, ITypeInfo is defined as follows:Code: Pascal
 [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i  
 ITypeInfo = Interface (IUnknown)   
 ['{00020401-0000-0000-C000-000000000046}']     {$ifndef Call_as}    
Function  GetTypeAttr(OUT ppTypeAttr: lpTYPEATTR):HResult;StdCall;   
 {$else}      Function  GetTypeAttr(OUT ppTypeAttr: LPTYPEATTR; OUT
pDummy: CLEANLOCALSTORAGE):HResult;StdCall;     {$endif}      Function
 GetTypeComp(OUT ppTComp: ITypeComp):HResult;StdCall;     {$ifndef
Call_as}      Function  GetFuncDesc(index: UINT; OUT ppFuncDesc:
lpFUNCDESC):HResult;StdCall;      Function  GetVarDesc(index: UINT;
OUT ppVarDesc: lpVARDESC):HResult;StdCall;      Function
 GetNames(memid: MEMBERID;  rgBstrNames: PBStrList; cMaxNames: UINT;
OUT pcNames: UINT):HResult;StdCall;     {$else}      Function
 GetFuncDesc(index: UINT; OUT ppFuncDesc: LPFUNCDESC; OUT pDummy:
CLEANLOCALSTORAGE):HResult;StdCall;      Function  GetVarDesc(index:
UINT; OUT ppVarDesc: LPVARDESC; OUT pDummy:
CLEANLOCALSTORAGE):HResult;StdCall;      Function  GetNames(memid:
MEMBERID;  rgBstrNames: PBStrList; cMaxNames: UINT; OUT pcNames:
UINT):HResult;StdCall;     {$endif}     Function
 GetRefTypeOfImplType(index: UINT; OUT pRefType:
HREFTYPE):HResult;StdCall;     Function  GetImplTypeFlags(index: UINT;
OUT pImplTypeFlags: WINT):HResult;StdCall;     {$ifndef Call_as}     
Function  GetIDsOfNames(CONST rgszNames: pOleStr; cNames: UINT; OUT
pMemId: MEMBERID):HResult;StdCall;     {$else}      Function
 LocalGetIDsOfNames():HResult;StdCall;     {$endif}     {$ifndef
Call_as}     Function  Invoke(pvInstance: Pointer; memid: MEMBERID;
wFlags: WORD; VAR pDispParams: DISPPARAMS; pVarResult: PVARIANT;
pExcepInfo: PEXCEPINFO; puArgErr: PUINT):HResult;StdCall;     {$else} 
   Function  LocalInvoke ():HResult;StdCall;     {$endif}     {$ifndef
Call_as}     //Function  GetDocumentation(memid: MEMBERID; OUT
pBstrName: WideString; OUT pBstrDocString: WideString; OUT
pdwHelpContext: DWORD; OUT pBstrHelpFile:
WideString):HResult;StdCall;         Function  GetDocumentation(memid:
MEMBERID; pBstrName: PWideString; pBstrDocString: PWideString;
pdwHelpContext: PDWORD; pBstrHelpFile: PWideString):HResult;StdCall; 
  {$else}         Function  GetDocumentation(memid: MEMBERID;
refPtrFlags: DWORD; OUT pBstrName: WideString; OUT pBstrDocString:
WideString; OUT pdwHelpContext: DWORD; OUT pBstrHelpFile:
WideString):HResult;StdCall;     {$endif}      {$ifndef Call_as}   
 Function  GetDllEntry(memid: MEMBERID; invKind: INVOKEKIND; OUT
pBstrDllName: WideString; OUT pBstrName: WideString; OUT pwOrdinal:
WORD):HResult;StdCall;     {$else}     Function  GetDllEntry(memid:
MEMBERID; invKind: INVOKEKIND; refPtrFlags: DWORD; OUT pBstrDllName:
WideString; OUT pBstrName: WideString; OUT pwOrdinal:
WORD):HResult;StdCall;     {$endif}      Function
 GetRefTypeInfo(hRefType: HREFTYPE; OUT ppTInfo:
ITypeInfo):HResult;StdCall;      {$ifndef Call_as}      Function
 AddressOfMember(memid: MEMBERID; invKind: INVOKEKIND; OUT ppv:
Pointer):HResult;StdCall;     {$else}      Function
 LocalAddressOfMember():HResult;StdCall;     {$endif}      {$ifndef
Call_as}      Function  CreateInstance(CONST pUnkOuter: IUnknown;
CONST riid: TIID; OUT ppvObj: Pointer):HResult;StdCall;     {$else}  
  Function  CreateInstance(CONST riid: TIID; OUT ppvObj:
pIUnknown):HResult;StdCall;     {$endif}     Function  GetMops(memid:
MEMBERID; OUT pBstrMops: WideString):HResult;StdCall;     {$ifndef
Call_as}     Function  GetContainingTypeLib(OUT ppTLib: ITypeLib; OUT
pIndex: UINT):HResult;StdCall;     {$else}     Function
 GetContainingTypeLib(OUT ppTLib: ITypeLib; OUT pIndex:
UINT):HResult;StdCall;     {$endif}     {$ifndef Call_as}     
Procedure ReleaseTypeAttr( pTypeAttr: pTypeAttr); StdCall;   
 {$else}      Function  ReleaseTypeAttr():HResult;StdCall;   
 {$endif}      {$ifndef Call_as}      Procedure ReleaseFuncDesc(
pFuncDesc : lpFUNCDESC); StdCall;     {$else}      Function
 LocalReleaseFuncDesc():HResult;StdCall;     {$endif}     {$ifndef
Call_as}      Procedure ReleaseVarDesc( pVarDesc : lpVarDesc);
stdcall;     {$else}      Function
 LocalReleaseVarDesc():HResult;StdCall;     {$endif}     End; The
method definitions change depending on whether "Call_as" is defined or
not. 

It does not seem that "Call_as" is defined anywhere, i.e, it seems to
always be undefined.

The question is: what are the definitions when "Call_as" is defined
for ?  (the number of parameters in the method are not the same but,
it is rather unclear as to why that is.)

Thank you for your help.

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marcov · 2025-06-28 08:17

I don't know. I assume it was in the original header.

If you search for the parameter https://learn.microsoft.com/zh-tw/dotn
et/api/microsoft.visualstudio.ole.interop.cleanlocalstorage?view=visua
lstudiosdk-2017 it points to being for interop.

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440bx · 2025-06-28 08:37

Quote from: marcov on June 28, 2025, 10:17:34 amI don't know. I assume
it was in the original header.

If you search for the parameter https://learn.microsoft.com/zh-tw/dotn
et/api/microsoft.visualstudio.ole.interop.cleanlocalstorage?view=visua
lstudiosdk-2017 it points to being for interop.
In another post, ASerge showed that in the .idl file, the call_as is
used to define synonyms for some methods.  I think that's the origin
of that stuff in the Pascal source but, I don't think the semantics of
"call_as" have a counterpart in FPC.

Anyway, I look at the C definitions because that's what gets
executed.  if it's not in the C++ class definition, I don't include it
but, I was curious as to where that came from and why.

Thanks for the info marco.

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marcov · 2025-06-28 08:45

Now that I read ASerge's post, I do think I used the IDLs for the
interface definitions back then, as they were (for me then) more 1:1
to interfaces than the generated C declarations.

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ASerge · 2025-06-28 08:47

Quote from: 440bx on June 28, 2025, 07:42:43 amThe question is: what
are the definitions when "Call_as" is defined for ?
It's MIDL attribute. See call-as, local.