Interfaces

The type infos TKIND_INTERFACE and TKIND_DISPATCH provide information about the implemented interfaces and its methods and properties.

' ----------------------------------------------------------------------------

' Interfaces

' ----------------------------------------------------------------------------

CASE TKIND_INTERFACE, TKIND_DISPATCH

cbstrName.Clear : cbstrHelpString.Clear

hr = m_pTypeLib->GetDocumentation(i, @cbstrName, @cbstrHelpString, NULL, NULL)

IF hr = S_OK THEN

TreeView_AddItem hTreeView, m_hIIDsNode, NULL, "IID_" & cbstrName & " = " & CHR(34) & AfxGuidText(pTypeAttr->guid) & CHR(34)

' ------------------------------------------------------------------------------------------

' If it is a dual interface and the VTable option has been set, try to change the view.

' ------------------------------------------------------------------------------------------

DIM VTableView AS BOOLEAN = m_VTableView

IF pTKind = TKIND_DISPATCH AND (pTypeAttr->wTypeFlags AND TYPEFLAG_FDUAL) = TYPEFLAG_FDUAL THEN

IF VTableView = TRUE THEN

DO ' // Fake DO LOOP to allow exit without GOTO

' // Attempt to change the view to VTable

pRefType = NULL

hr = pTypeInfo->GetRefTypeOfImplType(-1, @pRefType)

IF hr <> S_OK OR pRefType = NULL THEN

VTableView = FALSE

EXIT DO

END IF

hr = pTypeInfo->GetRefTypeInfo(pRefType, @pRefTypeInfo)

IF hr <> S_OK OR pRefTypeInfo = NULL THEN

VTableView = FALSE

EXIT DO

END IF

pRefTypeAttr = NULL

hr = pRefTypeInfo->GetTypeAttr(@pRefTypeAttr)

hSubNode = TreeView_AddItem(hTreeView, m_hDualIntNode, NULL, cbstrName)

IF AfxGuidText(pRefTypeAttr->guid) <> "{00000000-0000-0000-0000-000000000000}" THEN

TreeView_AddItem(hTreeView, hSubNode, NULL, "IID: " & AfxGuidText(pRefTypeAttr->guid))

END IF

IF LEN(cbstrHelpString) THEN TreeView_AddItem(hTreeView, hSubNode, NULL, "Documentation string: " & cbstrHelpString)

IF pRefTypeAttr->wTypeFlags THEN TreeView_AddItem(hTreeView, hSubNode, NULL, "Attributes = " & WSTR(pRefTypeAttr->wTypeFlags) & " [&h" & HEX(pRefTypeAttr->wTypeFlags, 8) & "]" & TLB_InterfaceFlagsToStr(pRefTypeAttr->wTypeFlags))

cbstrInheritedInterface = TLB_GetImplementedInterface(pRefTypeInfo)

TreeView_AddItem(hTreeView, hSubNode, NULL, "Inherited interface = " & cbstrInheritedInterface)

' /*** Datamembers ***/

IF pRefTypeAttr->cVars THEN

hSubNode2 = TreeView_AddItem(hTreeView, hSubNode, NULL, "Number of datamembers = " & WSTR(pRefTypeAttr->cVars))

this.GetMembers (pRefTypeInfo, pRefTypeAttr, hTreeView, hSubNode2)

END IF

' /*** Retrieves the methods and properties ***/

IF @pRefTypeAttr->cFuncs THEN

hSubNode2 = TreeView_AddItem(hTreeView, hSubNode, NULL, "Number of methods = " & WSTR(pRefTypeAttr->cFuncs))

this.GetFunctions(pRefTypeInfo, pREfTypeAttr, hTreeView, hSubNode2, VTableView, TRUE, pTKind, cbstrImplInterface)

ELSE

hSubNode2 = TreeView_AddItem(hTreeView, hSubNode, NULL, "Number of methods = 0")

END IF

IF pRefTypeInfo THEN

IF pTypeAttr THEN pRefTypeInfo->ReleaseTypeAttr(pRefTypeAttr)

pRefTypeInfo->Release

END IF

' // exit the fake loop

EXIT DO

LOOP

END IF

ELSE

VTableView = FALSE

END IF

' ------------------------------------------------------------------------------------------

' ...else use the default view

' ------------------------------------------------------------------------------------------

IF pTKind = TKIND_INTERFACE OR pTKind = TKIND_DISPATCH AND CLNG(VTableView) = FALSE THEN

cbstrImplInterface = TLB_GetImplementedInterface(pTypeInfo)

IF cbstrImplInterface <> "" THEN

IF UCASE(cbstrImplInterface) <> "IUNKNOWN" AND UCASE(cbstrImplInterface) <> "IDISPATCH" THEN

cbstrImplInterface = TLB_GetBaseClass(m_pTypeLib, cbstrName)

END IF

IF pTKind = TKIND_INTERFACE THEN

IF UCASE(cbstrImplInterface) = "IUNKNOWN" AND (pTypeAttr->wTypeFlags AND TYPEFLAG_FOLEAUTOMATION) = TYPEFLAG_FOLEAUTOMATION THEN

hSubNode = TreeView_AddItem(hTreeView, m_hOleAutIntNode, NULL, cbstrName)

ELSEIF UCASE(cbstrImplInterface) = "IDISPATCH" AND (pTypeAttr->wTypeFlags AND TYPEFLAG_FDUAL) <> TYPEFLAG_FDUAL THEN

hSubNode = TreeView_AddItem(hTreeView, m_hDispblIntNode, NULL, cbstrName)

ELSE

hSubNode = TreeView_AddItem(hTreeView, m_hIntNode, NULL, cbstrName)

END IF

ELSEIF pTKind = TKIND_DISPATCH THEN

IF (pTypeAttr->wTypeFlags AND TYPEFLAG_FDUAL) = TYPEFLAG_FDUAL THEN

hSubNode = TreeView_AddItem(hTreeView, m_hDualIntNode, NULL, cbstrName)

ELSEIF INSTR(cwsEvents, "#" & cbstrName & "#") THEN

hSubNode = TreeView_AddItem(hTreeView, m_hEventsNode, NULL, cbstrName)

ELSE

hSubNode = TreeView_AddItem(hTreeView, m_hDispIntNode, NULL, cbstrName)

END IF

IF AfxGuidText(pTypeAttr->guid) <> "{00000000-0000-0000-0000-000000000000}" THEN

TreeView_AddItem(hTreeView, hSubNode, NULL, "IID: " & AfxGuidText(pTypeAttr->guid))

END IF

IF LEN(cbstrHelpString) THEN TreeView_AddItem(hTreeView, hSubNode, NULL, "Documentation string: " & cbstrHelpString)

IF pTypeAttr->wTypeFlags THEN TreeView_AddItem(hTreeView, hSubNode, NULL, "Attributes = " & WSTR(pTypeAttr->wTypeFlags) & " [&h" & HEX(pTypeAttr->wTypeFlags, 8) & "]" & TLB_InterfaceFlagsToStr(pTypeAttr->wTypeFlags))

IF LEN(cbstrImplInterface) THEN TreeView_AddItem(hTreeView, hSubNode, NULL, "Inherited interface = " & cbstrImplInterface)

' /*** Datamembers ***/

IF pTypeAttr->cVars THEN

hSubNode2 = TreeView_AddItem(hTreeView, hSubNode, NULL, "Number of datamembers = " & WSTR(pTypeAttr->cVars))

this.GetMembers (pTypeInfo, pTypeAttr, hTreeView, hSubNode2)

END IF

' /*** Retrieves the methods and properties ***/

IF pTypeAttr->cFuncs THEN

hSubNode2 = TreeView_AddItem(hTreeView, hSubNode, NULL, "Number of methods = " & WSTR(pTypeAttr->cFuncs))

IF pTKind = TKIND_INTERFACE THEN

this.GetFunctions(pTypeInfo, pTypeAttr, hTreeView, hSubNode2, TRUE, TRUE, pTKind, cbstrImplInterface)

ELSE

this.GetFunctions(pTypeInfo, pTypeAttr, hTreeView, hSubNode2, VTableView, TRUE, pTKind, cbstrImplInterface)

END IF

ELSE

hSubNode2 = TreeView_AddItem(hTreeView, hSubNode, NULL, "Number of methods = 0")

END IF

A very important particularity is that the information can be returned in two different kind of views, the VTable view and the Automation view, aka Visual Basic view, that it is the default (after all, Automation was designed by te VB team).

To change the type of views from the default Automation one to the VTable one, we have to call the GetRefTypeOfImplType of the ITypeInfo interface. The meager documentation provided by Microsoft states that "If a type description describes a COM class, it retrieves the type description of the implemented interface types. For an interface, GetRefTypeOfImplType returns the type information for inherited interfaces, if any exist." See: https://msdn.microsoft.com/en-us/library/windows/desktop/ms221569(v=vs.85).aspx

This doesn't help much, does it? Fortunately, there is a remark at the bottom: "If the TKIND_DISPATCH type description is for a dual interface, the TKIND_INTERFACE type description can be obtained by calling GetRefTypeOfImplType with an indexof –1, and by passing the returned pRefTypehandle to GetRefTypeInfo to retrieve the type information."

So, if we have a TKIND_DISPATCH description and be want a TKIND_INTERFACE description (assuming that the Dispatch interface is dual and not a dispatch only interface), we can get it passing -1 to GetRefTypeOfImplType.

' // Attempt to change the view to VTable

pRefType = NULL

hr = pTypeInfo->GetRefTypeOfImplType(-1, @pRefType)

IF hr <> S_OK OR pRefType = NULL THEN

VTableView = FALSE

EXIT DO

END IF

hr = pTypeInfo->GetRefTypeInfo(pRefType, @pRefTypeInfo)

IF hr <> S_OK OR pRefTypeInfo = NULL THEN

VTableView = FALSE

EXIT DO

END IF

pRefTypeAttr = NULL

hr = pRefTypeInfo->GetTypeAttr(@pRefTypeAttr)