Outlook add-in integrating Skype

#ifndef RibbonExtensibility_H
#define RibbonExtensibility_H

    #include "IRibbonUI.h"

    //  ribbon callback DISPIDs
    #define DISPID_RIBBONCALLBACK_BASE              (0x00000000)

    #define DISPID_RIBBONCALLBACK_ONLOAD            (DISPID_RIBBONCALLBACK_BASE + 0x00000001)
    #define DISPID_RIBBONCALLBACK_ONGETVISIBLE      (DISPID_RIBBONCALLBACK_BASE + 0x00000002)
    #define DISPID_RIBBONCALLBACK_ONGETLABEL        (DISPID_RIBBONCALLBACK_BASE + 0x00000003)
    #define DISPID_RIBBONCALLBACK_ONGETSIZE         (DISPID_RIBBONCALLBACK_BASE + 0x00000004)
    #define DISPID_RIBBONCALLBACK_ONGETSCREENTIP    (DISPID_RIBBONCALLBACK_BASE + 0x00000005)
    #define DISPID_RIBBONCALLBACK_ONGETSUPERTIP     (DISPID_RIBBONCALLBACK_BASE + 0x00000006)
    #define DISPID_RIBBONCALLBACK_ONGETIMAGEMSO     (DISPID_RIBBONCALLBACK_BASE + 0x00000007)
    #define DISPID_RIBBONCALLBACK_ONGETIMAGE        (DISPID_RIBBONCALLBACK_BASE + 0x00000008)
    #define DISPID_RIBBONCALLBACK_ONGETENABLED      (DISPID_RIBBONCALLBACK_BASE + 0x00000009)
    #define DISPID_RIBBONCALLBACK_ONGETPRESSED      (DISPID_RIBBONCALLBACK_BASE + 0x0000000A)
    #define DISPID_RIBBONCALLBACK_ONACTION          (DISPID_RIBBONCALLBACK_BASE + 0x0000000B)
    #define DISPID_RIBBONCALLBACK_ONGETTEXT         (DISPID_RIBBONCALLBACK_BASE + 0x0000000C)
    #define DISPID_RIBBONCALLBACK_ONCHANGE          (DISPID_RIBBONCALLBACK_BASE + 0x0000000D)

    #define DISPID_RIBBONCALLBACK_FIRST             (DISPID_RIBBONCALLBACK_ONLOAD)
    #define DISPID_RIBBONCALLBACK_LAST              (DISPID_RIBBONCALLBACK_ONCHANGE)

    typedef enum RibbonElementType {
        RibbonElementType_Tab, 
        RibbonElementType_Group, 
        RibbonElementType_Button, 
        RibbonElementType_Label, 
        //  add more element types as needed
    } RibbonElementType;

    typedef enum RibbonControlSize
    {
	    RibbonControlSize_Regular   = 0,
	    RibbonControlSize_Large     = 1
    } RibbonControlSize;

    typedef struct IRibbonExtensibility IRibbonExtensibility;

    typedef struct IRibbonExtensibilityVtbl {
        HRESULT (NDAPI *QueryInterface)(
            IRibbonExtensibility    *This,
            REFIID                  riid,
            void                    **ppvObject
            );
        ULONG (NDAPI *AddRef)( 
            IRibbonExtensibility    *This
            );
        ULONG (NDAPI *Release)( 
            IRibbonExtensibility    *This
            );
        HRESULT (NDAPI *GetTypeInfoCount)( 
            IRibbonExtensibility    *This,
            UINT                    *pctinfo
            );
        HRESULT (NDAPI *GetTypeInfo)( 
            IRibbonExtensibility    *This,
            UINT                    iTInfo,
            LCID                    lcid,
            ITypeInfo               **ppTInfo
            );
        HRESULT (NDAPI *GetIDsOfNames)( 
            IRibbonExtensibility    *This,
            REFIID                  riid,
            LPOLESTR                *rgszNames,
            UINT                    cNames,
            LCID                    lcid,
            DISPID                  *rgDispId
            );
        HRESULT (NDAPI *Invoke)( 
            IRibbonExtensibility    *This,
            DISPID                  dispIdMember,
            REFIID                  riid,
            LCID                    lcid,
            WORD                    wFlags,
            DISPPARAMS              *pDispParams,
            VARIANT                 *pVarResult,
            EXCEPINFO               *pExcepInfo,
            UINT                    *puArgErr
            );
        HRESULT (NDAPI *GetCustomUI)(
            IRibbonExtensibility    *This,
            BSTR                    RibbonID, 
            BSTR                    *RibbonXml
            );
    } IRibbonExtensibilityVtbl;

    typedef struct IRibbonExtensibility
    {
        const struct IRibbonExtensibilityVtbl *lpVtbl;
    } IRibbonExtensibility;

    const IID*
    IRibbonExtensibility_GetIID(
        VOID
    );

    //  macros
    #define IRibbonExtensibility_QueryInterface(This, riid, ppv) \
        ((((This)->lpVtbl)->QueryInterface)((This), (riid), (ppv)))
    #define IRibbonExtensibility_AddRef(This) \
        ((((This)->lpVtbl)->AddRef)(This))
    #define IRibbonExtensibility_Release(This) \
        ((((This)->lpVtbl)->Release)(This))
    #define IRibbonExtensibility_GetTypeInfoCount(This, pctinfo) \
        ((((This)->lpVtbl)->GetTypeInfoCount)((This), (pctinfo)))
    #define IRibbonExtensibility_GetTypeInfo(This, iTInfo, lcid, ppTInfo) \
        ((((This)->lpVtbl)->GetTypeInfo)((This), (iTInfo), (lcid), (pctinfo)))
    #define IRibbonExtensibility_GetIDsOfNames(This, riid, rgszNames, cNames, lcid, rgDispId) \
        ((((This)->lpVtbl)->GetIDsOfNames)((This), (riid), (rgszNames), (cNames), (lcid), (rgDispId)))
    #define IRibbonExtensibility_Invoke(This, dispIdMember, riid, lcid, wFlags, pDispParams, pVarResult, pExcepInfo, puArgErr) \
        ((((This)->lpVtbl)->Invoke)((This), (riid), (lcid), (wFlags), (pDispParams), (pVarResult), (pExcepInfo), (puArgErr)))

#endif  //  RibbonExtensibility_H