ISelectionServicesListener Interface

IID_ISelectionServicesListener

{3050F699-98B5-11CF-BB82-00AA00BDCE0B}

This custom interface provides methods that the editing component of MSHTML calls whenever certain events fire for a selection object that has a registered ISelectionServicesListener interface. This interface provides processing for undo events, for selection type changes, and whenever the mouse pointer exits the scope of an element in the editable selection. An application should supply an implementation of this interface for a selection object so that the editing component of MSHTML can respond to these events.

Documentation: ISelectionServicesListener Interface

Methods in VTable order

IUnknown Methods

Description

QueryInterface

Returns pointers to supported interfaces.

AddRef

Increments reference count.

Release

Decrements reference count.

ISelectionServicesListener Method

Description

BeginSelectionUndo

Called by the editor just before processing an undo event that fires on a selection object.

EndSelectionUndo

Called by the editor just after processing an undo event that fires on a selection object with a registered ISelectionServicesListener interface.

OnSelectedElementExit

Called by the editor when an element in the current editable selection is removed from the document.

OnChangeType

Called by the editor when a selection's type changes.

GetTypeDetail

Called by MSHTML to obtain the name of the selection type.

ISelectionServicesListener interface implementation

$IID_ISelectionServicesListener = GUID$("{3050F699-98B5-11CF-BB82-00AA00BDCE0B}")

' ****************************************************************************************
' ISelectionServicesListener interface virtual table
' ****************************************************************************************
TYPE ISelectionServicesListenerVtbl
   ' IUnknown methods
   pQueryInterface         AS DWORD          ' // QueryInterface method
   pAddRef                 AS DWORD          ' // AddRef method
   pRelease                AS DWORD          ' // Release method
   ' ISelectionServicesListener method
   pBeginSelectionUndo     AS DWORD          ' // BeginSelectionUndo method
   pEndSelectionUndo       AS DWORD          ' // EndSelectionUndo method
   pOnSelectedElementExit  AS DWORD          ' // OnSelectedElementExit method
   pOnChangeType           AS DWORD          ' // OnChangeType method
   pGetTypeDetail          AS DWORD          ' // GetTypeDetail method
   ' Custom data
   pVtblAddr               AS DWORD          ' // Address of the virtual table
   cRef                    AS DWORD          ' // Reference count
END TYPE
' ****************************************************************************************

' ****************************************************************************************
' Builds the ISelectionServicesListener Virtual Table
' Returns a cookie that is a pointer to a ISelectionServicesListenerVtbl structure.
' ****************************************************************************************
FUNCTION ISelectionServicesListener_BuildVtbl () AS DWORD

   LOCAL pVtbl AS ISelectionServicesListenerVtbl PTR
   LOCAL pUnk AS ISelectionServicesListenerVtbl PTR

   pVtbl = HeapAlloc(GetProcessHeap(), %HEAP_ZERO_MEMORY, SIZEOF(@pVtbl))
   IF pVtbl = 0 THEN EXIT FUNCTION

   @pVtbl.pQueryInterface         = CODEPTR(ISelectionServicesListener_QueryInterface)
   @pVtbl.pAddRef                 = CODEPTR(ISelectionServicesListener_AddRef)
   @pVtbl.pRelease                = CODEPTR(ISelectionServicesListener_Release)

   @pVtbl.pBeginSelectionUndo     = CODEPTR(ISelectionServicesListener_BeginSelectionUndo)
   @pVtbl.pEndSelectionUndo       = CODEPTR(ISelectionServicesListener_EndSelectionUndo)
   @pVtbl.pOnSelectedElementExit  = CODEPTR(ISelectionServicesListener_OnSelectedElementExit)
   @pVtbl.pOnChangeType           = CODEPTR(ISelectionServicesListener_OnChangeType)
   @pVtbl.pGetTypeDetail          = CODEPTR(ISelectionServicesListener_GetTypeDetail)

   @pVtbl.pVtblAddr               = pVtbl
   @pVtbl.cRef                    = 1

   pUnk = VARPTR(@pVtbl.pVtblAddr)
   FUNCTION = pUnk

END FUNCTION
' ****************************************************************************************

' ****************************************************************************************
' ISelectionServicesListener_QueryInterface method
' Returns the IUnknown of our class and increments the reference counter.
' ****************************************************************************************
FUNCTION ISelectionServicesListener_QueryInterface (BYVAL pCookie AS ISelectionServicesListenerVtbl PTR, BYREF riid AS GUID, BYREF ppvObj AS DWORD) AS LONG
   IF riid = $IID_ISelectionServicesListener THEN
      ppvObj = pCookie
      INCR @@pCookie.cRef
      FUNCTION = %S_OK
   ELSE
      FUNCTION = %E_NOINTERFACE
   END IF
END FUNCTION
' ****************************************************************************************

' ****************************************************************************************
' ISelectionServicesListener_IUnknown_AddRef method
' Increments the reference counter.
' ****************************************************************************************
FUNCTION ISelectionServicesListener_AddRef (BYVAL pCookie AS ISelectionServicesListenerVtbl PTR) AS DWORD
   INCR @@pCookie.cRef
   FUNCTION = @@pCookie.cRef
END FUNCTION
' ****************************************************************************************

' ****************************************************************************************
' ISelectionServicesListener_IUnknown_Release method
' Releases our class if there is only a reference to him and decrements the reference counter.
' ****************************************************************************************
FUNCTION ISelectionServicesListener_Release (BYVAL pCookie AS ISelectionServicesListenerVtbl PTR) AS DWORD
   DECR @@pCookie.cRef
   FUNCTION = @@pCookie.cRef
   IF @@pCookie.cRef = 0 THEN
      IF ISTRUE @@pCookie.pVtblAddr THEN
         HeapFree(GetProcessHeap(), 0, BYVAL @@pCookie.pVtblAddr)
      END IF
   END IF
END FUNCTION
' ****************************************************************************************

' ****************************************************************************************
' Called by the editor just before processing an undo event that fires on a selection object.
' ****************************************************************************************
FUNCTION ISelectionServicesListener_BeginSelectionUndo ( _
  BYVAL pCookie AS ISelectionServicesListenerVtbl PTR _
) AS LONG

  ' Put your code here
  ' FUNCTION = %S_OK or an error value

END FUNCTION
' ****************************************************************************************

' ****************************************************************************************
' Called by the editor just after processing an undo event that fires on a selection
' object with a registered ISelectionServicesListener interface.
' ****************************************************************************************
FUNCTION ISelectionServicesListener_EndSelectionUndo ( _
  BYVAL pCookie AS ISelectionServicesListenerVtbl PTR _
) AS LONG

  ' Put your code here
  ' FUNCTION = %S_OK or an error value

END FUNCTION
' ****************************************************************************************

' ****************************************************************************************
' Called by the editor when an element in the current editable selection is removed from
' the document.
' ****************************************************************************************
FUNCTION ISelectionServicesListener_OnSelectedElementExit ( _
  BYVAL pCookie AS ISelectionServicesListenerVtbl PTR _
, BYVAL pIElementStart AS LONG _
, BYVAL pIElementEnd AS DWORD _
, BYVAL pIElementContentStart AS DWORD _
, BYVAL pIElementContentEnd AS DWORD _
) AS LONG

  ' Put your code here
  ' FUNCTION = %S_OK or an error value

END FUNCTION
' ****************************************************************************************

' ****************************************************************************************
' Called by the editor when a selection's type changes.
' ****************************************************************************************
FUNCTION ISelectionServicesListener_OnChangeType ( _
  BYVAL pCookie AS ISelectionServicesListenerVtbl PTR _
, BYVAL eType AS LONG _
, BYVAL pIListener AS DWORD _
) AS LONG

  ' Put your code here
  ' FUNCTION = %S_OK or an error value

END FUNCTION
' ****************************************************************************************

' ****************************************************************************************
' Called by MSHTML to obtain the name of the selection type.
' ****************************************************************************************
FUNCTION ISelectionServicesListener_GetTypeDetail ( _
  BYVAL pCookie AS ISelectionServicesListenerVtbl PTR _
, BYREF pTypeDetail AS STRING _
) AS LONG

  ' Put your code here
  ' FUNCTION = %S_OK or an error value

END FUNCTION
' ****************************************************************************************