IHTMLPainterOverlay Interface

IID_IHTMLPainterOverlay

{3050F7E3-98B5-11CF-BB82-00AA00BDCE0B}

This custom interface provides a method to MSHTML that enables a rendering behavior to use the Microsoft DirectDraw hardware overlay buffer, if the buffer is present.

Documentation: IHTMLPainterOverlay Interface

Methods in VTable order

IUnknown Methods

Description

QueryInterface

Returns pointers to supported interfaces.

AddRef

Increments reference count.

Release

Decrements reference count.

IHTMLPainterOverlay Method

Description

OnMove

Called by MSHTML when the element to which a rendering behavior is attached is repositioned or resized on the screen.

ITMLPainterOverlay interface implementation

$IID_IHTMLPainterOverlay = GUID$("{3050F7E3-98B5-11CF-BB82-00AA00BDCE0B}")

' ****************************************************************************************
' IHTMLPainterOverlay interface virtual table
' ****************************************************************************************
TYPE IHTMLPainterOverlayVtbl
   ' IUnknown methods
   pQueryInterface         AS DWORD          ' // QueryInterface method
   pAddRef                 AS DWORD          ' // AddRef method
   pRelease                AS DWORD          ' // Release method
   ' IHTMLPainterOverlay method
   pOnMove                 AS DWORD          ' // OnMove method
   ' Custom data
   pVtblAddr               AS DWORD          ' // Address of the virtual table
   cRef                    AS DWORD          ' // Reference count
END TYPE
' ****************************************************************************************

' ****************************************************************************************
' Builds the IHTMLPainterOverlay Virtual Table
' Returns a cookie that is a pointer to a IHTMLPainterOverlayVtbl structure.
' ****************************************************************************************
FUNCTION IHTMLPainterOverlay_BuildVtbl () AS DWORD

   LOCAL pVtbl AS IHTMLPainterOverlayVtbl PTR
   LOCAL pUnk AS IHTMLPainterOverlayVtbl PTR

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

   @pVtbl.pQueryInterface         = CODEPTR(IHTMLPainterOverlay_QueryInterface)
   @pVtbl.pAddRef                 = CODEPTR(IHTMLPainterOverlay_AddRef)
   @pVtbl.pRelease                = CODEPTR(IHTMLPainterOverlay_Release)

   @pVtbl.pOnMove                 = CODEPTR(IHTMLPainterOverlay_OnMove)

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

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

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

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

' ****************************************************************************************
' IHTMLPainterOverlay_IUnknown_AddRef method
' Increments the reference counter.
' ****************************************************************************************
FUNCTION IHTMLPainterOverlay_AddRef (BYVAL pCookie AS IHTMLPainterOverlayVtbl PTR) AS DWORD
   INCR @@pCookie.cRef
   FUNCTION = @@pCookie.cRef
END FUNCTION
' ****************************************************************************************

' ****************************************************************************************
' IHTMLPainterOverlay_IUnknown_Release method
' Releases our class if there is only a reference to him and decrements the reference counter.
' ****************************************************************************************
FUNCTION IHTMLPainterOverlay_Release (BYVAL pCookie AS IHTMLPainterOverlayVtbl 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 MSHTML when the element to which a rendering behavior is attached is
' repositioned or resized on the screen.
' ****************************************************************************************
FUNCTION IHTMLPainterOverlay_OnMove ( _
  BYVAL pCookie AS IHTMLPainterOverlayVtbl PTR _
, BYREF rcDevice AS RECT _
) AS LONG

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

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