IHTMLEditHost2 Interface

IID_IHTMLEditHost2

{3050F848-98B5-11CF-BB82-00AA00BDCE0D}

This interface extends IHTMLEditHost with a method that enables you to intercept drag-and-drop operations at a stage earlier than the ondragstart event.

Documentation: IHTMLEditHost2 Interface

Methods in VTable order

IUnknown Methods

Description

QueryInterface

Returns pointers to supported interfaces.

AddRef

Increments reference count.

Release

Decrements reference count.

IHTMLEditHost Method

Description

SnapRect

Called by MSHTML whenever a selected element is resized or moved in the editor.

IHTMLEditHost2 Method

Description

PreDrag

Called by MSHTML before an ondragstart event fires on a selected element in the editor, and before the element is cloned prior to a drag-and-drop operation.

ITMLEditHost2 interface implementation

$IID_IHTMLEditHost2 = GUID$("{3050F848-98B5-11CF-BB82-00AA00BDCE0D}")

' ****************************************************************************************
' IHTMLEditHost2 interface virtual table
' ****************************************************************************************
TYPE IHTMLEditHost2Vtbl
   ' IUnknown methods
   pQueryInterface         AS DWORD          ' // QueryInterface method
   pAddRef                 AS DWORD          ' // AddRef method
   pRelease                AS DWORD          ' // Release method
   ' IHTMLEditHost2 method
   pSnapRect               AS DWORD          ' // SnapRect method
   pPreDrag                AS DWORD          ' // PreDrag method
   ' Custom data
   pVtblAddr               AS DWORD          ' // Address of the virtual table
   cRef                    AS DWORD          ' // Reference count
END TYPE
' ****************************************************************************************

' ****************************************************************************************
' Builds the IHTMLEditHost2 Virtual Table
' Returns a cookie that is a pointer to a IHTMLEditHost2Vtbl structure.
' ****************************************************************************************
FUNCTION IHTMLEditHost2_BuildVtbl () AS DWORD

   LOCAL pVtbl AS IHTMLEditHost2Vtbl PTR
   LOCAL pUnk AS IHTMLEditHost2Vtbl PTR

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

   @pVtbl.pQueryInterface         = CODEPTR(IHTMLEditHost2_QueryInterface)
   @pVtbl.pAddRef                 = CODEPTR(IHTMLEditHost2_AddRef)
   @pVtbl.pRelease                = CODEPTR(IHTMLEditHost2_Release)

   @pVtbl.pSnapRect               = CODEPTR(IHTMLEditHost2_SnapRect)
   @pVtbl.pPreDrag                = CODEPTR(IHTMLEditHost2_PreDrag)

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

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

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

' ****************************************************************************************
' IHTMLEditHost2_QueryInterface method
' Returns the IUnknown of our class and increments the reference counter.
' ****************************************************************************************
FUNCTION IHTMLEditHost2_QueryInterface (BYVAL pCookie AS IHTMLEditHost2Vtbl PTR, BYREF riid AS GUID, BYREF ppvObj AS DWORD) AS LONG
   IF riid = $IID_IHTMLEditHost2 THEN
      ppvObj = pCookie
      INCR @@pCookie.cRef
      FUNCTION = %S_OK
   ELSE
      FUNCTION = %E_NOINTERFACE
   END IF
END FUNCTION
' ****************************************************************************************

' ****************************************************************************************
' IHTMLEditHost2_IUnknown_AddRef method
' Increments the reference counter.
' ****************************************************************************************
FUNCTION IHTMLEditHost2_AddRef (BYVAL pCookie AS IHTMLEditHost2Vtbl PTR) AS DWORD
   INCR @@pCookie.cRef
   FUNCTION = @@pCookie.cRef
END FUNCTION
' ****************************************************************************************

' ****************************************************************************************
' IHTMLEditHost2_IUnknown_Release method
' Releases our class if there is only a reference to him and decrements the reference counter.
' ****************************************************************************************
FUNCTION IHTMLEditHost2_Release (BYVAL pCookie AS IHTMLEditHost2Vtbl 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 whenever a selected element is resized or moved in the editor.
' ****************************************************************************************
FUNCTION IHTMLEditHost2_SnapRect ( _
  BYVAL pCookie AS IHTMLEditHost2Vtbl PTR _
, BYVAL pIElement AS DWORD _
, BYREF prcNew AS RECT _
, BYVAL eHandle AS LONG _
) AS LONG

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

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

' ****************************************************************************************
' Called by MSHTML before an ondragstart event fires on a selected element in the editor,
' and before the element is cloned prior to a drag-and-drop operation.
' ****************************************************************************************
FUNCTION IHTMLEditHost2_PreDrag ( _
  BYVAL pCookie AS IHTMLEditHost2Vtbl PTR _
) AS LONG

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

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