IRichEditOleCallback interface

The interface that a Rich Edit control calls on its client to get storage for new objects, to ask whether to accept inserted objects and pasted data, and to ask for drag and drop effects and a context menu.

IRichEditOleCallback has the interface identifier 00020D03-0000-0000-C000-000000000046 and extends stdole.IUnknown. It is declared [OleAutomation(False)]. The client implements the interface and gives it to the control by sending the EM_SETOLECALLBACK message. Microsoft Learn describes the Windows interface: IRichEditOleCallback.

The declaration is complete: it has all 10 methods of the Windows interface, and none is marked [PreserveSig], so a class can implement it. Every method is a Sub, which hides the HRESULT. An implementation returns a failure code by setting Err.ReturnHResult, and a success code other than S_OK the same way. Where a Windows method returns a pointer through a pointer-to-pointer parameter, the Sub takes a ByRef parameter of the interface type: assign it, or leave it Nothing.

A parameter that is a pointer to a structure the package does not declare (a CHARRANGE*) or to an object the package does not name (an IOleObject*) is a LongPtr. RECO is a clipboard operation flag: 0 for a paste (RECO_PASTE), 1 for a drop (RECO_DROP), 2 for a copy (RECO_COPY), 3 for a cut (RECO_CUT) and 4 for a drag (RECO_DRAG).

Methods

GetNewStorage

Sub GetNewStorage(ByRef ppStorage As OLEGuids.IStorage)

Supplies storage for a new object that was pasted from the clipboard or read from an RTF stream. The result is an IStorage.

GetInPlaceContext

Sub GetInPlaceContext(ByRef ppFrame As OLEGuids.IOleInPlaceFrame, ByRef ppDoc As OLEGuids.IOleInPlaceUIWindow, ByRef pFrameInfo As OLEGuids.OLEINPLACEFRAMEINFO)

Supplies what in-place activation needs: the client’s frame window in ppFrame as an IOleInPlaceFrame, its document window in ppDoc as an IOleInPlaceUIWindow, which can stay Nothing when the frame and document windows are the same, and the accelerator information in pFrameInfo, an OLEINPLACEFRAMEINFO.

ShowContainerUI

Sub ShowContainerUI(ByVal fShow As Long)

Tells the client to show its own user interface, when fShow is not 0, or to hide it, when it is 0. The control calls it when an object activates or deactivates its user interface in place.

QueryInsertObject

Sub QueryInsertObject(ByRef pCLSID As OLEGuids.OLECLSID, ByVal pStorage As OLEGuids.IStorage, ByVal CharPos As Long)

Asks whether the control may insert an object of the class pCLSID, which is stored in pStorage, at the character position CharPos. The control calls it when it pastes an object and when it reads RTF. Any result other than S_OK refuses the insertion.

DeleteObject

Sub DeleteObject(ByVal LpOleObject As LongPtr)

Tells the client that the object IOleObject* LpOleObject is about to be deleted from the control. The object is not necessarily released at that point.

QueryAcceptData

Sub QueryAcceptData(ByVal pDataObject As OLEGuids.IDataObject, ByRef CF As Integer, ByVal RECO As Long, ByVal fReally As Long, ByVal hMetaPict As LongPtr)

Asks whether the control should accept the data that is pasted or dragged in, an IDataObject. CF holds the clipboard format to use; 0 selects the best available format, and a value the client changes it to is the only format the control then uses. RECO is 0 for a paste and 1 for a drop. fReally is not 0 when the paste or drop is happening, and 0 when the control only asks, such as for EM_CANPASTE. hMetaPict is the handle of a metafile that holds the icon view of the object, and is used only when a paste special operation imposes the icon aspect. A failure code refuses the data and ends the operation.

ContextSensitiveHelp

Sub ContextSensitiveHelp(ByVal fEnterMode As Long)

Tells the client to turn context-sensitive help mode on, when fEnterMode is not 0, or off, when it is 0. It has the meaning of IOleWindow.ContextSensitiveHelp.

GetClipboardData

Sub GetClipboardData(ByVal lpCharRange As LongPtr, ByVal RECO As Long, ByRef ppDataObject As OLEGuids.IDataObject)

Lets the client supply its own clipboard object, an IDataObject, for the range of text that the CHARRANGE at lpCharRange holds.

GetDragDropEffect

Sub GetDragDropEffect(ByVal fDrag As Long, ByVal KeyState As Long, ByRef dwEffect As Long)

Lets the client set the effect of a drop. fDrag is not 0 when the query is for a drag over the control (IDropTarget::DragEnter or DragOver), and 0 when it is for the drop itself. KeyState is the key state as OLE defines it. On return, dwEffect is the effect that the control allows when fDrag is not 0, and the effect to use when it is 0.

GetContextMenu

Sub GetContextMenu(ByVal SelType As Integer, ByVal LpOleObject As LongPtr, ByVal lpCharRange As LongPtr, ByRef hMenu As LongPtr)

Asks the client for the context menu to show on a right-click. SelType describes the selection: 0 is empty (SEL_EMPTY), 1 is text (SEL_TEXT), 2 includes an object (SEL_OBJECT), 4 is more than one character of text (SEL_MULTICHAR) and 8 is more than one object (SEL_MULTIOBJECT). LpOleObject is an IOleObject* of the first selected object when SelType includes SEL_OBJECT, and 0 otherwise. lpCharRange points to the CHARRANGE of the selection. hMenu receives the handle of the menu; the control destroys it when it has finished. The control sends a WM_COMMAND message to its parent window when the user chooses an item.

Example

This class refuses every object that a Rich Edit control tries to insert, and answers the other methods with E_NOTIMPL or accepts the default. A method that supplies an object leaves its parameter Nothing and reports E_NOTIMPL.

Class NoObjects
    Implements IRichEditOleCallback

    Private Const E_NOTIMPL As Long = &H80004001
    Private Const E_FAIL As Long = &H80004005

    Private Sub IRichEditOleCallback_GetNewStorage(ByRef ppStorage As IStorage) Implements IRichEditOleCallback.GetNewStorage
        Err.ReturnHResult = E_NOTIMPL
    End Sub

    Private Sub IRichEditOleCallback_GetInPlaceContext(ByRef ppFrame As IOleInPlaceFrame, ByRef ppDoc As IOleInPlaceUIWindow, ByRef pFrameInfo As OLEINPLACEFRAMEINFO) Implements IRichEditOleCallback.GetInPlaceContext
        Err.ReturnHResult = E_NOTIMPL
    End Sub

    Private Sub IRichEditOleCallback_ShowContainerUI(ByVal fShow As Long) Implements IRichEditOleCallback.ShowContainerUI
    End Sub

    Private Sub IRichEditOleCallback_QueryInsertObject(ByRef pCLSID As OLECLSID, ByVal pStorage As IStorage, ByVal CharPos As Long) Implements IRichEditOleCallback.QueryInsertObject
        Err.ReturnHResult = E_FAIL
    End Sub

    Private Sub IRichEditOleCallback_DeleteObject(ByVal LpOleObject As LongPtr) Implements IRichEditOleCallback.DeleteObject
    End Sub

    Private Sub IRichEditOleCallback_QueryAcceptData(ByVal pDataObject As IDataObject, ByRef CF As Integer, ByVal RECO As Long, ByVal fReally As Long, ByVal hMetaPict As LongPtr) Implements IRichEditOleCallback.QueryAcceptData
    End Sub

    Private Sub IRichEditOleCallback_ContextSensitiveHelp(ByVal fEnterMode As Long) Implements IRichEditOleCallback.ContextSensitiveHelp
    End Sub

    Private Sub IRichEditOleCallback_GetClipboardData(ByVal lpCharRange As LongPtr, ByVal RECO As Long, ByRef ppDataObject As IDataObject) Implements IRichEditOleCallback.GetClipboardData
        Err.ReturnHResult = E_NOTIMPL
    End Sub

    Private Sub IRichEditOleCallback_GetDragDropEffect(ByVal fDrag As Long, ByVal KeyState As Long, ByRef dwEffect As Long) Implements IRichEditOleCallback.GetDragDropEffect
    End Sub

    Private Sub IRichEditOleCallback_GetContextMenu(ByVal SelType As Integer, ByVal LpOleObject As LongPtr, ByVal lpCharRange As LongPtr, ByRef hMenu As LongPtr) Implements IRichEditOleCallback.GetContextMenu
        Err.ReturnHResult = E_NOTIMPL
    End Sub
End Class