Determining If an Object Is Capable of Visual Editing

• Microsoft OLE Libraries for Windows and Win32s, versions 2.0 and 2.01
• Microsoft OLE Libraries, included with:

      - Microsoft Windows NT, versions 3.5 and 3.51
      - Microsoft Windows 95
  

SUMMARY

It is impossible for a container to consistently determine whether an object will attempt negotiation for visual editing. However, by determining whether the object supports the IOleInPlaceObject interface, the container may want to assume that the negotiation will occur.

The default object handler will always fail a call to QueryInterface for IOleInPlaceObject if the object is in the loaded state. The container must first run the object and then query for the IOleInPlaceObject interface. If this QueryInterface call succeeds, then the container can assume that the object supports visual editing, and may start negotiation on the execution of a verb.

MORE INFORMATION

The following C++ code returns TRUE if an object may start visual negotiation when IOleObject::DoVerb is called:

BOOL fCanInPlaceActivate(LPOLEOBJECT lpObject) { LPOLEINPLACEOBJECT lpInPlaceObject; BOOL retval;

    // Run the object.
    OleRun(lpObject);

    // Query for IOleInPlaceObject.
    HRESULT herr = lpObject->QueryInterface(IID_IOleInPlaceObject,
                                            (LPVOID FAR *)
                                            lpInPlaceObject);

    // Check the return value.
    if (herr == NOERROR)
        {
        retval = TRUE;
        lpInPlaceObject->Release();
        }
    else
        retval = FALSE;

    lpObject::Close(OLECLOSE_NOSAVE);

    return retval;