ISelectionContainer::GetObjects

Returns either all selectable objects or all selected objects, depending on the flag passed.

HRESULT GetObjects(
   DWORD dwFlags,
   ULONG cObjects,
   IUnknown **apUnkObjects
);

Parameters

dwFlags

[in] Flag specifying which objects to return, either GETOBJS_ALL or GETOBJS_SELECTED.

cObjects

[in] Number of objects to return.

apUnkObjects

[out] Pointer to an array of returned objects.

Return Values

The designer returns one of the following values:

Return Value	Meaning
S_OK	Success.
E_INVALIDARG	One or more of the arguments is invalid.

Comments

The ActiveX designer implements this method.

The GetObjects method returns either all selectable objects or all selected objects, depending on the flag passed. The returned array of objects is used as the basis for SelectObjects.

In apUnkObjects, the designer should pass a pointer to its extended object rather than to itself. The extended object includes the ambient properties that the host supplies and the user can browse. The extended object is available through the site. See the COM Programmer's Reference in the Platform Software Development Kit (SDK) for more information.

Because the returned objects support IDispatch, the host can obtain information directly from them. For example, to get an object's name, the host calls IDispatch::Invoke (or ITypeInfo::Invoke) with a predefined dispatch identifier (DISPID) that signifies the name. The predeclared DISPIDs are negative to avoid conflicts with user-defined identifiers. The following table describes some of this information and how it is obtained. These DISPIDs are defined in the header file Typelib2.h.

Item	How It Is Obtained
Object name	DISPID_NAME
Object index	DISPID_OBJECT
Object type	IProvideClassInfo::QueryInterface

Example

The following example implements GetObjects; the returned array is used by the SelectObjects method.

STDMETHODIMP CMySelectionContainer::GetObjects
(
  DWORD dwFlags,
  ULONG cObjects, 
  IUnknown **apUnkObjects
)
{
  // Initialize the array.
  for (ULONG i = 0; i < cObjects; i++) {
      apUnkObjects[i] = NULL;
  }     

  IUnknown * pUnkUs;
  HRESULT hr;
  BOOL bUsedUnkUs = FALSE;

  // Can't pass self as an object because the user won't be 
  // able to browse ambient properties, so need to pass
  // extender. Get it from site. 
  IDispatch * pDisp = NULL;
  hr = m_pControlSite->GetExtendedControl(&pDisp);
  if (SUCCEEDED(hr)) {
      hr = pDisp->QueryInterface(IID_IUnknown, (void**)&pUnkUs);
      pDisp->Release();
  }

  if (FAILED(hr)) {
      // Can't get the extender, so use self anyway.
      pUnkUs = (IUnknown*)(ISelectionContainer*)this;
      pUnkUs->AddRef();
  }
  
  if (GETOBJS_ALL == dwFlags) {
      ULONG x = 0;
      for (int i = 0; i < MAXOBJECTS && x < (int) cObjects; i++) {
           If (m_state.rgObjects[i].bHaveIt) {
            apUnkObjects[x] = m_state.rgObjects[i].pObject;
            apUnkObjects[x]->AddRef();
            x++;
           }
      }
   if (x < (int) cObjects) {
     apUnkObjects[x] = pUnkUs;
     bUsedUnkUs = TRUE;
      }
  }
  else { 
   // Host requested all selected objects.
   if (cObjects > 0) {
     if (m_state.iSelectedObject != -1) {   
         apUnkObjects[0] =             
            m_state.rgCircles[m_state.iSelectedObject].pObject;
         apUnkObjects[0]->AddRef();
           }
     else {
         apUnkObjects[0] = pUnkUs;
         bUsedUnkUs = TRUE;
           }
      }
  }
  if (!bUsedUnkUs) {
      pUnkUs->Release();
  }
  return S_OK;
}