HOWTO: How to Enable Edit Menu Commands for Edit Controls

MORE INFORMATION

• Your UPDATE_COMMAND_UI handlers will need to determine if the control with the focus is really a CEdit and if there is any text available for the operation.
• Because you have menu items for Cut, Copy, or Paste that are tied to the standard accelerators, you need to write handlers for the actions.

Step-by-Step Example

1. First, determine if it is a CEdit control that has the focus:

      // IsEdit: a helper function to determine if a given CWnd pointer
      // points to a CEDit control.
      // Use the SDK ::GetClassName() function because MFC IsKindOf
      // fails if no CEdit variable has been created for the control you're
      // trying to test.
   
      BOOL CMyFormView::IsEdit( CWnd* pWnd )
      {
         ASSERT( pWnd != NULL );
         HWND hWnd = pWnd->GetSafeHwnd();
         if (hWnd == NULL)
            return FALSE;
   
         TCHAR szClassName[6];
         return ::GetClassName(hWnd, szClassName, 6) &&
                _tcsicmp(szClassName, _T("Edit")) == 0;
      }
   						

2. Add an UPDATE_COMMAND_UI handler for ID_EDIT_COPY & ID_EDIT_CUT:

      // UPDATE_COMMAND_UI handler for Edit Copy and Edit Cut which both
      // require that the current focus is on an edit control that has
      // text selected.
   
      void CMyFormView::OnUpdateNeedSel(CCmdUI* pCmdUI)
      {
        // get the current focus & determine if its on a CEdit control
         CWnd* pWnd = GetFocus();
         if (NULL == pWnd || !IsEdit( pWnd ))
         {
            pCmdUI->Enable( FALSE );
         }
         else
         {
            CEdit* pEdit = (CEdit*)pWnd;
            int nBeg, nEnd;
   
            pEdit->GetSel( nBeg, nEnd );
            pCmdUI->Enable( nBeg != nEnd );
         }
      }
   						

3. Add UPDATE_COMMAND_UI handlers for ID_EDIT_PASTE:

      // UPDATE_COMMAND_UI handlers for Edit Paste requires that focus be
      // on an edit control and that the clipboard contains text to be
      // pasted into the control.
   
      void CMyFormView::OnUpdateNeedClip(CCmdUI* pCmdUI)
      {
         // get the current focus & determine if its on a CEdit control
         // also check to see if the control is read-only.
         CWnd* pWnd = GetFocus();
         if (  NULL == pWnd ||
               !IsEdit( pWnd ) ||
               (pWnd->GetStyle() & ES_READONLY) != 0 )
         {
            pCmdUI->Enable( FALSE );
         }
         else
            pCmdUI->Enable(::IsClipboardFormatAvailable(CF_TEXT));
      }
   						

4. Add standard handlers for ID_EDIT_COPY, ID_EDIT_CUT, and ID_EDIT_PASTE:

      void CMyFormView::OnEditCopy()
      {
         CEdit* pEdit = (CEdit*)GetFocus();
         ASSERT( IsEdit( pEdit) );
         pEdit->Copy();
      }
   
      void CMyFormView::OnEditCut()
      {
         CEdit* pEdit = (CEdit*)GetFocus();
         ASSERT( IsEdit( pEdit) );
         pEdit->Cut();
      }
   
      void CMyFormView::OnEditPaste()
      {
         CEdit* pEdit = (CEdit*)GetFocus();
         ASSERT( IsEdit( pEdit) );
         ASSERT(::IsClipboardFormatAvailable(CF_TEXT));
         pEdit->Paste();
      }