C / C++ / MFC

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

"One must learn from the bite of the fire to leave it alone." - Native American Proverb

/* Assuming the following is in a member function of
   a class derived from CHtmlView
 */
VARIANT var;
ExecWB(OLECMDID_ZOOM, OLECMDEXECOPT_DONTPROMPTUSER, NULL, &var);
// var.vt should equal VT_I4
// var.lVal should contain 0 (smallest) to 4 (largest)

/* Assuming the following is in a member function of
   a class derived from CHtmlView
 */
VARIANT var;
var.vt = VT_I4;
var.lVal = 1; // 1 means small
ExecWB(OLECMDID_ZOOM, OLECMDEXECOPT_DONTPROMPTUSER, &var, NULL);

//////////////////////////////////////
// In YourView.h
 
class CYourView : public CHtmlView
{
   .
   .
   .
   //{{AFX_MSG(CYourView)
   <code>afx_msg void OnViewLargest();</code>
   .
   .
   .
   //}}AFX_MSG
   DECLARE_MESSAGE_MAP()
};

//////////////////////////////////////
// In YourView.cpp
 
BEGIN_MESSAGE_MAP(CYourView, CHtmlView)
   //{{AFX_MSG_MAP(CYourView)
   <code>ON_COMMAND(ID_VIEW_LARGEST, OnViewLargest)</code>
   .
   .
   .
   //}}AFX_MSG_MAP
END_MESSAGE_MAP()
 
.
.
.
<code>void CYourView::OnViewLargest()
{
   VARIANT var;
   var.vt = VT_I4;
   var.lVal = 4; // 1 means small
   ExecWB(OLECMDID_ZOOM, OLECMDEXECOPT_DONTPROMPTUSER, &var, NULL);
}</code>

// In the class declaration
   afx_msg void OnUpdateViewTextSize(CCmdUI* pCmdUI);

// In the message map
   ON_UPDATE_COMMAND_UI(ID_VIEW_SMALLEST, OnUpdateViewTextSize)
   ON_UPDATE_COMMAND_UI(ID_VIEW_SMALL, OnUpdateViewTextSize)
   ON_UPDATE_COMMAND_UI(ID_VIEW_MEDIUM, OnUpdateViewTextSize)
   ON_UPDATE_COMMAND_UI(ID_VIEW_LARGE, OnUpdateViewTextSize)
   ON_UPDATE_COMMAND_UI(ID_VIEW_LARGEST, OnUpdateViewTextSize)

// After the message map
long GetTextSizeFromMenuID(UINT nId)
{
   /*
   If the menu IDs are consecutive and in the
   appropriate order, you can simply do
 
   return nId - ID_VIEW_SMALLEST;
 
   Otherwise...
   */
 
   long lVal = 2;
   switch (nId)
   {
     default:
        ASSERT(FALSE);
        break;
     case ID_VIEW_SMALLEST:
        lVal = 0;
        break;
     case ID_VIEW_SMALL:
        lVal = 1;
        break;
     case ID_VIEW_MEDIUM:
        lVal = 2;
        break;
     case ID_VIEW_LARGE:
        lVal = 3;
        break;
     case ID_VIEW_LARGEST:
        lVal = 4;
        break;
   }
   return lVal;
}
 
void CYourView::OnUpdateViewTextSize(CCmdUI* pCmdUI)
{
   long lSize = GetTextSizeFromMenuID(pCmdUI->m_nID);
 
   VARIANT var;
   ExecWB(OLECMDID_ZOOM, OLECMDEXECOPT_DONTPROMPTUSER, NULL, &var);
   pCmdUI->SetRadio(var.vt == VT_I4 && var.lVal == lSize);
}