get rid of MSVC warning about possibly uninitialized variable in CalcAndSendEvent() and also make its code somewhat more structured

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@53797 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/lboxcmn.cpp

@@ -103,91 +103,95 @@ static void LBSendEvent( wxCommandEvent &event, wxListBoxBase *listbox, int item
 
 void wxListBoxBase::CalcAndSendEvent()
 {
-    wxCommandEvent event(wxEVT_COMMAND_LISTBOX_SELECTED, GetId() );
+    wxCommandEvent event(wxEVT_COMMAND_LISTBOX_SELECTED, GetId());
     event.SetEventObject( this );
 
     wxArrayInt selections;
-    GetSelections( selections );
+    GetSelections(selections);
 
-        if ((selections.GetCount() == 0) && (m_oldSelections.GetCount() == 0))
+    if ( selections.empty() && m_oldSelections.empty() )
-        {
+    {
-            // nothing changed, just leave
+        // nothing changed, just leave
-            return;
+        return;
-        }
+    }
 
-        if (selections.GetCount() == m_oldSelections.GetCount())
+    const size_t countSel = selections.size(),
+                 countSelOld = m_oldSelections.size();
+    if ( countSel == countSelOld )
+    {
+        bool changed = false;
+        for ( size_t idx = 0; idx < countSel; idx++ )
         {
-            bool changed = false;
+            if (selections[idx] != m_oldSelections[idx])
-            size_t idx;
-            for (idx = 0; idx < selections.GetCount(); idx++)
             {
-                if (selections[idx] != m_oldSelections[idx])
+                changed = true;
-                {
+                break;
-                    changed = true;
-                    break;
-                }
             }
-            
-            // nothing changed, just leave
-            if (!changed)
-               return;
         }
 
-        if (selections.GetCount() == 0)
+        // nothing changed, just leave
-        {
+        if ( !changed )
-            // indicate that this is a deselection
+           return;
-            event.SetExtraLong( 0 );
+    }
-            int item = m_oldSelections[0];
-            m_oldSelections = selections;
-            LBSendEvent( event, this, item );
-            return;
-        }
 
-        int item;
+    int item = wxNOT_FOUND;
+    if ( selections.empty() )
+    {
+        // indicate that this is a deselection
+        event.SetExtraLong(0);
+        item = m_oldSelections[0];
+    }
+    else // we [still] have some selections
+    {
         // Now test if any new item is selected
         bool any_new_selected = false;
-        size_t idx;
+        for ( size_t idx = 0; idx < countSel; idx++ )
-        for (idx = 0; idx < selections.GetCount(); idx++)
         {
             item = selections[idx];
-            if (m_oldSelections.Index(item) == wxNOT_FOUND)
+            if ( m_oldSelections.Index(item) == wxNOT_FOUND )
             {
                 any_new_selected = true;
                 break;
             }
         }
 
-        if (any_new_selected)
+        if ( any_new_selected )
         {
             // indicate that this is a selection
-            event.SetExtraLong( 1 );
+            event.SetExtraLong(1);
-            m_oldSelections = selections;
-            LBSendEvent( event, this, item );
-            return;
         }
-        
+        else // no new items selected
-        // Now test if any new item is deselected
-        bool any_new_deselected = false;
-        for (idx = 0; idx < m_oldSelections.GetCount(); idx++)
         {
-            item = m_oldSelections[idx];
+            // Now test if any new item is deselected
-            if (selections.Index(item) == wxNOT_FOUND)
+            bool any_new_deselected = false;
+            for ( size_t idx = 0; idx < countSelOld; idx++ )
             {
-                any_new_deselected = true;
+                item = m_oldSelections[idx];
-                break;
+                if ( selections.Index(item) == wxNOT_FOUND )
+                {
+                    any_new_deselected = true;
+                    break;
+                }
+            }
+
+            if ( any_new_deselected )
+            {
+                // indicate that this is a selection
+                event.SetExtraLong(0);
+            }
+            else
+            {
+                item = wxNOT_FOUND; // this should be impossible
             }
         }
+    }
 
-        if (any_new_deselected)
+    wxASSERT_MSG( item != wxNOT_FOUND,
-        {
+                  "Logic error in wxListBox selection event generation code" );
-            // indicate that this is a selection
-            event.SetExtraLong( 0 );
-            m_oldSelections = selections;
-            LBSendEvent( event, this, item );
-            return;
-        }
 
-        wxLogError( wxT("Wrong wxListBox selection") );
+    m_oldSelections = selections;
+
+    LBSendEvent(event, this, item);
 }
 
 // ----------------------------------------------------------------------------