fix best size caluclation for the notebooks with multiple rows (#2335) [backport of r57024 from trunk]

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@57033 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -129,6 +129,7 @@ wxMSW:
 - Fixed toolbar buttons so that they don't disappear temporarily when clicked
   if the event handler causes window update.
 - Fix display enumeration under WinCE (Vince Harron).
+- Fix best size calculation for wxNotebook with multiple rows (Alex McCarthy).
 
 wxGTK:
 

src/msw/notebook.cpp

@@ -656,16 +656,18 @@ wxSize wxNotebook::CalcSizeFromPage(const wxSize& sizePage) const
         tabSize.y = rect.bottom - rect.top;
     }
 
+    const int rows = GetRowCount();
+
     // add an extra margin in both directions
     const int MARGIN = 8;
     if ( IsVertical() )
     {
         sizeTotal.x += MARGIN;
-        sizeTotal.y += tabSize.y + MARGIN;
+        sizeTotal.y += tabSize.y * rows + MARGIN;
     }
     else // horizontal layout
     {
-        sizeTotal.x += tabSize.x + MARGIN;
+        sizeTotal.x += tabSize.x * rows + MARGIN;
         sizeTotal.y += MARGIN;
     }
 
@@ -1027,6 +1029,10 @@ void wxNotebook::OnSize(wxSizeEvent& event)
                     MAKELPARAM(rc.right, rc.bottom));
             s_isInOnSize = false;
         }
+
+        // The best size depends on the number of rows of tabs, which can
+        // change when the notepad is resized.
+        InvalidateBestSize();
     }
 
 #if wxUSE_UXTHEME