wxWindow::Freeze()/Thaw() can now be nested

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@26030 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -74,6 +74,13 @@ versions, please update your code to not use them.
 OTHER CHANGES
 =============
 
+2.5.2
+-----
+
+wxMSW:
+- wxWindow::Freeze()/Thaw() can now be nested
+
+
 2.5.1
 -----
 

include/wx/msw/window.h

@@ -463,6 +463,9 @@ private:
     // list of disabled children before last call to our Disable()
     wxWindowList *m_childrenDisabled;
 
+    // number of calls to Freeze() minus number of calls to Thaw()
+    unsigned int m_frozenness;
+
     DECLARE_DYNAMIC_CLASS(wxWindowMSW)
     DECLARE_NO_COPY_CLASS(wxWindowMSW)
     DECLARE_EVENT_TABLE()

src/msw/window.cpp

@@ -431,6 +431,7 @@ void wxWindowMSW::Init()
     m_lastKeydownProcessed = false;
 
     m_childrenDisabled = NULL;
+    m_frozenness = 0;
 
     // wxWnd
     m_hMenu = 0;
@@ -1294,16 +1295,24 @@ static inline void SendSetRedraw(HWND hwnd, bool on)
 
 void wxWindowMSW::Freeze()
 {
+    if ( !m_frozenness++ )
+    {
         SendSetRedraw(GetHwnd(), false);
+    }
 }
 
 void wxWindowMSW::Thaw()
 {
+    wxASSERT_MSG( m_frozenness > 0, _T("Thaw() without matching Freeze()") );
+
+    if ( !--m_frozenness )
+    {
         SendSetRedraw(GetHwnd(), true);
 
         // we need to refresh everything or otherwise he invalidated area is not
         // repainted
         Refresh();
+    }
 }
 
 void wxWindowMSW::Refresh(bool eraseBack, const wxRect *rect)