added Freeze/Thaw implementation for Windows

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@11207 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/window.h

@@ -90,6 +90,8 @@ public:
                           const wxRect *rect = (const wxRect *) NULL );
     virtual void Update();
     virtual void Clear();
+    virtual void Freeze();
+    virtual void Thaw();
 
     virtual bool SetCursor( const wxCursor &cursor );
     virtual bool SetFont( const wxFont &font );

src/msw/window.cpp

@@ -1194,6 +1194,21 @@ void wxWindowMSW::Clear()
     dc.Clear();
 }
 
+static inline void SendSetRedraw(HWND hwnd, bool on)
+{
+    ::SendMessage(hwnd, WM_SETREDRAW, (WPARAM)on, 0);
+}
+
+void wxWindowMSW::Freeze()
+{
+    SendSetRedraw(FALSE);
+}
+
+void wxWindowMSW::Thaw()
+{
+    SendSetRedraw(TRUE);
+}
+
 void wxWindowMSW::Refresh(bool eraseBack, const wxRect *rect)
 {
     HWND hWnd = GetHwnd();