synchronize GTK2 minimum version in docs

[wxWidgets.git] / include / wx / msw / private.h

diff --git a/include/wx/msw/private.h b/include/wx/msw/private.h
index 2875d294c727f57cb7ce6aaac01e0f9b7dda4247..6c10cfa60dd7ae5e7afbee8503b222b67e57e087 100644 (file)
--- a/include/wx/msw/private.h
+++ b/include/wx/msw/private.h
@@ -218,6 +218,21 @@ struct WinStruct : public T
 };
 
 
+// Macros for converting wxString to the type expected by API functions.
+//
+// Normally it is enough to just use wxString::t_str() which is implicitly
+// convertible to LPCTSTR, but in some cases an explicit conversion is required.
+//
+// In such cases wxMSW_CONV_LPCTSTR() should be used. But if an API function
+// takes a non-const pointer, wxMSW_CONV_LPTSTR() which casts away the
+// constness (but doesn't make it possible to really modify the returned
+// pointer, of course) should be used. And if a string is passed as LPARAM, use
+// wxMSW_CONV_LPARAM() which does the required ugly reinterpret_cast<> too.
+#define wxMSW_CONV_LPCTSTR(s) static_cast<const wxChar *>((s).t_str())
+#define wxMSW_CONV_LPTSTR(s) const_cast<wxChar *>(wxMSW_CONV_LPCTSTR(s))
+#define wxMSW_CONV_LPARAM(s) reinterpret_cast<LPARAM>(wxMSW_CONV_LPCTSTR(s))
+
+
 #if wxUSE_GUI
 
 #include "wx/gdicmn.h"
@@ -417,8 +432,9 @@ private:
 class WindowHDC
 {
 public:
+    WindowHDC() : m_hwnd(NULL), m_hdc(NULL) { }
     WindowHDC(HWND hwnd) { m_hdc = ::GetDC(m_hwnd = hwnd); }
-   ~WindowHDC() { ::ReleaseDC(m_hwnd, m_hdc); }
+   ~WindowHDC() { if ( m_hwnd && m_hdc ) { ::ReleaseDC(m_hwnd, m_hdc); } }
 
     operator HDC() const { return m_hdc; }
 
@@ -780,7 +796,7 @@ public:
     {
         if ( IsRegistered() )
         {
-            if ( !::UnregisterClass(m_clsname.wx_str(), wxGetInstance()) )
+            if ( !::UnregisterClass(m_clsname.t_str(), wxGetInstance()) )
             {
                 wxLogLastError(wxT("UnregisterClass"));
             }