Fix wxCairoContext creation from wxWindow under MSW.

cairo_win32_surface_create() must be passed the window HDC and not HWND
itself, the old code calling it was broken.

Add WindowHDC object and pass its HDC to this function now to make it work.

Closes #14194.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@71209 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/graphicc.cpp

@@ -71,6 +71,10 @@ using namespace std;
 #include <cairo.h>
 #ifdef __WXMSW__
 #include <cairo-win32.h>
+// Notice that the order is important: cairo-win32.h includes windows.h which
+// pollutes the global name space with macros so include our own header which
+// #undefines them after it.
+#include "wx/msw/private.h"
 #endif
 
 #ifdef __WXGTK__
@@ -79,13 +83,6 @@ using namespace std;
 #include "wx/gtk/dc.h"
 #endif
 
-#ifdef __WXMSW__
-#include <cairo-win32.h>
-// We must do this as cairo-win32.h includes windows.h which pollutes the
-// global name space with macros.
-#include "wx/msw/winundef.h"
-#endif
-
 #ifdef __WXMAC__
 #include "wx/osx/private.h"
 #include <cairo-quartz.h>
@@ -400,6 +397,7 @@ public:
     virtual void Clip( const wxRegion &region );
 #ifdef __WXMSW__
     cairo_surface_t* m_mswSurface;
+    WindowHDC m_mswWindowHDC;
 #endif
 
     // clips drawings to the rect
@@ -1744,7 +1742,10 @@ wxCairoContext::wxCairoContext( wxGraphicsRenderer* renderer, cairo_t *context )
 }
 
 wxCairoContext::wxCairoContext( wxGraphicsRenderer* renderer, wxWindow *window)
-: wxGraphicsContext(renderer)
+    : wxGraphicsContext(renderer)
+#ifdef __WXMSW__
+    , m_mswWindowHDC(GetHwndOf(window))
+#endif
 {
     m_enableOffset = true;    
 #ifdef __WXGTK__
@@ -1768,7 +1769,7 @@ wxCairoContext::wxCairoContext( wxGraphicsRenderer* renderer, wxWindow *window)
 #endif
 
 #ifdef __WXMSW__
-    m_mswSurface = cairo_win32_surface_create((HDC)window->GetHandle());
+    m_mswSurface = cairo_win32_surface_create((HDC)m_mswWindowHDC);
     Init(cairo_create(m_mswSurface));
 #endif