Make it easier to compare wxImages in the unit tests.

Instead of forcing the tests to manually use memcmp(), specialize
CppUnit::assertion_traits<> for wxImage. This allows to simply use
CPPUNIT_ASSERT_EQUAL() and related macros with wxImage objects.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67616 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

tests/testimage.h

@@ -0,0 +1,43 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        tests/testimage.h
+// Purpose:     Unit test helpers for dealing with wxImage.
+// Author:      Vadim Zeitlin
+// RCS-ID:      $Id$
+// Copyright:   (c) 2011 Vadim Zeitlin <vadim@wxwidgets.org>
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_TESTS_TESTIMAGE_H_
+#define _WX_TESTS_TESTIMAGE_H_
+
+#include "wx/image.h"
+
+CPPUNIT_NS_BEGIN
+
+template <>
+struct assertion_traits<wxImage>
+{
+    static bool equal(const wxImage& i1, const wxImage& i2)
+    {
+        if ( i1.GetWidth() != i2.GetWidth() )
+            return false;
+
+        if ( i1.GetHeight() != i2.GetHeight() )
+            return false;
+
+        return memcmp(i1.GetData(), i2.GetData(),
+                      i1.GetWidth()*i1.GetHeight()*3) == 0;
+    }
+
+    static std::string toString(const wxImage& image)
+    {
+        return wxString::Format("image of size %d*%d",
+                                image.GetWidth(),
+                                image.GetHeight())
+                .ToStdString();
+    }
+};
+
+CPPUNIT_NS_END
+
+#endif // _WX_TESTS_TESTIMAGE_H_