Document and test behaviour of wxRegion methods when it is invalid.

[wxWidgets.git] / tests / geometry / region.cpp

diff --git a/tests/geometry/region.cpp b/tests/geometry/region.cpp
new file mode 100644 (file)
index 0000000..f6ae795
--- /dev/null
+++ b/tests/geometry/region.cpp
@@ -0,0 +1,114 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        tests/geometry/region.cpp
+// Purpose:     wxRegion unit test
+// Author:      Vadim Zeitlin
+// Created:     2011-10-12
+// RCS-ID:      $Id$
+// Copyright:   (c) 2011 Vadim Zeitlin <vadim@wxwidgets.org>
+///////////////////////////////////////////////////////////////////////////////
+
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+
+#include "testprec.h"
+
+#ifdef __BORLANDC__
+    #pragma hdrstop
+#endif
+
+#ifndef WX_PRECOMP
+    #include "wx/region.h"
+#endif // WX_PRECOMP
+
+#include "wx/iosfwrap.h"
+
+// ----------------------------------------------------------------------------
+// helper functions
+// ----------------------------------------------------------------------------
+
+namespace
+{
+
+// This function could be easily added to wxRegionIterator itself, where it
+// could be implemented far more efficiently as all major platforms store the
+// number of rectangles anyhow, but as we only use it for debugging purposes,
+// just keep it here for now.
+unsigned GetRectsCount(const wxRegion& rgn)
+{
+    unsigned count = 0;
+    for ( wxRegionIterator iter(rgn); iter.HaveRects(); ++iter )
+        count++;
+    return count;
+}
+
+} // anonymous namespace
+
+// this operator is needed to use CPPUNIT_ASSERT_EQUAL with wxRegions
+std::ostream& operator<<(std::ostream& os, const wxRegion& rgn)
+{
+    wxRect r = rgn.GetBox();
+    os << "# rects = " << GetRectsCount(rgn)
+       << "; bounding box {"
+       << r.x << ", " << r.y << ", " << r.width << ", " << r.height
+       << "}";
+    return os;
+}
+
+// ----------------------------------------------------------------------------
+// test class
+// ----------------------------------------------------------------------------
+
+class RegionTestCase : public CppUnit::TestCase
+{
+public:
+    RegionTestCase() { }
+
+private:
+    CPPUNIT_TEST_SUITE( RegionTestCase );
+        CPPUNIT_TEST( Validity );
+    CPPUNIT_TEST_SUITE_END();
+
+    void Validity();
+
+    wxDECLARE_NO_COPY_CLASS(RegionTestCase);
+};
+
+// register in the unnamed registry so that these tests are run by default
+CPPUNIT_TEST_SUITE_REGISTRATION( RegionTestCase );
+
+// also include in its own registry so that these tests can be run alone
+CPPUNIT_TEST_SUITE_NAMED_REGISTRATION( RegionTestCase, "RegionTestCase" );
+
+void RegionTestCase::Validity()
+{
+    wxRegion r;
+
+    CPPUNIT_ASSERT_MESSAGE
+    (
+        "Default constructed region must be invalid",
+        !r.IsOk()
+    );
+
+    CPPUNIT_ASSERT_MESSAGE
+    (
+        "Invalid region should be empty",
+        r.IsEmpty()
+    );
+
+    // Offsetting an invalid region doesn't make sense.
+    WX_ASSERT_FAILS_WITH_ASSERT( r.Offset(1, 1) );
+
+    CPPUNIT_ASSERT_MESSAGE
+    (
+        "Combining with a valid region should create a valid region",
+        r.Union(0, 0, 10, 10)
+    );
+
+    CPPUNIT_ASSERT_EQUAL_MESSAGE
+    (
+        "Union() with invalid region should give the same region",
+        wxRegion(0, 0, 10, 10),
+        r
+    );
+}