Add tests and fix a bug in UserFontFace

	* cairomm/fontface.cc: fixed a bug in UserFont where I was incorrectly using a
	function static variable and so it was not returning negative numbers for
	num_glyphs when I expected it to
	* tests/Makefile.am:
	* tests/test-font-face.cc:
	* tests/test-user-font.cc: Added tests for UserFontFace

6 files changed, 346 insertions, 251 deletions

diff --git a/.gitignore b/.gitignore
index f56f7a3..20c26ed 100644
--- a/.gitignore
+++ b/.gitignore
@@ -58,6 +58,7 @@ tests/test-surface
 tests/test-scaled-font
 tests/test-font-options
 tests/test-matrix
+tests/test-user-font
 
 cairomm/cairommconfig.h*
 cairomm/stamp-*
diff --git a/ChangeLog b/ChangeLog
index 3dc8b71..fddad41 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 2008-12-14  Jonathon Jongsma  <jonathon@quotidian.org>
 
+	* cairomm/fontface.cc: fixed a bug in UserFont where I was incorrectly using a
+	function static variable and so it was not returning negative numbers for
+	num_glyphs when I expected it to
+	* tests/Makefile.am:
+	* tests/test-font-face.cc:
+	* tests/test-user-font.cc: Added tests for UserFontFace
+
+2008-12-14  Jonathon Jongsma  <jonathon@quotidian.org>
+
 	* cairomm/scaledfont.cc: actually fix a reference-counting issue with
 	ScaledFont::get_font_face() that I thought I had fixed in b1d01ff7
 	* tests/test-scaled-font.cc: add a test for the get_font_face() bug
diff --git a/cairomm/fontface.cc b/cairomm/fontface.cc
index 2d305bf..0ffa5c3 100644
--- a/cairomm/fontface.cc
+++ b/cairomm/fontface.cc
@@ -309,11 +309,7 @@ UserFontFace::text_to_glyphs(const RefPtr<ScaledFont>& /*scaled_font*/,
   // bool value in the user_data, which we can read back in the
   // text_to_glyphs_cb and used as a signal to return -1 for the num_glyphs
   // parameter.
-  static bool first_time = true;
-  if (first_time) {
-    cairo_font_face_set_user_data(cobj(), &USER_DATA_KEY_DEFAULT_TEXT_TO_GLYPHS, reinterpret_cast<void*>(true), NULL);
-    first_time = false;
-  }
+  cairo_font_face_set_user_data(cobj(), &USER_DATA_KEY_DEFAULT_TEXT_TO_GLYPHS, reinterpret_cast<void*>(true), NULL);
   return CAIRO_STATUS_SUCCESS;
 }
 
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 250d60c..c18d975 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -1,10 +1,11 @@
 if AUTOTESTS
 
 # build automated 'tests'
-TESTS=test-context test-font-face test-surface test-scaled-font test-font-options test-matrix
+TESTS=test-context test-font-face test-surface test-scaled-font test-font-options test-matrix test-user-font
 noinst_PROGRAMS = $(TESTS)
 test_context_SOURCES=test-context.cc
 test_font_face_SOURCES=test-font-face.cc
+test_user_font_SOURCES=test-user-font.cc
 test_surface_SOURCES=test-surface.cc
 test_scaled_font_SOURCES=test-scaled-font.cc
 test_font_options_SOURCES=test-font-options.cc
diff --git a/tests/test-font-face.cc b/tests/test-font-face.cc
index 85ccccf..466f408 100644
--- a/tests/test-font-face.cc
+++ b/tests/test-font-face.cc
@@ -46,243 +46,6 @@ void test_toy_getters ()
   BOOST_CHECK_EQUAL (Cairo::FONT_TYPE_TOY, toy->get_type());
 }
 
-#if 0
-void test_user_font_create()
-{
-  Cairo::RefPtr<Cairo::UserFontFace> font = Cairo::UserFontFace::create();
-  BOOST_CHECK_EQUAL (Cairo::FONT_TYPE_USER, font->get_type());
-}
-
-// create some dummy callbacks
-static unsigned int init_call_count = 0;
-Cairo::ErrorStatus my_init(const Cairo::RefPtr<Cairo::ScaledFont>&, const Cairo::RefPtr<Cairo::Context>&, Cairo::FontExtents&)
-{
-  init_call_count++;
-  return CAIRO_STATUS_SUCCESS;
-}
-
-static unsigned int unicode_to_glyph_call_count = 0;
-Cairo::ErrorStatus my_unicode_to_glyph(const Cairo::RefPtr<Cairo::ScaledFont>&, unsigned long, unsigned long&)
-{
-  unicode_to_glyph_call_count++;
-  return CAIRO_STATUS_SUCCESS;
-}
-
-static unsigned int render_glyph_call_count = 0;
-Cairo::ErrorStatus my_render_glyph(const Cairo::RefPtr<Cairo::ScaledFont>&, unsigned long, const Cairo::RefPtr<Cairo::Context>&, Cairo::TextExtents&)
-{
-  render_glyph_call_count++;
-  return CAIRO_STATUS_SUCCESS;
-}
-
-static unsigned int text_to_glyphs_call_count = 0;
-Cairo::ErrorStatus my_text_to_glyphs(const Cairo::RefPtr<Cairo::ScaledFont>&, const std::string& utf8, std::vector<Cairo::Glyph>& glyphs, std::vector<Cairo::TextCluster>& /*clusters*/, Cairo::TextClusterFlags& /*cluster_flags*/)
-{
-  text_to_glyphs_call_count++;
-  if (glyphs.size())
-    glyphs.clear();
-  // just fill in some bogus glyph indexes
-  std::string::const_iterator str_iter = utf8.begin();
-  for (; str_iter != utf8.end(); ++str_iter)
-  {
-    Cairo::Glyph g;
-    g.index = (unsigned long) *str_iter;
-    glyphs.push_back(g);
-  }
-  return CAIRO_STATUS_SUCCESS;
-}
-
-void test_user_font_callbacks_ptr()
-{
-  render_glyph_call_count = 0;
-  unicode_to_glyph_call_count = 0;
-  init_call_count = 0;
-  Cairo::RefPtr<Cairo::UserFontFace> font = Cairo::UserFontFace::create();
-  BOOST_CHECK(font);
-  font->set_init_func(sigc::ptr_fun(my_init));
-  font->set_unicode_to_glyph_func(sigc::ptr_fun(my_unicode_to_glyph));
-  font->set_render_glyph_func(sigc::ptr_fun(my_render_glyph));
-  Cairo::RefPtr<Cairo::ScaledFont> scaled_font =
-    Cairo::ScaledFont::create(font, Cairo::scaled_matrix(10, 10), Cairo::identity_matrix(),
-                              Cairo::FontOptions());
-  BOOST_CHECK (init_call_count > 0);
-  Cairo::RefPtr<Cairo::ImageSurface> surface =
-    Cairo::ImageSurface::create(Cairo::FORMAT_ARGB32, 100, 100);
-  Cairo::RefPtr<Cairo::Context> cr = Cairo::Context::create(surface);
-  cr->set_font_face(font);
-  cr->show_text("Hello, world");
-  BOOST_CHECK (unicode_to_glyph_call_count > 0);
-  BOOST_CHECK (render_glyph_call_count > 0);
-}
-
-// since unicode_to_glyph_func and text_to_glyphs_func are mutually exclusive,
-// we must test them separately.  This test tests the text_to_glyphs_func
-void test_user_font_callbacks_ptr_text()
-{
-  render_glyph_call_count = 0;
-  text_to_glyphs_call_count = 0;
-  init_call_count = 0;
-  Cairo::RefPtr<Cairo::UserFontFace> font = Cairo::UserFontFace::create();
-  BOOST_CHECK(font);
-  font->set_init_func(sigc::ptr_fun(my_init));
-  font->set_render_glyph_func(sigc::ptr_fun(my_render_glyph));
-  font->set_text_to_glyphs_func(sigc::ptr_fun(my_text_to_glyphs));
-  Cairo::RefPtr<Cairo::ScaledFont> scaled_font =
-    Cairo::ScaledFont::create(font, Cairo::scaled_matrix(10, 10), Cairo::identity_matrix(),
-                              Cairo::FontOptions());
-  BOOST_CHECK (init_call_count > 0);
-  Cairo::RefPtr<Cairo::ImageSurface> surface =
-    Cairo::ImageSurface::create(Cairo::FORMAT_ARGB32, 100, 100);
-  Cairo::RefPtr<Cairo::Context> cr = Cairo::Context::create(surface);
-  cr->set_font_face(font);
-  cr->show_text("Hello, world");
-  BOOST_CHECK (render_glyph_call_count > 0);
-  BOOST_CHECK (text_to_glyphs_call_count > 0);
-}
-
-struct UserFontCallbacks
-{
-Cairo::ErrorStatus init(const Cairo::RefPtr<Cairo::ScaledFont>&, const Cairo::RefPtr<Cairo::Context>&, Cairo::FontExtents&)
-{
-  init_call_count++;
-  return CAIRO_STATUS_SUCCESS;
-}
-
-Cairo::ErrorStatus unicode_to_glyph(const Cairo::RefPtr<Cairo::ScaledFont>&, unsigned long, unsigned long&)
-{
-  unicode_to_glyph_call_count++;
-  return CAIRO_STATUS_SUCCESS;
-}
-
-Cairo::ErrorStatus render_glyph(const Cairo::RefPtr<Cairo::ScaledFont>&, unsigned long, const Cairo::RefPtr<Cairo::Context>&, Cairo::TextExtents&)
-{
-  render_glyph_call_count++;
-  return CAIRO_STATUS_SUCCESS;
-}
-
-static unsigned int init_call_count;
-static unsigned int unicode_to_glyph_call_count;
-static unsigned int render_glyph_call_count;
-};
-
-unsigned int UserFontCallbacks::init_call_count = 0;
-unsigned int UserFontCallbacks::unicode_to_glyph_call_count = 0;
-unsigned int UserFontCallbacks::render_glyph_call_count = 0;
-
-void test_user_font_callbacks_mem()
-{
-  Cairo::RefPtr<Cairo::UserFontFace> font = Cairo::UserFontFace::create();
-  BOOST_CHECK(font);
-  UserFontCallbacks callbacks;
-  font->set_init_func(sigc::mem_fun(&callbacks, &UserFontCallbacks::init));
-  font->set_unicode_to_glyph_func(sigc::mem_fun(&callbacks,
-                                                &UserFontCallbacks::unicode_to_glyph));
-  font->set_render_glyph_func(sigc::mem_fun(&callbacks,
-                                            &UserFontCallbacks::render_glyph));
-  Cairo::RefPtr<Cairo::ScaledFont> scaled_font =
-    Cairo::ScaledFont::create(font, Cairo::scaled_matrix(10, 10), Cairo::identity_matrix(),
-                              Cairo::FontOptions());
-  BOOST_CHECK (UserFontCallbacks::init_call_count > 0);
-  Cairo::RefPtr<Cairo::ImageSurface> surface =
-    Cairo::ImageSurface::create(Cairo::FORMAT_ARGB32, 100, 100);
-  Cairo::RefPtr<Cairo::Context> cr = Cairo::Context::create(surface);
-  cr->set_font_face(font);
-  cr->show_text("Hello, world");
-  BOOST_CHECK (UserFontCallbacks::unicode_to_glyph_call_count > 0);
-  BOOST_CHECK (UserFontCallbacks::render_glyph_call_count > 0);
-}
-
-static unsigned int init_exception_call_count = 0;
-Cairo::ErrorStatus my_init_exception(const Cairo::RefPtr<Cairo::ScaledFont>&, const Cairo::RefPtr<Cairo::Context>&, Cairo::FontExtents&)
-{
-  init_exception_call_count++;
-  throw std::logic_error("init exception");
-}
-
-static unsigned int unicode_to_glyph_exception_call_count = 0;
-Cairo::ErrorStatus my_unicode_to_glyph_exception(const Cairo::RefPtr<Cairo::ScaledFont>&, unsigned long, unsigned long&)
-{
-  unicode_to_glyph_exception_call_count++;
-  throw std::logic_error("unicode-to-glyph exception");
-}
-
-static unsigned int render_glyph_exception_call_count = 0;
-Cairo::ErrorStatus my_render_glyph_exception(const Cairo::RefPtr<Cairo::ScaledFont>&, unsigned long, const Cairo::RefPtr<Cairo::Context>&, Cairo::TextExtents&)
-{
-  render_glyph_exception_call_count++;
-  throw std::logic_error("render-glyph exception");
-}
-
-
-void test_user_font_callbacks_exception()
-{
-  Cairo::RefPtr<Cairo::UserFontFace> font = Cairo::UserFontFace::create();
-  BOOST_CHECK(font);
-  font->set_init_func(sigc::ptr_fun(my_init_exception));
-
-  // the init() callback will throw an exception, if this isn't handled in the
-  // callback wrapper, the program will abort since an exception can't unwind
-  // through C code.  However, due to the exception being thrown, the create()
-  // function will fail and throw a new exception.  So if the executable doesn't
-  // abort, we should get an exception here.
-  Cairo::RefPtr<Cairo::ScaledFont> scaled_font;
-  BOOST_CHECK_THROW (scaled_font = Cairo::ScaledFont::create(font,
-                                                             Cairo::scaled_matrix(10, 10),
-                                                             Cairo::identity_matrix(),
-                                                             Cairo::FontOptions()),
-                     Cairo::logic_error);
-  BOOST_CHECK (init_exception_call_count > 0);
-
-  // now initialize a scaled font properly so we can test the other callbacks
-  font = Cairo::UserFontFace::create();
-  font->set_init_func(sigc::ptr_fun(my_init));
-  font->set_render_glyph_func(sigc::ptr_fun(my_render_glyph_exception));
-  font->set_unicode_to_glyph_func(sigc::ptr_fun(my_unicode_to_glyph_exception));
-  BOOST_CHECK_NO_THROW (scaled_font = Cairo::ScaledFont::create(font,
-                                                                Cairo::scaled_matrix(10, 10),
-                                                                Cairo::identity_matrix(),
-                                                                Cairo::FontOptions()))
-  Cairo::RefPtr<Cairo::ImageSurface> surface =
-    Cairo::ImageSurface::create(Cairo::FORMAT_ARGB32, 100, 100);
-  Cairo::RefPtr<Cairo::Context> cr = Cairo::Context::create(surface);
-  cr->set_font_face(font);
-  // this call should throw an exception since the callback wrapper will return
-  // an error status (that will be translated into an exception) but the test
-  // shouldn't abort sindce the callback exceptions are handled by the callback
-  // wrapper
-  BOOST_REQUIRE_EQUAL (CAIRO_STATUS_SUCCESS, font->get_status());
-  BOOST_CHECK_THROW(cr->show_text("Hello, world"), Cairo::logic_error);
-  BOOST_CHECK (UserFontCallbacks::unicode_to_glyph_call_count > 0);
-  BOOST_CHECK (UserFontCallbacks::render_glyph_call_count > 0);
-}
-
-// create some dummy callbacks
-static unsigned int init2_call_count = 0;
-Cairo::ErrorStatus my_init2(const Cairo::RefPtr<Cairo::ScaledFont>&, const Cairo::RefPtr<Cairo::Context>&, Cairo::FontExtents&)
-{
-  init2_call_count++;
-  return CAIRO_STATUS_SUCCESS;
-}
-
-void test_user_font_replace_callback()
-{
-  // reset
-  init_call_count = 0;
-  Cairo::RefPtr<Cairo::UserFontFace> font = Cairo::UserFontFace::create();
-  font->set_init_func(sigc::ptr_fun(my_init));
-  // now replace the init function with my_init2 and make sure that the 2nd
-  // function is called, not the first
-  font->set_init_func(sigc::ptr_fun(my_init2));
-  Cairo::RefPtr<Cairo::ScaledFont> scaled_font;
-  BOOST_CHECK_NO_THROW (scaled_font = Cairo::ScaledFont::create(font,
-                                                                Cairo::scaled_matrix(10, 10),
-                                                                Cairo::identity_matrix(),
-                                                                Cairo::FontOptions()))
-  BOOST_CHECK (init2_call_count > 0);
-  BOOST_CHECK_EQUAL (init_call_count, 0);
-}
-#endif // UserFont disabled
-
 #ifdef CAIRO_HAS_FT_FONT
 void test_ft_font_face()
 {
@@ -346,14 +109,6 @@ init_unit_test_suite(int argc, char* argv[])
 
   test->add (BOOST_TEST_CASE (&test_create_toy));
   test->add (BOOST_TEST_CASE (&test_toy_getters));
-  /*
-  test->add (BOOST_TEST_CASE (&test_user_font_create));
-  test->add (BOOST_TEST_CASE (&test_user_font_callbacks_ptr));
-  test->add (BOOST_TEST_CASE (&test_user_font_callbacks_ptr_text));
-  test->add (BOOST_TEST_CASE (&test_user_font_callbacks_mem));
-  test->add (BOOST_TEST_CASE (&test_user_font_callbacks_exception));
-  test->add (BOOST_TEST_CASE (&test_user_font_replace_callback));
-  */
 #ifdef CAIRO_HAS_FT_FONT
   test->add (BOOST_TEST_CASE (&test_ft_font_face));
 #endif // CAIRO_HAS_FT_FONT
diff --git a/tests/test-user-font.cc b/tests/test-user-font.cc
new file mode 100644
index 0000000..a7d9647
--- /dev/null
+++ b/tests/test-user-font.cc
@@ -0,0 +1,333 @@
+// vim: ts=2 sw=2 et
+/*
+ * These tests are of limited usefulness.  In fact, you might even say that
+ * they're not really tests at all.  But I felt that it would be useful to have
+ * some basic usage of most functions just to verify that things compile and
+ * work generally
+ */
+
+#include <cfloat>
+#include <stdexcept>
+#include <boost/test/unit_test.hpp>
+#include <boost/test/test_tools.hpp>
+#include <boost/test/floating_point_comparison.hpp>
+using namespace boost::unit_test;
+#include <cairomm/fontface.h>
+#include <cairomm/scaledfont.h>
+#include <cairomm/surface.h>
+#include <cairomm/context.h>
+
+using namespace Cairo;
+
+// little utility helper classes
+struct TestSetup
+{
+  TestSetup()
+  {
+    surface = ImageSurface::create(Cairo::FORMAT_ARGB32, 100, 100);
+    cr = Cairo::Context::create(surface);
+  }
+
+  RefPtr<Context> cr;
+  RefPtr<Surface> surface;
+};
+
+// a no-op-render user font base class
+class NullRenderUserFont : public UserFontFace
+{
+public:
+  ErrorStatus
+    render_glyph(const RefPtr<ScaledFont>& /*scaled_font*/,
+                 unsigned long /*glyph*/,
+                 const RefPtr<Context>& /*cr*/,
+                 TextExtents& /*metrics*/)
+    { ++count_render_glyph; return CAIRO_STATUS_SUCCESS; }
+
+  int count_render_glyph;
+
+protected:
+  NullRenderUserFont() : UserFontFace(), count_render_glyph(0) {}
+};
+
+/******************************
+ * test_implement_text
+ ******************************/
+class ImplTextUserFont: public NullRenderUserFont
+{
+public:
+  static RefPtr<ImplTextUserFont> create() { return RefPtr<ImplTextUserFont>(new ImplTextUserFont());};
+  virtual ErrorStatus text_to_glyphs(const RefPtr<ScaledFont>& /*scaled_font*/,
+                                     const std::string& /*utf8*/,
+                                     std::vector<Glyph>& glyphs,
+                                     std::vector<TextCluster>& /*clusters*/,
+                                     TextClusterFlags& /*cluster_flags*/)
+  {
+    ++count_text_to_glyphs;
+    // return an arbitrary glyph
+    Glyph g = {84, 0, 0};
+    glyphs.push_back(g);
+    return CAIRO_STATUS_SUCCESS;
+  }
+  int count_text_to_glyphs;
+
+protected:
+  ImplTextUserFont() : count_text_to_glyphs(0) {}
+};
+
+void test_implement_text()
+{
+  TestSetup setup;
+  RefPtr<ImplTextUserFont> font = ImplTextUserFont::create();
+  setup.cr->set_font_face(font);
+  setup.cr->show_text("hello");
+  BOOST_REQUIRE(font->count_text_to_glyphs > 0);
+  BOOST_REQUIRE(font->count_render_glyph > 0);
+}
+
+/******************************
+ * test_implement_unicode
+ ******************************/
+class ImplUnicodeUserFont: public NullRenderUserFont
+{
+public:
+  static RefPtr<ImplUnicodeUserFont> create() { return RefPtr<ImplUnicodeUserFont>(new ImplUnicodeUserFont());};
+  virtual ErrorStatus unicode_to_glyph(const RefPtr<ScaledFont>& /*scaled_font*/,
+                                       unsigned long /*unicode*/,
+                                       unsigned long& /*glyph*/)
+  { ++count_unicode_to_glyph;  return CAIRO_STATUS_SUCCESS;}
+  int count_unicode_to_glyph;
+
+protected:
+  ImplUnicodeUserFont() : NullRenderUserFont(), count_unicode_to_glyph(0) {}
+};
+
+void test_implement_unicode()
+{
+  TestSetup setup;
+  RefPtr<ImplTextUserFont> font = ImplTextUserFont::create();
+  setup.cr->set_font_face(font);
+  setup.cr->show_text("hello");
+  BOOST_REQUIRE(font->count_text_to_glyphs > 0);
+  BOOST_REQUIRE(font->count_render_glyph > 0);
+}
+
+/******************************
+ * test_implement_both
+ ******************************/
+class ImplBothUserFont: public NullRenderUserFont
+{
+public:
+  static RefPtr<ImplBothUserFont> create() { return RefPtr<ImplBothUserFont>(new ImplBothUserFont());};
+  virtual ErrorStatus unicode_to_glyph(const RefPtr<ScaledFont>& /*scaled_font*/,
+                                       unsigned long /*unicode*/,
+                                       unsigned long& /*glyph*/)
+  { ++count_unicode_to_glyph;  return CAIRO_STATUS_SUCCESS;}
+  int count_unicode_to_glyph;
+
+  virtual ErrorStatus text_to_glyphs(const RefPtr<ScaledFont>& /*scaled_font*/,
+                                     const std::string& /*utf8*/,
+                                     std::vector<Glyph>& glyphs,
+                                     std::vector<TextCluster>& /*clusters*/,
+                                     TextClusterFlags& /*cluster_flags*/)
+  {
+    ++count_text_to_glyphs;
+    // return an arbitrary glyph
+    Glyph g = {84, 0, 0};
+    glyphs.push_back(g);
+    return CAIRO_STATUS_SUCCESS;
+  }
+  int count_text_to_glyphs;
+
+protected:
+  ImplBothUserFont() : NullRenderUserFont(), count_unicode_to_glyph(0),
+  count_text_to_glyphs(0) {}
+};
+
+void test_implement_both()
+{
+  TestSetup setup;
+  RefPtr<ImplBothUserFont> font = ImplBothUserFont::create();
+  setup.cr->set_font_face(font);
+  setup.cr->show_text("hello");
+  // text_to_glyphs should take precedence
+  BOOST_REQUIRE(font->count_text_to_glyphs > 0);
+  BOOST_REQUIRE(font->count_unicode_to_glyph == 0);
+  BOOST_REQUIRE(font->count_render_glyph > 0);
+}
+
+/******************************
+ * test_implement_neither
+ ******************************/
+class ImplNeitherUserFont: public NullRenderUserFont
+{
+public:
+  static RefPtr<ImplNeitherUserFont> create() { return RefPtr<ImplNeitherUserFont>(new ImplNeitherUserFont());};
+
+protected:
+  ImplNeitherUserFont() : NullRenderUserFont() {}
+};
+
+void test_implement_neither()
+{
+  TestSetup setup;
+  RefPtr<ImplNeitherUserFont> font = ImplNeitherUserFont::create();
+  setup.cr->set_font_face(font);
+  setup.cr->show_text("hello");
+  BOOST_REQUIRE(font->count_render_glyph > 0);
+}
+
+/******************************
+ * test_implement_init
+ ******************************/
+class ImplInitUserFont: public NullRenderUserFont
+{
+public:
+  static RefPtr<ImplInitUserFont> create() { return RefPtr<ImplInitUserFont>(new ImplInitUserFont());};
+  ErrorStatus init(const RefPtr<ScaledFont>& /*scaled_font*/,
+                           const RefPtr<Context>& /*cr*/,
+                           FontExtents& /*extents*/)
+  {++count_init; return CAIRO_STATUS_SUCCESS;}
+
+  int count_init;
+
+protected:
+  ImplInitUserFont() : NullRenderUserFont(), count_init(0) {}
+};
+
+void test_implement_init()
+{
+  TestSetup setup;
+  RefPtr<ImplInitUserFont> font = ImplInitUserFont::create();
+  setup.cr->set_font_face(font);
+  setup.cr->show_text("hello");
+  BOOST_REQUIRE(font->count_init > 0);
+  BOOST_REQUIRE(font->count_render_glyph > 0);
+}
+
+class ExceptionUserFont : public UserFontFace
+{
+public:
+  static RefPtr<ExceptionUserFont> create(int flags) { return RefPtr<ExceptionUserFont>(new ExceptionUserFont(flags));};
+
+  ErrorStatus
+  render_glyph(const RefPtr<ScaledFont>& /*scaled_font*/,
+               unsigned long /*glyph*/,
+               const RefPtr<Context>& /*cr*/,
+               TextExtents& /*metrics*/)
+  {
+    count_render_glyph++;
+    if (m_flags & FLAG_RENDER)
+      throw std::logic_error("render-glyph exception");
+    return CAIRO_STATUS_SUCCESS;
+  }
+
+  ErrorStatus
+  unicode_to_glyph(const RefPtr<ScaledFont>& /*scaled_font*/,
+                                       unsigned long unicode,
+                                       unsigned long& glyph)
+  {
+    count_unicode_to_glyph++;
+    if (m_flags & FLAG_UNICODE)
+      throw std::logic_error("unicode-to-glyph exception");
+
+    glyph = unicode;
+    return CAIRO_STATUS_SUCCESS;
+  }
+
+  ErrorStatus
+  init(const RefPtr<ScaledFont>& /*scaled_font*/,
+                         const RefPtr<Context>& /*cr*/,
+                         FontExtents& /*extents*/)
+  {
+    count_init++;
+    if (m_flags & FLAG_INIT)
+      throw std::logic_error("init exception");
+    return CAIRO_STATUS_SUCCESS;
+  }
+
+  int count_render_glyph;
+  int count_text_to_glyphs;
+  int count_unicode_to_glyph;
+  int count_init;
+  int m_flags;
+
+  static const int FLAG_INIT = 1 << 0;
+  static const int FLAG_UNICODE = 1 << 1;
+  static const int FLAG_RENDER = 1 << 2;
+
+protected:
+  ExceptionUserFont(int flags) : UserFontFace(), count_render_glyph(0),
+  count_text_to_glyphs(0), count_unicode_to_glyph(0), count_init(0),
+  m_flags(flags) {}
+};
+
+void test_user_font_exception()
+{
+  Cairo::RefPtr<ExceptionUserFont> font =
+    ExceptionUserFont::create(ExceptionUserFont::FLAG_INIT);
+  BOOST_CHECK(font);
+
+  // the init() callback will throw an exception, if this isn't handled in the
+  // callback wrapper, the program will abort since an exception can't unwind
+  // through C code.  However, due to the exception being thrown, the create()
+  // function will fail and throw a new exception.  So if the executable doesn't
+  // abort, we should get an exception here.
+  Cairo::RefPtr<Cairo::ScaledFont> scaled_font;
+  BOOST_CHECK_THROW (scaled_font = Cairo::ScaledFont::create(font,
+                                                             Cairo::scaled_matrix(10, 10),
+                                                             Cairo::identity_matrix(),
+                                                             Cairo::FontOptions()),
+                     Cairo::logic_error);
+  BOOST_CHECK (font->count_init > 0);
+
+  // now test when an exception is thrown in unicode_to_glyph
+  font = ExceptionUserFont::create(ExceptionUserFont::FLAG_UNICODE);
+  BOOST_CHECK_NO_THROW (scaled_font = Cairo::ScaledFont::create(font,
+                                                                Cairo::scaled_matrix(10, 10),
+                                                                Cairo::identity_matrix(),
+                                                                Cairo::FontOptions()));
+  TestSetup setup;
+  setup.cr->set_font_face(font);
+  // this call should throw an exception since the callback wrapper will return
+  // an error status (that will be translated into an exception) but the test
+  // shouldn't abort since the callback exceptions are handled by the callback
+  // wrapper
+  BOOST_REQUIRE_EQUAL (CAIRO_STATUS_SUCCESS, font->get_status());
+  BOOST_CHECK_THROW(setup.cr->show_text("Hello, world"), Cairo::logic_error);
+  BOOST_CHECK(font->count_unicode_to_glyph > 0);
+  BOOST_CHECK_EQUAL(font->count_render_glyph, 0);
+
+  // now test when an exception is thrown in render_glyph
+  font = ExceptionUserFont::create(ExceptionUserFont::FLAG_RENDER);
+  BOOST_CHECK_NO_THROW (scaled_font = Cairo::ScaledFont::create(font,
+                                                                Cairo::scaled_matrix(10, 10),
+                                                                Cairo::identity_matrix(),
+                                                                Cairo::FontOptions()));
+  // need a new setup since the old cr is now in an error state, so attemtping
+  // to use it will throw an exception
+  TestSetup setup2;
+  BOOST_CHECK_NO_THROW(setup2.cr->set_font_face(font));
+  BOOST_REQUIRE_EQUAL (CAIRO_STATUS_SUCCESS, font->get_status());
+  BOOST_CHECK_THROW(setup2.cr->show_text("Hello, world"), Cairo::logic_error);
+  BOOST_CHECK (font->count_unicode_to_glyph > 0);
+  BOOST_CHECK (font->count_render_glyph > 0);
+}
+
+
+test_suite*
+init_unit_test_suite(int argc, char* argv[])
+{
+  // compile even with -Werror
+  if (argc && argv) {}
+
+  test_suite* test= BOOST_TEST_SUITE( "Cairo::UserFontFace Tests" );
+
+  test->add (BOOST_TEST_CASE (&test_implement_text));
+  test->add (BOOST_TEST_CASE (&test_implement_unicode));
+  test->add (BOOST_TEST_CASE (&test_implement_both));
+  test->add (BOOST_TEST_CASE (&test_implement_neither));
+  test->add (BOOST_TEST_CASE (&test_implement_init));
+  test->add (BOOST_TEST_CASE (&test_user_font_exception));
+
+  return test;
+}