PlatformFontWin::DeriveFontWithHeight insensitive to base font's height

ui/gfx/platform_font_win_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gfx/platform_font_win.h"
 
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/gfx/font.h"
@@ skipping 49 matching lines @@
     EXPECT_EQ(Font::BOLD, derived_font.GetStyle());
 
     // Test that deriving from the new font has the expected result.
     Font rederived_font = derived_font.Derive(1, 0);
     expected_font = Font(derived_font.GetFontName(),
                          derived_font.GetFontSize() + 1);
     EXPECT_EQ(expected_font.GetFontName(), rederived_font.GetFontName());
     EXPECT_EQ(expected_font.GetFontSize(), rederived_font.GetFontSize());
     EXPECT_EQ(expected_font.GetHeight(), rederived_font.GetHeight());
   }
+
+  const Font bigger_font(base_font.GetFontName(), base_font.GetFontSize() + 10);

[Alexei Svitkine (slow), 2014/05/09 21:21:00]

Oops, I see you already added a test.

Can you make it a separate test case?

A good convention to use is to add a _ and suffix after the name of the method,
so it could be something like:

DeriveFontWithHeight_Consistency

[Tomasz Moniuszko, 2014/05/29 10:46:40]

Done.

+  PlatformFontWin* bigger_platform_font =
+      static_cast<PlatformFontWin*>(bigger_font.platform_font());
+
+  int requested_height = (base_font.GetHeight() + bigger_font.GetHeight()) / 2;

[Alexei Svitkine (slow), 2014/05/09 21:21:00]

Is it possible to do something more straight forward like your email example?
(i.e. with hardcoded heights), rather than this kind of more complicated
calculation?

[Tomasz Moniuszko, 2014/05/29 10:46:40]

Done.

+  ASSERT_GT(requested_height, base_font.GetHeight());
+  ASSERT_LT(requested_height, bigger_font.GetHeight());
+
+  Font derived_font_1 =
+      platform_font->DeriveFontWithHeight(requested_height, 0);
+  Font derived_font_2 =
+      bigger_platform_font->DeriveFontWithHeight(requested_height, 0);
+
+  // Derived fonts should be the same height for both higher and lower base
+  // fonts.
+  EXPECT_EQ(derived_font_1.GetHeight(), derived_font_2.GetHeight());
 }
 
 // Callback function used by DeriveFontWithHeight_MinSize() below.
 static int GetMinFontSize() {
   return 10;
 }
 
 TEST(PlatformFontWinTest, DeriveFontWithHeight_MinSize) {
   PlatformFontWin::GetMinimumFontSizeCallback old_callback =
     PlatformFontWin::get_minimum_font_size_callback;
@@ skipping 15 matching lines @@
 TEST(PlatformFontWinTest, DeriveFontWithHeight_TooSmall) {
   const Font base_font;
   PlatformFontWin* platform_font =
       static_cast<PlatformFontWin*>(base_font.platform_font());
 
   const Font derived_font = platform_font->DeriveFontWithHeight(1, 0);
   EXPECT_GT(derived_font.GetHeight(), 1);
 }
 
 }  // namespace gfx