linux: Force full hinting when antialiasing is disabled.

ui/gfx/font_render_params_linux_unittest.cc

 // Copyright 2014 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/font_render_params.h"
 
 #include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/logging.h"
 #include "base/macros.h"
@@ skipping 140 matching lines @@
   query.point_size = 20;
   params = GetFontRenderParams(query, NULL);
   EXPECT_TRUE(params.antialiasing);
   EXPECT_EQ(FontRenderParams::HINTING_SLIGHT, params.hinting);
   EXPECT_EQ(FontRenderParams::SUBPIXEL_RENDERING_RGB,
             params.subpixel_rendering);
 }
 
 TEST_F(FontRenderParamsTest, Style) {
   ASSERT_TRUE(LoadSystemFont("arial.ttf"));
-  // Load a config that disables antialiasing for bold text and disables
-  // hinting for italic text.
+  // Load a config that disables hinting for bold text and disables subpixel
+  // rendering for italic text.
   ASSERT_TRUE(LoadConfigDataIntoFontconfig(temp_dir_.path(),
       std::string(kFontconfigFileHeader) +
       kFontconfigMatchHeader +
       CreateFontconfigEditStanza("antialias", "bool", "true") +

[msw, 2014/07/24 22:25:43]

nit: remove the antialias setting and checks below, now that this property is
irrelevant to the test.

[Daniel Erat, 2014/07/24 22:52:01]

i'll remove the checks, but i believe that setting this is actually needed since
it doesn't default to true in fontconfig (unlike most other boolean properties).

[msw, 2014/07/24 22:58:25]

Acknowledged.

       CreateFontconfigEditStanza("hinting", "bool", "true") +
-      CreateFontconfigEditStanza("hintstyle", "const", "hintfull") +
+      CreateFontconfigEditStanza("hintstyle", "const", "hintslight") +
+      CreateFontconfigEditStanza("rgba", "const", "rgb") +
       kFontconfigMatchFooter +
       kFontconfigMatchHeader +
       CreateFontconfigTestStanza("weight", "eq", "const", "bold") +
-      CreateFontconfigEditStanza("antialias", "bool", "false") +
+      CreateFontconfigEditStanza("hinting", "bool", "false") +

[msw, 2014/07/24 22:25:43]

optional nit: continue disabling hinting for italic, as before, and disable
subpixel for bold to reduce the volume of changes here.

[Daniel Erat, 2014/07/24 22:52:01]

Done.

       kFontconfigMatchFooter +
       kFontconfigMatchHeader +
       CreateFontconfigTestStanza("slant", "eq", "const", "italic") +
-      CreateFontconfigEditStanza("hinting", "bool", "false") +
+      CreateFontconfigEditStanza("rgba", "const", "none") +
       kFontconfigMatchFooter +
       kFontconfigFileFooter));
 
   FontRenderParamsQuery query(false);
   query.style = Font::NORMAL;
   FontRenderParams params = GetFontRenderParams(query, NULL);
   EXPECT_TRUE(params.antialiasing);
-  EXPECT_EQ(FontRenderParams::HINTING_FULL, params.hinting);
+  EXPECT_EQ(FontRenderParams::HINTING_SLIGHT, params.hinting);
+  EXPECT_EQ(FontRenderParams::SUBPIXEL_RENDERING_RGB,
+            params.subpixel_rendering);
 
   query.style = Font::BOLD;
   params = GetFontRenderParams(query, NULL);
-  EXPECT_FALSE(params.antialiasing);
-  EXPECT_EQ(FontRenderParams::HINTING_FULL, params.hinting);
+  EXPECT_TRUE(params.antialiasing);
+  EXPECT_EQ(FontRenderParams::HINTING_NONE, params.hinting);
+  EXPECT_EQ(FontRenderParams::SUBPIXEL_RENDERING_RGB,
+            params.subpixel_rendering);
 
   query.style = Font::ITALIC;
   params = GetFontRenderParams(query, NULL);
   EXPECT_TRUE(params.antialiasing);
-  EXPECT_EQ(FontRenderParams::HINTING_NONE, params.hinting);
+  EXPECT_EQ(FontRenderParams::HINTING_SLIGHT, params.hinting);
+  EXPECT_EQ(FontRenderParams::SUBPIXEL_RENDERING_NONE,
+            params.subpixel_rendering);
 
   query.style = Font::BOLD | Font::ITALIC;
   params = GetFontRenderParams(query, NULL);
-  EXPECT_FALSE(params.antialiasing);
+  EXPECT_TRUE(params.antialiasing);
   EXPECT_EQ(FontRenderParams::HINTING_NONE, params.hinting);
+  EXPECT_EQ(FontRenderParams::SUBPIXEL_RENDERING_NONE,
+            params.subpixel_rendering);
 }
 
 TEST_F(FontRenderParamsTest, Scalable) {
   ASSERT_TRUE(LoadSystemFont("arial.ttf"));
   // Load a config that only enables antialiasing for scalable fonts.
   ASSERT_TRUE(LoadConfigDataIntoFontconfig(temp_dir_.path(),
       std::string(kFontconfigFileHeader) +
       kFontconfigMatchHeader +
       CreateFontconfigEditStanza("antialias", "bool", "false") +
       kFontconfigMatchFooter +
@@ skipping 25 matching lines @@
 
   FontRenderParamsQuery query(false);
   FontRenderParams params = GetFontRenderParams(query, NULL);
   EXPECT_FALSE(params.use_bitmaps);
 
   query.pixel_size = 5;
   params = GetFontRenderParams(query, NULL);
   EXPECT_TRUE(params.use_bitmaps);
 }
 
+TEST_F(FontRenderParamsTest, ForceFullHintingWhenAntialiasingIsDisabled) {
+  // Load a config that disables antialiasing and hinting while requesting
+  // subpixel rendering.
+  ASSERT_TRUE(LoadSystemFont("arial.ttf"));
+  ASSERT_TRUE(LoadConfigDataIntoFontconfig(temp_dir_.path(),
+      std::string(kFontconfigFileHeader) +
+      kFontconfigMatchHeader +
+      CreateFontconfigEditStanza("antialias", "bool", "false") +
+      CreateFontconfigEditStanza("hinting", "bool", "false") +
+      CreateFontconfigEditStanza("hintstyle", "const", "hintnone") +
+      CreateFontconfigEditStanza("rgba", "const", "rgb") +
+      kFontconfigMatchFooter +
+      kFontconfigFileFooter));
+
+  // Full hinting should be forced.

[msw, 2014/07/24 22:25:44]

optional nit: add "See the comment in GetFontRenderParams for more information."

[Daniel Erat, 2014/07/24 22:52:00]

Done.

+  FontRenderParams params = GetFontRenderParams(
+      FontRenderParamsQuery(false), NULL);
+  EXPECT_FALSE(params.antialiasing);
+  EXPECT_EQ(FontRenderParams::HINTING_FULL, params.hinting);
+  EXPECT_EQ(FontRenderParams::SUBPIXEL_RENDERING_NONE,
+            params.subpixel_rendering);
+  EXPECT_FALSE(params.subpixel_positioning);
+}
+
 TEST_F(FontRenderParamsTest, OnlySetConfiguredValues) {
   // Configure the LinuxFontDelegate (which queries GtkSettings on desktop
   // Linux) to request subpixel rendering.
   FontRenderParams system_params;
   system_params.subpixel_rendering = FontRenderParams::SUBPIXEL_RENDERING_RGB;
   test_font_delegate_.set_params(system_params);
 
   // Load a Fontconfig config that enables antialiasing but doesn't say anything
   // about subpixel rendering.
   ASSERT_TRUE(LoadSystemFont("arial.ttf"));
@@ skipping 26 matching lines @@
   FontRenderParams params = GetFontRenderParams(query, &suggested_family);
 
   // The system params and the first requested family should be returned.
   EXPECT_EQ(system_params.antialiasing, params.antialiasing);
   EXPECT_EQ(system_params.hinting, params.hinting);
   EXPECT_EQ(system_params.subpixel_rendering, params.subpixel_rendering);
   EXPECT_EQ(query.families[0], suggested_family);
 }
 
 }  // namespace gfx