linux: Force full hinting when antialiasing is disabled.

ui/gfx/font_render_params_linux_unittest.cc

Index: ui/gfx/font_render_params_linux_unittest.cc
diff --git a/ui/gfx/font_render_params_linux_unittest.cc b/ui/gfx/font_render_params_linux_unittest.cc
index a7924833234db3646a4808c978e956041878191d..af1e0821b8f1012be9724e8f90756cd08cb3d712 100644
--- a/ui/gfx/font_render_params_linux_unittest.cc
+++ b/ui/gfx/font_render_params_linux_unittest.cc
@@ -158,22 +158,23 @@ TEST_F(FontRenderParamsTest, Size) {
 
 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));
 
@@ -181,22 +182,30 @@ TEST_F(FontRenderParamsTest, Style) {
   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) {
@@ -242,6 +251,30 @@ TEST_F(FontRenderParamsTest, UseBitmaps) {
   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.