linux: Add tests for FontRenderParams on Linux.

ui/gfx/test/fontconfig_util_linux.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/test/fontconfig_util_linux.h"
+
+#include <fontconfig/fontconfig.h>
+
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/strings/stringprintf.h"
+
+namespace gfx {
+
+const char* const kSystemFontsForFontconfig[] = {
+  "/usr/share/fonts/truetype/msttcorefonts/Arial.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Arial_Bold.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Arial_Bold_Italic.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Arial_Italic.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Comic_Sans_MS.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Comic_Sans_MS_Bold.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Courier_New.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Courier_New_Bold.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Courier_New_Bold_Italic.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Courier_New_Italic.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Georgia.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Georgia_Bold.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Georgia_Bold_Italic.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Georgia_Italic.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Impact.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Trebuchet_MS.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Trebuchet_MS_Bold.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Trebuchet_MS_Bold_Italic.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Trebuchet_MS_Italic.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Times_New_Roman.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Times_New_Roman_Bold.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Times_New_Roman_Bold_Italic.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Times_New_Roman_Italic.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Verdana.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Verdana_Bold.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Verdana_Bold_Italic.ttf",
+  "/usr/share/fonts/truetype/msttcorefonts/Verdana_Italic.ttf",
+  // The DejaVuSans font is used by the css2.1 tests.
+  "/usr/share/fonts/truetype/ttf-dejavu/DejaVuSans.ttf",
+  "/usr/share/fonts/truetype/ttf-indic-fonts-core/lohit_hi.ttf",
+  "/usr/share/fonts/truetype/ttf-indic-fonts-core/lohit_ta.ttf",
+  "/usr/share/fonts/truetype/ttf-indic-fonts-core/MuktiNarrow.ttf",
+  "/usr/share/fonts/truetype/kochi/kochi-gothic.ttf",

[msw, 2014/07/16 22:38:07]

nit: Why reorder these? They previously were alphabetical, right? Maybe replace
the use of kSystemFontsForFontconfig[0] in the new test file with a hardcoded
index 2 or a separate const value if this font doesn't work for the test there?
Or maybe this is fine out of order.

[Daniel Erat, 2014/07/16 23:10:18]

sure, changed the order back and added a new helper to
font_render_params_linux_unittest.cc that loads a font by base name. (i was
planning to add another test in a later change that matches by family, so i need
this anyway.)

+  "/usr/share/fonts/truetype/kochi/kochi-mincho.ttf",
+  NULL,

[msw, 2014/07/16 22:38:07]

Can users do arraysize(kSystemFontsForFontconfig) instead? Or maybe create a
separate const here, like chrome/common/url_constants.cc's "const size_t
kNumberOfChromeHostURLs = arraysize(kChromeHostURLs)";

[Daniel Erat, 2014/07/16 23:10:18]

i wasn't sure this would work with a const extern value, but it does, so i've
updated this.

+};
+
+const char kFontconfigFileHeader[] =
+    "<?xml version=\"1.0\"?>\n"
+    "<!DOCTYPE fontconfig SYSTEM \"fonts.dtd\">\n"
+    "<fontconfig>\n";
+const char kFontconfigFileFooter[] = "</fontconfig>";
+const char kFontconfigMatchHeader[] = "  <match>\n";
+const char kFontconfigMatchFooter[] = "  </match>\n";
+
+void SetUpFontconfig() {
+  FcInit();
+
+  // A primer on undocumented FcConfig reference-counting:
+  //
+  // - FcConfigCreate() creates a config with a refcount of 1.
+  // - FcConfigReference() increments a config's refcount.
+  // - FcConfigDestroy() decrements a config's refcount, deallocating the
+  //   config when the count reaches 0.
+  // - FcConfigSetCurrent() calls FcConfigDestroy() on the old config, but
+  //   interestingly does not call FcConfigReference() on the new config.
+  CHECK(FcConfigSetCurrent(FcConfigCreate()));
+}
+
+void TearDownFontconfig() {
+  FcFini();
+}
+
+bool LoadFontIntoFontconfig(const base::FilePath& path) {
+  if (!base::PathExists(path)) {
+    LOG(ERROR) << "You are missing " << path.value() << ". Try re-running "
+               << "build/install-build-deps.sh. Also see "
+               << "http://code.google.com/p/chromium/wiki/LayoutTestsLinux";
+    return false;
+  }
+
+  if (!FcConfigAppFontAddFile(
+          NULL, reinterpret_cast<const FcChar8*>(path.value().c_str()))) {
+    LOG(ERROR) << "Failed to load font " << path.value();
+    return false;
+  }
+
+  return true;
+}
+
+bool LoadConfigFileIntoFontconfig(const base::FilePath& path) {
+  // Unlike other FcConfig functions, FcConfigParseAndLoad() doesn't default to
+  // the current config when passed NULL. So that's cool.
+  if (!FcConfigParseAndLoad(FcConfigGetCurrent(),
+          reinterpret_cast<const FcChar8*>(path.value().c_str()), FcTrue)) {
+    LOG(ERROR) << "Fontconfig failed to load " << path.value();
+    return false;
+  }
+  return true;
+}
+
+bool LoadConfigDataIntoFontconfig(const base::FilePath& temp_dir,

[msw, 2014/07/16 22:38:07]

nit: consider encapsulating the TempDir creation here.

[Daniel Erat, 2014/07/16 23:10:18]

i believe that fontconfig watches config files for changes, and i wasn't sure
about what would happen if i deleted the temp dir immediately after loading the
config. see e.g. "The <rescan> element holds an <int> element which indicates
the default interval between automatic checks for font configuration changes.
Fontconfig will validate all of the configuration files and directories and
automatically rebuild the internal datastructures when this interval passes." at
http://www.freedesktop.org/software/fontconfig/fontconfig-user.html

[msw, 2014/07/16 23:19:23]

Hmmm, Maybe it doesn't automatically rescan the file if <rescan> isn't supplied,
or maybe we could call FcConfigSetRescanInverval to ensure this doesn't happen,
or maybe you can just ignore my original suggestion...

+                                  const std::string& data) {
+  base::FilePath path;
+  if (!CreateTemporaryFileInDir(temp_dir, &path)) {
+    PLOG(ERROR) << "Unable to create temporary file in " << temp_dir.value();
+    return false;
+  }
+  VLOG(1) << "Writing config to " << path.value() << ":\n" << data;

[msw, 2014/07/16 22:38:07]

nit: is logging the entire file content helpful or necessary?

[Daniel Erat, 2014/07/16 23:10:18]

i found it useful when writing a test that generated its own configs, but it's
easy enough for the developer to add there own logging statement here when they
need it instead of running with --vmodule, i guess. i don't have much of an
opinion one way or the other; deleted for now

[msw, 2014/07/16 23:19:23]

It's not output by default, so it's probably fine if you like it.

+  if (base::WriteFile(path, data.data(), data.size()) !=
+      static_cast<int>(data.size())) {
+    PLOG(ERROR) << "Unable to write config data to " << path.value();
+    return false;
+  }
+  return LoadConfigFileIntoFontconfig(path);
+}
+
+std::string CreateFontconfigEditStanza(const std::string& name,
+                                       const std::string& type,
+                                       const std::string& value) {
+  return base::StringPrintf(
+      "    <edit name=\"%s\" mode=\"assign\">\n"
+      "      <%s>%s</%s>\n"
+      "    </edit>\n",
+      name.c_str(), type.c_str(), value.c_str(), type.c_str());
+}
+
+std::string CreateFontconfigTestStanza(const std::string& name,
+                                       const std::string& op,
+                                       const std::string& type,
+                                       const std::string& value) {
+  return base::StringPrintf(
+      "    <test name=\"%s\" compare=\"%s\" qual=\"any\">\n"
+      "      <%s>%s</%s>\n"
+      "    </test>\n",
+      name.c_str(), op.c_str(), type.c_str(), value.c_str(), type.c_str());
+}
+
+}  // namespace gfx