Filter font list, use Fontconfig and build on Ozone

content/common/font_list_fontconfig.cc

+// Copyright 2016 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 "content/common/font_list.h"
+
+#include <memory>
+#include <set>
+#include <string>
+#include <utility>
+
+#include <fontconfig/fontconfig.h>
+
+#include "base/values.h"
+
+namespace content {
+
+std::unique_ptr<FcPattern, decltype(&FcPatternDestroy)> CreateFormatPattern(
+    const char* format) {
+  std::unique_ptr<FcPattern, decltype(&FcPatternDestroy)> pattern(
+      FcPatternCreate(), FcPatternDestroy);
+  FcPatternAddBool(pattern.get(), FC_SCALABLE, FcTrue);
+  FcPatternAddString(pattern.get(), FC_FONTFORMAT,
+                     reinterpret_cast<const FcChar8*>(format));
+  return pattern;
+}
+
+std::unique_ptr<base::ListValue> GetFontList_SlowBlocking() {
+  std::unique_ptr<base::ListValue> font_list(new base::ListValue);
+
+  std::unique_ptr<FcObjectSet, decltype(&FcObjectSetDestroy)> object_set(
+      FcObjectSetBuild(FC_FAMILY, NULL), FcObjectSetDestroy);
+
+  std::set<std::string> sorted_families;
+
+  // See https://www.freetype.org/freetype2/docs/reference/ft2-font_formats.html
+  // for the list of possible formats.
+  const char* allowed_formats[] = { "TrueType", "CFF" };
+  for (size_t i = 0; i < arraysize(allowed_formats); ++i) {
+    auto format_pattern = CreateFormatPattern(allowed_formats[i]);
+    std::unique_ptr<FcFontSet, decltype(&FcFontSetDestroy)> fontset(
+        FcFontList(0, format_pattern.get(), object_set.get()),
+        FcFontSetDestroy);
+    for (int j = 0; j < fontset->nfont; ++j) {
+      char* family_string;
+      FcPatternGetString(fontset->fonts[j], FC_FAMILY, 0,
+                         reinterpret_cast<FcChar8**>(&family_string));
+      sorted_families.insert(family_string);
+    }
+  }
+
+  // For backwards compatibility with the older pango implementation, add the
+  // three Fontconfig aliases that pango added. Our linux default settings for
+  // fixed-width was "Monospace". If we remove that, this entry is not found in
+  // the list anymore, see also:
+  // https://git.gnome.org/browse/pango/tree/pango/pangofc-fontmap.c?h=1.40.1#n1351
+  sorted_families.insert("Monospace");
+  sorted_families.insert("Sans");
+  sorted_families.insert("Serif");
+
+  for (const auto& family : sorted_families) {
+    std::unique_ptr<base::ListValue> font_item(new base::ListValue());
+    font_item->AppendString(family);
+    font_item->AppendString(family);  // localized name.
+    // TODO(yusukes): Support localized family names.
+    font_list->Append(std::move(font_item));
+  }
+
+  return font_list;
+}
+
+}  // namespace content