[Favicon] Adding FallbackIconUrlParser.

chrome/common/favicon/fallback_icon_url_parser.cc

+// Copyright 2015 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 "chrome/common/favicon/fallback_icon_url_parser.h"
+
+#include "base/logging.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_split.h"
+#include "third_party/skia/include/utils/SkParse.h"
+#include "ui/gfx/favicon_size.h"
+
+namespace chrome {
+
+ParsedFallbackIconPath::ParsedFallbackIconPath()
+    : size_in_pixels_(gfx::kFaviconSize) {
+}
+
+ParsedFallbackIconPath::~ParsedFallbackIconPath() {
+}
+
+bool ParsedFallbackIconPath::Parse(const std::string& path) {
+  if (path.empty())
+    return false;
+
+  size_t slash = path.find("/", 0);
+  if (slash == std::string::npos)
+    return false;
+  std::string spec_str = path.substr(0, slash);
+  if (!ParseSpecs(spec_str, &size_in_pixels_, &style_))
+    return false;  // Parse failed.
+
+  // Extract URL, which may be empty (if first slash appears at the end).
+  std::string url_str = path.substr(slash + 1);
+  url_ = GURL(url_str);
+  return url_str.empty() || url_.is_valid();  // Allow empty URL.
+}
+
+// static
+bool ParsedFallbackIconPath::ParseSpecs(
+    const std::string& specs_str,
+    int *size,
+    favicon_base::FallbackIconStyle* style) {
+  DCHECK(size);
+  DCHECK(style);
+
+  std::vector<std::string> tokens;
+  base::SplitStringDontTrim(specs_str, ',', &tokens);
+  if (tokens.size() != 5)  // Force "," for empty fields.
+    return false;
+
+  *size = gfx::kFaviconSize;
+  if (!tokens[0].empty() && !base::StringToInt(tokens[0], size))
+    return false;
+  if (*size <= 0)
+    return false;
+
+  if (!tokens[1].empty() && !ParseColor(tokens[1], &style->background_color))
+    return false;
+
+  if (tokens[2].empty())
+    favicon_base::MatchFallbackIconTextColorAgainstBackgroundColor(style);
+  else if (!ParseColor(tokens[2], &style->text_color))
+    return false;
+
+  if (!tokens[3].empty() &&
+      !base::StringToDouble(tokens[3], &style->font_size_ratio))
+    return false;
+
+  if (!tokens[4].empty() && !base::StringToDouble(tokens[4], &style->roundness))
+    return false;
+
+  return favicon_base::ValidateFallbackIconStyle(*style);
+}
+
+// static
+bool ParsedFallbackIconPath::ParseColor(const std::string& color_str,
+                                        SkColor* color) {
+  const char* end = SkParse::FindColor(color_str.c_str(), color);
+  // Return true if FindColor() succeeds and |color_str| is entirely consumed.
+  return end && !*end;
+}
+
+}  // namespace chrome