[Favicon] Add new fallback icon rendering flow.

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/strings/string_number_conversions.h"
+#include "base/strings/string_split.h"
+#include "ui/gfx/favicon_size.h"
+
+namespace {
+
+// Returns 0-15 for given hex char (case-insensitive), and -1 if invalid.
+int ParseHexChar(char ch) {
+  if (ch >= '0' && ch <= '9')
+    return ch - '0';
+  if (ch >= 'A' && ch <= 'F')
+    return (ch - 'A') + 10;
+  if (ch >= 'a' && ch <= 'f')
+    return (ch - 'a') + 10;
+  return -1;
+}
+
+}  // namespace
+
+namespace chrome {
+
+bool ParseIconColor(const std::string& str, SkColor* color) {
+  size_t len = str.length();
+  if (len != 3 && len != 6 && len != 8)
+    return false;
+  // Translate and validate each digit.
+  int d[8];
+  for (size_t i = 0; i < len; ++i) {
+    d[i] = ParseHexChar(str[i]);
+    if (d[i] < 0)
+      return false;
+  }
+  if (len == 3) {  // RGB.
+    *color = SkColorSetRGB(d[0] * 0x11, d[1] * 0x11, d[2] * 0x11);
+  } else if (len == 6) {  // RRGGBB.
+    *color = SkColorSetRGB(
+        (d[0] << 4) | d[1], (d[2] << 4) | d[3], (d[4] << 4) | d[5]);
+  } else {  // RRGGBBAA.
+    DCHECK(len == 8);
+    *color = SkColorSetARGB((d[6] << 4) | d[7], (d[0] << 4) | d[1],
+                            (d[2] << 4) | d[3], (d[4] << 4) | d[5]);
+  }
+  return true;
+}
+
+bool ParseFallbackIconSpecs(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() &&
+      !ParseIconColor(tokens[1], &style->background_color))
+    return false;
+
+  if (tokens[2].empty())
+    style->MatchTextColorWithBackgroundColor();
+  else if (!ParseIconColor(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 style->is_valid();
+}
+
+bool ParseFallbackIconPath(const std::string& path,
+                           ParsedFallbackIconPath* parsed) {
+  DCHECK(parsed);
+  parsed->url = "";
+  parsed->size_in_pixels = gfx::kFaviconSize;
+  parsed->style = favicon_base::FallbackIconStyle();
+
+  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 (!ParseFallbackIconSpecs(
+          spec_str, &parsed->size_in_pixels, &parsed->style))
+    return false;  // Parse failed.
+
+  // Extract URL.
+  parsed->url = path.substr(slash + 1);
+  return true;
+}
+
+}  // namespace chrome