chrome/common/favicon/fallback_icon_url_parser.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/common/favicon/fallback_icon_url_parser.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/logging.h"
  10 #include "base/macros.h"
  11 #include "base/strings/string_number_conversions.h"
  12 #include "base/strings/string_split.h"
  13 #include "base/strings/string_util.h"
  14 #include "third_party/skia/include/utils/SkParse.h"
  15 #include "ui/gfx/favicon_size.h"
  16
  17 namespace {
  18
  19 // List of sizes corresponding to RGB, ARGB, RRGGBB, AARRGGBB.
  20 const size_t kValidHexColorSizes[] = {3, 4, 6, 8};
  21
  22 // Returns whether |color_str| is a valid CSS color in hex format if we prepend
  23 // '#', i.e., whether |color_str| matches /^[0-9A-Fa-f]{3,4,6,8}$/.
  24 bool IsHexColorString(const std::string& color_str) {
  25   size_t len = color_str.length();
  26   const size_t* end = kValidHexColorSizes + arraysize(kValidHexColorSizes);
  27   if (std::find(kValidHexColorSizes, end, len) == end)
  28     return false;
  29   for (auto ch : color_str)
  30     if (!IsHexDigit(ch))
  31       return false;
  32   return true;
  33 }
  34
  35 }  // namespace
  36
  37 namespace chrome {
  38
  39 ParsedFallbackIconPath::ParsedFallbackIconPath()
  40     : size_in_pixels_(gfx::kFaviconSize) {
  41 }
  42
  43 ParsedFallbackIconPath::~ParsedFallbackIconPath() {
  44 }
  45
  46 bool ParsedFallbackIconPath::Parse(const std::string& path) {
  47   if (path.empty())
  48     return false;
  49
  50   size_t slash = path.find("/", 0);
  51   if (slash == std::string::npos)
  52     return false;
  53   std::string spec_str = path.substr(0, slash);
  54   if (!ParseSpecs(spec_str, &size_in_pixels_, &style_))
  55     return false;  // Parse failed.
  56
  57   // Need to store the index of the URL field, so Instant Extended can translate
  58   // fallback icon URLs using advanced parameters.
  59   // Example:
  60   //   "chrome-search://fallback-icon/48/<renderer-id>/<most-visited-id>"
  61   // would be translated to:
  62   //   "chrome-search://fallback-icon/48/<most-visited-item-with-given-id>".
  63   path_index_ = slash + 1;
  64   url_string_ = path.substr(path_index_);
  65   return true;
  66 }
  67
  68 // static
  69 bool ParsedFallbackIconPath::ParseSpecs(
  70     const std::string& specs_str,
  71     int *size,
  72     favicon_base::FallbackIconStyle* style) {
  73   DCHECK(size);
  74   DCHECK(style);
  75
  76   std::vector<std::string> tokens;
  77   base::SplitStringDontTrim(specs_str, ',', &tokens);
  78   if (tokens.size() != 5)  // Force "," for empty fields.
  79     return false;
  80
  81   *size = gfx::kFaviconSize;
  82   if (!tokens[0].empty() && !base::StringToInt(tokens[0], size))
  83     return false;
  84   if (*size <= 0)
  85     return false;
  86
  87   if (!tokens[1].empty() && !ParseColor(tokens[1], &style->background_color))
  88     return false;
  89
  90   if (tokens[2].empty())
  91     favicon_base::MatchFallbackIconTextColorAgainstBackgroundColor(style);
  92   else if (!ParseColor(tokens[2], &style->text_color))
  93     return false;
  94
  95   if (!tokens[3].empty() &&
  96       !base::StringToDouble(tokens[3], &style->font_size_ratio))
  97     return false;
  98
  99   if (!tokens[4].empty() && !base::StringToDouble(tokens[4], &style->roundness))
 100     return false;
 101
 102   return favicon_base::ValidateFallbackIconStyle(*style);
 103 }
 104
 105 // static
 106 bool ParsedFallbackIconPath::ParseColor(const std::string& color_str,
 107                                         SkColor* color) {
 108   DCHECK(color);
 109   // Exclude the empty case. Also disallow the '#' prefix, since we want color
 110   // to be part of an URL, but in URL '#' is used for ref fragment.
 111   if (color_str.empty() || color_str[0] == '#')
 112     return false;
 113
 114   // If a valid color hex string is given, prepend '#' and parse (always works).
 115   // This is unambiguous since named color never only use leters 'a' to 'f'.
 116   if (IsHexColorString(color_str)) {
 117     // Default alpha to 0xFF since FindColor() preserves unspecified alpha.
 118     *color = SK_ColorWHITE;
 119     // Need temp variable to avoid use-after-free of returned pointer.
 120     std::string color_str_with_hash = "#" + color_str;
 121     const char* end = SkParse::FindColor(color_str_with_hash.c_str(), color);
 122     DCHECK(end && !*end);  // Call should succeed and consume string.
 123     return true;
 124   }
 125
 126   // Default alpha to 0xFF.
 127   SkColor temp_color = SK_ColorWHITE;
 128   const char* end = SkParse::FindColor(color_str.c_str(), &temp_color);
 129   if (end && !*end) {  // Successful if call succeeds and string is consumed.
 130     *color = temp_color;
 131     return true;
 132   }
 133   return false;
 134 }
 135
 136 }  // namespace chrome