components/favicon_base/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 "components/favicon_base/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 (!base::IsHexDigit(ch))
  31       return false;
  32   }
  33   return true;
  34 }
  35
  36 }  // namespace
  37
  38 namespace chrome {
  39
  40 ParsedFallbackIconPath::ParsedFallbackIconPath()
  41     : size_in_pixels_(gfx::kFaviconSize) {
  42 }
  43
  44 ParsedFallbackIconPath::~ParsedFallbackIconPath() {
  45 }
  46
  47 bool ParsedFallbackIconPath::Parse(const std::string& path) {
  48   if (path.empty())
  49     return false;
  50
  51   size_t slash = path.find("/", 0);
  52   if (slash == std::string::npos)
  53     return false;
  54   std::string spec_str = path.substr(0, slash);
  55   if (!ParseSpecs(spec_str, &size_in_pixels_, &style_))
  56     return false;  // Parse failed.
  57
  58   // Need to store the index of the URL field, so Instant Extended can translate
  59   // fallback icon URLs using advanced parameters.
  60   // Example:
  61   //   "chrome-search://fallback-icon/48/<renderer-id>/<most-visited-id>"
  62   // would be translated to:
  63   //   "chrome-search://fallback-icon/48/<most-visited-item-with-given-id>".
  64   path_index_ = slash + 1;
  65   url_string_ = path.substr(path_index_);
  66   return true;
  67 }
  68
  69 // static
  70 bool ParsedFallbackIconPath::ParseSpecs(
  71     const std::string& specs_str,
  72     int *size,
  73     favicon_base::FallbackIconStyle* style) {
  74   DCHECK(size);
  75   DCHECK(style);
  76
  77   std::vector<std::string> tokens = base::SplitString(
  78       specs_str, ",", base::KEEP_WHITESPACE, base::SPLIT_WANT_ALL);
  79   if (tokens.size() != 5)  // Force "," for empty fields.
  80     return false;
  81
  82   *size = gfx::kFaviconSize;
  83   if (!tokens[0].empty() && !base::StringToInt(tokens[0], size))
  84     return false;
  85   if (*size <= 0)
  86     return false;
  87
  88   if (!tokens[1].empty() && !ParseColor(tokens[1], &style->background_color))
  89     return false;
  90
  91   if (tokens[2].empty())
  92     favicon_base::MatchFallbackIconTextColorAgainstBackgroundColor(style);
  93   else if (!ParseColor(tokens[2], &style->text_color))
  94     return false;
  95
  96   if (!tokens[3].empty() &&
  97       !base::StringToDouble(tokens[3], &style->font_size_ratio))
  98     return false;
  99
 100   if (!tokens[4].empty() && !base::StringToDouble(tokens[4], &style->roundness))
 101     return false;
 102
 103   return favicon_base::ValidateFallbackIconStyle(*style);
 104 }
 105
 106 // static
 107 bool ParsedFallbackIconPath::ParseColor(const std::string& color_str,
 108                                         SkColor* color) {
 109   DCHECK(color);
 110   // Exclude the empty case. Also disallow the '#' prefix, since we want color
 111   // to be part of an URL, but in URL '#' is used for ref fragment.
 112   if (color_str.empty() || color_str[0] == '#')
 113     return false;
 114
 115   // If a valid color hex string is given, prepend '#' and parse (always works).
 116   // This is unambiguous since named color never only use leters 'a' to 'f'.
 117   if (IsHexColorString(color_str)) {
 118     // Default alpha to 0xFF since FindColor() preserves unspecified alpha.
 119     *color = SK_ColorWHITE;
 120     // Need temp variable to avoid use-after-free of returned pointer.
 121     std::string color_str_with_hash = "#" + color_str;
 122     const char* end = SkParse::FindColor(color_str_with_hash.c_str(), color);
 123     DCHECK(end && !*end);  // Call should succeed and consume string.
 124     return true;
 125   }
 126
 127   // Default alpha to 0xFF.
 128   SkColor temp_color = SK_ColorWHITE;
 129   const char* end = SkParse::FindColor(color_str.c_str(), &temp_color);
 130   if (end && !*end) {  // Successful if call succeeds and string is consumed.
 131     *color = temp_color;
 132     return true;
 133   }
 134   return false;
 135 }
 136
 137 }  // namespace chrome