chrome/browser/extensions/extension_install_prompt_experiment.cc

   1 // Copyright 2013 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 "base/basictypes.h"
   6 #include "base/logging.h"
   7 #include "base/metrics/field_trial.h"
   8 #include "base/strings/string_number_conversions.h"
   9 #include "base/strings/string_split.h"
  10 #include "base/strings/stringprintf.h"
  11 #include "chrome/browser/extensions/extension_install_prompt_experiment.h"
  12 #include "chrome/grit/generated_resources.h"
  13 #include "ui/base/l10n/l10n_util.h"
  14
  15 namespace {
  16
  17 const char kExperimentName[] = "ExtensionPermissionDialog";
  18 const char kGroupPrefix[] = "Group";
  19
  20 // Flags for groups. Not all combinations make sense.
  21 // Refer to the UI screens at http://goo.gl/f2KzPj for those that do.
  22 enum GroupFlag {
  23   // No changes (Control group).
  24   NONE = 0,
  25   // Indicates that the experiment is text only. A text only experiment
  26   // only adds an explanation text at the bottom of the permission dialog and
  27   // modifies the text on accept/cancel buttons.
  28   TEXT_ONLY = 1 << 0,
  29   // Indicates that the experiment shows inline explanations for permissions.
  30   INLINE_EXPLANATIONS = 1 << 1,
  31   // Indicates that the experiment highlights permission text color.
  32   SHOULD_HIGHLIGHT_TEXT = 1 << 2,
  33   // Indicates that the experiment highlights permission text background.
  34   SHOULD_HIGHLIGHT_BACKGROUND = 1 << 3,
  35   // Indicates that the experiment highlights all permissions.
  36   SHOULD_HIGHLIGHT_ALL_PERMISSIONS = 1 << 4,
  37   // Indicates that the experiment puts a "show details" link in the UI.
  38   SHOULD_SHOW_DETAILS_LINK = 1 << 5,
  39   // Indicates that the experiment hides the permissions by default and the list
  40   // can be expanded.
  41   EXPANDABLE_PERMISSION_LIST = 1 << 6,
  42   // Indicates that the experiment shows checkboxes for each permission.
  43   SHOULD_SHOW_CHECKBOXES = 1 << 7
  44 };
  45
  46 // Flags for the actual experiment groups. These flags define what kind of
  47 // UI changes each experiment group does. An experiment group may change
  48 // multiple aspects of the extension install dialog  (e.g. one of the groups
  49 // show a details link and inline explanations for permissions). The control
  50 // group doesn't change the UI. Text only groups add a text warning to the UI,
  51 // with the text changing depending on the group number. Groups with inline
  52 // explanations show detailed explanations for a subset of permissions. Some
  53 // groups highlight the foreground or the background of permission texts.
  54 // The flags reflect the UI screens at http://goo.gl/f2KzPj.
  55 const unsigned int kGroupFlags[] = {
  56   // Control group doesn't change the UI.
  57   NONE,
  58   // Adds "Do you trust this extension to use these privileges safely" text.
  59   TEXT_ONLY,
  60   // Adds "Extension can be malicious" text.
  61   TEXT_ONLY,
  62   // Adds "Are you sure you want to install" text.
  63   TEXT_ONLY,
  64   // Adds "Make sure these privileges make sense for this extension" text.
  65   TEXT_ONLY,
  66   // Adds "Do you trust this extension to perform these actions" text.
  67   TEXT_ONLY,
  68   // Adds inline explanations displayed by default.
  69   INLINE_EXPLANATIONS,
  70   // Adds expandable inline explanations with a "Show Details" link.
  71   SHOULD_SHOW_DETAILS_LINK | INLINE_EXPLANATIONS,
  72   // Adds expandable permission list with a "Show Permissions" link.
  73   SHOULD_SHOW_DETAILS_LINK | EXPANDABLE_PERMISSION_LIST,
  74   // Highlights text for risky permissions.
  75   SHOULD_HIGHLIGHT_TEXT,
  76   // Highlights background for risky permissions.
  77   SHOULD_HIGHLIGHT_BACKGROUND,
  78   // Highlights background for all permissions
  79   SHOULD_HIGHLIGHT_BACKGROUND | SHOULD_HIGHLIGHT_ALL_PERMISSIONS,
  80   // Displays checkboxes for all permissions.
  81   SHOULD_SHOW_CHECKBOXES
  82 };
  83
  84 const size_t kGroupCount = arraysize(kGroupFlags);
  85
  86 // Parameters for text only experiments.
  87 const struct TextParams {
  88   int text_id;
  89   int ok_text_id;
  90   int cancel_text_id;
  91 } kTextParams[] = {
  92   {
  93     IDS_EXTENSION_PROMPT_EXPERIMENT_EXPLANATION1,
  94     IDS_EXTENSION_PROMPT_EXPERIMENT_INSTALL_BUTTON_TRUST,
  95     IDS_CANCEL,
  96   },
  97   {
  98     IDS_EXTENSION_PROMPT_EXPERIMENT_EXPLANATION2,
  99     IDS_EXTENSION_PROMPT_EXPERIMENT_INSTALL_BUTTON_YES,
 100     IDS_EXTENSION_PROMPT_EXPERIMENT_INSTALL_BUTTON_NOPE
 101   },
 102   {
 103     IDS_EXTENSION_PROMPT_EXPERIMENT_EXPLANATION3,
 104     IDS_EXTENSION_PROMPT_EXPERIMENT_INSTALL_BUTTON_SURE,
 105     IDS_EXTENSION_PROMPT_EXPERIMENT_INSTALL_BUTTON_NOPE
 106   },
 107   {
 108     IDS_EXTENSION_PROMPT_EXPERIMENT_EXPLANATION4,
 109     IDS_EXTENSION_PROMPT_INSTALL_BUTTON,
 110     IDS_CANCEL
 111   },
 112   {
 113     IDS_EXTENSION_PROMPT_EXPERIMENT_EXPLANATION5,
 114     IDS_EXTENSION_PROMPT_EXPERIMENT_INSTALL_BUTTON_TRUST2,
 115     IDS_EXTENSION_PROMPT_EXPERIMENT_INSTALL_BUTTON_NOPE
 116   }
 117 };
 118
 119 // Permission warnings in this list have inline explanation texts.
 120 const struct PermissionExplanations {
 121   int warning_msg_id;
 122   int extra_explanation_id;
 123 } kPermissionExplanations[] = {
 124   {
 125     IDS_EXTENSION_PROMPT_WARNING_FULL_ACCESS,
 126     IDS_EXTENSION_PROMPT_WARNING_FULL_ACCESS_EXPLANATION
 127   },
 128   {
 129     IDS_EXTENSION_PROMPT_WARNING_ALL_HOSTS,
 130     IDS_EXTENSION_PROMPT_WARNING_ALL_HOSTS_EXPLANATION
 131   }
 132 };
 133
 134 // Permission warnings in this list are going to be highlighted.
 135 // Note that the matching is done by string comparison, so this list must not
 136 // contain any dynamic strings (e.g. permission for 3 hosts with the host list).
 137 const int kHighlightedWarnings[] = {
 138   IDS_EXTENSION_PROMPT_WARNING_FULL_ACCESS,
 139   IDS_EXTENSION_PROMPT_WARNING_ALL_HOSTS,
 140   IDS_EXTENSION_PROMPT_WARNING_BOOKMARKS,
 141   IDS_EXTENSION_PROMPT_WARNING_CONTENT_SETTINGS,
 142   IDS_EXTENSION_PROMPT_WARNING_HISTORY_WRITE,
 143   IDS_EXTENSION_PROMPT_WARNING_INPUT,
 144   IDS_EXTENSION_PROMPT_WARNING_MANAGEMENT,
 145   IDS_EXTENSION_PROMPT_WARNING_HISTORY_READ,
 146   IDS_EXTENSION_PROMPT_WARNING_DEBUGGER
 147 };
 148
 149 bool IsImportantWarning(const base::string16& message) {
 150   for (size_t i = 0; i < arraysize(kHighlightedWarnings); ++i) {
 151     if (message == l10n_util::GetStringUTF16(kHighlightedWarnings[i]))
 152       return true;
 153   }
 154   return false;
 155 }
 156
 157 }  // namespace
 158
 159 ExtensionInstallPromptExperiment::ExtensionInstallPromptExperiment(
 160     unsigned int group_id, unsigned int flags)
 161     : group_id_(group_id),
 162       flags_(flags) {
 163 }
 164
 165 ExtensionInstallPromptExperiment::~ExtensionInstallPromptExperiment() {
 166 }
 167
 168 // static
 169 ExtensionInstallPromptExperiment*
 170     ExtensionInstallPromptExperiment::ControlGroup() {
 171   return new ExtensionInstallPromptExperiment(0, kGroupFlags[0]);
 172 }
 173
 174 // static
 175 ExtensionInstallPromptExperiment*
 176     ExtensionInstallPromptExperiment::Find() {
 177   base::FieldTrial* trial = base::FieldTrialList::Find(kExperimentName);
 178   // Default is control group.
 179   unsigned int group_id = 0;
 180   if (trial) {
 181     std::vector<std::string> tokens;
 182     base::SplitString(trial->group_name().c_str(), '_', &tokens);
 183     if (tokens.size() == 2 && tokens[0] == kGroupPrefix) {
 184       base::StringToUint(tokens[1], &group_id);
 185       if (group_id >= kGroupCount)
 186         group_id = 0;
 187     }
 188   }
 189   return new ExtensionInstallPromptExperiment(group_id, kGroupFlags[group_id]);
 190 }
 191
 192 base::string16 ExtensionInstallPromptExperiment::GetExplanationText() const {
 193   DCHECK(group_id_ > 0 && group_id_ - 1 < arraysize(kTextParams));
 194   return l10n_util::GetStringUTF16(kTextParams[group_id_ - 1].text_id);
 195 }
 196
 197 base::string16 ExtensionInstallPromptExperiment::GetOkButtonText() const {
 198   DCHECK(group_id_ > 0 && group_id_ - 1 < arraysize(kTextParams));
 199   return l10n_util::GetStringUTF16(kTextParams[group_id_ - 1].ok_text_id);
 200 }
 201
 202 base::string16 ExtensionInstallPromptExperiment::GetCancelButtonText() const {
 203   DCHECK(group_id_ > 0 && group_id_ - 1 < arraysize(kTextParams));
 204   return l10n_util::GetStringUTF16(kTextParams[group_id_ - 1].cancel_text_id);
 205 }
 206
 207 bool ExtensionInstallPromptExperiment::text_only() const {
 208   return (flags_ & TEXT_ONLY) != 0;
 209 }
 210
 211 bool ExtensionInstallPromptExperiment::ShouldHighlightText(
 212     const base::string16& message) const {
 213   return (flags_ & SHOULD_HIGHLIGHT_TEXT) != 0 && IsImportantWarning(message);
 214 }
 215
 216 bool ExtensionInstallPromptExperiment::ShouldHighlightBackground(
 217     const base::string16& message) const {
 218   return (flags_ & SHOULD_HIGHLIGHT_BACKGROUND) != 0 &&
 219       ((flags_ & SHOULD_HIGHLIGHT_ALL_PERMISSIONS) != 0 ||
 220       IsImportantWarning(message));
 221 }
 222
 223 bool ExtensionInstallPromptExperiment::show_details_link() const {
 224   return (flags_ & SHOULD_SHOW_DETAILS_LINK) != 0;
 225 }
 226
 227 bool ExtensionInstallPromptExperiment::show_checkboxes() const {
 228   return (flags_ & SHOULD_SHOW_CHECKBOXES) != 0;
 229 }
 230
 231 bool ExtensionInstallPromptExperiment::should_show_expandable_permission_list()
 232     const {
 233   return (flags_ & EXPANDABLE_PERMISSION_LIST) != 0;
 234 }
 235
 236 bool ExtensionInstallPromptExperiment::should_show_inline_explanations() const {
 237   return (flags_ & INLINE_EXPLANATIONS) != 0;
 238 }
 239
 240 base::string16 ExtensionInstallPromptExperiment::GetInlineExplanation(
 241     const base::string16& message) const {
 242   for (size_t i = 0; i < arraysize(kPermissionExplanations); ++i) {
 243     if (message == l10n_util::GetStringUTF16(
 244         kPermissionExplanations[i].warning_msg_id)) {
 245       return l10n_util::GetStringUTF16(
 246           kPermissionExplanations[i].extra_explanation_id);
 247     }
 248   }
 249   return base::string16();
 250 }