tor-browser

The Tor Browser
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PreferenceSheet.cpp (10611B)

      1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
      3 /* This Source Code Form is subject to the terms of the Mozilla Public
      4 * License, v. 2.0. If a copy of the MPL was not distributed with this
      5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      6 
      7 #include "PreferenceSheet.h"
      8 
      9 #include "MainThreadUtils.h"
     10 #include "ServoCSSParser.h"
     11 #include "mozilla/Encoding.h"
     12 #include "mozilla/LookAndFeel.h"
     13 #include "mozilla/Preferences.h"
     14 #include "mozilla/ServoBindings.h"
     15 #include "mozilla/StaticPrefs_browser.h"
     16 #include "mozilla/StaticPrefs_layout.h"
     17 #include "mozilla/StaticPrefs_ui.h"
     18 #include "mozilla/StaticPrefs_widget.h"
     19 #include "mozilla/dom/Document.h"
     20 #include "mozilla/glean/AccessibleMetrics.h"
     21 #include "nsContentUtils.h"
     22 
     23 namespace mozilla {
     24 
     25 using dom::Document;
     26 
     27 bool PreferenceSheet::sInitialized;
     28 PreferenceSheet::Prefs PreferenceSheet::sContentPrefs;
     29 PreferenceSheet::Prefs PreferenceSheet::sChromePrefs;
     30 PreferenceSheet::Prefs PreferenceSheet::sPrintPrefs;
     31 
     32 static void GetColor(const char* aPrefName, ColorScheme aColorScheme,
     33                     nscolor& aColor) {
     34  nsAutoCString darkPrefName;
     35  if (aColorScheme == ColorScheme::Dark) {
     36    darkPrefName.Append(aPrefName);
     37    darkPrefName.AppendLiteral(".dark");
     38    aPrefName = darkPrefName.get();
     39  }
     40 
     41  nsAutoCString value;
     42  Preferences::GetCString(aPrefName, value);
     43  if (value.IsEmpty() || Encoding::UTF8ValidUpTo(value) != value.Length()) {
     44    return;
     45  }
     46  nscolor result;
     47  if (!ServoCSSParser::ComputeColor(nullptr, NS_RGB(0, 0, 0), value, &result)) {
     48    return;
     49  }
     50  aColor = result;
     51 }
     52 
     53 auto PreferenceSheet::PrefsKindFor(const Document& aDoc) -> PrefsKind {
     54  if (aDoc.IsInChromeDocShell()) {
     55    return PrefsKind::Chrome;
     56  }
     57 
     58  if (aDoc.IsBeingUsedAsImage() && aDoc.ChromeRulesEnabled()) {
     59    return PrefsKind::Chrome;
     60  }
     61 
     62  if (aDoc.IsStaticDocument()) {
     63    return PrefsKind::Print;
     64  }
     65 
     66  return PrefsKind::Content;
     67 }
     68 
     69 static bool UseStandinsForNativeColors() {
     70  return nsContentUtils::ShouldResistFingerprinting(
     71             "we want to have consistent colors across the browser if RFP is "
     72             "enabled, so we check the global preference"
     73             "not excluding chrome browsers or webpages, so we call the legacy "
     74             "RFP function to prevent that",
     75             RFPTarget::UseStandinsForNativeColors) ||
     76         StaticPrefs::ui_use_standins_for_native_colors();
     77 }
     78 
     79 void PreferenceSheet::Prefs::LoadColors(bool aIsLight) {
     80  auto& colors = aIsLight ? mLightColors : mDarkColors;
     81 
     82  if (!aIsLight) {
     83    // Initialize the dark-color-scheme foreground/background colors as being
     84    // the reverse of these members' default values, for ~reasonable fallback if
     85    // the user configures broken pref values.
     86    std::swap(colors.mDefault, colors.mDefaultBackground);
     87  }
     88 
     89  const auto scheme = aIsLight ? ColorScheme::Light : ColorScheme::Dark;
     90  using ColorID = LookAndFeel::ColorID;
     91 
     92  if (!mIsChrome && (mUseDocumentColors || mUseStandins)) {
     93    // Tab content not in HCM, or we need to use standins.
     94    auto GetStandinColor = [&scheme](ColorID aColorID, nscolor& aColor) {
     95      aColor = LookAndFeel::Color(aColorID, scheme,
     96                                  LookAndFeel::UseStandins::Yes, aColor);
     97    };
     98 
     99    GetStandinColor(ColorID::Windowtext, colors.mDefault);
    100    GetStandinColor(ColorID::Window, colors.mDefaultBackground);
    101    GetStandinColor(ColorID::Linktext, colors.mLink);
    102    GetStandinColor(ColorID::Visitedtext, colors.mVisitedLink);
    103    GetStandinColor(ColorID::Activetext, colors.mActiveLink);
    104  } else if (!mIsChrome && mUsePrefColors) {
    105    // Tab content with explicit browser HCM, use our prefs for colors.
    106    GetColor("browser.display.background_color", scheme,
    107             colors.mDefaultBackground);
    108    GetColor("browser.display.foreground_color", scheme, colors.mDefault);
    109    GetColor("browser.anchor_color", scheme, colors.mLink);
    110    GetColor("browser.active_color", scheme, colors.mActiveLink);
    111    GetColor("browser.visited_color", scheme, colors.mVisitedLink);
    112  } else {
    113    // Browser UI or OS HCM, use system colors.
    114    auto GetSystemColor = [&scheme](ColorID aColorID, nscolor& aColor) {
    115      aColor = LookAndFeel::Color(aColorID, scheme,
    116                                  LookAndFeel::UseStandins::No, aColor);
    117    };
    118 
    119    GetSystemColor(ColorID::Windowtext, colors.mDefault);
    120    GetSystemColor(ColorID::Window, colors.mDefaultBackground);
    121    GetSystemColor(ColorID::Linktext, colors.mLink);
    122    GetSystemColor(ColorID::Visitedtext, colors.mVisitedLink);
    123    GetSystemColor(ColorID::Activetext, colors.mActiveLink);
    124  }
    125 
    126  // Wherever we got the default background color from, ensure it is opaque.
    127  colors.mDefaultBackground =
    128      NS_ComposeColors(NS_RGB(0xFF, 0xFF, 0xFF), colors.mDefaultBackground);
    129 }
    130 
    131 auto PreferenceSheet::ColorSchemeSettingForChrome()
    132    -> ChromeColorSchemeSetting {
    133  switch (StaticPrefs::browser_theme_toolbar_theme()) {
    134    case 0:  // Dark
    135      return ChromeColorSchemeSetting::Dark;
    136    case 1:  // Light
    137      return ChromeColorSchemeSetting::Light;
    138    default:
    139      return ChromeColorSchemeSetting::System;
    140  }
    141 }
    142 
    143 ColorScheme PreferenceSheet::ThemeDerivedColorSchemeForContent() {
    144  switch (StaticPrefs::browser_theme_content_theme()) {
    145    case 0:  // Dark
    146      return ColorScheme::Dark;
    147    case 1:  // Light
    148      return ColorScheme::Light;
    149    default:
    150      return LookAndFeel::SystemColorScheme();
    151  }
    152 }
    153 
    154 void PreferenceSheet::Prefs::Load(bool aIsChrome) {
    155  *this = {};
    156 
    157  mIsChrome = aIsChrome;
    158  mUseAccessibilityTheme =
    159      LookAndFeel::GetInt(LookAndFeel::IntID::UseAccessibilityTheme);
    160  // Chrome documents always use system colors, not stand-ins, not forced, etc.
    161  if (!aIsChrome) {
    162    switch (StaticPrefs::browser_display_document_color_use()) {
    163      case 1:
    164        // Never High Contrast
    165        mUsePrefColors = false;
    166        mUseDocumentColors = true;
    167        break;
    168      case 2:
    169        // Always High Contrast
    170        mUsePrefColors = true;
    171        mUseDocumentColors = false;
    172        break;
    173      default:
    174        // Only with OS HCM
    175        mUsePrefColors = false;
    176        mUseDocumentColors = !mUseAccessibilityTheme;
    177        break;
    178    }
    179    mUseStandins = UseStandinsForNativeColors();
    180  }
    181 
    182  LoadColors(true);
    183  LoadColors(false);
    184 
    185  // When forcing the pref colors, we need to forcibly use the light color-set,
    186  // as those are the colors exposed to the user in the colors dialog.
    187  mMustUseLightColorSet = mUsePrefColors && !mUseDocumentColors;
    188 #ifdef XP_WIN
    189  if (mUseAccessibilityTheme && (mIsChrome || !mUseDocumentColors)) {
    190    // Windows overrides the light colors with the HCM colors when HCM is
    191    // active, so make sure to always use the light system colors in that case,
    192    // and also make sure that we always use the light color set for the same
    193    // reason.
    194    mMustUseLightSystemColors = mMustUseLightColorSet = true;
    195  }
    196 #endif
    197 
    198  mColorScheme = [&] {
    199    if (aIsChrome) {
    200      switch (ColorSchemeSettingForChrome()) {
    201        case ChromeColorSchemeSetting::Light:
    202          return ColorScheme::Light;
    203        case ChromeColorSchemeSetting::Dark:
    204          return ColorScheme::Dark;
    205        case ChromeColorSchemeSetting::System:
    206          break;
    207      }
    208      return LookAndFeel::SystemColorScheme();
    209    }
    210    if (mMustUseLightColorSet) {
    211      // When forcing colors in a way such as color-scheme isn't respected, we
    212      // compute a preference based on the darkness of
    213      // our background.
    214      return LookAndFeel::IsDarkColor(mLightColors.mDefaultBackground)
    215                 ? ColorScheme::Dark
    216                 : ColorScheme::Light;
    217    }
    218    switch (StaticPrefs::layout_css_prefers_color_scheme_content_override()) {
    219      case 0:
    220        return ColorScheme::Dark;
    221      case 1:
    222        return ColorScheme::Light;
    223      default:
    224        return ThemeDerivedColorSchemeForContent();
    225    }
    226  }();
    227 }
    228 
    229 void PreferenceSheet::Initialize() {
    230  MOZ_ASSERT(NS_IsMainThread());
    231  MOZ_ASSERT(!sInitialized);
    232 
    233  sInitialized = true;
    234 
    235  sContentPrefs.Load(false);
    236  sChromePrefs.Load(true);
    237  sPrintPrefs = sContentPrefs;
    238  {
    239    // For printing, we always use a preferred-light color scheme.
    240    sPrintPrefs.mColorScheme = ColorScheme::Light;
    241    if (!sPrintPrefs.mUseDocumentColors) {
    242      // When overriding document colors, we ignore the `color-scheme` property,
    243      // but we still don't want to use the system colors (which might be dark,
    244      // despite having made it into mLightColors), because it both wastes ink
    245      // and it might interact poorly with the color adjustments we do while
    246      // printing.
    247      //
    248      // So we override the light colors with our hardcoded default colors, and
    249      // force the use of stand-ins.
    250      sPrintPrefs.mLightColors = Prefs().mLightColors;
    251      sPrintPrefs.mUseStandins = true;
    252    }
    253  }
    254 
    255  // Telemetry for these preferences is only collected on the parent process.
    256  if (!XRE_IsParentProcess()) {
    257    return;
    258  }
    259 
    260  glean::a11y::ThemeLabel gleanLabel;
    261  switch (StaticPrefs::browser_display_document_color_use()) {
    262    case 1:
    263      gleanLabel = glean::a11y::ThemeLabel::eAlways;
    264      break;
    265    case 2:
    266      gleanLabel = glean::a11y::ThemeLabel::eNever;
    267      break;
    268    default:
    269      gleanLabel = glean::a11y::ThemeLabel::eDefault;
    270      break;
    271  }
    272 
    273  glean::a11y::theme.EnumGet(gleanLabel)
    274      .Set(sContentPrefs.mUseAccessibilityTheme);
    275  if (!sContentPrefs.mUseDocumentColors) {
    276    // If a user has chosen to override doc colors through OS HCM or our HCM,
    277    // we should log the user's current foreground (text) color and background
    278    // color. Note, the document color use pref is the inverse of the HCM
    279    // dropdown option in preferences.
    280    //
    281    // Note that we only look at light colors because that's the color set we
    282    // use when forcing colors (since color-scheme is ignored when colors are
    283    // forced).
    284    //
    285    // The light color set is the one that potentially contains the Windows HCM
    286    // theme color/background (if we're using system colors and the user is
    287    // using a High Contrast theme), and also the colors that as of today we
    288    // allow setting in about:preferences.
    289    glean::a11y::hcm_foreground.Set(sContentPrefs.mLightColors.mDefault);
    290    glean::a11y::hcm_background.Set(
    291        sContentPrefs.mLightColors.mDefaultBackground);
    292  }
    293 
    294  glean::a11y::backplate.Set(StaticPrefs::browser_display_permit_backplate());
    295  glean::a11y::always_underline_links.Set(
    296      StaticPrefs::layout_css_always_underline_links());
    297 }
    298 
    299 }  // namespace mozilla