widget/RemoteLookAndFeel.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * vim: sw=2 ts=8 et :
   3  */
   4 /* This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this
   6  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   7
   8 #include "RemoteLookAndFeel.h"
   9
  10 #include "gfxFont.h"
  11 #include "MainThreadUtils.h"
  12 #include "mozilla/Assertions.h"
  13 #include "mozilla/ClearOnShutdown.h"
  14 #include "mozilla/Result.h"
  15 #include "mozilla/ResultExtensions.h"
  16 #include "mozilla/StaticPrefs_widget.h"
  17 #include "nsLookAndFeel.h"
  18 #include "nsXULAppAPI.h"
  19
  20 #include <limits>
  21 #include <type_traits>
  22 #include <utility>
  23
  24 namespace mozilla::widget {
  25
  26 RemoteLookAndFeel::RemoteLookAndFeel(FullLookAndFeel&& aData)
  27     : mTables(std::move(aData.tables())) {
  28   MOZ_ASSERT(XRE_IsContentProcess(),
  29              "Only content processes should be using a RemoteLookAndFeel");
  30
  31 #ifdef MOZ_WIDGET_GTK
  32   if (!StaticPrefs::widget_non_native_theme_enabled()) {
  33     // Configure the theme in this content process with the Gtk theme that was
  34     // chosen by WithThemeConfiguredForContent in the parent process.
  35     nsLookAndFeel::ConfigureTheme(aData.theme());
  36   }
  37 #endif
  38 }
  39
  40 RemoteLookAndFeel::~RemoteLookAndFeel() = default;
  41
  42 void RemoteLookAndFeel::SetDataImpl(FullLookAndFeel&& aData) {
  43   MOZ_ASSERT(XRE_IsContentProcess(),
  44              "Only content processes should be using a RemoteLookAndFeel");
  45   MOZ_ASSERT(NS_IsMainThread());
  46   mTables = std::move(aData.tables());
  47
  48 #ifdef MOZ_WIDGET_GTK
  49   if (!StaticPrefs::widget_non_native_theme_enabled()) {
  50     // Configure the theme in this content process with the Gtk theme that was
  51     // chosen by WithThemeConfiguredForContent in the parent process.
  52     nsLookAndFeel::ConfigureTheme(aData.theme());
  53   }
  54 #endif
  55 }
  56
  57 namespace {
  58
  59 template <typename Item, typename UInt, typename ID>
  60 Result<const Item*, nsresult> MapLookup(const nsTArray<Item>& aItems,
  61                                         const nsTArray<UInt>& aMap, ID aID,
  62                                         ID aMinimum = ID(0)) {
  63   UInt mapped = aMap[static_cast<size_t>(aID) - static_cast<size_t>(aMinimum)];
  64
  65   if (mapped == std::numeric_limits<UInt>::max()) {
  66     return Err(NS_ERROR_NOT_IMPLEMENTED);
  67   }
  68
  69   return &aItems[static_cast<size_t>(mapped)];
  70 }
  71
  72 template <typename Item, typename UInt>
  73 void AddToMap(nsTArray<Item>* aItems, nsTArray<UInt>* aMap,
  74               Maybe<Item>&& aNewItem) {
  75   if (aNewItem.isNothing()) {
  76     aMap->AppendElement(std::numeric_limits<UInt>::max());
  77     return;
  78   }
  79
  80   size_t newIndex = aItems->Length();
  81   MOZ_ASSERT(newIndex < std::numeric_limits<UInt>::max());
  82
  83   // Check if there is an existing value in aItems that we can point to.
  84   //
  85   // The arrays should be small enough and contain few enough unique
  86   // values that sequential search here is reasonable.
  87   for (size_t i = 0; i < newIndex; ++i) {
  88     if ((*aItems)[i] == aNewItem.ref()) {
  89       aMap->AppendElement(static_cast<UInt>(i));
  90       return;
  91     }
  92   }
  93
  94   aItems->AppendElement(aNewItem.extract());
  95   aMap->AppendElement(static_cast<UInt>(newIndex));
  96 }
  97
  98 }  // namespace
  99
 100 nsresult RemoteLookAndFeel::NativeGetColor(ColorID aID, nscolor& aResult) {
 101   const nscolor* result;
 102   MOZ_TRY_VAR(result, MapLookup(mTables.colors(), mTables.colorMap(), aID));
 103   aResult = *result;
 104   return NS_OK;
 105 }
 106
 107 nsresult RemoteLookAndFeel::NativeGetInt(IntID aID, int32_t& aResult) {
 108   const int32_t* result;
 109   MOZ_TRY_VAR(result, MapLookup(mTables.ints(), mTables.intMap(), aID));
 110   aResult = *result;
 111   return NS_OK;
 112 }
 113
 114 nsresult RemoteLookAndFeel::NativeGetFloat(FloatID aID, float& aResult) {
 115   const float* result;
 116   MOZ_TRY_VAR(result, MapLookup(mTables.floats(), mTables.floatMap(), aID));
 117   aResult = *result;
 118   return NS_OK;
 119 }
 120
 121 bool RemoteLookAndFeel::NativeGetFont(FontID aID, nsString& aFontName,
 122                                       gfxFontStyle& aFontStyle) {
 123   auto result =
 124       MapLookup(mTables.fonts(), mTables.fontMap(), aID, FontID::MINIMUM);
 125   if (result.isErr()) {
 126     return false;
 127   }
 128
 129   const LookAndFeelFont& font = *result.unwrap();
 130   MOZ_ASSERT(font.haveFont());
 131   aFontName = font.name();
 132   aFontStyle = gfxFontStyle();
 133   aFontStyle.size = font.size();
 134   aFontStyle.weight = FontWeight(font.weight());
 135   aFontStyle.style =
 136       font.italic() ? FontSlantStyle::Italic() : FontSlantStyle::Normal();
 137
 138   return true;
 139 }
 140
 141 char16_t RemoteLookAndFeel::GetPasswordCharacterImpl() {
 142   return static_cast<char16_t>(mTables.passwordChar());
 143 }
 144
 145 bool RemoteLookAndFeel::GetEchoPasswordImpl() { return mTables.passwordEcho(); }
 146
 147 // static
 148 const FullLookAndFeel* RemoteLookAndFeel::ExtractData() {
 149   MOZ_ASSERT(XRE_IsParentProcess(),
 150              "Only parent processes should be extracting LookAndFeel data");
 151
 152   if (sCachedLookAndFeelData) {
 153     return sCachedLookAndFeelData;
 154   }
 155
 156   static bool sInitialized = false;
 157   if (!sInitialized) {
 158     sInitialized = true;
 159     ClearOnShutdown(&sCachedLookAndFeelData);
 160   }
 161
 162   FullLookAndFeel* lf = new FullLookAndFeel{};
 163   nsXPLookAndFeel* impl = nsXPLookAndFeel::GetInstance();
 164
 165   int32_t darkTheme = 0;
 166   int32_t accessibilityTheme = 0;
 167   impl->NativeGetInt(IntID::SystemUsesDarkTheme, darkTheme);
 168   impl->NativeGetInt(IntID::UseAccessibilityTheme, accessibilityTheme);
 169
 170   impl->WithThemeConfiguredForContent([&](const LookAndFeelTheme& aTheme) {
 171     for (auto id : MakeEnumeratedRange(IntID::End)) {
 172       int32_t theInt;
 173       nsresult rv;
 174       // We want to take SystemUsesDarkTheme and UseAccessibilityTheme from
 175       // the parent process theme rather than the content configured theme.
 176       // This ensures that media queries like (prefers-color-scheme: dark) will
 177       // match correctly in content processes.
 178       //
 179       // (When the RemoteLookAndFeel is not in use, the LookAndFeelCache
 180       // ensures we get these values from the parent process theme.)
 181       switch (id) {
 182         case IntID::SystemUsesDarkTheme:
 183           theInt = darkTheme;
 184           rv = NS_OK;
 185           break;
 186         case IntID::UseAccessibilityTheme:
 187           theInt = accessibilityTheme;
 188           rv = NS_OK;
 189           break;
 190         default:
 191           rv = impl->NativeGetInt(id, theInt);
 192           break;
 193       }
 194       AddToMap(&lf->tables().ints(), &lf->tables().intMap(),
 195                NS_SUCCEEDED(rv) ? Some(theInt) : Nothing{});
 196     }
 197
 198     for (auto id : MakeEnumeratedRange(FloatID::End)) {
 199       float theFloat;
 200       nsresult rv = impl->NativeGetFloat(id, theFloat);
 201       AddToMap(&lf->tables().floats(), &lf->tables().floatMap(),
 202                NS_SUCCEEDED(rv) ? Some(theFloat) : Nothing{});
 203     }
 204
 205     for (auto id : MakeEnumeratedRange(ColorID::End)) {
 206       nscolor theColor;
 207       nsresult rv = impl->NativeGetColor(id, theColor);
 208       AddToMap(&lf->tables().colors(), &lf->tables().colorMap(),
 209                NS_SUCCEEDED(rv) ? Some(theColor) : Nothing{});
 210     }
 211
 212     for (auto id :
 213          MakeInclusiveEnumeratedRange(FontID::MINIMUM, FontID::MAXIMUM)) {
 214       LookAndFeelFont font{};
 215       gfxFontStyle fontStyle{};
 216
 217       bool rv = impl->NativeGetFont(id, font.name(), fontStyle);
 218       Maybe<LookAndFeelFont> maybeFont;
 219       if (rv) {
 220         font.haveFont() = true;
 221         font.size() = fontStyle.size;
 222         font.weight() = fontStyle.weight.ToFloat();
 223         font.italic() = fontStyle.style.IsItalic();
 224         MOZ_ASSERT(fontStyle.style.IsNormal() || fontStyle.style.IsItalic(),
 225                    "Cannot handle oblique font style");
 226 #ifdef DEBUG
 227         {
 228           // Assert that all the remaining font style properties have their
 229           // default values.
 230           gfxFontStyle candidate = fontStyle;
 231           gfxFontStyle defaults{};
 232           candidate.size = defaults.size;
 233           candidate.weight = defaults.weight;
 234           candidate.style = defaults.style;
 235           MOZ_ASSERT(candidate.Equals(defaults),
 236                      "Some font style properties not supported");
 237         }
 238 #endif
 239         maybeFont = Some(std::move(font));
 240       }
 241       AddToMap(&lf->tables().fonts(), &lf->tables().fontMap(),
 242                std::move(maybeFont));
 243     }
 244
 245     lf->tables().passwordChar() = impl->GetPasswordCharacterImpl();
 246     lf->tables().passwordEcho() = impl->GetEchoPasswordImpl();
 247 #ifdef MOZ_WIDGET_GTK
 248     lf->theme() = aTheme;
 249 #endif
 250   });
 251
 252   // This assignment to sCachedLookAndFeelData must be done after the
 253   // WithThemeConfiguredForContent call, since it can end up calling RefreshImpl
 254   // on the LookAndFeel, which will clear out sCachedTables.
 255   sCachedLookAndFeelData = lf;
 256   return sCachedLookAndFeelData;
 257 }
 258
 259 void RemoteLookAndFeel::ClearCachedData() {
 260   MOZ_ASSERT(XRE_IsParentProcess());
 261   sCachedLookAndFeelData = nullptr;
 262 }
 263
 264 StaticAutoPtr<FullLookAndFeel> RemoteLookAndFeel::sCachedLookAndFeelData;
 265
 266 }  // namespace mozilla::widget