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/ResultExtensions.h"
  15 #include "mozilla/StaticPrefs_widget.h"
  16 #include "mozilla/Try.h"
  17 #include "nsXULAppAPI.h"
  18
  19 #include <limits>
  20 #include <type_traits>
  21 #include <utility>
  22
  23 namespace mozilla::widget {
  24
  25 // A cached copy of the data extracted by ExtractData.
  26 //
  27 // Storing this lets us avoid doing most of the work of ExtractData each
  28 // time we create a new content process.
  29 //
  30 // Only used in the parent process.
  31 static StaticAutoPtr<FullLookAndFeel> sCachedLookAndFeelData;
  32
  33 RemoteLookAndFeel::RemoteLookAndFeel(FullLookAndFeel&& aData)
  34     : mTables(std::move(aData.tables())) {
  35   MOZ_ASSERT(XRE_IsContentProcess(),
  36              "Only content processes should be using a RemoteLookAndFeel");
  37 }
  38
  39 RemoteLookAndFeel::~RemoteLookAndFeel() = default;
  40
  41 void RemoteLookAndFeel::SetDataImpl(FullLookAndFeel&& aData) {
  42   MOZ_ASSERT(XRE_IsContentProcess(),
  43              "Only content processes should be using a RemoteLookAndFeel");
  44   MOZ_ASSERT(NS_IsMainThread());
  45   mTables = std::move(aData.tables());
  46 }
  47
  48 namespace {
  49
  50 // Some lnf values are somewhat expensive to get, and are not needed in child
  51 // processes, so we can avoid querying them.
  52 bool IsNeededInChildProcess(LookAndFeel::IntID aId) {
  53   switch (aId) {
  54     case LookAndFeel::IntID::AlertNotificationOrigin:
  55       return false;  // see bug 1703205
  56     default:
  57       return true;
  58   }
  59 }
  60
  61 template <typename Item, typename UInt, typename ID>
  62 Result<const Item*, nsresult> MapLookup(const nsTArray<Item>& aItems,
  63                                         const nsTArray<UInt>& aMap, ID aID) {
  64   UInt mapped = aMap[static_cast<size_t>(aID)];
  65
  66   if (mapped == std::numeric_limits<UInt>::max()) {
  67     return Err(NS_ERROR_NOT_IMPLEMENTED);
  68   }
  69
  70   return &aItems[static_cast<size_t>(mapped)];
  71 }
  72
  73 template <typename Item, typename UInt, typename Id>
  74 void AddToMap(nsTArray<Item>& aItems, nsTArray<UInt>& aMap, Id aId,
  75               Maybe<Item>&& aNewItem) {
  76   auto mapIndex = size_t(aId);
  77   aMap.EnsureLengthAtLeast(mapIndex + 1);
  78   if (aNewItem.isNothing()) {
  79     aMap[mapIndex] = std::numeric_limits<UInt>::max();
  80     return;
  81   }
  82
  83   size_t newIndex = aItems.Length();
  84   MOZ_ASSERT(newIndex < std::numeric_limits<UInt>::max());
  85
  86   // Check if there is an existing value in aItems that we can point to.
  87   //
  88   // The arrays should be small enough and contain few enough unique
  89   // values that sequential search here is reasonable.
  90   for (size_t i = 0; i < newIndex; ++i) {
  91     if (aItems[i] == aNewItem.ref()) {
  92       aMap[mapIndex] = static_cast<UInt>(i);
  93       return;
  94     }
  95   }
  96
  97   aItems.AppendElement(aNewItem.extract());
  98   aMap[mapIndex] = static_cast<UInt>(newIndex);
  99 }
 100
 101 }  // namespace
 102
 103 nsresult RemoteLookAndFeel::NativeGetColor(ColorID aID, ColorScheme aScheme,
 104                                            nscolor& aResult) {
 105   const nscolor* result;
 106   const bool dark = aScheme == ColorScheme::Dark;
 107   MOZ_TRY_VAR(
 108       result,
 109       MapLookup(dark ? mTables.darkColors() : mTables.lightColors(),
 110                 dark ? mTables.darkColorMap() : mTables.lightColorMap(), aID));
 111   aResult = *result;
 112   return NS_OK;
 113 }
 114
 115 nsresult RemoteLookAndFeel::NativeGetInt(IntID aID, int32_t& aResult) {
 116   MOZ_DIAGNOSTIC_ASSERT(
 117       IsNeededInChildProcess(aID),
 118       "Querying value that we didn't bother getting from the parent process!");
 119
 120   const int32_t* result;
 121   MOZ_TRY_VAR(result, MapLookup(mTables.ints(), mTables.intMap(), aID));
 122   aResult = *result;
 123   return NS_OK;
 124 }
 125
 126 nsresult RemoteLookAndFeel::NativeGetFloat(FloatID aID, float& aResult) {
 127   const float* result;
 128   MOZ_TRY_VAR(result, MapLookup(mTables.floats(), mTables.floatMap(), aID));
 129   aResult = *result;
 130   return NS_OK;
 131 }
 132
 133 bool RemoteLookAndFeel::NativeGetFont(FontID aID, nsString& aFontName,
 134                                       gfxFontStyle& aFontStyle) {
 135   auto result = MapLookup(mTables.fonts(), mTables.fontMap(), aID);
 136   if (result.isErr()) {
 137     return false;
 138   }
 139   const LookAndFeelFont& font = *result.unwrap();
 140   return LookAndFeelFontToStyle(font, aFontName, aFontStyle);
 141 }
 142
 143 char16_t RemoteLookAndFeel::GetPasswordCharacterImpl() {
 144   return static_cast<char16_t>(mTables.passwordChar());
 145 }
 146
 147 bool RemoteLookAndFeel::GetEchoPasswordImpl() { return mTables.passwordEcho(); }
 148
 149 static bool AddIDsToMap(nsXPLookAndFeel* aImpl, FullLookAndFeel* aLf) {
 150   using IntID = LookAndFeel::IntID;
 151   using FontID = LookAndFeel::FontID;
 152   using FloatID = LookAndFeel::FloatID;
 153   using ColorID = LookAndFeel::ColorID;
 154   using ColorScheme = LookAndFeel::ColorScheme;
 155
 156   bool anyFromOtherTheme = false;
 157   for (auto id : MakeEnumeratedRange(IntID::End)) {
 158     if (!IsNeededInChildProcess(id)) {
 159       continue;
 160     }
 161     int32_t theInt;
 162     nsresult rv = aImpl->NativeGetInt(id, theInt);
 163     AddToMap(aLf->tables().ints(), aLf->tables().intMap(), id,
 164              NS_SUCCEEDED(rv) ? Some(theInt) : Nothing{});
 165   }
 166
 167   for (auto id : MakeEnumeratedRange(ColorID::End)) {
 168     nscolor theColor;
 169     nsresult rv = aImpl->NativeGetColor(id, ColorScheme::Light, theColor);
 170     AddToMap(aLf->tables().lightColors(), aLf->tables().lightColorMap(), id,
 171              NS_SUCCEEDED(rv) ? Some(theColor) : Nothing{});
 172     rv = aImpl->NativeGetColor(id, ColorScheme::Dark, theColor);
 173     AddToMap(aLf->tables().darkColors(), aLf->tables().darkColorMap(), id,
 174              NS_SUCCEEDED(rv) ? Some(theColor) : Nothing{});
 175   }
 176
 177   for (auto id : MakeEnumeratedRange(FloatID::End)) {
 178     float theFloat;
 179     nsresult rv = aImpl->NativeGetFloat(id, theFloat);
 180     AddToMap(aLf->tables().floats(), aLf->tables().floatMap(), id,
 181              NS_SUCCEEDED(rv) ? Some(theFloat) : Nothing{});
 182   }
 183
 184   for (auto id : MakeEnumeratedRange(FontID::End)) {
 185     gfxFontStyle fontStyle{};
 186
 187     nsString name;
 188     bool rv = aImpl->NativeGetFont(id, name, fontStyle);
 189     Maybe<LookAndFeelFont> maybeFont;
 190     if (rv) {
 191       maybeFont.emplace(
 192           nsXPLookAndFeel::StyleToLookAndFeelFont(name, fontStyle));
 193     }
 194     AddToMap(aLf->tables().fonts(), aLf->tables().fontMap(), id,
 195              std::move(maybeFont));
 196   }
 197
 198   return anyFromOtherTheme;
 199 }
 200
 201 // static
 202 const FullLookAndFeel* RemoteLookAndFeel::ExtractData() {
 203   MOZ_ASSERT(XRE_IsParentProcess(),
 204              "Only parent processes should be extracting LookAndFeel data");
 205
 206   if (sCachedLookAndFeelData) {
 207     return sCachedLookAndFeelData;
 208   }
 209
 210   static bool sInitialized = false;
 211   if (!sInitialized) {
 212     sInitialized = true;
 213     ClearOnShutdown(&sCachedLookAndFeelData);
 214   }
 215
 216   FullLookAndFeel* lf = new FullLookAndFeel{};
 217   nsXPLookAndFeel* impl = nsXPLookAndFeel::GetInstance();
 218
 219   lf->tables().passwordChar() = impl->GetPasswordCharacterImpl();
 220   lf->tables().passwordEcho() = impl->GetEchoPasswordImpl();
 221
 222   AddIDsToMap(impl, lf);
 223
 224   // This assignment to sCachedLookAndFeelData must be done after the
 225   // WithThemeConfiguredForContent call, since it can end up calling RefreshImpl
 226   // on the LookAndFeel, which will clear out sCachedTables.
 227   sCachedLookAndFeelData = lf;
 228   return sCachedLookAndFeelData;
 229 }
 230
 231 void RemoteLookAndFeel::ClearCachedData() {
 232   MOZ_ASSERT(XRE_IsParentProcess());
 233   sCachedLookAndFeelData = nullptr;
 234 }
 235
 236 }  // namespace mozilla::widget