dom/l10n/L10nMutations.cpp

   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 "L10nMutations.h"
   8 #include "mozilla/dom/DocumentInlines.h"
   9 #include "nsRefreshDriver.h"
  10 #include "DOMLocalization.h"
  11 #include "mozilla/intl/Localization.h"
  12 #include "nsThreadManager.h"
  13
  14 using namespace mozilla;
  15 using namespace mozilla::intl;
  16 using namespace mozilla::dom;
  17
  18 NS_IMPL_CYCLE_COLLECTION_CLASS(L10nMutations)
  19
  20 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(L10nMutations)
  21   NS_IMPL_CYCLE_COLLECTION_UNLINK(mPendingElements)
  22   NS_IMPL_CYCLE_COLLECTION_UNLINK(mPendingElementsHash)
  23 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
  24
  25 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(L10nMutations)
  26   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPendingElements)
  27   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPendingElementsHash)
  28 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
  29
  30 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(L10nMutations)
  31   NS_INTERFACE_MAP_ENTRY(nsIMutationObserver)
  32   NS_INTERFACE_MAP_ENTRY(nsISupports)
  33 NS_INTERFACE_MAP_END
  34
  35 NS_IMPL_CYCLE_COLLECTING_ADDREF(L10nMutations)
  36 NS_IMPL_CYCLE_COLLECTING_RELEASE(L10nMutations)
  37
  38 L10nMutations::L10nMutations(DOMLocalization* aDOMLocalization)
  39     : mDOMLocalization(aDOMLocalization) {
  40   mObserving = true;
  41 }
  42
  43 L10nMutations::~L10nMutations() {
  44   StopRefreshObserver();
  45   MOZ_ASSERT(!mDOMLocalization,
  46              "DOMLocalization<-->L10nMutations cycle should be broken.");
  47 }
  48
  49 void L10nMutations::AttributeChanged(Element* aElement, int32_t aNameSpaceID,
  50                                      nsAtom* aAttribute, int32_t aModType,
  51                                      const nsAttrValue* aOldValue) {
  52   if (!mObserving) {
  53     return;
  54   }
  55
  56   if (aNameSpaceID == kNameSpaceID_None &&
  57       (aAttribute == nsGkAtoms::datal10nid ||
  58        aAttribute == nsGkAtoms::datal10nargs)) {
  59     if (IsInRoots(aElement)) {
  60       L10nElementChanged(aElement);
  61     }
  62   }
  63 }
  64
  65 void L10nMutations::ContentAppended(nsIContent* aChild) {
  66   if (!mObserving) {
  67     return;
  68   }
  69
  70   if (!IsInRoots(aChild)) {
  71     return;
  72   }
  73
  74   Sequence<OwningNonNull<Element>> elements;
  75   for (nsIContent* node = aChild; node; node = node->GetNextSibling()) {
  76     if (node->IsElement()) {
  77       DOMLocalization::GetTranslatables(*node, elements, IgnoreErrors());
  78     }
  79   }
  80
  81   for (auto& elem : elements) {
  82     L10nElementChanged(elem);
  83   }
  84 }
  85
  86 void L10nMutations::ContentInserted(nsIContent* aChild) {
  87   if (!mObserving) {
  88     return;
  89   }
  90
  91   if (!aChild->IsElement()) {
  92     return;
  93   }
  94   Element* elem = aChild->AsElement();
  95
  96   if (!IsInRoots(elem)) {
  97     return;
  98   }
  99
 100   Sequence<OwningNonNull<Element>> elements;
 101   DOMLocalization::GetTranslatables(*aChild, elements, IgnoreErrors());
 102
 103   for (auto& elem : elements) {
 104     L10nElementChanged(elem);
 105   }
 106 }
 107
 108 void L10nMutations::ContentWillBeRemoved(nsIContent* aChild,
 109                                          const BatchRemovalState*) {
 110   if (!mObserving || mPendingElements.IsEmpty()) {
 111     return;
 112   }
 113
 114   Element* elem = Element::FromNode(*aChild);
 115   if (!elem || !IsInRoots(elem)) {
 116     return;
 117   }
 118
 119   Sequence<OwningNonNull<Element>> elements;
 120   DOMLocalization::GetTranslatables(*aChild, elements, IgnoreErrors());
 121
 122   for (auto& elem : elements) {
 123     if (mPendingElementsHash.EnsureRemoved(elem)) {
 124       mPendingElements.RemoveElement(elem);
 125     }
 126   }
 127
 128   if (!HasPendingMutations()) {
 129     nsContentUtils::AddScriptRunner(NewRunnableMethod(
 130         "MaybeFirePendingTranslationsFinished", this,
 131         &L10nMutations::MaybeFirePendingTranslationsFinished));
 132   }
 133 }
 134
 135 void L10nMutations::L10nElementChanged(Element* aElement) {
 136   const bool wasEmpty = mPendingElements.IsEmpty();
 137
 138   if (mPendingElementsHash.EnsureInserted(aElement)) {
 139     mPendingElements.AppendElement(aElement);
 140   }
 141
 142   if (!wasEmpty) {
 143     return;
 144   }
 145
 146   if (!mRefreshDriver) {
 147     StartRefreshObserver();
 148   }
 149
 150   if (!mBlockingLoad) {
 151     Document* doc = GetDocument();
 152     if (doc && doc->GetReadyStateEnum() != Document::READYSTATE_COMPLETE) {
 153       doc->BlockOnload();
 154       mBlockingLoad = true;
 155     }
 156   }
 157
 158   if (mBlockingLoad && !mPendingBlockingLoadFlush) {
 159     // We want to make sure we flush translations and don't block the load
 160     // indefinitely (and, in fact, that we do it rather soon, even if the
 161     // refresh driver is not ticking yet).
 162     //
 163     // In some platforms (mainly Wayland) the load of the main document
 164     // causes vsync to start running and start ticking the refresh driver,
 165     // so we can't rely on the refresh driver ticking yet.
 166     RefPtr<nsIRunnable> task =
 167         NewRunnableMethod("FlushPendingTranslationsBeforeLoad", this,
 168                           &L10nMutations::FlushPendingTranslationsBeforeLoad);
 169     nsThreadManager::get().DispatchDirectTaskToCurrentThread(task);
 170     mPendingBlockingLoadFlush = true;
 171   }
 172 }
 173
 174 void L10nMutations::PauseObserving() { mObserving = false; }
 175
 176 void L10nMutations::ResumeObserving() { mObserving = true; }
 177
 178 void L10nMutations::WillRefresh(mozilla::TimeStamp aTime) {
 179   StopRefreshObserver();
 180   FlushPendingTranslations();
 181 }
 182
 183 /**
 184  * The handler for the `TranslateElements` promise used to turn
 185  * a potential rejection into a console warning.
 186  **/
 187 class L10nMutationFinalizationHandler final : public PromiseNativeHandler {
 188  public:
 189   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
 190   NS_DECL_CYCLE_COLLECTION_CLASS(L10nMutationFinalizationHandler)
 191
 192   explicit L10nMutationFinalizationHandler(L10nMutations* aMutations,
 193                                            nsIGlobalObject* aGlobal)
 194       : mMutations(aMutations), mGlobal(aGlobal) {}
 195
 196   MOZ_CAN_RUN_SCRIPT void Settled() {
 197     if (RefPtr mutations = mMutations) {
 198       mutations->PendingPromiseSettled();
 199     }
 200   }
 201
 202   MOZ_CAN_RUN_SCRIPT void ResolvedCallback(JSContext* aCx,
 203                                            JS::Handle<JS::Value> aValue,
 204                                            ErrorResult& aRv) override {
 205     Settled();
 206   }
 207
 208   MOZ_CAN_RUN_SCRIPT void RejectedCallback(JSContext* aCx,
 209                                            JS::Handle<JS::Value> aValue,
 210                                            ErrorResult& aRv) override {
 211     nsTArray<nsCString> errors{
 212         "[dom/l10n] Errors during l10n mutation frame."_ns,
 213     };
 214     MaybeReportErrorsToGecko(errors, IgnoreErrors(), mGlobal);
 215     Settled();
 216   }
 217
 218  private:
 219   ~L10nMutationFinalizationHandler() = default;
 220
 221   RefPtr<L10nMutations> mMutations;
 222   nsCOMPtr<nsIGlobalObject> mGlobal;
 223 };
 224
 225 NS_IMPL_CYCLE_COLLECTION(L10nMutationFinalizationHandler, mGlobal, mMutations)
 226
 227 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(L10nMutationFinalizationHandler)
 228   NS_INTERFACE_MAP_ENTRY(nsISupports)
 229 NS_INTERFACE_MAP_END
 230
 231 NS_IMPL_CYCLE_COLLECTING_ADDREF(L10nMutationFinalizationHandler)
 232 NS_IMPL_CYCLE_COLLECTING_RELEASE(L10nMutationFinalizationHandler)
 233
 234 void L10nMutations::FlushPendingTranslationsBeforeLoad() {
 235   MOZ_ASSERT(mPendingBlockingLoadFlush);
 236   mPendingBlockingLoadFlush = false;
 237   FlushPendingTranslations();
 238 }
 239
 240 void L10nMutations::FlushPendingTranslations() {
 241   if (!mDOMLocalization) {
 242     return;
 243   }
 244
 245   nsTArray<OwningNonNull<Element>> elements;
 246   for (auto& elem : mPendingElements) {
 247     if (elem->HasAttr(nsGkAtoms::datal10nid)) {
 248       elements.AppendElement(*elem);
 249     }
 250   }
 251
 252   mPendingElementsHash.Clear();
 253   mPendingElements.Clear();
 254
 255   RefPtr<Promise> promise =
 256       mDOMLocalization->TranslateElements(elements, IgnoreErrors());
 257   if (promise && promise->State() == Promise::PromiseState::Pending) {
 258     mPendingPromises++;
 259     auto l10nMutationFinalizationHandler =
 260         MakeRefPtr<L10nMutationFinalizationHandler>(
 261             this, mDOMLocalization->GetParentObject());
 262     promise->AppendNativeHandler(l10nMutationFinalizationHandler);
 263   }
 264
 265   MaybeFirePendingTranslationsFinished();
 266 }
 267
 268 void L10nMutations::PendingPromiseSettled() {
 269   MOZ_DIAGNOSTIC_ASSERT(mPendingPromises);
 270   mPendingPromises--;
 271   MaybeFirePendingTranslationsFinished();
 272 }
 273
 274 void L10nMutations::MaybeFirePendingTranslationsFinished() {
 275   if (HasPendingMutations()) {
 276     return;
 277   }
 278
 279   RefPtr doc = GetDocument();
 280   if (NS_WARN_IF(!doc)) {
 281     return;
 282   }
 283
 284   if (mBlockingLoad) {
 285     mBlockingLoad = false;
 286     doc->UnblockOnload(false);
 287   }
 288   nsContentUtils::DispatchEventOnlyToChrome(
 289       doc, doc, u"L10nMutationsFinished"_ns, CanBubble::eNo, Cancelable::eNo,
 290       Composed::eNo, nullptr);
 291 }
 292
 293 void L10nMutations::Disconnect() {
 294   StopRefreshObserver();
 295   mDOMLocalization = nullptr;
 296 }
 297
 298 Document* L10nMutations::GetDocument() const {
 299   if (!mDOMLocalization) {
 300     return nullptr;
 301   }
 302   auto* innerWindow = mDOMLocalization->GetParentObject()->GetAsInnerWindow();
 303   if (!innerWindow) {
 304     return nullptr;
 305   }
 306   return innerWindow->GetExtantDoc();
 307 }
 308
 309 void L10nMutations::StartRefreshObserver() {
 310   if (!mDOMLocalization || mRefreshDriver) {
 311     return;
 312   }
 313   if (Document* doc = GetDocument()) {
 314     if (nsPresContext* ctx = doc->GetPresContext()) {
 315       mRefreshDriver = ctx->RefreshDriver();
 316     }
 317   }
 318
 319   // If we can't start the refresh driver, it means
 320   // that the presContext is not available yet.
 321   // In that case, we'll trigger the flush of pending
 322   // elements in Document::CreatePresShell.
 323   if (mRefreshDriver) {
 324     mRefreshDriver->AddRefreshObserver(this, FlushType::Style,
 325                                        "L10n mutations");
 326   } else {
 327     NS_WARNING("[l10n][mutations] Failed to start a refresh observer.");
 328   }
 329 }
 330
 331 void L10nMutations::StopRefreshObserver() {
 332   if (mRefreshDriver) {
 333     mRefreshDriver->RemoveRefreshObserver(this, FlushType::Style);
 334     mRefreshDriver = nullptr;
 335   }
 336 }
 337
 338 void L10nMutations::OnCreatePresShell() {
 339   StopRefreshObserver();
 340   if (!mPendingElements.IsEmpty()) {
 341     StartRefreshObserver();
 342   }
 343 }
 344
 345 bool L10nMutations::IsInRoots(nsINode* aNode) {
 346   // If the root of the mutated element is in the light DOM,
 347   // we know it must be covered by our observer directly.
 348   //
 349   // Otherwise, we need to check if its subtree root is the same
 350   // as any of the `DOMLocalization::mRoots` subtree roots.
 351   nsINode* root = aNode->SubtreeRoot();
 352
 353   // If element is in light DOM, it must be covered by one of
 354   // the DOMLocalization roots to end up here.
 355   MOZ_ASSERT_IF(!root->IsShadowRoot(),
 356                 mDOMLocalization->SubtreeRootInRoots(root));
 357
 358   return !root->IsShadowRoot() || mDOMLocalization->SubtreeRootInRoots(root);
 359 }