1 files changed, 371 insertions, 0 deletions

diff --git a/layout/base/nsCounterManager.cpp b/layout/base/nsCounterManager.cpp
new file mode 100644
index 0000000000..eab6a3ba91
--- /dev/null
+++ b/layout/base/nsCounterManager.cpp
@@ -0,0 +1,371 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* implementation of CSS counters (for numbering things) */
+
+#include "nsCounterManager.h"
+
+#include "mozilla/Likely.h"
+#include "mozilla/IntegerRange.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/StaticPrefs_layout.h"
+#include "mozilla/WritingModes.h"
+#include "nsBulletFrame.h"  // legacy location for list style type to text code
+#include "nsContentUtils.h"
+#include "nsIContent.h"
+#include "nsTArray.h"
+#include "mozilla/dom/Text.h"
+
+using namespace mozilla;
+
+bool nsCounterUseNode::InitTextFrame(nsGenConList* aList,
+                                     nsIFrame* aPseudoFrame,
+                                     nsIFrame* aTextFrame) {
+  nsCounterNode::InitTextFrame(aList, aPseudoFrame, aTextFrame);
+
+  auto* counterList = static_cast<nsCounterList*>(aList);
+  counterList->Insert(this);
+  aPseudoFrame->AddStateBits(NS_FRAME_HAS_CSS_COUNTER_STYLE);
+  // If the list is already dirty, or the node is not at the end, just start
+  // with an empty string for now and when we recalculate the list we'll change
+  // the value to the right one.
+  if (counterList->IsDirty()) {
+    return false;
+  }
+  if (!counterList->IsLast(this)) {
+    counterList->SetDirty();
+    return true;
+  }
+  Calc(counterList, /* aNotify = */ false);
+  return false;
+}
+
+bool nsCounterUseNode::InitBullet(nsGenConList* aList, nsIFrame* aBullet) {
+  MOZ_ASSERT(aBullet->IsBulletFrame());
+  MOZ_ASSERT(aBullet->Style()->GetPseudoType() == PseudoStyleType::marker);
+  MOZ_ASSERT(mForLegacyBullet);
+  return InitTextFrame(aList, aBullet, nullptr);
+}
+
+// assign the correct |mValueAfter| value to a node that has been inserted
+// Should be called immediately after calling |Insert|.
+void nsCounterUseNode::Calc(nsCounterList* aList, bool aNotify) {
+  NS_ASSERTION(!aList->IsDirty(), "Why are we calculating with a dirty list?");
+  mValueAfter = nsCounterList::ValueBefore(this);
+  if (mText) {
+    nsAutoString contentString;
+    GetText(contentString);
+    mText->SetText(contentString, aNotify);
+  } else if (mForLegacyBullet) {
+    MOZ_ASSERT_IF(mPseudoFrame, mPseudoFrame->IsBulletFrame());
+    if (nsBulletFrame* f = do_QueryFrame(mPseudoFrame)) {
+      f->SetOrdinal(mValueAfter, aNotify);
+    }
+  }
+}
+
+// assign the correct |mValueAfter| value to a node that has been inserted
+// Should be called immediately after calling |Insert|.
+void nsCounterChangeNode::Calc(nsCounterList* aList) {
+  NS_ASSERTION(!aList->IsDirty(), "Why are we calculating with a dirty list?");
+  if (IsContentBasedReset()) {
+    // RecalcAll takes care of this case.
+  } else if (mType == RESET || mType == SET) {
+    mValueAfter = mChangeValue;
+  } else {
+    NS_ASSERTION(mType == INCREMENT, "invalid type");
+    mValueAfter = nsCounterManager::IncrementCounter(
+        nsCounterList::ValueBefore(this), mChangeValue);
+  }
+}
+
+// The text that should be displayed for this counter.
+void nsCounterUseNode::GetText(nsString& aResult) {
+  aResult.Truncate();
+
+  AutoTArray<nsCounterNode*, 8> stack;
+  stack.AppendElement(static_cast<nsCounterNode*>(this));
+
+  if (mAllCounters && mScopeStart) {
+    for (nsCounterNode* n = mScopeStart; n->mScopePrev; n = n->mScopeStart) {
+      stack.AppendElement(n->mScopePrev);
+    }
+  }
+
+  WritingMode wm = mPseudoFrame->GetWritingMode();
+  CounterStyle* style =
+      mPseudoFrame->PresContext()->CounterStyleManager()->ResolveCounterStyle(
+          mCounterStyle);
+  for (uint32_t i = stack.Length() - 1;; --i) {
+    nsCounterNode* n = stack[i];
+    nsAutoString text;
+    bool isTextRTL;
+    style->GetCounterText(n->mValueAfter, wm, text, isTextRTL);
+    aResult.Append(text);
+    if (i == 0) {
+      break;
+    }
+    aResult.Append(mSeparator);
+  }
+}
+
+void nsCounterList::SetScope(nsCounterNode* aNode) {
+  // This function is responsible for setting |mScopeStart| and
+  // |mScopePrev| (whose purpose is described in nsCounterManager.h).
+  // We do this by starting from the node immediately preceding
+  // |aNode| in content tree order, which is reasonably likely to be
+  // the previous element in our scope (or, for a reset, the previous
+  // element in the containing scope, which is what we want).  If
+  // we're not in the same scope that it is, then it's too deep in the
+  // frame tree, so we walk up parent scopes until we find something
+  // appropriate.
+
+  if (aNode == First()) {
+    aNode->mScopeStart = nullptr;
+    aNode->mScopePrev = nullptr;
+    return;
+  }
+
+  // If there exist an explicit RESET scope created by an ancestor or
+  // the element itself, then we use that scope.
+  // Otherwise, fall through to consider scopes created by siblings (and
+  // their descendants) in reverse document order.
+  if (aNode->mType != nsCounterNode::USE &&
+      StaticPrefs::layout_css_counter_ancestor_scope_enabled()) {
+    nsIContent* const counterNode = aNode->mPseudoFrame->GetContent();
+    nsCounterNode* lastPrev = nullptr;
+    for (nsCounterNode* prev = Prev(aNode); prev; prev = prev->mScopePrev) {
+      if (prev->mType == nsCounterNode::RESET) {
+        if (aNode->mPseudoFrame == prev->mPseudoFrame) {
+          break;
+        }
+        // FIXME(bug 1477524): should use flattened tree here:
+        nsIContent* resetNode = prev->mPseudoFrame->GetContent();
+        if (counterNode->IsInclusiveDescendantOf(resetNode)) {
+          aNode->mScopeStart = prev;
+          aNode->mScopePrev = lastPrev ? lastPrev : prev;
+          return;
+        }
+        lastPrev = prev->mScopePrev;
+      } else if (!lastPrev) {
+        lastPrev = prev;
+      }
+    }
+  }
+
+  // Get the content node for aNode's rendering object's *parent*,
+  // since scope includes siblings, so we want a descendant check on
+  // parents.
+  nsIContent* nodeContent = aNode->mPseudoFrame->GetContent()->GetParent();
+
+  for (nsCounterNode *prev = Prev(aNode), *start; prev;
+       prev = start->mScopePrev) {
+    // If |prev| starts a scope (because it's a real or implied
+    // reset), we want it as the scope start rather than the start
+    // of its enclosing scope.  Otherwise, there's no enclosing
+    // scope, so the next thing in prev's scope shares its scope
+    // start.
+    start = (prev->mType == nsCounterNode::RESET || !prev->mScopeStart)
+                ? prev
+                : prev->mScopeStart;
+
+    // |startContent| is analogous to |nodeContent| (see above).
+    nsIContent* startContent = start->mPseudoFrame->GetContent()->GetParent();
+    NS_ASSERTION(nodeContent || !startContent,
+                 "null check on startContent should be sufficient to "
+                 "null check nodeContent as well, since if nodeContent "
+                 "is for the root, startContent (which is before it) "
+                 "must be too");
+
+    // A reset's outer scope can't be a scope created by a sibling.
+    if (!(aNode->mType == nsCounterNode::RESET &&
+          nodeContent == startContent) &&
+        // everything is inside the root (except the case above,
+        // a second reset on the root)
+        // FIXME(bug 1477524): should use flattened tree here:
+        (!startContent || nodeContent->IsInclusiveDescendantOf(startContent))) {
+      aNode->mScopeStart = start;
+      aNode->mScopePrev = prev;
+      return;
+    }
+  }
+
+  aNode->mScopeStart = nullptr;
+  aNode->mScopePrev = nullptr;
+}
+
+void nsCounterList::RecalcAll() {
+  mDirty = false;
+
+  // Setup the scope and calculate the default start value for <ol reversed>.
+  for (nsCounterNode* node = First(); node; node = Next(node)) {
+    SetScope(node);
+    if (node->IsContentBasedReset()) {
+      node->mValueAfter = 1;
+    } else if (node->mType == nsCounterChangeNode::INCREMENT &&
+               node->mScopeStart && node->mScopeStart->IsContentBasedReset() &&
+               node->mPseudoFrame->StyleDisplay()->IsListItem()) {
+      ++node->mScopeStart->mValueAfter;
+    }
+  }
+
+  for (nsCounterNode* node = First(); node; node = Next(node)) {
+    node->Calc(this, /* aNotify = */ true);
+  }
+}
+
+static bool AddCounterChangeNode(nsCounterManager& aManager, nsIFrame* aFrame,
+                                 int32_t aIndex,
+                                 const nsStyleContent::CounterPair& aPair,
+                                 nsCounterNode::Type aType) {
+  auto* node = new nsCounterChangeNode(aFrame, aType, aPair.value, aIndex);
+  nsCounterList* counterList = aManager.CounterListFor(aPair.name.AsAtom());
+  counterList->Insert(node);
+  if (!counterList->IsLast(node)) {
+    // Tell the caller it's responsible for recalculating the entire
+    // list.
+    counterList->SetDirty();
+    return true;
+  }
+
+  // Don't call Calc() if the list is already dirty -- it'll be recalculated
+  // anyway, and trying to calculate with a dirty list doesn't work.
+  if (MOZ_LIKELY(!counterList->IsDirty())) {
+    node->Calc(counterList);
+  }
+  return false;
+}
+
+static bool HasCounters(const nsStyleContent& aStyle) {
+  return !aStyle.mCounterIncrement.IsEmpty() ||
+         !aStyle.mCounterReset.IsEmpty() || !aStyle.mCounterSet.IsEmpty();
+}
+
+bool nsCounterManager::AddCounterChanges(nsIFrame* aFrame) {
+  // For elements with 'display:list-item' we add a default
+  // 'counter-increment:list-item' unless 'counter-increment' already has a
+  // value for 'list-item'.
+  //
+  // https://drafts.csswg.org/css-lists-3/#declaring-a-list-item
+  //
+  // We inherit `display` for some anonymous boxes, but we don't want them to
+  // increment the list-item counter.
+  const bool requiresListItemIncrement =
+      aFrame->StyleDisplay()->IsListItem() && !aFrame->Style()->IsAnonBox();
+
+  const nsStyleContent* styleContent = aFrame->StyleContent();
+
+  if (!requiresListItemIncrement && !HasCounters(*styleContent)) {
+    MOZ_ASSERT(!aFrame->HasAnyStateBits(NS_FRAME_HAS_CSS_COUNTER_STYLE));
+    return false;
+  }
+
+  aFrame->AddStateBits(NS_FRAME_HAS_CSS_COUNTER_STYLE);
+
+  bool dirty = false;
+  // Add in order, resets first, so all the comparisons will be optimized
+  // for addition at the end of the list.
+  {
+    int32_t i = 0;
+    for (const auto& pair : styleContent->mCounterReset.AsSpan()) {
+      dirty |= AddCounterChangeNode(*this, aFrame, i++, pair,
+                                    nsCounterChangeNode::RESET);
+    }
+  }
+  bool hasListItemIncrement = false;
+  {
+    int32_t i = 0;
+    for (const auto& pair : styleContent->mCounterIncrement.AsSpan()) {
+      hasListItemIncrement |= pair.name.AsAtom() == nsGkAtoms::list_item;
+      dirty |= AddCounterChangeNode(*this, aFrame, i++, pair,
+                                    nsCounterChangeNode::INCREMENT);
+    }
+  }
+
+  if (requiresListItemIncrement && !hasListItemIncrement) {
+    bool reversed =
+        aFrame->StyleList()->mMozListReversed == StyleMozListReversed::True;
+    RefPtr<nsAtom> atom = nsGkAtoms::list_item;
+    auto listItemIncrement = nsStyleContent::CounterPair{
+        {StyleAtom(atom.forget())}, reversed ? -1 : 1};
+    dirty |= AddCounterChangeNode(
+        *this, aFrame, styleContent->mCounterIncrement.Length(),
+        listItemIncrement, nsCounterChangeNode::INCREMENT);
+  }
+
+  {
+    int32_t i = 0;
+    for (const auto& pair : styleContent->mCounterSet.AsSpan()) {
+      dirty |= AddCounterChangeNode(*this, aFrame, i++, pair,
+                                    nsCounterChangeNode::SET);
+    }
+  }
+  return dirty;
+}
+
+nsCounterList* nsCounterManager::CounterListFor(nsAtom* aCounterName) {
+  MOZ_ASSERT(aCounterName);
+  return mNames.LookupForAdd(aCounterName)
+      .OrInsert([]() { return new nsCounterList(); })
+      .get();
+}
+
+void nsCounterManager::RecalcAll() {
+  for (auto iter = mNames.Iter(); !iter.Done(); iter.Next()) {
+    nsCounterList* list = iter.UserData();
+    if (list->IsDirty()) {
+      list->RecalcAll();
+    }
+  }
+}
+
+void nsCounterManager::SetAllDirty() {
+  for (auto iter = mNames.Iter(); !iter.Done(); iter.Next()) {
+    iter.UserData()->SetDirty();
+  }
+}
+
+bool nsCounterManager::DestroyNodesFor(nsIFrame* aFrame) {
+  MOZ_ASSERT(aFrame->HasAnyStateBits(NS_FRAME_HAS_CSS_COUNTER_STYLE),
+             "why call me?");
+  bool destroyedAny = false;
+  for (auto iter = mNames.Iter(); !iter.Done(); iter.Next()) {
+    nsCounterList* list = iter.UserData();
+    if (list->DestroyNodesFor(aFrame)) {
+      destroyedAny = true;
+      list->SetDirty();
+    }
+  }
+  return destroyedAny;
+}
+
+#ifdef DEBUG
+void nsCounterManager::Dump() {
+  printf("\n\nCounter Manager Lists:\n");
+  for (auto iter = mNames.Iter(); !iter.Done(); iter.Next()) {
+    printf("Counter named \"%s\":\n", nsAtomCString(iter.Key()).get());
+
+    nsCounterList* list = iter.UserData();
+    int32_t i = 0;
+    for (nsCounterNode* node = list->First(); node; node = list->Next(node)) {
+      const char* types[] = {"RESET", "SET", "INCREMENT", "USE"};
+      printf(
+          "  Node #%d @%p frame=%p index=%d type=%s valAfter=%d\n"
+          "       scope-start=%p scope-prev=%p",
+          i++, (void*)node, (void*)node->mPseudoFrame, node->mContentIndex,
+          types[node->mType], node->mValueAfter, (void*)node->mScopeStart,
+          (void*)node->mScopePrev);
+      if (node->mType == nsCounterNode::USE) {
+        nsAutoString text;
+        node->UseNode()->GetText(text);
+        printf(" text=%s", NS_ConvertUTF16toUTF8(text).get());
+      }
+      printf("\n");
+    }
+  }
+  printf("\n\n");
+}
+#endif