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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+// vim:cindent:ai:sw=4:ts=4:et:
+/* 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) */
+
+#ifndef nsCounterManager_h_
+#define nsCounterManager_h_
+
+#include "mozilla/Attributes.h"
+#include "nsGenConList.h"
+#include "nsClassHashtable.h"
+#include "mozilla/Likely.h"
+#include "CounterStyleManager.h"
+
+class nsCounterList;
+struct nsCounterUseNode;
+struct nsCounterChangeNode;
+
+namespace mozilla {
+
+class ContainStyleScope;
+
+} // namespace mozilla
+
+struct nsCounterNode : public nsGenConNode {
+ enum Type {
+ RESET, // a "counter number" pair in 'counter-reset'
+ INCREMENT, // a "counter number" pair in 'counter-increment'
+ SET, // a "counter number" pair in 'counter-set'
+ USE // counter() or counters() in 'content'
+ };
+
+ Type mType;
+
+ // Counter value after this node
+ int32_t mValueAfter = 0;
+
+ // mScopeStart points to the node (usually a RESET, but not in the
+ // case of an implied 'counter-reset') that created the scope for
+ // this element (for a RESET, its outer scope, i.e., the one it is
+ // inside rather than the one it creates).
+
+ // May be null for all types, but only when mScopePrev is also null.
+ // Being null for a non-RESET means that it is an implied
+ // 'counter-reset'. Being null for a RESET means it has no outer
+ // scope.
+ nsCounterNode* mScopeStart = nullptr;
+
+ // mScopePrev points to the previous node that is in the same scope,
+ // or for a RESET, the previous node in the scope outside of the
+ // reset.
+
+ // May be null for all types, but only when mScopeStart is also
+ // null. Following the mScopePrev links will eventually lead to
+ // mScopeStart. Being null for a non-RESET means that it is an
+ // implied 'counter-reset'. Being null for a RESET means it has no
+ // outer scope.
+ nsCounterNode* mScopePrev = nullptr;
+
+ // Whether or not this node's scope crosses `contain: style` boundaries.
+ // This can happen for USE nodes that come before any other types of
+ // nodes in a `contain: style` boundary's list.
+ bool mCrossesContainStyleBoundaries = false;
+
+ inline nsCounterUseNode* UseNode();
+ inline nsCounterChangeNode* ChangeNode();
+
+ // For RESET, INCREMENT and SET nodes, aPseudoFrame need not be a
+ // pseudo-element, and aContentIndex represents the index within the
+ // 'counter-reset', 'counter-increment' or 'counter-set' property
+ // instead of within the 'content' property but offset to ensure
+ // that (reset, increment, set, use) sort in that order.
+ // It is zero for legacy bullet USE counter nodes.
+ // (This slight weirdness allows sharing a lot of code with 'quotes'.)
+ nsCounterNode(int32_t aContentIndex, Type aType)
+ : nsGenConNode(aContentIndex), mType(aType) {}
+
+ // to avoid virtual function calls in the common case
+ inline void Calc(nsCounterList* aList, bool aNotify);
+
+ // Is this a RESET node for a content-based (i.e. without a start value)
+ // reversed() counter?
+ inline bool IsContentBasedReset();
+
+ // Is this a RESET node for a reversed() counter?
+ inline bool IsReversed();
+
+ // Is this an INCREMENT node that needs to be initialized to -1 or 1
+ // depending on if our scope is reversed() or not?
+ inline bool IsUnitializedIncrementNode();
+};
+
+struct nsCounterUseNode : public nsCounterNode {
+ mozilla::CounterStylePtr mCounterStyle;
+ nsString mSeparator;
+
+ // false for counter(), true for counters()
+ bool mAllCounters = false;
+
+ bool mForLegacyBullet = false;
+
+ enum ForLegacyBullet { ForLegacyBullet };
+ nsCounterUseNode(enum ForLegacyBullet, mozilla::CounterStylePtr aCounterStyle)
+ : nsCounterNode(0, USE),
+ mCounterStyle(std::move(aCounterStyle)),
+ mForLegacyBullet(true) {}
+
+ // args go directly to member variables here and of nsGenConNode
+ nsCounterUseNode(mozilla::CounterStylePtr aCounterStyle, nsString aSeparator,
+ uint32_t aContentIndex, bool aAllCounters)
+ : nsCounterNode(aContentIndex, USE),
+ mCounterStyle(std::move(aCounterStyle)),
+ mSeparator(std::move(aSeparator)),
+ mAllCounters(aAllCounters) {
+ NS_ASSERTION(aContentIndex <= INT32_MAX, "out of range");
+ }
+
+ bool InitTextFrame(nsGenConList* aList, nsIFrame* aPseudoFrame,
+ nsIFrame* aTextFrame) override;
+
+ // assign the correct |mValueAfter| value to a node that has been inserted,
+ // and update the value of the text node, notifying if `aNotify` is true.
+ // Should be called immediately after calling |Insert|.
+ void Calc(nsCounterList* aList, bool aNotify);
+
+ // The text that should be displayed for this counter.
+ void GetText(nsString& aResult);
+ void GetText(mozilla::WritingMode aWM, mozilla::CounterStyle* aStyle,
+ nsString& aResult);
+};
+
+struct nsCounterChangeNode : public nsCounterNode {
+ // |aPseudoFrame| is not necessarily a pseudo-element's frame, but
+ // since it is for every other subclass of nsGenConNode, we follow
+ // the naming convention here.
+ // |aPropIndex| is the index of the value within the list in the
+ // 'counter-increment', 'counter-reset' or 'counter-set' property.
+ nsCounterChangeNode(nsIFrame* aPseudoFrame, nsCounterNode::Type aChangeType,
+ int32_t aChangeValue, int32_t aPropIndex,
+ bool aIsReversed)
+ : nsCounterNode( // Fake a content index for resets, increments and sets
+ // that comes before all the real content, with
+ // the resets first, in order, and then the increments
+ // and then the sets.
+ aPropIndex + (aChangeType == RESET ? (INT32_MIN)
+ : (aChangeType == INCREMENT
+ ? ((INT32_MIN / 3) * 2)
+ : INT32_MIN / 3)),
+ aChangeType),
+ mChangeValue(aChangeValue),
+ mIsReversed(aIsReversed),
+ mSeenSetNode(false) {
+ NS_ASSERTION(aPropIndex >= 0, "out of range");
+ NS_ASSERTION(
+ aChangeType == INCREMENT || aChangeType == SET || aChangeType == RESET,
+ "bad type");
+ mPseudoFrame = aPseudoFrame;
+ CheckFrameAssertions();
+ }
+
+ // assign the correct |mValueAfter| value to a node that has been inserted
+ // Should be called immediately after calling |Insert|.
+ void Calc(nsCounterList* aList);
+
+ // The numeric value of the INCREMENT, SET or RESET.
+ // Note: numeric_limits<int32_t>::min() is used for content-based reversed()
+ // RESET nodes, and temporarily on INCREMENT nodes to signal that it should be
+ // initialized to -1 or 1 depending on if the scope is reversed() or not.
+ int32_t mChangeValue;
+
+ // True if the counter is reversed(). Only used on RESET nodes.
+ bool mIsReversed : 1;
+ // True if we've seen a SET node during the initialization of
+ // an IsContentBasedReset() node; always false on other nodes.
+ bool mSeenSetNode : 1;
+};
+
+inline nsCounterUseNode* nsCounterNode::UseNode() {
+ NS_ASSERTION(mType == USE, "wrong type");
+ return static_cast<nsCounterUseNode*>(this);
+}
+
+inline nsCounterChangeNode* nsCounterNode::ChangeNode() {
+ MOZ_ASSERT(mType == INCREMENT || mType == SET || mType == RESET);
+ return static_cast<nsCounterChangeNode*>(this);
+}
+
+inline void nsCounterNode::Calc(nsCounterList* aList, bool aNotify) {
+ if (mType == USE)
+ UseNode()->Calc(aList, aNotify);
+ else
+ ChangeNode()->Calc(aList);
+}
+
+inline bool nsCounterNode::IsContentBasedReset() {
+ return mType == RESET &&
+ ChangeNode()->mChangeValue == std::numeric_limits<int32_t>::min();
+}
+
+inline bool nsCounterNode::IsReversed() {
+ return mType == RESET && ChangeNode()->mIsReversed;
+}
+
+inline bool nsCounterNode::IsUnitializedIncrementNode() {
+ return mType == INCREMENT &&
+ ChangeNode()->mChangeValue == std::numeric_limits<int32_t>::min();
+}
+
+class nsCounterList : public nsGenConList {
+ public:
+ nsCounterList(nsAtom* aCounterName, mozilla::ContainStyleScope* aScope)
+ : nsGenConList(), mCounterName(aCounterName), mScope(aScope) {
+ MOZ_ASSERT(aScope);
+ }
+
+ // Return the first node for aFrame on this list, or nullptr.
+ nsCounterNode* GetFirstNodeFor(nsIFrame* aFrame) const {
+ return static_cast<nsCounterNode*>(nsGenConList::GetFirstNodeFor(aFrame));
+ }
+
+ void Insert(nsCounterNode* aNode) {
+ nsGenConList::Insert(aNode);
+ // Don't SetScope if we're dirty -- we'll reset all the scopes anyway,
+ // and we can't usefully compute scopes right now.
+ if (MOZ_LIKELY(!IsDirty())) {
+ SetScope(aNode);
+ }
+ }
+
+ nsCounterNode* First() {
+ return static_cast<nsCounterNode*>(mList.getFirst());
+ }
+
+ static nsCounterNode* Next(nsCounterNode* aNode) {
+ return static_cast<nsCounterNode*>(nsGenConList::Next(aNode));
+ }
+ static nsCounterNode* Prev(nsCounterNode* aNode) {
+ return static_cast<nsCounterNode*>(nsGenConList::Prev(aNode));
+ }
+
+ static int32_t ValueBefore(nsCounterNode* aNode) {
+ if (!aNode->mScopePrev) {
+ return 0;
+ }
+
+ if (aNode->mType != nsCounterNode::USE &&
+ aNode->mScopePrev->mCrossesContainStyleBoundaries) {
+ return 0;
+ }
+
+ return aNode->mScopePrev->mValueAfter;
+ }
+
+ // Correctly set |aNode->mScopeStart| and |aNode->mScopePrev|
+ void SetScope(nsCounterNode* aNode);
+
+ // Recalculate |mScopeStart|, |mScopePrev|, and |mValueAfter| for
+ // all nodes and update text in text content nodes.
+ void RecalcAll();
+
+ bool IsDirty() const;
+ void SetDirty();
+ bool IsRecalculatingAll() const { return mRecalculatingAll; }
+
+ private:
+ bool SetScopeByWalkingBackwardThroughList(
+ nsCounterNode* aNodeToSetScopeFor, const nsIContent* aNodeContent,
+ nsCounterNode* aNodeToBeginLookingAt);
+
+ RefPtr<nsAtom> mCounterName;
+ mozilla::ContainStyleScope* mScope;
+ bool mRecalculatingAll = false;
+};
+
+/**
+ * The counter manager maintains an |nsCounterList| for each named
+ * counter to keep track of all scopes with that name.
+ */
+class nsCounterManager {
+ public:
+ explicit nsCounterManager(mozilla::ContainStyleScope* scope)
+ : mScope(scope) {}
+
+ // Returns true if dirty
+ bool AddCounterChanges(nsIFrame* aFrame);
+
+ // Gets the appropriate counter list, creating it if necessary.
+ // Guaranteed to return non-null. (Uses an infallible hashtable API.)
+ nsCounterList* GetOrCreateCounterList(nsAtom* aCounterName);
+
+ // Gets the appropriate counter list, returning null if it doesn't exist.
+ nsCounterList* GetCounterList(nsAtom* aCounterName);
+
+ // Clean up data in any dirty counter lists.
+ void RecalcAll();
+
+ // Set all counter lists dirty
+ void SetAllDirty();
+
+ // Destroy nodes for the frame in any lists, and return whether any
+ // nodes were destroyed.
+ bool DestroyNodesFor(nsIFrame* aFrame);
+
+ // Clear all data.
+ void Clear() { mNames.Clear(); }
+
+#ifdef ACCESSIBILITY
+ // Set |aOrdinal| to the first used counter value for the given frame and
+ // return true. If no USE node for the given frame can be found, return false
+ // and do not change the value of |aOrdinal|.
+ bool GetFirstCounterValueForFrame(nsIFrame* aFrame,
+ mozilla::CounterValue& aOrdinal) const;
+#endif
+
+#if defined(DEBUG) || defined(MOZ_LAYOUT_DEBUGGER)
+ void Dump() const;
+#endif
+
+ static int32_t IncrementCounter(int32_t aOldValue, int32_t aIncrement) {
+ // Addition of unsigned values is defined to be arithmetic
+ // modulo 2^bits (C++ 2011, 3.9.1 [basic.fundamental], clause 4);
+ // addition of signed values is undefined (and clang does
+ // something very strange if we use it here). Likewise integral
+ // conversion from signed to unsigned is also defined as modulo
+ // 2^bits (C++ 2011, 4.7 [conv.integral], clause 2); conversion
+ // from unsigned to signed is however undefined (ibid., clause 3),
+ // but to do what we want we must nonetheless depend on that
+ // small piece of undefined behavior.
+ int32_t newValue = int32_t(uint32_t(aOldValue) + uint32_t(aIncrement));
+ // The CSS Working Group resolved that a counter-increment that
+ // exceeds internal limits should not increment at all.
+ // http://lists.w3.org/Archives/Public/www-style/2013Feb/0392.html
+ // (This means, for example, that if aIncrement is 5, the
+ // counter will get stuck at the largest multiple of 5 less than
+ // the maximum 32-bit integer.)
+ if ((aIncrement > 0) != (newValue > aOldValue)) {
+ newValue = aOldValue;
+ }
+ return newValue;
+ }
+
+ private:
+ mozilla::ContainStyleScope* mScope;
+ nsClassHashtable<nsRefPtrHashKey<nsAtom>, nsCounterList> mNames;
+};
+
+#endif /* nsCounterManager_h_ */
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