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/*
* Copyright (C) 2004 Allan Sandfeld Jensen ([email protected])
* Copyright (C) 2006-2024 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#include "config.h"
#include "RenderCounter.h"
#include "CSSCounterStyleRegistry.h"
#include "ContainerNodeInlines.h"
#include "CounterDirectives.h"
#include "CounterNode.h"
#include "Document.h"
#include "ElementInlines.h"
#include "ElementTraversal.h"
#include "HTMLNames.h"
#include "HTMLOListElement.h"
#include "PseudoElement.h"
#include "RenderElementStyleInlines.h"
#include "RenderElementInlines.h"
#include "RenderListItem.h"
#include "RenderObjectInlines.h"
#include "RenderStyle.h"
#include "RenderView.h"
#include <wtf/StdLibExtras.h>
#include <wtf/TZoneMallocInlines.h>
#if ENABLE(TREE_DEBUGGING)
#include <stdio.h>
#endif
namespace WebCore {
using namespace HTMLNames;
WTF_MAKE_TZONE_ALLOCATED_IMPL(RenderCounter);
using CounterMap = HashMap<AtomString, Ref<CounterNode>>;
using CounterMaps = SingleThreadWeakHashMap<RenderElement, std::unique_ptr<CounterMap>>;
static CounterNode* makeCounterNode(RenderElement&, const AtomString& identifier, bool alwaysCreateCounter);
static CounterMaps& counterMaps()
{
static NeverDestroyed<CounterMaps> staticCounterMaps;
return staticCounterMaps;
}
static Element* ancestorStyleContainmentObject(const Element& element)
{
auto* pseudoElement = dynamicDowncast<PseudoElement>(element);
SUPPRESS_UNCOUNTED_LOCAL auto* ancestor = pseudoElement ? pseudoElement->hostElement() : element.parentElement();
while (ancestor) {
if (auto* style = ancestor->existingComputedStyle()) {
if (style->usedContain().contains(Style::ContainValue::Style))
break;
}
// FIXME: this should use parentInComposedTree but for now matches the rest of RenderCounter.
ancestor = ancestor->parentElement();
}
return ancestor;
}
// This function processes the renderer tree in the order of the DOM tree
// including pseudo elements as defined in CSS 2.1. This method will always
// return either a previous element within the same contain: style scope or nullptr.
static RenderElement* previousInPreOrderRespectingContainment(const RenderElement& renderer)
{
ASSERT(renderer.element());
RefPtr previous = ElementTraversal::previousIncludingPseudo(*renderer.element());
RefPtr styleContainmentAncestor = ancestorStyleContainmentObject(*renderer.element());
while (previous) {
while (previous && !previous->renderer())
previous = ElementTraversal::previousIncludingPseudo(*previous, styleContainmentAncestor);
if (!previous)
break;
RefPtr previousStyleContainmentAncestor = ancestorStyleContainmentObject(*previous);
// If the candidate's containment ancestor is the same as elements, then
// that's a valid candidate.
if (previousStyleContainmentAncestor == styleContainmentAncestor)
return previous->renderer();
// If the candidate does have a containment ancestor, it could be
// that we entered a new sub-containment. Try again starting from the
// contain ancestor.
previous = previousStyleContainmentAncestor;
}
return nullptr;
}
static inline Element* parentOrPseudoHostElement(const RenderElement& renderer)
{
if (renderer.isPseudoElement())
return renderer.generatingElement();
return renderer.element() ? renderer.element()->parentElement() : nullptr;
}
static Element* previousSiblingOrParentElement(const Element& element)
{
if (SUPPRESS_UNCHECKED_LOCAL auto* previous = ElementTraversal::pseudoAwarePreviousSibling(element)) {
while (previous && !previous->renderer())
previous = ElementTraversal::pseudoAwarePreviousSibling(*previous);
if (previous)
return previous;
}
if (auto* pseudoElement = dynamicDowncast<PseudoElement>(element)) {
SUPPRESS_UNCOUNTED_LOCAL auto* hostElement = pseudoElement->hostElement();
ASSERT(hostElement);
if (hostElement->renderer())
return hostElement;
return previousSiblingOrParentElement(*hostElement);
}
SUPPRESS_UNCOUNTED_LOCAL auto* parent = element.parentElement();
if (parent && !parent->renderer())
parent = previousSiblingOrParentElement(*parent);
if (parent && parent->renderer() && parent->renderer()->style().usedContain().contains(Style::ContainValue::Style))
return nullptr;
return parent;
}
// This function processes the renderer tree in the order of the DOM tree
// including pseudo elements as defined in CSS 2.1.
static RenderElement* previousSiblingOrParent(const RenderElement& renderer)
{
ASSERT(renderer.element());
RefPtr previous = previousSiblingOrParentElement(*renderer.element());
return previous ? previous->renderer() : nullptr;
}
static inline bool areRenderersElementsSiblings(const RenderElement& first, const RenderElement& second)
{
return parentOrPseudoHostElement(first) == parentOrPseudoHostElement(second);
}
// This function processes the renderer tree in the order of the DOM tree
// including pseudo elements as defined in CSS 2.1.
static RenderElement* nextInPreOrder(const RenderElement& renderer, const Element* stayWithin, bool skipDescendants = false)
{
ASSERT(renderer.element());
Ref self = *renderer.element();
RefPtr next = skipDescendants ? ElementTraversal::nextIncludingPseudoSkippingChildren(self, stayWithin) : ElementTraversal::nextIncludingPseudo(self, stayWithin);
while (next && !next->renderer())
next = skipDescendants ? ElementTraversal::nextIncludingPseudoSkippingChildren(*next, stayWithin) : ElementTraversal::nextIncludingPseudo(*next, stayWithin);
return next ? next->renderer() : nullptr;
}
static CounterDirectives listItemCounterDirectives(RenderElement& renderer)
{
if (auto* item = dynamicDowncast<RenderListItem>(renderer)) {
return {
.resetValue = std::nullopt,
.incrementValue = item->isInReversedOrderedList() ? -1 : 1,
.setValue = std::nullopt
};
}
if (RefPtr element = renderer.element()) {
if (RefPtr list = dynamicDowncast<HTMLOListElement>(*element)) {
return {
.resetValue = list->start(),
.incrementValue = list->isReversed() ? 1 : -1,
.setValue = std::nullopt
};
}
if (isHTMLListElement(*element))
return {
.resetValue = 0,
.incrementValue = std::nullopt,
.setValue = std::nullopt
};
}
return { };
}
struct CounterPlan {
OptionSet<CounterNode::Type> type;
int value;
};
static std::optional<CounterPlan> planCounter(RenderElement& renderer, const AtomString& identifier)
{
// We must have a generating node or else we cannot have a counter.
RefPtr generatingElement = renderer.generatingElement();
if (!generatingElement)
return std::nullopt;
auto& style = renderer.style();
if (style.pseudoElementType()) {
switch (*style.pseudoElementType()) {
case PseudoElementType::Before:
case PseudoElementType::After:
break;
default:
return std::nullopt; // Counters are forbidden from all other pseudo elements.
}
} else {
// Sometimes elements have more then one renderer. Only the first one gets the counter
// LayoutTests/http/tests/css/counter-crash.html
if (generatingElement->renderer() != &renderer)
return std::nullopt;
}
auto directives = style.usedCounterDirectives().map.get(identifier);
if (identifier == "list-item"_s) {
auto itemDirectives = listItemCounterDirectives(renderer);
if (!directives.resetValue)
directives.resetValue = itemDirectives.resetValue;
if (!directives.incrementValue)
directives.incrementValue = itemDirectives.incrementValue;
if (!directives.setValue)
directives.setValue = itemDirectives.setValue;
}
OptionSet<CounterNode::Type> type;
if (directives.setValue)
type.add(CounterNode::Type::Set);
if (directives.resetValue)
type.add(CounterNode::Type::Reset);
if (directives.incrementValue)
type.add(CounterNode::Type::Increment);
if (directives.setValue)
return CounterPlan { type, *directives.setValue };
if (directives.resetValue)
return CounterPlan { type, saturatedSum<int>(*directives.resetValue, directives.incrementValue.value_or(0)) };
if (directives.incrementValue)
return CounterPlan { type, *directives.incrementValue };
return std::nullopt;
}
// - Finds the insertion point for the counter described by counterOwner, isReset and
// identifier in the CounterNode tree for identifier and sets parent and
// previousSibling accordingly.
// - The function returns true if the counter whose insertion point is searched is NOT
// the root of the tree.
// - The root of the tree is a counter reference that is not in the scope of any other
// counter with the same identifier.
// - All the counter references with the same identifier as this one that are in
// children or subsequent siblings of the renderer that owns the root of the tree
// form the rest of of the nodes of the tree.
// - The root of the tree is always a reset type reference.
// - A subtree rooted at any reset node in the tree is equivalent to all counter
// references that are in the scope of the counter or nested counter defined by that
// reset node.
// - Non-reset CounterNodes cannot have descendants.
struct CounterInsertionPoint {
RefPtr<CounterNode> parent;
RefPtr<CounterNode> previousSibling;
};
static CounterInsertionPoint findPlaceForCounter(RenderElement& counterOwner, const AtomString& identifier, OptionSet<CounterNode::Type> type)
{
// We cannot stop searching for counters with the same identifier before we also
// check this renderer, because it may affect the positioning in the tree of our counter.
RenderElement* searchEndRenderer = previousSiblingOrParent(counterOwner);
// We check renderers in preOrder from the renderer that our counter is attached to
// towards the begining of the document for counters with the same identifier as the one
// we are trying to find a place for. This is the next renderer to be checked.
RenderElement* currentRenderer = previousInPreOrderRespectingContainment(counterOwner);
RefPtr<CounterNode> previousSibling;
// Establish counter nodes previous to currentRenderer in order that calling
// makeCounterNode on currentRenderer does not recurse into this function.
if (currentRenderer && !currentRenderer->hasCounterNodeMap()) {
Vector<RenderElement*> previousRenderers;
RenderElement* current = currentRenderer;
while (current && !current->hasCounterNodeMap()) {
if (!current->style().usedCounterDirectives().map.isEmpty())
previousRenderers.append(current);
current = previousInPreOrderRespectingContainment(*current);
}
while (!previousRenderers.isEmpty())
makeCounterNode(*previousRenderers.takeLast(), identifier, false);
}
bool isReset = type.contains(CounterNode::Type::Reset);
while (currentRenderer) {
auto currentCounter = makeCounterNode(*currentRenderer, identifier, false);
if (searchEndRenderer == currentRenderer) {
// We may be at the end of our search.
if (currentCounter) {
// We have a suitable counter on the EndSearchRenderer.
if (previousSibling) {
// But we already found another counter that we come after.
if (currentCounter->actsAsReset()) {
// We found a reset counter that is on a renderer that is a sibling of ours or a parent.
if (isReset && areRenderersElementsSiblings(*currentRenderer, counterOwner)) {
// We are also a reset counter and the previous reset was on a sibling renderer
// hence we are the next sibling of that counter if that reset is not a root or
// we are a root node if that reset is a root.
auto* parent = currentCounter->parent();
return { parent, parent ? currentCounter : nullptr };
}
// We are not a reset node or the previous reset must be on an ancestor of our owner renderer
// hence we must be a child of that reset counter.
// In some cases renders can be reparented (ex. nodes inside a table but not in a column or row).
// In these cases the identified previousSibling will be invalid as its parent is different from
// our identified parent.
if (previousSibling->parent() != currentCounter)
previousSibling = nullptr;
return { currentCounter, WTF::move(previousSibling) };
}
// CurrentCounter, the counter at the EndSearchRenderer, is not reset.
if (!isReset || !areRenderersElementsSiblings(*currentRenderer, counterOwner)) {
// If the node we are placing is not reset or we have found a counter that is attached
// to an ancestor of the placed counter's owner renderer we know we are a sibling of that node.
if (currentCounter->parent() != previousSibling->parent())
return { };
return { currentCounter->parent(), WTF::move(previousSibling) };
}
} else {
// We are at the potential end of the search, but we had no previous sibling candidate
// In this case we follow pretty much the same logic as above but no ASSERTs about
// previousSibling, and when we are a sibling of the end counter we must set previousSibling
// to currentCounter.
if (currentCounter->actsAsReset()) {
if (isReset && areRenderersElementsSiblings(*currentRenderer, counterOwner))
return { currentCounter->parent(), currentCounter };
return { currentCounter, WTF::move(previousSibling) };
}
if (!isReset || !areRenderersElementsSiblings(*currentRenderer, counterOwner))
return { currentCounter->parent(), currentCounter };
previousSibling = currentCounter;
}
}
// We come here if the previous sibling or parent of our owner renderer had no
// good counter, or we are a reset node and the counter on the previous sibling
// of our owner renderer was not a reset counter.
// Set a new goal for the end of the search.
searchEndRenderer = previousSiblingOrParent(*currentRenderer);
} else {
// We are searching descendants of a previous sibling of the renderer that the
// counter being placed is attached to.
if (currentCounter) {
// We found a suitable counter.
if (previousSibling) {
// Since we had a suitable previous counter before, we should only consider this one as our
// previousSibling if it is a reset counter and hence the current previousSibling is its child.
if (currentCounter->actsAsReset()) {
previousSibling = currentCounter;
// We are no longer interested in previous siblings of the currentRenderer or their children
// as counters they may have attached cannot be the previous sibling of the counter we are placing.
auto* parent = parentOrPseudoHostElement(*currentRenderer);
currentRenderer = parent ? parent->renderer() : nullptr;
continue;
}
} else
previousSibling = currentCounter;
currentRenderer = previousSiblingOrParent(*currentRenderer);
continue;
}
}
// This function is designed so that the same test is not done twice in an iteration, except for this one
// which may be done twice in some cases. Rearranging the decision points though, to accommodate this
// performance improvement would create more code duplication than is worthwhile in my oppinion and may further
// impede the readability of this already complex algorithm.
if (previousSibling)
currentRenderer = previousSiblingOrParent(*currentRenderer);
else
currentRenderer = previousInPreOrderRespectingContainment(*currentRenderer);
}
return { };
}
static CounterNode* makeCounterNode(RenderElement& renderer, const AtomString& identifier, bool alwaysCreateCounter)
{
if (renderer.hasCounterNodeMap()) {
ASSERT(counterMaps().contains(renderer));
if (auto* node = counterMaps().find(renderer)->value->get(identifier))
return node;
}
auto plan = planCounter(renderer, identifier);
if (!plan && !alwaysCreateCounter)
return nullptr;
auto& maps = counterMaps();
auto newNode = CounterNode::create(renderer, plan ? plan->type : OptionSet<CounterNode::Type> { }, plan ? plan->value : 0);
auto place = findPlaceForCounter(renderer, identifier, plan ? plan->type : OptionSet<CounterNode::Type> { });
if (place.parent)
place.parent->insertAfter(newNode, place.previousSibling.get(), identifier);
maps.add(renderer, makeUnique<CounterMap>()).iterator->value->add(identifier, newNode.copyRef());
renderer.setHasCounterNodeMap(true);
if (newNode->parent() || renderer.shouldApplyStyleContainment())
return newNode.unsafePtr();
// Check if some nodes that were previously root nodes should become children of this node now.
auto* currentRenderer = &renderer;
RefPtr stayWithin = parentOrPseudoHostElement(renderer);
bool skipDescendants = false;
while ((currentRenderer = nextInPreOrder(*currentRenderer, stayWithin, skipDescendants))) {
skipDescendants = currentRenderer->shouldApplyStyleContainment();
if (!currentRenderer->hasCounterNodeMap())
continue;
RefPtr currentCounter = maps.find(*currentRenderer)->value->get(identifier);
if (!currentCounter)
continue;
skipDescendants = true;
if (currentCounter->parent())
continue;
if (stayWithin == parentOrPseudoHostElement(*currentRenderer) && currentCounter->hasResetType())
break;
newNode->insertAfter(*currentCounter, newNode->lastChild(), identifier);
}
return newNode.unsafePtr();
}
RenderCounter::RenderCounter(Document& document, const Style::Content::Counter& counter)
: RenderText(Type::Counter, document, emptyString())
, m_counter(counter)
{
ASSERT(isRenderCounter());
view().addCounterNeedingUpdate(*this);
}
// Do not add any code in below destructor. Add it to willBeDestroyed() instead.
RenderCounter::~RenderCounter() = default;
void RenderCounter::willBeDestroyed()
{
if (m_counterNode) {
m_counterNode->removeRenderer(*this);
ASSERT(!m_counterNode);
}
RenderText::willBeDestroyed();
}
ASCIILiteral RenderCounter::renderName() const
{
return "RenderCounter"_s;
}
String RenderCounter::originalText() const
{
if (!m_counterNode)
return emptyString();
RefPtr child = m_counterNode.get();
int value = child->actsAsReset() ? child->value() : child->countInParent();
auto counterText = [&](int value) {
return counterStyle()->text(value, writingMode());
};
auto text = counterText(value);
if (!m_counter.separator.isNull()) {
if (!child->actsAsReset())
child = child->parent();
while (RefPtr parent = child->parent()) {
text = makeString(counterText(child->countInParent()), m_counter.separator, text);
child = parent;
}
}
return text;
}
void RenderCounter::updateCounter()
{
if (!m_counterNode) {
RenderElement* beforeAfterContainer = parent();
while (true) {
if (!beforeAfterContainer)
return;
if (!beforeAfterContainer->isAnonymous() && !beforeAfterContainer->isPseudoElement())
return;
auto containerStyle = beforeAfterContainer->style().pseudoElementType();
if (containerStyle == PseudoElementType::Before || containerStyle == PseudoElementType::After)
break;
beforeAfterContainer = beforeAfterContainer->parent();
}
makeCounterNode(*beforeAfterContainer, m_counter.identifier, true)->addRenderer(const_cast<RenderCounter&>(*this));
}
setText(originalText(), true);
}
static void destroyCounterNodeWithoutMapRemoval(const AtomString& identifier, CounterNode& node)
{
RefPtr<CounterNode> previous;
for (RefPtr<CounterNode> child = node.lastDescendant(); child && child != &node; child = WTF::move(previous)) {
previous = child->previousInPreOrder();
child->parent()->removeChild(*child);
ASSERT(counterMaps().find(child->owner())->value->get(identifier) == child);
counterMaps().find(child->owner())->value->remove(identifier);
}
if (RefPtr parent = node.parent())
parent->removeChild(node);
}
void RenderCounter::destroyCounterNodes(RenderElement& owner)
{
ASSERT(owner.hasCounterNodeMap());
auto& maps = counterMaps();
ASSERT(maps.contains(owner));
auto counterMap = maps.take(owner);
for (auto& counterMapEntry : *counterMap)
destroyCounterNodeWithoutMapRemoval(counterMapEntry.key, counterMapEntry.value);
owner.setHasCounterNodeMap(false);
}
void RenderCounter::destroyCounterNode(RenderElement& owner, const AtomString& identifier)
{
auto map = counterMaps().find(owner);
if (map == counterMaps().end())
return;
auto node = map->value->take(identifier);
if (!node)
return;
destroyCounterNodeWithoutMapRemoval(identifier, *node);
// We do not delete the map here even if it is now empty because we expect to
// reuse it. In order for a renderer to lose all its counters permanently,
// a style change for the renderer involving removal of all counter
// directives must occur, in which case, RenderCounter::destroyCounterNodes()
// will be called.
}
void RenderCounter::rendererStyleChangedSlowCase(RenderElement& renderer, const RenderStyle* oldStyle, const RenderStyle& newStyle)
{
Element* element = renderer.generatingElement();
if (!element || !element->renderer())
return; // cannot have generated content or if it can have, it will be handled during attaching
const CounterDirectiveMap* oldCounterDirectives;
if (oldStyle && !(oldCounterDirectives = &oldStyle->usedCounterDirectives())->map.isEmpty()) {
if (auto& newCounterDirectives = newStyle.usedCounterDirectives().map; !newCounterDirectives.isEmpty()) {
for (auto& keyValue : newCounterDirectives) {
auto existingEntry = oldCounterDirectives->map.find(keyValue.key);
if (existingEntry != oldCounterDirectives->map.end()) {
if (existingEntry->value == keyValue.value)
continue;
RenderCounter::destroyCounterNode(renderer, keyValue.key);
}
// We must create this node here, because the changed node may be a node with no display such as
// as those created by the increment or reset directives and the re-layout that will happen will
// not catch the change if the node had no children.
makeCounterNode(renderer, keyValue.key, false);
}
// Destroying old counters that do not exist in the new counterDirective map.
for (auto& key : oldCounterDirectives->map.keys()) {
if (!newCounterDirectives.contains(key))
RenderCounter::destroyCounterNode(renderer, key);
}
} else {
if (renderer.hasCounterNodeMap())
RenderCounter::destroyCounterNodes(renderer);
}
} else {
if (renderer.hasCounterNodeMap())
RenderCounter::destroyCounterNodes(renderer);
for (auto& key : newStyle.usedCounterDirectives().map.keys()) {
// We must create this node here, because the added node may be a node with no display such as
// as those created by the increment or reset directives and the re-layout that will happen will
// not catch the change if the node had no children.
makeCounterNode(renderer, key, false);
}
}
}
Ref<CSSCounterStyle> RenderCounter::counterStyle() const
{
return document().counterStyleRegistry().resolvedCounterStyle(m_counter.style);
}
} // namespace WebCore
#if ENABLE(TREE_DEBUGGING)
void showCounterRendererTree(const WebCore::RenderObject* renderer, ASCIILiteral counterName)
{
if (!renderer)
return;
auto* root = renderer;
while (root->parent())
root = root->parent();
AtomString identifier { counterName };
for (auto* current = root; current; current = current->nextInPreOrder()) {
auto* element = dynamicDowncast<WebCore::RenderElement>(*current);
if (!element)
continue;
fprintf(stderr, "%c", (current == renderer) ? '*' : ' ');
for (auto* ancestor = current; ancestor && ancestor != root; ancestor = ancestor->parent())
fprintf(stderr, " ");
fprintf(stderr, "%p N:%p P:%p PS:%p NS:%p C:%p\n",
current, current->node(), current->parent(), current->previousSibling(),
current->nextSibling(), element->hasCounterNodeMap() ?
!counterName.isNull() ? WebCore::counterMaps().find(*downcast<WebCore::RenderElement>(current))->value->get(identifier) : (WebCore::CounterNode*)1 : (WebCore::CounterNode*)0);
}
fflush(stderr);
}
#endif // NDEBUG