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/*
* Copyright (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
* Copyright (C) 2006-2018 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 "CounterNode.h"
#include "Document.h"
#include "Element.h"
#include "ElementInlines.h"
#include "ElementTraversal.h"
#include "HTMLNames.h"
#include "HTMLOListElement.h"
#include "PseudoElement.h"
#include "RenderListItem.h"
#include "RenderListMarker.h"
#include "RenderStyle.h"
#include "RenderView.h"
#include <wtf/IsoMallocInlines.h>
#include <wtf/StdLibExtras.h>
#if ENABLE(TREE_DEBUGGING)
#include <stdio.h>
#endif
namespace WebCore {
using namespace HTMLNames;
WTF_MAKE_ISO_ALLOCATED_IMPL(RenderCounter);
using CounterMap = HashMap<AtomString, Ref<CounterNode>>;
using CounterMaps = HashMap<const 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)
{
Element* ancestor = is<PseudoElement>(element) ? downcast<PseudoElement>(element).hostElement() : element.parentElement();
while (ancestor) {
if (auto* style = ancestor->existingComputedStyle()) {
if (style->containsStyle())
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.
static RenderElement* previousInPreOrder(const RenderElement& renderer)
{
ASSERT(renderer.element());
Element* previous = ElementTraversal::previousIncludingPseudo(*renderer.element());
Element* styleContainAncestor = ancestorStyleContainmentObject(*renderer.element());
while (previous && !previous->renderer())
previous = ElementTraversal::previousIncludingPseudo(*previous, styleContainAncestor);
if (!previous)
return nullptr;
return previous->renderer();
}
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 (auto* previous = ElementTraversal::pseudoAwarePreviousSibling(element)) {
while (previous && !previous->renderer())
previous = ElementTraversal::pseudoAwarePreviousSibling(*previous);
if (previous)
return previous;
}
if (is<PseudoElement>(element)) {
auto* hostElement = downcast<PseudoElement>(element).hostElement();
ASSERT(hostElement);
if (hostElement->renderer())
return hostElement;
return previousSiblingOrParentElement(*hostElement);
}
auto* parent = element.parentElement();
if (parent && !parent->renderer())
parent = previousSiblingOrParentElement(*parent);
if (parent && parent->renderer() && parent->renderer()->style().containsStyle())
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());
auto* 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());
Element& self = *renderer.element();
Element* 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 (is<RenderListItem>(renderer)) {
auto& item = downcast<RenderListItem>(renderer);
if (auto explicitValue = item.explicitValue())
return { *explicitValue, std::nullopt };
return { std::nullopt, item.isInReversedOrderedList() ? -1 : 1 };
}
if (auto element = renderer.element()) {
if (is<HTMLOListElement>(*element)) {
auto& list = downcast<HTMLOListElement>(*element);
return { list.start(), list.isReversed() ? 1 : -1 };
}
if (isHTMLListElement(*element))
return { 0, std::nullopt };
}
return { };
}
struct CounterPlan {
bool isReset;
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.
Element* generatingElement = renderer.generatingElement();
if (!generatingElement)
return std::nullopt;
auto& style = renderer.style();
switch (style.styleType()) {
case PseudoId::None:
// 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;
break;
case PseudoId::Before:
case PseudoId::After:
break;
default:
return std::nullopt; // Counters are forbidden from all other pseudo elements.
}
CounterDirectives directives;
if (auto map = style.counterDirectives())
directives = 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.resetValue)
return CounterPlan { true, saturatedSum<int>(*directives.resetValue, directives.incrementValue.value_or(0)) };
if (directives.incrementValue)
return CounterPlan { false, *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, bool isReset)
{
// 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 = previousInPreOrder(counterOwner);
RefPtr<CounterNode> previousSibling;
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, WTFMove(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(), WTFMove(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, WTFMove(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 = previousInPreOrder(*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->isReset, plan ? plan->value : 0);
auto place = findPlaceForCounter(renderer, identifier, plan && plan->isReset);
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.ptr();
// Check if some nodes that were previously root nodes should become children of this node now.
auto* currentRenderer = &renderer;
auto* stayWithin = parentOrPseudoHostElement(renderer);
bool skipDescendants = false;
while ((currentRenderer = nextInPreOrder(*currentRenderer, stayWithin, skipDescendants))) {
skipDescendants = currentRenderer->shouldApplyStyleContainment();
if (!currentRenderer->hasCounterNodeMap())
continue;
auto* 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.ptr();
}
RenderCounter::RenderCounter(Document& document, const CounterContent& counter)
: RenderText(document, emptyString())
, m_counter(counter)
{
view().addRenderCounter();
}
RenderCounter::~RenderCounter()
{
// Do not add any code here. Add it to willBeDestroyed() instead.
}
void RenderCounter::willBeDestroyed()
{
view().removeRenderCounter();
if (m_counterNode) {
m_counterNode->removeRenderer(*this);
ASSERT(!m_counterNode);
}
RenderText::willBeDestroyed();
}
ASCIILiteral RenderCounter::renderName() const
{
return "RenderCounter"_s;
}
bool RenderCounter::isCounter() const
{
return true;
}
String RenderCounter::originalText() const
{
if (!m_counterNode) {
RenderElement* beforeAfterContainer = parent();
while (true) {
if (!beforeAfterContainer)
return String();
if (!beforeAfterContainer->isAnonymous() && !beforeAfterContainer->isPseudoElement())
return String(); // RenderCounters are restricted to before and after pseudo elements
PseudoId containerStyle = beforeAfterContainer->style().styleType();
if ((containerStyle == PseudoId::Before) || (containerStyle == PseudoId::After))
break;
beforeAfterContainer = beforeAfterContainer->parent();
}
makeCounterNode(*beforeAfterContainer, m_counter.identifier(), true)->addRenderer(const_cast<RenderCounter&>(*this));
ASSERT(m_counterNode);
}
CounterNode* child = m_counterNode;
int value = child->actsAsReset() ? child->value() : child->countInParent();
String text = listMarkerText(m_counter.listStyle(), value);
if (!m_counter.separator().isNull()) {
if (!child->actsAsReset())
child = child->parent();
while (CounterNode* parent = child->parent()) {
text = listMarkerText(m_counter.listStyle(), child->countInParent())
+ m_counter.separator() + text;
child = parent;
}
}
return text;
}
void RenderCounter::updateCounter()
{
computePreferredLogicalWidths(0);
}
void RenderCounter::computePreferredLogicalWidths(float lead)
{
// FIXME: We shouldn't be modifying the tree in computePreferredLogicalWidths.
// Instead, we should properly hook the appropriate changes in the DOM and modify
// the render tree then. When that's done, we also won't need to override
// computePreferredLogicalWidths at all.
// https://bugs.webkit.org/show_bug.cgi?id=104829
SetLayoutNeededForbiddenScope layoutForbiddenScope(*this, false);
setRenderedText(originalText());
RenderText::computePreferredLogicalWidths(lead);
}
static void destroyCounterNodeWithoutMapRemoval(const AtomString& identifier, CounterNode& node)
{
RefPtr<CounterNode> previous;
for (RefPtr<CounterNode> child = node.lastDescendant(); child && child != &node; child = WTFMove(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 (auto* 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::rendererRemovedFromTree(RenderElement& renderer)
{
if (!renderer.view().hasRenderCounters())
return;
RenderObject* currentRenderer = renderer.lastLeafChild();
if (!currentRenderer)
currentRenderer = &renderer;
while (true) {
if (is<RenderElement>(*currentRenderer)) {
auto& counterNodeRenderer = downcast<RenderElement>(*currentRenderer);
if (counterNodeRenderer.hasCounterNodeMap())
destroyCounterNodes(counterNodeRenderer);
}
if (currentRenderer == &renderer)
break;
currentRenderer = currentRenderer->previousInPreOrder();
}
}
static void updateCounters(RenderElement& renderer)
{
auto* directiveMap = renderer.style().counterDirectives();
if (!directiveMap)
return;
if (!renderer.hasCounterNodeMap()) {
for (auto& key : directiveMap->keys())
makeCounterNode(renderer, key, false);
return;
}
ASSERT(counterMaps().contains(&renderer));
auto* counterMap = counterMaps().find(&renderer)->value.get();
for (auto& key : directiveMap->keys()) {
RefPtr<CounterNode> node = counterMap->get(key);
if (!node) {
makeCounterNode(renderer, key, false);
continue;
}
auto place = findPlaceForCounter(renderer, key, node->hasResetType());
if (node != counterMap->get(key))
continue;
CounterNode* parent = node->parent();
if (place.parent == parent && place.previousSibling == node->previousSibling())
continue;
if (parent)
parent->removeChild(*node);
if (place.parent)
place.parent->insertAfter(*node, place.previousSibling.get(), key);
}
}
void RenderCounter::rendererSubtreeAttached(RenderElement& renderer)
{
if (!renderer.view().hasRenderCounters())
return;
Element* element = renderer.element();
if (element && !element->isPseudoElement())
element = element->parentElement();
else
element = renderer.generatingElement();
if (element && !element->renderer())
return; // No need to update if the parent is not attached yet
bool crossedStyleContainmentBoundary = false;
for (RenderObject* descendant = &renderer; descendant; descendant = descendant->nextInPreOrder(&renderer)) {
if (!is<RenderElement>(descendant))
continue;
crossedStyleContainmentBoundary = crossedStyleContainmentBoundary || downcast<RenderElement>(*descendant).shouldApplyStyleContainment();
if (crossedStyleContainmentBoundary)
updateCounters(downcast<RenderElement>(*descendant));
}
}
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->counterDirectives())) {
if (auto* newCounterDirectives = newStyle.counterDirectives()) {
for (auto& keyValue : *newCounterDirectives) {
auto existingEntry = oldCounterDirectives->find(keyValue.key);
if (existingEntry != oldCounterDirectives->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->keys()) {
if (!newCounterDirectives->contains(key))
RenderCounter::destroyCounterNode(renderer, key);
}
} else {
if (renderer.hasCounterNodeMap())
RenderCounter::destroyCounterNodes(renderer);
}
} else {
if (auto* newCounterDirectives = newStyle.counterDirectives()) {
for (auto& key : newCounterDirectives->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);
}
}
}
}
} // namespace WebCore
#if ENABLE(TREE_DEBUGGING)
void showCounterRendererTree(const WebCore::RenderObject* renderer, const char* counterName)
{
if (!renderer)
return;
auto* root = renderer;
while (root->parent())
root = root->parent();
auto identifier = AtomString::fromLatin1(counterName);
for (auto* current = root; current; current = current->nextInPreOrder()) {
if (!is<WebCore::RenderElement>(*current))
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(), downcast<WebCore::RenderElement>(*current).hasCounterNodeMap() ?
counterName ? WebCore::counterMaps().find(downcast<WebCore::RenderElement>(current))->value->get(identifier) : (WebCore::CounterNode*)1 : (WebCore::CounterNode*)0);
}
fflush(stderr);
}
#endif // NDEBUG