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/**
* Copyright (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
* Copyright (C) 2006, 2007 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 "core/layout/LayoutCounter.h"
#include "core/HTMLNames.h"
#include "core/dom/Element.h"
#include "core/dom/ElementTraversal.h"
#include "core/html/HTMLOListElement.h"
#include "core/layout/CounterNode.h"
#include "core/layout/LayoutListItem.h"
#include "core/layout/LayoutView.h"
#include "core/layout/ListMarkerText.h"
#include "core/style/ComputedStyle.h"
#include "wtf/StdLibExtras.h"
#ifndef NDEBUG
#include <stdio.h>
#endif
namespace blink {
using namespace HTMLNames;
typedef HashMap<AtomicString, RefPtr<CounterNode>> CounterMap;
typedef HashMap<const LayoutObject*, OwnPtr<CounterMap>> CounterMaps;
static CounterNode* makeCounterNode(LayoutObject&, const AtomicString& identifier, bool alwaysCreateCounter);
// See class definition as to why we have this map.
static CounterMaps& counterMaps()
{
DEFINE_STATIC_LOCAL(CounterMaps, staticCounterMaps, ());
return staticCounterMaps;
}
// This function processes the layoutObject tree in the order of the DOM tree
// including pseudo elements as defined in CSS 2.1.
static LayoutObject* previousInPreOrder(const LayoutObject& object)
{
Element* self = toElement(object.node());
ASSERT(self);
Element* previous = ElementTraversal::previousIncludingPseudo(*self);
while (previous && !previous->layoutObject())
previous = ElementTraversal::previousIncludingPseudo(*previous);
return previous ? previous->layoutObject() : 0;
}
// This function processes the layoutObject tree in the order of the DOM tree
// including pseudo elements as defined in CSS 2.1.
static LayoutObject* previousSiblingOrParent(const LayoutObject& object)
{
Element* self = toElement(object.node());
ASSERT(self);
Element* previous = ElementTraversal::pseudoAwarePreviousSibling(*self);
while (previous && !previous->layoutObject())
previous = ElementTraversal::pseudoAwarePreviousSibling(*previous);
if (previous)
return previous->layoutObject();
previous = self->parentElement();
return previous ? previous->layoutObject() : 0;
}
static inline Element* parentElement(LayoutObject& object)
{
return toElement(object.node())->parentElement();
}
static inline bool areLayoutObjectsElementsSiblings(LayoutObject& first, LayoutObject& second)
{
return parentElement(first) == parentElement(second);
}
// This function processes the layoutObject tree in the order of the DOM tree
// including pseudo elements as defined in CSS 2.1.
static LayoutObject* nextInPreOrder(const LayoutObject& object, const Element* stayWithin, bool skipDescendants = false)
{
Element* self = toElement(object.node());
ASSERT(self);
Element* next = skipDescendants ? ElementTraversal::nextIncludingPseudoSkippingChildren(*self, stayWithin) : ElementTraversal::nextIncludingPseudo(*self, stayWithin);
while (next && !next->layoutObject())
next = skipDescendants ? ElementTraversal::nextIncludingPseudoSkippingChildren(*next, stayWithin) : ElementTraversal::nextIncludingPseudo(*next, stayWithin);
return next ? next->layoutObject() : 0;
}
static bool planCounter(LayoutObject& object, const AtomicString& identifier, bool& isReset, int& value)
{
// Real text nodes don't have their own style so they can't have counters.
// We can't even look at their styles or we'll see extra resets and increments!
if (object.isText() && !object.isBR())
return false;
Node* generatingNode = object.generatingNode();
// We must have a generating node or else we cannot have a counter.
if (!generatingNode)
return false;
const ComputedStyle& style = object.styleRef();
switch (style.styleType()) {
case NOPSEUDO:
// Sometimes nodes have more then one layoutObject. Only the first one gets the counter
// LayoutTests/http/tests/css/counter-crash.html
if (generatingNode->layoutObject() != &object)
return false;
break;
case BEFORE:
case AFTER:
break;
default:
return false; // Counters are forbidden from all other pseudo elements.
}
const CounterDirectives directives = style.getCounterDirectives(identifier);
if (directives.isDefined()) {
value = directives.combinedValue();
isReset = directives.isReset();
return true;
}
if (identifier == "list-item") {
if (object.isListItem()) {
if (toLayoutListItem(object).hasExplicitValue()) {
value = toLayoutListItem(object).explicitValue();
isReset = true;
return true;
}
value = 1;
isReset = false;
return true;
}
if (Node* e = object.node()) {
if (isHTMLOListElement(*e)) {
value = toHTMLOListElement(e)->start();
isReset = true;
return true;
}
if (isHTMLUListElement(*e) || isHTMLMenuElement(*e) || isHTMLDirectoryElement(*e)) {
value = 0;
isReset = true;
return true;
}
}
}
return false;
}
// - 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 layoutObject 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.
static bool findPlaceForCounter(LayoutObject& counterOwner, const AtomicString& identifier, bool isReset, RefPtr<CounterNode>& parent, RefPtr<CounterNode>& previousSibling)
{
// We cannot stop searching for counters with the same identifier before we also
// check this layoutObject, because it may affect the positioning in the tree of our counter.
LayoutObject* searchEndLayoutObject = previousSiblingOrParent(counterOwner);
// We check layoutObjects in preOrder from the layoutObject 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 layoutObject to be checked.
LayoutObject* currentLayoutObject = previousInPreOrder(counterOwner);
previousSibling = nullptr;
RefPtr<CounterNode> previousSiblingProtector = nullptr;
while (currentLayoutObject) {
CounterNode* currentCounter = makeCounterNode(*currentLayoutObject, identifier, false);
if (searchEndLayoutObject == currentLayoutObject) {
// We may be at the end of our search.
if (currentCounter) {
// We have a suitable counter on the EndSearchLayoutObject.
if (previousSiblingProtector) { // But we already found another counter that we come after.
if (currentCounter->actsAsReset()) {
// We found a reset counter that is on a layoutObject that is a sibling of ours or a parent.
if (isReset && areLayoutObjectsElementsSiblings(*currentLayoutObject, counterOwner)) {
// We are also a reset counter and the previous reset was on a sibling layoutObject
// 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.
parent = currentCounter->parent();
previousSibling = parent ? currentCounter : 0;
return parent;
}
// We are not a reset node or the previous reset must be on an ancestor of our owner layoutObject
// hence we must be a child of that reset counter.
parent = currentCounter;
// In some cases layoutObjects 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 (previousSiblingProtector->parent() != currentCounter)
previousSiblingProtector = nullptr;
previousSibling = previousSiblingProtector.get();
return true;
}
// CurrentCounter, the counter at the EndSearchLayoutObject, is not reset.
if (!isReset || !areLayoutObjectsElementsSiblings(*currentLayoutObject, 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 layoutObject we know we are a sibling of that node.
if (currentCounter->parent() != previousSiblingProtector->parent())
return false;
parent = currentCounter->parent();
previousSibling = previousSiblingProtector.get();
return true;
}
} 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 && areLayoutObjectsElementsSiblings(*currentLayoutObject, counterOwner)) {
parent = currentCounter->parent();
previousSibling = currentCounter;
return parent;
}
parent = currentCounter;
previousSibling = previousSiblingProtector.get();
return true;
}
if (!isReset || !areLayoutObjectsElementsSiblings(*currentLayoutObject, counterOwner)) {
parent = currentCounter->parent();
previousSibling = currentCounter;
return true;
}
previousSiblingProtector = currentCounter;
}
}
// We come here if the previous sibling or parent of our owner layoutObject had no
// good counter, or we are a reset node and the counter on the previous sibling
// of our owner layoutObject was not a reset counter.
// Set a new goal for the end of the search.
searchEndLayoutObject = previousSiblingOrParent(*currentLayoutObject);
} else {
// We are searching descendants of a previous sibling of the layoutObject that the
// counter being placed is attached to.
if (currentCounter) {
// We found a suitable counter.
if (previousSiblingProtector) {
// 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()) {
previousSiblingProtector = currentCounter;
// We are no longer interested in previous siblings of the currentLayoutObject or their children
// as counters they may have attached cannot be the previous sibling of the counter we are placing.
currentLayoutObject = parentElement(*currentLayoutObject)->layoutObject();
continue;
}
} else {
previousSiblingProtector = currentCounter;
}
currentLayoutObject = previousSiblingOrParent(*currentLayoutObject);
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 (previousSiblingProtector)
currentLayoutObject = previousSiblingOrParent(*currentLayoutObject);
else
currentLayoutObject = previousInPreOrder(*currentLayoutObject);
}
return false;
}
static CounterNode* makeCounterNode(LayoutObject& object, const AtomicString& identifier, bool alwaysCreateCounter)
{
if (object.hasCounterNodeMap()) {
if (CounterMap* nodeMap = counterMaps().get(&object)) {
if (CounterNode* node = nodeMap->get(identifier))
return node;
}
}
bool isReset = false;
int value = 0;
if (!planCounter(object, identifier, isReset, value) && !alwaysCreateCounter)
return nullptr;
RefPtr<CounterNode> newParent = nullptr;
RefPtr<CounterNode> newPreviousSibling = nullptr;
RefPtr<CounterNode> newNode = CounterNode::create(object, isReset, value);
if (findPlaceForCounter(object, identifier, isReset, newParent, newPreviousSibling))
newParent->insertAfter(newNode.get(), newPreviousSibling.get(), identifier);
CounterMap* nodeMap;
if (object.hasCounterNodeMap()) {
nodeMap = counterMaps().get(&object);
} else {
nodeMap = new CounterMap;
counterMaps().set(&object, adoptPtr(nodeMap));
object.setHasCounterNodeMap(true);
}
nodeMap->set(identifier, newNode);
if (newNode->parent())
return newNode.get();
// Checking if some nodes that were previously counter tree root nodes
// should become children of this node now.
CounterMaps& maps = counterMaps();
Element* stayWithin = parentElement(object);
bool skipDescendants;
for (LayoutObject* currentLayoutObject = nextInPreOrder(object, stayWithin); currentLayoutObject; currentLayoutObject = nextInPreOrder(*currentLayoutObject, stayWithin, skipDescendants)) {
skipDescendants = false;
if (!currentLayoutObject->hasCounterNodeMap())
continue;
CounterNode* currentCounter = maps.get(currentLayoutObject)->get(identifier);
if (!currentCounter)
continue;
skipDescendants = true;
if (currentCounter->parent())
continue;
if (stayWithin == parentElement(*currentLayoutObject) && currentCounter->hasResetType())
break;
newNode->insertAfter(currentCounter, newNode->lastChild(), identifier);
}
return newNode.get();
}
LayoutCounter::LayoutCounter(Document* node, const CounterContent& counter)
: LayoutText(node, StringImpl::empty())
, m_counter(counter)
, m_counterNode(nullptr)
, m_nextForSameCounter(nullptr)
{
view()->addLayoutCounter();
}
LayoutCounter::~LayoutCounter()
{
}
void LayoutCounter::willBeDestroyed()
{
if (m_counterNode) {
m_counterNode->removeLayoutObject(this);
ASSERT(!m_counterNode);
}
if (view())
view()->removeLayoutCounter();
LayoutText::willBeDestroyed();
}
PassRefPtr<StringImpl> LayoutCounter::originalText() const
{
if (!m_counterNode) {
LayoutObject* beforeAfterContainer = parent();
while (true) {
if (!beforeAfterContainer)
return nullptr;
if (!beforeAfterContainer->isAnonymous() && !beforeAfterContainer->isPseudoElement())
return nullptr; // LayoutCounters are restricted to before and after pseudo elements
PseudoId containerStyle = beforeAfterContainer->style()->styleType();
if ((containerStyle == BEFORE) || (containerStyle == AFTER))
break;
beforeAfterContainer = beforeAfterContainer->parent();
}
makeCounterNode(*beforeAfterContainer, m_counter.identifier(), true)->addLayoutObject(const_cast<LayoutCounter*>(this));
ASSERT(m_counterNode);
}
CounterNode* child = m_counterNode;
int value = child->actsAsReset() ? child->value() : child->countInParent();
String text = ListMarkerText::text(m_counter.listStyle(), value);
if (!m_counter.separator().isNull()) {
if (!child->actsAsReset())
child = child->parent();
while (CounterNode* parent = child->parent()) {
text = ListMarkerText::text(m_counter.listStyle(), child->countInParent())
+ m_counter.separator() + text;
child = parent;
}
}
return text.impl();
}
void LayoutCounter::updateCounter()
{
setText(originalText());
}
void LayoutCounter::invalidate()
{
m_counterNode->removeLayoutObject(this);
ASSERT(!m_counterNode);
if (documentBeingDestroyed())
return;
setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation(LayoutInvalidationReason::CountersChanged);
}
static void destroyCounterNodeWithoutMapRemoval(const AtomicString& identifier, CounterNode* node)
{
CounterNode* previous;
for (RefPtr<CounterNode> child = node->lastDescendant(); child && child != node; child = previous) {
previous = child->previousInPreOrder();
child->parent()->removeChild(child.get());
ASSERT(counterMaps().get(&child->owner())->get(identifier) == child);
counterMaps().get(&child->owner())->remove(identifier);
}
if (CounterNode* parent = node->parent())
parent->removeChild(node);
}
void LayoutCounter::destroyCounterNodes(LayoutObject& owner)
{
CounterMaps& maps = counterMaps();
CounterMaps::iterator mapsIterator = maps.find(&owner);
if (mapsIterator == maps.end())
return;
CounterMap* map = mapsIterator->value.get();
CounterMap::const_iterator end = map->end();
for (CounterMap::const_iterator it = map->begin(); it != end; ++it) {
destroyCounterNodeWithoutMapRemoval(it->key, it->value.get());
}
maps.remove(mapsIterator);
owner.setHasCounterNodeMap(false);
}
void LayoutCounter::destroyCounterNode(LayoutObject& owner, const AtomicString& identifier)
{
CounterMap* map = counterMaps().get(&owner);
if (!map)
return;
CounterMap::iterator mapIterator = map->find(identifier);
if (mapIterator == map->end())
return;
destroyCounterNodeWithoutMapRemoval(identifier, mapIterator->value.get());
map->remove(mapIterator);
// We do not delete "map" here even if empty because we expect to reuse
// it soon. In order for a layoutObject to lose all its counters permanently,
// a style change for the layoutObject involving removal of all counter
// directives must occur, in which case, LayoutCounter::destroyCounterNodes()
// must be called.
// The destruction of the LayoutObject (possibly caused by the removal of its
// associated DOM node) is the other case that leads to the permanent
// destruction of all counters attached to a LayoutObject. In this case
// LayoutCounter::destroyCounterNodes() must be and is now called, too.
// LayoutCounter::destroyCounterNodes() handles destruction of the counter
// map associated with a layoutObject, so there is no risk in leaking the map.
}
void LayoutCounter::layoutObjectSubtreeWillBeDetached(LayoutObject* layoutObject)
{
ASSERT(layoutObject->view());
// View should never be non-zero. crbug.com/546939
if (!layoutObject->view() || !layoutObject->view()->hasLayoutCounters())
return;
LayoutObject* currentLayoutObject = layoutObject->lastLeafChild();
if (!currentLayoutObject)
currentLayoutObject = layoutObject;
while (true) {
destroyCounterNodes(*currentLayoutObject);
if (currentLayoutObject == layoutObject)
break;
currentLayoutObject = currentLayoutObject->previousInPreOrder();
}
}
static void updateCounters(LayoutObject& layoutObject)
{
ASSERT(layoutObject.style());
const CounterDirectiveMap* directiveMap = layoutObject.style()->counterDirectives();
if (!directiveMap)
return;
CounterDirectiveMap::const_iterator end = directiveMap->end();
if (!layoutObject.hasCounterNodeMap()) {
for (CounterDirectiveMap::const_iterator it = directiveMap->begin(); it != end; ++it)
makeCounterNode(layoutObject, it->key, false);
return;
}
CounterMap* counterMap = counterMaps().get(&layoutObject);
ASSERT(counterMap);
for (CounterDirectiveMap::const_iterator it = directiveMap->begin(); it != end; ++it) {
RefPtr<CounterNode> node = counterMap->get(it->key);
if (!node) {
makeCounterNode(layoutObject, it->key, false);
continue;
}
RefPtr<CounterNode> newParent = nullptr;
RefPtr<CounterNode> newPreviousSibling = nullptr;
findPlaceForCounter(layoutObject, it->key, node->hasResetType(), newParent, newPreviousSibling);
if (node != counterMap->get(it->key))
continue;
CounterNode* parent = node->parent();
if (newParent == parent && newPreviousSibling == node->previousSibling())
continue;
if (parent)
parent->removeChild(node.get());
if (newParent)
newParent->insertAfter(node.get(), newPreviousSibling.get(), it->key);
}
}
void LayoutCounter::layoutObjectSubtreeAttached(LayoutObject* layoutObject)
{
ASSERT(layoutObject->view());
if (!layoutObject->view()->hasLayoutCounters())
return;
Node* node = layoutObject->node();
if (node)
node = node->parentNode();
else
node = layoutObject->generatingNode();
if (node && node->needsAttach())
return; // No need to update if the parent is not attached yet
for (LayoutObject* descendant = layoutObject; descendant; descendant = descendant->nextInPreOrder(layoutObject))
updateCounters(*descendant);
}
void LayoutCounter::layoutObjectStyleChanged(LayoutObject& layoutObject, const ComputedStyle* oldStyle, const ComputedStyle& newStyle)
{
Node* node = layoutObject.generatingNode();
if (!node || node->needsAttach())
return; // cannot have generated content or if it can have, it will be handled during attaching
const CounterDirectiveMap* oldCounterDirectives = oldStyle ? oldStyle->counterDirectives() : 0;
const CounterDirectiveMap* newCounterDirectives = newStyle.counterDirectives();
if (oldCounterDirectives) {
if (newCounterDirectives) {
CounterDirectiveMap::const_iterator newMapEnd = newCounterDirectives->end();
CounterDirectiveMap::const_iterator oldMapEnd = oldCounterDirectives->end();
for (CounterDirectiveMap::const_iterator it = newCounterDirectives->begin(); it != newMapEnd; ++it) {
CounterDirectiveMap::const_iterator oldMapIt = oldCounterDirectives->find(it->key);
if (oldMapIt != oldMapEnd) {
if (oldMapIt->value == it->value)
continue;
LayoutCounter::destroyCounterNode(layoutObject, it->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(layoutObject, it->key, false);
}
// Destroying old counters that do not exist in the new counterDirective map.
for (CounterDirectiveMap::const_iterator it = oldCounterDirectives->begin(); it !=oldMapEnd; ++it) {
if (!newCounterDirectives->contains(it->key))
LayoutCounter::destroyCounterNode(layoutObject, it->key);
}
} else {
if (layoutObject.hasCounterNodeMap())
LayoutCounter::destroyCounterNodes(layoutObject);
}
} else if (newCounterDirectives) {
if (layoutObject.hasCounterNodeMap())
LayoutCounter::destroyCounterNodes(layoutObject);
CounterDirectiveMap::const_iterator newMapEnd = newCounterDirectives->end();
for (CounterDirectiveMap::const_iterator it = newCounterDirectives->begin(); it != newMapEnd; ++it) {
// 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(layoutObject, it->key, false);
}
}
}
} // namespace blink
#ifndef NDEBUG
void showCounterLayoutObjectTree(const blink::LayoutObject* layoutObject, const char* counterName)
{
if (!layoutObject)
return;
const blink::LayoutObject* root = layoutObject;
while (root->parent())
root = root->parent();
AtomicString identifier(counterName);
for (const blink::LayoutObject* current = root; current; current = current->nextInPreOrder()) {
fprintf(stderr, "%c", (current == layoutObject) ? '*' : ' ');
for (const blink::LayoutObject* parent = current; parent && parent != root; parent = parent->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(), current->hasCounterNodeMap() ?
counterName ? blink::counterMaps().get(current)->get(identifier) : (blink::CounterNode*)1 : (blink::CounterNode*)0);
}
fflush(stderr);
}
#endif // NDEBUG