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/* -*- 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/. */
#include "ChildIterator.h"
#include "mozilla/dom/Document.h"
#include "mozilla/dom/HTMLSlotElement.h"
#include "mozilla/dom/ShadowRoot.h"
#include "nsContentUtils.h"
#include "nsIAnonymousContentCreator.h"
#include "nsIFrame.h"
#include "nsLayoutUtils.h"
namespace mozilla::dom {
FlattenedChildIterator::FlattenedChildIterator(const nsIContent* aParent,
bool aStartAtBeginning)
: mParent(aParent), mOriginalParent(aParent), mIsFirst(aStartAtBeginning) {
if (!mParent->IsElement()) {
// TODO(emilio): I think it probably makes sense to only allow constructing
// FlattenedChildIterators with Element.
return;
}
if (ShadowRoot* shadow = mParent->AsElement()->GetShadowRoot()) {
mParent = shadow;
mShadowDOMInvolved = true;
return;
}
if (const auto* slot = HTMLSlotElement::FromNode(mParent)) {
if (!slot->AssignedNodes().IsEmpty()) {
mParentAsSlot = slot;
if (!aStartAtBeginning) {
mIndexInInserted = slot->AssignedNodes().Length();
}
mShadowDOMInvolved = true;
}
}
}
uint32_t FlattenedChildIterator::GetLength(const nsINode* aParent) {
if (const auto* element = Element::FromNode(aParent)) {
if (const auto* slot = HTMLSlotElement::FromNode(element)) {
if (uint32_t len = slot->AssignedNodes().Length()) {
return len;
}
} else if (auto* shadowRoot = element->GetShadowRoot()) {
return shadowRoot->GetChildCount();
}
}
return aParent->GetChildCount();
}
Maybe<uint32_t> FlattenedChildIterator::GetIndexOf(
const nsINode* aParent, const nsINode* aPossibleChild) {
if (const auto* element = Element::FromNode(aParent)) {
if (const auto* slot = HTMLSlotElement::FromNode(element)) {
const Span assigned = slot->AssignedNodes();
if (!assigned.IsEmpty()) {
auto index = assigned.IndexOf(aPossibleChild);
if (index == assigned.npos) {
return Nothing();
}
return Some(index);
}
} else if (auto* shadowRoot = element->GetShadowRoot()) {
return shadowRoot->ComputeIndexOf(aPossibleChild);
}
}
return aParent->ComputeIndexOf(aPossibleChild);
}
nsIContent* FlattenedChildIterator::GetNextChild() {
// If we're already in the inserted-children array, look there first
if (mParentAsSlot) {
const Span assignedNodes = mParentAsSlot->AssignedNodes();
if (mIsFirst) {
mIsFirst = false;
MOZ_ASSERT(mIndexInInserted == 0);
mChild = assignedNodes[0]->AsContent();
return mChild;
}
MOZ_ASSERT(mIndexInInserted <= assignedNodes.Length());
if (mIndexInInserted + 1 >= assignedNodes.Length()) {
mIndexInInserted = assignedNodes.Length();
return nullptr;
}
mChild = assignedNodes[++mIndexInInserted]->AsContent();
return mChild;
}
if (mIsFirst) { // at the beginning of the child list
mChild = mParent->GetFirstChild();
mIsFirst = false;
} else if (mChild) { // in the middle of the child list
mChild = mChild->GetNextSibling();
}
return mChild;
}
bool FlattenedChildIterator::Seek(const nsIContent* aChildToFind) {
if (!mParentAsSlot && aChildToFind->GetParent() == mParent &&
!aChildToFind->IsRootOfNativeAnonymousSubtree()) {
// Fast path: just point ourselves to aChildToFind, which is a
// normal DOM child of ours.
mChild = const_cast<nsIContent*>(aChildToFind);
mIndexInInserted = 0;
mIsFirst = false;
return true;
}
// Can we add more fast paths here based on whether the parent of aChildToFind
// is a This version can take shortcuts that the two-argument version
// can't, so can be faster (and in fact cshadow insertion point or content
// insertion point?
// It would be nice to assert that we find aChildToFind, but bz thinks that
// we might not find aChildToFind when called from ContentInserted
// if first-letter frames are about.
while (nsIContent* child = GetNextChild()) {
if (child == aChildToFind) {
return true;
}
}
return false;
}
nsIContent* FlattenedChildIterator::GetPreviousChild() {
if (mIsFirst) { // at the beginning of the child list
return nullptr;
}
if (mParentAsSlot) {
const Span assignedNodes = mParentAsSlot->AssignedNodes();
MOZ_ASSERT(mIndexInInserted <= assignedNodes.Length());
if (mIndexInInserted == 0) {
mIsFirst = true;
return nullptr;
}
mChild = assignedNodes[--mIndexInInserted]->AsContent();
return mChild;
}
if (mChild) { // in the middle of the child list
mChild = mChild->GetPreviousSibling();
} else { // at the end of the child list
mChild = mParent->GetLastChild();
}
if (!mChild) {
mIsFirst = true;
}
return mChild;
}
nsIContent* AllChildrenIterator::Get() const {
switch (mPhase) {
case Phase::AtBackdropKid: {
Element* backdrop = nsLayoutUtils::GetBackdropPseudo(Parent());
MOZ_ASSERT(backdrop, "No content marker frame at AtBackdropKid phase");
return backdrop;
}
case Phase::AtMarkerKid: {
Element* marker = nsLayoutUtils::GetMarkerPseudo(Parent());
MOZ_ASSERT(marker, "No content marker frame at AtMarkerKid phase");
return marker;
}
case Phase::AtBeforeKid: {
Element* before = nsLayoutUtils::GetBeforePseudo(Parent());
MOZ_ASSERT(before, "No content before frame at AtBeforeKid phase");
return before;
}
case Phase::AtFlatTreeKids:
return FlattenedChildIterator::Get();
case Phase::AtAnonKids:
return mAnonKids[mAnonKidsIdx];
case Phase::AtAfterKid: {
Element* after = nsLayoutUtils::GetAfterPseudo(Parent());
MOZ_ASSERT(after, "No content after frame at AtAfterKid phase");
return after;
}
default:
return nullptr;
}
}
bool AllChildrenIterator::Seek(const nsIContent* aChildToFind) {
while (mPhase != Phase::AtEnd) {
if (mPhase == Phase::AtFlatTreeKids) {
if (FlattenedChildIterator::Seek(aChildToFind)) {
return true;
}
mPhase = Phase::AtAnonKids;
}
if (GetNextChild() == aChildToFind) {
return true;
}
}
return false;
}
void AllChildrenIterator::AppendNativeAnonymousChildren() {
nsContentUtils::AppendNativeAnonymousChildren(Parent(), mAnonKids, mFlags);
}
nsIContent* AllChildrenIterator::GetNextChild() {
switch (mPhase) {
case Phase::AtBegin:
if (Element* backdropPseudo =
nsLayoutUtils::GetBackdropPseudo(Parent())) {
mPhase = Phase::AtBackdropKid;
return backdropPseudo;
}
[[fallthrough]];
case Phase::AtBackdropKid:
if (Element* markerContent = nsLayoutUtils::GetMarkerPseudo(Parent())) {
mPhase = Phase::AtMarkerKid;
return markerContent;
}
[[fallthrough]];
case Phase::AtMarkerKid:
if (Element* beforeContent = nsLayoutUtils::GetBeforePseudo(Parent())) {
mPhase = Phase::AtBeforeKid;
return beforeContent;
}
[[fallthrough]];
case Phase::AtBeforeKid:
[[fallthrough]];
case Phase::AtFlatTreeKids:
if (nsIContent* kid = FlattenedChildIterator::GetNextChild()) {
mPhase = Phase::AtFlatTreeKids;
return kid;
}
[[fallthrough]];
case Phase::AtAnonKids:
if (mAnonKids.IsEmpty()) {
MOZ_ASSERT(mAnonKidsIdx == UINT32_MAX);
AppendNativeAnonymousChildren();
mAnonKidsIdx = 0;
} else if (mAnonKidsIdx == UINT32_MAX) {
mAnonKidsIdx = 0;
} else {
mAnonKidsIdx++;
}
if (mAnonKidsIdx < mAnonKids.Length()) {
mPhase = Phase::AtAnonKids;
return mAnonKids[mAnonKidsIdx];
}
if (Element* afterContent = nsLayoutUtils::GetAfterPseudo(Parent())) {
mPhase = Phase::AtAfterKid;
return afterContent;
}
[[fallthrough]];
case Phase::AtAfterKid:
case Phase::AtEnd:
break;
}
mPhase = Phase::AtEnd;
return nullptr;
}
nsIContent* AllChildrenIterator::GetPreviousChild() {
switch (mPhase) {
case Phase::AtEnd:
if (Element* afterContent = nsLayoutUtils::GetAfterPseudo(Parent())) {
mPhase = Phase::AtAfterKid;
return afterContent;
}
[[fallthrough]];
case Phase::AtAfterKid:
MOZ_ASSERT(mAnonKidsIdx == mAnonKids.Length());
[[fallthrough]];
case Phase::AtAnonKids:
if (mAnonKids.IsEmpty()) {
AppendNativeAnonymousChildren();
mAnonKidsIdx = mAnonKids.Length();
}
// If 0 then it turns into UINT32_MAX, which indicates the iterator is
// before the anonymous children.
--mAnonKidsIdx;
if (mAnonKidsIdx < mAnonKids.Length()) {
mPhase = Phase::AtAnonKids;
return mAnonKids[mAnonKidsIdx];
}
[[fallthrough]];
case Phase::AtFlatTreeKids:
if (nsIContent* kid = FlattenedChildIterator::GetPreviousChild()) {
mPhase = Phase::AtFlatTreeKids;
return kid;
}
if (Element* beforeContent = nsLayoutUtils::GetBeforePseudo(Parent())) {
mPhase = Phase::AtBeforeKid;
return beforeContent;
}
[[fallthrough]];
case Phase::AtBeforeKid:
if (Element* markerContent = nsLayoutUtils::GetMarkerPseudo(Parent())) {
mPhase = Phase::AtMarkerKid;
return markerContent;
}
[[fallthrough]];
case Phase::AtMarkerKid:
if (Element* backdrop = nsLayoutUtils::GetBackdropPseudo(Parent())) {
mPhase = Phase::AtBackdropKid;
return backdrop;
}
[[fallthrough]];
case Phase::AtBackdropKid:
case Phase::AtBegin:
break;
}
mPhase = Phase::AtBegin;
return nullptr;
}
} // namespace mozilla::dom