nsIContent*
ExplicitChildIterator::GetNextChild()
{
// If we're already in the inserted-children array, look there first
if (mIndexInInserted) {
MOZ_ASSERT(mChild);
MOZ_ASSERT(nsContentUtils::IsContentInsertionPoint(mChild));
MOZ_ASSERT(!mDefaultChild);
MatchedNodes assignedChildren = GetMatchedNodesForPoint(mChild);
if (mIndexInInserted < assignedChildren.Length()) {
return assignedChildren[mIndexInInserted++];
}
mIndexInInserted = 0;
mChild = mChild->GetNextSibling();
} else if (mShadowIterator) {
// If we're inside of a <shadow> element, look through the
// explicit children of the projected ShadowRoot via
// the mShadowIterator.
nsIContent* nextChild = mShadowIterator->GetNextChild();
if (nextChild) {
return nextChild;
}
mShadowIterator = nullptr;
mChild = mChild->GetNextSibling();
} else if (mDefaultChild) {
// If we're already in default content, check if there are more nodes there
MOZ_ASSERT(mChild);
MOZ_ASSERT(nsContentUtils::IsContentInsertionPoint(mChild));
mDefaultChild = mDefaultChild->GetNextSibling();
if (mDefaultChild) {
return mDefaultChild;
}
mChild = mChild->GetNextSibling();
} else 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();
}
// Iterate until we find a non-insertion point, or an insertion point with
// content.
while (mChild) {
// If the current child being iterated is a shadow insertion point then
// the iterator needs to go into the projected ShadowRoot.
if (ShadowRoot::IsShadowInsertionPoint(mChild)) {
// Look for the next child in the projected ShadowRoot for the <shadow>
// element.
HTMLShadowElement* shadowElem = static_cast<HTMLShadowElement*>(mChild);
ShadowRoot* projectedShadow = shadowElem->GetOlderShadowRoot();
if (projectedShadow) {
mShadowIterator = new ExplicitChildIterator(projectedShadow);
nsIContent* nextChild = mShadowIterator->GetNextChild();
if (nextChild) {
return nextChild;
}
mShadowIterator = nullptr;
}
mChild = mChild->GetNextSibling();
} else if (nsContentUtils::IsContentInsertionPoint(mChild)) {
// If the current child being iterated is a content insertion point
// then the iterator needs to return the nodes distributed into
// the content insertion point.
MatchedNodes assignedChildren = GetMatchedNodesForPoint(mChild);
if (!assignedChildren.IsEmpty()) {
// Iterate through elements projected on insertion point.
mIndexInInserted = 1;
return assignedChildren[0];
}
// Insertion points inside fallback/default content
// are considered inactive and do not get assigned nodes.
mDefaultChild = mChild->GetFirstChild();
if (mDefaultChild) {
return mDefaultChild;
}
// If we have an insertion point with no assigned nodes and
// no default content, move on to the next node.
mChild = mChild->GetNextSibling();
} else {
// mChild is not an insertion point, thus it is the next node to
// return from this iterator.
break;
}
}
return mChild;
}
nsIContent*
ExplicitChildIterator::GetPreviousChild()
{
// If we're already in the inserted-children array, look there first
if (mIndexInInserted) {
// NB: mIndexInInserted points one past the last returned child so we need
// to look *two* indices back in order to return the previous child.
MatchedNodes assignedChildren = GetMatchedNodesForPoint(mChild);
if (--mIndexInInserted) {
return assignedChildren[mIndexInInserted - 1];
}
mChild = mChild->GetPreviousSibling();
} else if (mShadowIterator) {
nsIContent* previousChild = mShadowIterator->GetPreviousChild();
if (previousChild) {
return previousChild;
}
mShadowIterator = nullptr;
mChild = mChild->GetPreviousSibling();
} else if (mDefaultChild) {
// If we're already in default content, check if there are more nodes there
mDefaultChild = mDefaultChild->GetPreviousSibling();
if (mDefaultChild) {
return mDefaultChild;
}
mChild = mChild->GetPreviousSibling();
} else if (mIsFirst) { // at the beginning of the child list
return nullptr;
} else if (mChild) { // in the middle of the child list
mChild = mChild->GetPreviousSibling();
} else { // at the end of the child list
mChild = mParent->GetLastChild();
}
// Iterate until we find a non-insertion point, or an insertion point with
// content.
while (mChild) {
if (ShadowRoot::IsShadowInsertionPoint(mChild)) {
// If the current child being iterated is a shadow insertion point then
// the iterator needs to go into the projected ShadowRoot.
HTMLShadowElement* shadowElem = static_cast<HTMLShadowElement*>(mChild);
ShadowRoot* projectedShadow = shadowElem->GetOlderShadowRoot();
if (projectedShadow) {
// Create a ExplicitChildIterator that begins iterating from the end.
mShadowIterator = new ExplicitChildIterator(projectedShadow, false);
nsIContent* previousChild = mShadowIterator->GetPreviousChild();
if (previousChild) {
return previousChild;
}
mShadowIterator = nullptr;
}
mChild = mChild->GetPreviousSibling();
} else if (nsContentUtils::IsContentInsertionPoint(mChild)) {
// If the current child being iterated is a content insertion point
// then the iterator needs to return the nodes distributed into
// the content insertion point.
MatchedNodes assignedChildren = GetMatchedNodesForPoint(mChild);
if (!assignedChildren.IsEmpty()) {
mIndexInInserted = assignedChildren.Length();
return assignedChildren[mIndexInInserted - 1];
}
mDefaultChild = mChild->GetLastChild();
if (mDefaultChild) {
return mDefaultChild;
}
mChild = mChild->GetPreviousSibling();
} else {
// mChild is not an insertion point, thus it is the next node to
// return from this iterator.
break;
}
}
if (!mChild) {
mIsFirst = true;
}
return mChild;
}
