michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim: set ts=2 sw=2 et tw=80: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "ChildIterator.h"
michael@0: #include "nsContentUtils.h"
michael@0: #include "mozilla/dom/XBLChildrenElement.h"
michael@0: #include "mozilla/dom/HTMLContentElement.h"
michael@0: #include "mozilla/dom/HTMLShadowElement.h"
michael@0: #include "mozilla/dom/ShadowRoot.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace dom {
michael@0: 
michael@0: class MatchedNodes {
michael@0: public:
michael@0:   MatchedNodes(HTMLContentElement* aInsertionPoint)
michael@0:     : mIsContentElement(true), mContentElement(aInsertionPoint) {}
michael@0: 
michael@0:   MatchedNodes(XBLChildrenElement* aInsertionPoint)
michael@0:     : mIsContentElement(false), mChildrenElement(aInsertionPoint) {}
michael@0: 
michael@0:   uint32_t Length() const
michael@0:   {
michael@0:     return mIsContentElement ? mContentElement->MatchedNodes().Length()
michael@0:                              : mChildrenElement->mInsertedChildren.Length();
michael@0:   }
michael@0: 
michael@0:   nsIContent* operator[](int32_t aIndex) const
michael@0:   {
michael@0:     return mIsContentElement ? mContentElement->MatchedNodes()[aIndex]
michael@0:                              : mChildrenElement->mInsertedChildren[aIndex];
michael@0:   }
michael@0: 
michael@0:   bool IsEmpty() const
michael@0:   {
michael@0:     return mIsContentElement ? mContentElement->MatchedNodes().IsEmpty()
michael@0:                              : mChildrenElement->mInsertedChildren.IsEmpty();
michael@0:   }
michael@0: protected:
michael@0:   bool mIsContentElement;
michael@0:   union {
michael@0:     HTMLContentElement* mContentElement;
michael@0:     XBLChildrenElement* mChildrenElement;
michael@0:   };
michael@0: };
michael@0: 
michael@0: static inline MatchedNodes
michael@0: GetMatchedNodesForPoint(nsIContent* aContent)
michael@0: {
michael@0:   if (aContent->NodeInfo()->Equals(nsGkAtoms::children, kNameSpaceID_XBL)) {
michael@0:     // XBL case
michael@0:     return MatchedNodes(static_cast<XBLChildrenElement*>(aContent));
michael@0:   }
michael@0: 
michael@0:   // Web components case
michael@0:   MOZ_ASSERT(aContent->IsHTML(nsGkAtoms::content));
michael@0:   return MatchedNodes(static_cast<HTMLContentElement*>(aContent));
michael@0: }
michael@0: 
michael@0: nsIContent*
michael@0: ExplicitChildIterator::GetNextChild()
michael@0: {
michael@0:   // If we're already in the inserted-children array, look there first
michael@0:   if (mIndexInInserted) {
michael@0:     MOZ_ASSERT(mChild);
michael@0:     MOZ_ASSERT(nsContentUtils::IsContentInsertionPoint(mChild));
michael@0:     MOZ_ASSERT(!mDefaultChild);
michael@0: 
michael@0:     MatchedNodes assignedChildren = GetMatchedNodesForPoint(mChild);
michael@0:     if (mIndexInInserted < assignedChildren.Length()) {
michael@0:       return assignedChildren[mIndexInInserted++];
michael@0:     }
michael@0:     mIndexInInserted = 0;
michael@0:     mChild = mChild->GetNextSibling();
michael@0:   } else if (mShadowIterator) {
michael@0:     // If we're inside of a <shadow> element, look through the
michael@0:     // explicit children of the projected ShadowRoot via
michael@0:     // the mShadowIterator.
michael@0:     nsIContent* nextChild = mShadowIterator->GetNextChild();
michael@0:     if (nextChild) {
michael@0:       return nextChild;
michael@0:     }
michael@0: 
michael@0:     mShadowIterator = nullptr;
michael@0:     mChild = mChild->GetNextSibling();
michael@0:   } else if (mDefaultChild) {
michael@0:     // If we're already in default content, check if there are more nodes there
michael@0:     MOZ_ASSERT(mChild);
michael@0:     MOZ_ASSERT(nsContentUtils::IsContentInsertionPoint(mChild));
michael@0: 
michael@0:     mDefaultChild = mDefaultChild->GetNextSibling();
michael@0:     if (mDefaultChild) {
michael@0:       return mDefaultChild;
michael@0:     }
michael@0: 
michael@0:     mChild = mChild->GetNextSibling();
michael@0:   } else if (mIsFirst) {  // at the beginning of the child list
michael@0:     mChild = mParent->GetFirstChild();
michael@0:     mIsFirst = false;
michael@0:   } else if (mChild) { // in the middle of the child list
michael@0:     mChild = mChild->GetNextSibling();
michael@0:   }
michael@0: 
michael@0:   // Iterate until we find a non-insertion point, or an insertion point with
michael@0:   // content.
michael@0:   while (mChild) {
michael@0:     // If the current child being iterated is a shadow insertion point then
michael@0:     // the iterator needs to go into the projected ShadowRoot.
michael@0:     if (ShadowRoot::IsShadowInsertionPoint(mChild)) {
michael@0:       // Look for the next child in the projected ShadowRoot for the <shadow>
michael@0:       // element.
michael@0:       HTMLShadowElement* shadowElem = static_cast<HTMLShadowElement*>(mChild);
michael@0:       ShadowRoot* projectedShadow = shadowElem->GetOlderShadowRoot();
michael@0:       if (projectedShadow) {
michael@0:         mShadowIterator = new ExplicitChildIterator(projectedShadow);
michael@0:         nsIContent* nextChild = mShadowIterator->GetNextChild();
michael@0:         if (nextChild) {
michael@0:           return nextChild;
michael@0:         }
michael@0:         mShadowIterator = nullptr;
michael@0:       }
michael@0:       mChild = mChild->GetNextSibling();
michael@0:     } else if (nsContentUtils::IsContentInsertionPoint(mChild)) {
michael@0:       // If the current child being iterated is a content insertion point
michael@0:       // then the iterator needs to return the nodes distributed into
michael@0:       // the content insertion point.
michael@0:       MatchedNodes assignedChildren = GetMatchedNodesForPoint(mChild);
michael@0:       if (!assignedChildren.IsEmpty()) {
michael@0:         // Iterate through elements projected on insertion point.
michael@0:         mIndexInInserted = 1;
michael@0:         return assignedChildren[0];
michael@0:       }
michael@0: 
michael@0:       // Insertion points inside fallback/default content
michael@0:       // are considered inactive and do not get assigned nodes.
michael@0:       mDefaultChild = mChild->GetFirstChild();
michael@0:       if (mDefaultChild) {
michael@0:         return mDefaultChild;
michael@0:       }
michael@0: 
michael@0:       // If we have an insertion point with no assigned nodes and
michael@0:       // no default content, move on to the next node.
michael@0:       mChild = mChild->GetNextSibling();
michael@0:     } else {
michael@0:       // mChild is not an insertion point, thus it is the next node to
michael@0:       // return from this iterator.
michael@0:       break;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   return mChild;
michael@0: }
michael@0: 
michael@0: FlattenedChildIterator::FlattenedChildIterator(nsIContent* aParent)
michael@0:   : ExplicitChildIterator(aParent), mXBLInvolved(false)
michael@0: {
michael@0:   nsXBLBinding* binding =
michael@0:     aParent->OwnerDoc()->BindingManager()->GetBindingWithContent(aParent);
michael@0: 
michael@0:   if (binding) {
michael@0:     nsIContent* anon = binding->GetAnonymousContent();
michael@0:     if (anon) {
michael@0:       mParent = anon;
michael@0:       mXBLInvolved = true;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   // We set mXBLInvolved to true if either:
michael@0:   // - The node we're iterating has a binding with content attached to it.
michael@0:   // - The node is generated XBL content and has an <xbl:children> child.
michael@0:   if (!mXBLInvolved && aParent->GetBindingParent()) {
michael@0:     for (nsIContent* child = aParent->GetFirstChild();
michael@0:          child;
michael@0:          child = child->GetNextSibling()) {
michael@0:       if (child->NodeInfo()->Equals(nsGkAtoms::children, kNameSpaceID_XBL)) {
michael@0:         MOZ_ASSERT(child->GetBindingParent());
michael@0:         mXBLInvolved = true;
michael@0:         break;
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: nsIContent*
michael@0: ExplicitChildIterator::Get()
michael@0: {
michael@0:   MOZ_ASSERT(!mIsFirst);
michael@0: 
michael@0:   if (mIndexInInserted) {
michael@0:     XBLChildrenElement* point = static_cast<XBLChildrenElement*>(mChild);
michael@0:     return point->mInsertedChildren[mIndexInInserted - 1];
michael@0:   } else if (mShadowIterator)  {
michael@0:     return mShadowIterator->Get();
michael@0:   }
michael@0:   return mDefaultChild ? mDefaultChild : mChild;
michael@0: }
michael@0: 
michael@0: nsIContent*
michael@0: ExplicitChildIterator::GetPreviousChild()
michael@0: {
michael@0:   // If we're already in the inserted-children array, look there first
michael@0:   if (mIndexInInserted) {
michael@0:     // NB: mIndexInInserted points one past the last returned child so we need
michael@0:     // to look *two* indices back in order to return the previous child.
michael@0:     MatchedNodes assignedChildren = GetMatchedNodesForPoint(mChild);
michael@0:     if (--mIndexInInserted) {
michael@0:       return assignedChildren[mIndexInInserted - 1];
michael@0:     }
michael@0:     mChild = mChild->GetPreviousSibling();
michael@0:   } else if (mShadowIterator) {
michael@0:     nsIContent* previousChild = mShadowIterator->GetPreviousChild();
michael@0:     if (previousChild) {
michael@0:       return previousChild;
michael@0:     }
michael@0:     mShadowIterator = nullptr;
michael@0:     mChild = mChild->GetPreviousSibling();
michael@0:   } else if (mDefaultChild) {
michael@0:     // If we're already in default content, check if there are more nodes there
michael@0:     mDefaultChild = mDefaultChild->GetPreviousSibling();
michael@0:     if (mDefaultChild) {
michael@0:       return mDefaultChild;
michael@0:     }
michael@0: 
michael@0:     mChild = mChild->GetPreviousSibling();
michael@0:   } else if (mIsFirst) { // at the beginning of the child list
michael@0:     return nullptr;
michael@0:   } else if (mChild) { // in the middle of the child list
michael@0:     mChild = mChild->GetPreviousSibling();
michael@0:   } else { // at the end of the child list
michael@0:     mChild = mParent->GetLastChild();
michael@0:   }
michael@0: 
michael@0:   // Iterate until we find a non-insertion point, or an insertion point with
michael@0:   // content.
michael@0:   while (mChild) {
michael@0:     if (ShadowRoot::IsShadowInsertionPoint(mChild)) {
michael@0:       // If the current child being iterated is a shadow insertion point then
michael@0:       // the iterator needs to go into the projected ShadowRoot.
michael@0:       HTMLShadowElement* shadowElem = static_cast<HTMLShadowElement*>(mChild);
michael@0:       ShadowRoot* projectedShadow = shadowElem->GetOlderShadowRoot();
michael@0:       if (projectedShadow) {
michael@0:         // Create a ExplicitChildIterator that begins iterating from the end.
michael@0:         mShadowIterator = new ExplicitChildIterator(projectedShadow, false);
michael@0:         nsIContent* previousChild = mShadowIterator->GetPreviousChild();
michael@0:         if (previousChild) {
michael@0:           return previousChild;
michael@0:         }
michael@0:         mShadowIterator = nullptr;
michael@0:       }
michael@0:       mChild = mChild->GetPreviousSibling();
michael@0:     } else if (nsContentUtils::IsContentInsertionPoint(mChild)) {
michael@0:       // If the current child being iterated is a content insertion point
michael@0:       // then the iterator needs to return the nodes distributed into
michael@0:       // the content insertion point.
michael@0:       MatchedNodes assignedChildren = GetMatchedNodesForPoint(mChild);
michael@0:       if (!assignedChildren.IsEmpty()) {
michael@0:         mIndexInInserted = assignedChildren.Length();
michael@0:         return assignedChildren[mIndexInInserted - 1];
michael@0:       }
michael@0: 
michael@0:       mDefaultChild = mChild->GetLastChild();
michael@0:       if (mDefaultChild) {
michael@0:         return mDefaultChild;
michael@0:       }
michael@0: 
michael@0:       mChild = mChild->GetPreviousSibling();
michael@0:     } else {
michael@0:       // mChild is not an insertion point, thus it is the next node to
michael@0:       // return from this iterator.
michael@0:       break;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   if (!mChild) {
michael@0:     mIsFirst = true;
michael@0:   }
michael@0: 
michael@0:   return mChild;
michael@0: }
michael@0: 
michael@0: } // namespace dom
michael@0: } // namespace mozilla