/* 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/. */
#ifndef mozilla_ConnectedAncestorTracker_h
#define mozilla_ConnectedAncestorTracker_h
#include "mozilla/Attributes.h"
#include "mozilla/PresShell.h"
#include "mozilla/dom/Document.h"
#include "mozilla/dom/Element.h"
#include "nsIContent.h"
namespace mozilla {
/**
* AutoConnectedAncestorTracker is a struct which keeps referring the connected
* and closest ancestor of a content node. E.g., say, there are nodes are:
* Document -> <html> -> <body> -> <div> and starts tracking it with the <div>,
* and the <body> is removed, this refers the <html> with mConnectedAncestor.
* Note that even after reconnected the <body>, this won't refer the <div> as
* connected one.
*/
struct MOZ_STACK_CLASS AutoConnectedAncestorTracker final {
explicit AutoConnectedAncestorTracker(nsIContent& aContent)
: mContent(aContent),
mPresShell(aContent.IsInComposedDoc()
? aContent.OwnerDoc()->GetPresShell()
: nullptr) {
if (mPresShell) {
mPresShell->AddConnectedAncestorTracker(*this);
}
}
~AutoConnectedAncestorTracker() {
if (mPresShell) {
mPresShell->RemoveConnectedAncestorTracker(*this);
}
}
[[nodiscard]]
bool ContentWasRemoved()
const {
return mPresShell && mConnectedAncestor;
}
[[nodiscard]] dom::Element* GetConnectedElement()
const {
return ContentWasRemoved()
? mConnectedAncestor->GetAsElementOrParentElement()
: mContent->GetAsElementOrParentElement();
}
[[nodiscard]] nsIContent* GetConnectedContent()
const {
return ContentWasRemoved() ? nsIContent::FromNode(mConnectedAncestor)
: mContent.get();
}
[[nodiscard]] nsINode& ConnectedNode()
const {
return ContentWasRemoved() ? *mConnectedAncestor : mContent.ref();
}
// Store the original content node.
const OwningNonNull<nsIContent> mContent;
// Store the connected ancestor node if and only if mContent has been deleted
// from the document.
nsCOMPtr<nsINode> mConnectedAncestor;
// The PresShell which manages this instance.
const RefPtr<PresShell> mPresShell;
AutoConnectedAncestorTracker* mPreviousTracker = nullptr;
};
}
// namespace mozilla
#endif // #ifndef mozilla_ConnectedAncestorTracker_h
