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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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_ManualNAC_h
#define mozilla_ManualNAC_h
#include "mozilla/dom/Element.h"
#include "mozilla/RefPtr.h"
namespace mozilla {
// 16 seems to be the maximum number of manual Native Anonymous Content (NAC)
// nodes that editor creates for a given element.
//
// These need to be manually removed by the machinery that sets the NAC,
// otherwise we'll leak.
typedef AutoTArray<RefPtr<dom::Element>, 16> ManualNACArray;
/**
* Smart pointer class to own "manual" Native Anonymous Content, and perform
* the necessary registration and deregistration on the parent element.
*/
class ManualNACPtr final {
public:
ManualNACPtr() = default;
MOZ_IMPLICIT ManualNACPtr(decltype(nullptr)) {}
explicit ManualNACPtr(already_AddRefed<dom::Element> aNewNAC)
: mPtr(aNewNAC) {
if (!mPtr) {
return;
}
// Record the NAC on the element, so that AllChildrenIterator can find it.
nsIContent* parentContent = mPtr->GetParent();
auto nac = static_cast<ManualNACArray*>(
parentContent->GetProperty(nsGkAtoms::manualNACProperty));
if (!nac) {
nac = new ManualNACArray();
parentContent->SetProperty(nsGkAtoms::manualNACProperty, nac,
nsINode::DeleteProperty<ManualNACArray>);
}
nac->AppendElement(mPtr);
}
// We use move semantics, and delete the copy-constructor and operator=.
ManualNACPtr(ManualNACPtr&& aOther) : mPtr(std::move(aOther.mPtr)) {}
ManualNACPtr(ManualNACPtr& aOther) = delete;
ManualNACPtr& operator=(ManualNACPtr&& aOther) {
mPtr = std::move(aOther.mPtr);
return *this;
}
ManualNACPtr& operator=(ManualNACPtr& aOther) = delete;
~ManualNACPtr() { Reset(); }
void Reset() {
if (!mPtr) {
return;
}
RefPtr<dom::Element> ptr = std::move(mPtr);
RemoveContentFromNACArray(ptr);
}
static bool IsManualNAC(nsIContent* aAnonContent) {
MOZ_ASSERT(aAnonContent->IsRootOfNativeAnonymousSubtree());
MOZ_ASSERT(aAnonContent->IsInComposedDoc());
auto* nac = static_cast<ManualNACArray*>(
aAnonContent->GetParent()->GetProperty(nsGkAtoms::manualNACProperty));
return nac && nac->Contains(aAnonContent);
}
static void RemoveContentFromNACArray(nsIContent* aAnonymousContent) {
nsIContent* parentContent = aAnonymousContent->GetParent();
if (!parentContent) {
NS_WARNING("Potentially leaking manual NAC");
return;
}
// Remove reference from the parent element.
auto* nac = static_cast<ManualNACArray*>(
parentContent->GetProperty(nsGkAtoms::manualNACProperty));
// Document::AdoptNode might remove all properties before destroying editor.
// So we have to consider that NAC could be already removed.
if (nac) {
nac->RemoveElement(aAnonymousContent);
if (nac->IsEmpty()) {
parentContent->RemoveProperty(nsGkAtoms::manualNACProperty);
}
}
aAnonymousContent->UnbindFromTree();
}
dom::Element* get() const { return mPtr.get(); }
dom::Element* operator->() const { return get(); }
operator dom::Element*() const& { return get(); }
private:
RefPtr<dom::Element> mPtr;
};
} // namespace mozilla
inline void ImplCycleCollectionUnlink(mozilla::ManualNACPtr& field) {
field.Reset();
}
inline void ImplCycleCollectionTraverse(
nsCycleCollectionTraversalCallback& callback,
const mozilla::ManualNACPtr& field, const char* name, uint32_t flags = 0) {
CycleCollectionNoteChild(callback, field.get(), name, flags);
}
#endif // #ifndef mozilla_ManualNAC_h