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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
commit | 6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /editor/libeditor/ManualNAC.h | |
parent | Initial commit. (diff) | |
download | thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.tar.xz thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | editor/libeditor/ManualNAC.h | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/editor/libeditor/ManualNAC.h b/editor/libeditor/ManualNAC.h new file mode 100644 index 0000000000..17d0e4d273 --- /dev/null +++ b/editor/libeditor/ManualNAC.h @@ -0,0 +1,118 @@ +/* -*- 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. +using ManualNACArray = AutoTArray<RefPtr<dom::Element>, 16>; + +/** + * 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 |