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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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
#ifndef nsChildContentList_h__
#define nsChildContentList_h__
#include "mozilla/RefPtr.h"
#include "nsISupportsImpl.h"
#include "nsINodeList.h" // base class
#include "js/TypeDecls.h" // for Handle, Value, JSObject, JSContext
class nsIContent;
class nsINode;
/**
* Class that implements the nsINodeList interface (a list of children of
* the content), by holding a reference to the content and delegating Length
* and Item to its existing child list.
* @see nsINodeList
*/
class nsAttrChildContentList : public nsINodeList {
public:
explicit nsAttrChildContentList(nsINode* aNode) : mNode(aNode) {}
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_SKIPPABLE_WRAPPERCACHE_CLASS(nsAttrChildContentList)
// nsWrapperCache
JSObject* WrapObject(JSContext*, JS::Handle<JSObject*> aGivenProto) override;
// nsINodeList interface
int32_t IndexOf(nsIContent* aContent) override;
nsIContent* Item(uint32_t aIndex) override;
uint32_t Length() override;
nsINode* GetParentObject() final { return mNode; }
virtual void InvalidateCacheIfAvailable() {}
protected:
virtual ~nsAttrChildContentList() = default;
// The node whose children make up the list.
RefPtr<nsINode> mNode;
};
class nsParentNodeChildContentList final : public nsAttrChildContentList {
public:
explicit nsParentNodeChildContentList(nsINode* aNode)
: nsAttrChildContentList(aNode) {
ValidateCache();
}
// nsINodeList interface
int32_t IndexOf(nsIContent* aContent) override;
nsIContent* Item(uint32_t aIndex) override;
uint32_t Length() override;
void InvalidateCacheIfAvailable() final { InvalidateCache(); }
void InvalidateCache() {
mIsCacheValid = false;
mCachedChildArray.Clear();
}
private:
~nsParentNodeChildContentList() = default;
// Return true if validation succeeds, false otherwise
void ValidateCache();
void EnsureCacheValid() {
if (!mIsCacheValid) {
ValidateCache();
}
MOZ_ASSERT(mIsCacheValid);
}
// Whether cached array of child nodes is valid
bool mIsCacheValid = false;
// Cached array of child nodes
AutoTArray<nsIContent*, 8> mCachedChildArray;
};
#endif /* nsChildContentList_h__ */