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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=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 mozilla_a11y_relation_h_
#define mozilla_a11y_relation_h_
#include "AccIterator.h"
#include <memory>
namespace mozilla {
namespace a11y {
/**
* A collection of relation targets of a certain type. Targets are computed
* lazily while enumerating.
*/
class Relation {
public:
Relation() : mFirstIter(nullptr), mLastIter(nullptr) {}
explicit Relation(AccIterable* aIter) : mFirstIter(aIter), mLastIter(aIter) {}
explicit Relation(Accessible* aAcc)
: mFirstIter(nullptr), mLastIter(nullptr) {
AppendTarget(aAcc);
}
Relation(DocAccessible* aDocument, nsIContent* aContent)
: mFirstIter(nullptr), mLastIter(nullptr) {
AppendTarget(aDocument, aContent);
}
Relation(Relation&& aOther)
: mFirstIter(std::move(aOther.mFirstIter)), mLastIter(aOther.mLastIter) {
aOther.mLastIter = nullptr;
}
Relation& operator=(Relation&& aRH) {
mFirstIter = std::move(aRH.mFirstIter);
mLastIter = aRH.mLastIter;
aRH.mLastIter = nullptr;
return *this;
}
inline void AppendIter(AccIterable* aIter) {
if (mLastIter) {
mLastIter->mNextIter.reset(aIter);
} else {
mFirstIter.reset(aIter);
}
mLastIter = aIter;
}
/**
* Append the given accessible to the set of related accessibles.
*/
inline void AppendTarget(Accessible* aAcc) {
if (aAcc) AppendIter(new SingleAccIterator(aAcc));
}
/**
* Append the one accessible for this content node to the set of related
* accessibles.
*/
void AppendTarget(DocAccessible* aDocument, nsIContent* aContent) {
if (aContent) AppendTarget(aDocument->GetAccessible(aContent));
}
/**
* compute and return the next related accessible.
*/
inline Accessible* Next() {
Accessible* target = nullptr;
while (mFirstIter && !(target = mFirstIter->Next())) {
mFirstIter = std::move(mFirstIter->mNextIter);
}
if (!mFirstIter) mLastIter = nullptr;
return target;
}
inline LocalAccessible* LocalNext() {
Accessible* next = Next();
return next ? next->AsLocal() : nullptr;
}
private:
Relation& operator=(const Relation&) = delete;
Relation(const Relation&) = delete;
std::unique_ptr<AccIterable> mFirstIter;
AccIterable* mLastIter;
};
} // namespace a11y
} // namespace mozilla
#endif