/* -*- 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 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #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(Move(aOther.mFirstIter)), mLastIter(aOther.mLastIter) { aOther.mLastIter = nullptr; } Relation& operator = (Relation&& aRH) { mFirstIter = 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; } private: Relation& operator = (const Relation&) = delete; Relation(const Relation&) = delete; std::unique_ptr<AccIterable> mFirstIter; AccIterable* mLastIter; }; } // namespace a11y } // namespace mozilla #endif