/* -*- 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_AccessibleOrProxy_h #define mozilla_a11y_AccessibleOrProxy_h #include "mozilla/a11y/Accessible.h" #include "mozilla/a11y/ProxyAccessible.h" #include "mozilla/a11y/Role.h" #include <stdint.h> namespace mozilla { namespace a11y { /** * This class stores an Accessible* or a ProxyAccessible* in a safe manner * with size sizeof(void*). */ class AccessibleOrProxy { public: MOZ_IMPLICIT AccessibleOrProxy(Accessible* aAcc) : mBits(reinterpret_cast<uintptr_t>(aAcc)) {} MOZ_IMPLICIT AccessibleOrProxy(ProxyAccessible* aProxy) : mBits(aProxy ? (reinterpret_cast<uintptr_t>(aProxy) | IS_PROXY) : 0) {} MOZ_IMPLICIT AccessibleOrProxy(decltype(nullptr)) : mBits(0) {} bool IsProxy() const { return mBits & IS_PROXY; } ProxyAccessible* AsProxy() const { if (IsProxy()) { return reinterpret_cast<ProxyAccessible*>(mBits & ~IS_PROXY); } return nullptr; } bool IsAccessible() const { return !IsProxy(); } Accessible* AsAccessible() const { if (IsAccessible()) { return reinterpret_cast<Accessible*>(mBits); } return nullptr; } bool IsNull() const { return mBits == 0; } uint32_t ChildCount() const { if (IsProxy()) { return AsProxy()->ChildrenCount(); } return AsAccessible()->ChildCount(); } /** * Return the child object either an accessible or a proxied accessible at * the given index. */ AccessibleOrProxy ChildAt(uint32_t aIdx) { if (IsProxy()) { return AsProxy()->ChildAt(aIdx); } return AsAccessible()->GetChildAt(aIdx); } /** * Return the first child object. */ AccessibleOrProxy FirstChild() { if (IsProxy()) { return AsProxy()->FirstChild(); } return AsAccessible()->FirstChild(); } /** * Return the first child object. */ AccessibleOrProxy LastChild() { if (IsProxy()) { return AsProxy()->LastChild(); } return AsAccessible()->LastChild(); } role Role() const { if (IsProxy()) { return AsProxy()->Role(); } return AsAccessible()->Role(); } AccessibleOrProxy Parent() const; // XXX these are implementation details that ideally would not be exposed. uintptr_t Bits() const { return mBits; } void SetBits(uintptr_t aBits) { mBits = aBits; } private: uintptr_t mBits; static const uintptr_t IS_PROXY = 0x1; }; } } #endif