diff options
Diffstat (limited to 'accessible/windows/msaa/MsaaAccessible.cpp')
| -rw-r--r-- | accessible/windows/msaa/MsaaAccessible.cpp | 1368 |
1 files changed, 1368 insertions, 0 deletions
diff --git a/accessible/windows/msaa/MsaaAccessible.cpp b/accessible/windows/msaa/MsaaAccessible.cpp new file mode 100644 index 0000000000..702f8341dc --- /dev/null +++ b/accessible/windows/msaa/MsaaAccessible.cpp @@ -0,0 +1,1368 @@ +/* -*- 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/. */ + +#include "EnumVariant.h" +#include "ia2AccessibleApplication.h" +#include "ia2AccessibleHypertext.h" +#include "ia2AccessibleImage.h" +#include "ia2AccessibleTable.h" +#include "ia2AccessibleTableCell.h" +#include "LocalAccessible-inl.h" +#include "mozilla/a11y/AccessibleWrap.h" +#include "mozilla/a11y/Compatibility.h" +#include "mozilla/a11y/DocAccessibleParent.h" +#include "MsaaAccessible.h" +#include "MsaaDocAccessible.h" +#include "MsaaRootAccessible.h" +#include "MsaaXULMenuAccessible.h" +#include "nsEventMap.h" +#include "nsViewManager.h" +#include "nsWinUtils.h" +#include "Relation.h" +#include "sdnAccessible.h" +#include "sdnTextAccessible.h" +#include "HyperTextAccessible-inl.h" +#include "ServiceProvider.h" +#include "Statistics.h" +#include "ARIAMap.h" +#include "mozilla/PresShell.h" + +using namespace mozilla; +using namespace mozilla::a11y; + +static const VARIANT kVarChildIdSelf = {{{VT_I4}}}; + +// Used internally to safely get an MsaaAccessible from a COM pointer provided +// to us by a client. +static const GUID IID_MsaaAccessible = { + /* a94aded3-1a9c-4afc-a32c-d6b5c010046b */ + 0xa94aded3, + 0x1a9c, + 0x4afc, + {0xa3, 0x2c, 0xd6, 0xb5, 0xc0, 0x10, 0x04, 0x6b}}; + +MsaaIdGenerator MsaaAccessible::sIDGen; +ITypeInfo* MsaaAccessible::gTypeInfo = nullptr; + +/* static */ +MsaaAccessible* MsaaAccessible::Create(Accessible* aAcc) { + // This should only ever be called in the parent process. + MOZ_ASSERT(XRE_IsParentProcess()); + // The order of some of these is important! For example, when isRoot is true, + // IsDoc will also be true, so we must check IsRoot first. IsTable/Cell and + // IsHyperText are a similar case. + if (aAcc->IsRoot()) { + MOZ_ASSERT(aAcc->IsLocal()); + return new MsaaRootAccessible(aAcc); + } + if (aAcc->IsDoc()) { + return new MsaaDocAccessible(aAcc); + } + if (aAcc->IsTable()) { + return new ia2AccessibleTable(aAcc); + } + if (aAcc->IsTableCell()) { + return new ia2AccessibleTableCell(aAcc); + } + if (aAcc->IsApplication()) { + MOZ_ASSERT(aAcc->IsLocal()); + return new ia2AccessibleApplication(aAcc); + } + if (aAcc->IsImage()) { + return new ia2AccessibleImage(aAcc); + } + if (LocalAccessible* localAcc = aAcc->AsLocal()) { + if (localAcc->GetContent() && + localAcc->GetContent()->IsXULElement(nsGkAtoms::menuitem)) { + return new MsaaXULMenuitemAccessible(aAcc); + } + } + if (aAcc->IsHyperText()) { + return new ia2AccessibleHypertext(aAcc); + } + return new MsaaAccessible(aAcc); +} + +MsaaAccessible::MsaaAccessible(Accessible* aAcc) : mAcc(aAcc), mID(kNoID) {} + +MsaaAccessible::~MsaaAccessible() { + MOZ_ASSERT(!mAcc, "MsaaShutdown wasn't called!"); + if (mID != kNoID) { + sIDGen.ReleaseID(WrapNotNull(this)); + } +} + +void MsaaAccessible::MsaaShutdown() { + // Accessibles can be shut down twice in some cases. If that happens, + // MsaaShutdown will also be called twice because AccessibleWrap holds + // the reference until its destructor is called; see the comments in + // AccessibleWrap::Shutdown. + if (!mAcc) { + return; + } + + if (mID != kNoID) { + auto doc = MsaaDocAccessible::GetFromOwned(mAcc); + MOZ_ASSERT(doc); + doc->RemoveID(mID); + } + + mAcc = nullptr; +} + +int32_t MsaaAccessible::GetChildIDFor(Accessible* aAccessible) { + // A child ID of the window is required, when we use NotifyWinEvent, + // so that the 3rd party application can call back and get the IAccessible + // the event occurred on. + + if (!aAccessible) { + return 0; + } + + auto doc = MsaaDocAccessible::GetFromOwned(aAccessible); + if (!doc) { + return 0; + } + + uint32_t* id = &MsaaAccessible::GetFrom(aAccessible)->mID; + if (*id != kNoID) return *id; + + *id = sIDGen.GetID(); + doc->AddID(*id, aAccessible); + + return *id; +} + +/* static */ +void MsaaAccessible::AssignChildIDTo(NotNull<sdnAccessible*> aSdnAcc) { + aSdnAcc->SetUniqueID(sIDGen.GetID()); +} + +/* static */ +void MsaaAccessible::ReleaseChildID(NotNull<sdnAccessible*> aSdnAcc) { + sIDGen.ReleaseID(aSdnAcc); +} + +HWND MsaaAccessible::GetHWNDFor(Accessible* aAccessible) { + if (!aAccessible) { + return nullptr; + } + + LocalAccessible* localAcc = aAccessible->AsLocal(); + if (!localAcc) { + RemoteAccessible* proxy = aAccessible->AsRemote(); + if (!proxy) { + return nullptr; + } + + // If window emulation is enabled, retrieve the emulated window from the + // containing document document proxy. + if (nsWinUtils::IsWindowEmulationStarted()) { + DocAccessibleParent* doc = proxy->Document(); + HWND hWnd = doc->GetEmulatedWindowHandle(); + if (hWnd) { + return hWnd; + } + } + + // Accessibles in child processes are said to have the HWND of the window + // their tab is within. Popups are always in the parent process, and so + // never proxied, which means this is basically correct. + LocalAccessible* outerDoc = proxy->OuterDocOfRemoteBrowser(); + if (!outerDoc) { + // In some cases, the outer document accessible may be unattached from its + // document at this point, if it is scheduled for removal. Do not assert + // in such case. An example: putting aria-hidden="true" on HTML:iframe + // element will destroy iframe's document asynchroniously, but + // the document may be a target of selection events until then, and thus + // it may attempt to deliever these events to MSAA clients. + return nullptr; + } + + return GetHWNDFor(outerDoc); + } + + DocAccessible* document = localAcc->Document(); + if (!document) return nullptr; + + // Popup lives in own windows, use its HWND until the popup window is + // hidden to make old JAWS versions work with collapsed comboboxes (see + // discussion in bug 379678). + nsIFrame* frame = localAcc->GetFrame(); + if (frame) { + nsIWidget* widget = frame->GetNearestWidget(); + if (widget && widget->IsVisible()) { + if (nsViewManager* vm = document->PresShellPtr()->GetViewManager()) { + nsCOMPtr<nsIWidget> rootWidget = vm->GetRootWidget(); + // Make sure the accessible belongs to popup. If not then use + // document HWND (which might be different from root widget in the + // case of window emulation). + if (rootWidget != widget) + return static_cast<HWND>(widget->GetNativeData(NS_NATIVE_WINDOW)); + } + } + } + + return static_cast<HWND>(document->GetNativeWindow()); +} + +void MsaaAccessible::FireWinEvent(Accessible* aTarget, uint32_t aEventType) { + MOZ_ASSERT(XRE_IsParentProcess()); + static_assert(sizeof(gWinEventMap) / sizeof(gWinEventMap[0]) == + nsIAccessibleEvent::EVENT_LAST_ENTRY, + "MSAA event map skewed"); + + if (aEventType == 0 || aEventType >= ArrayLength(gWinEventMap)) { + MOZ_ASSERT_UNREACHABLE("invalid event type"); + return; + } + + uint32_t winEvent = gWinEventMap[aEventType]; + if (!winEvent) return; + + int32_t childID = MsaaAccessible::GetChildIDFor(aTarget); + if (!childID) return; // Can't fire an event without a child ID + + HWND hwnd = GetHWNDFor(aTarget); + if (!hwnd) { + return; + } + + // Fire MSAA event for client area window. + ::NotifyWinEvent(winEvent, hwnd, OBJID_CLIENT, childID); +} + +AccessibleWrap* MsaaAccessible::LocalAcc() { + if (!mAcc || mAcc->IsRemote()) { + return nullptr; + } + auto acc = static_cast<AccessibleWrap*>(mAcc); + MOZ_ASSERT(!acc || !acc->IsDefunct(), + "mAcc defunct but MsaaShutdown wasn't called"); + return acc; +} + +/** + * This function is a helper for implementing IAccessible methods that accept + * a Child ID as a parameter. If the child ID is CHILDID_SELF, the function + * returns S_OK but a null *aOutInterface. Otherwise, *aOutInterface points + * to the resolved IAccessible. + * + * The CHILDID_SELF case is special because in that case we actually execute + * the implementation of the IAccessible method, whereas in the non-self case, + * we delegate the method call to that object for execution. + * + * A sample invocation of this would look like: + * + * RefPtr<IAccessible> accessible; + * HRESULT hr = ResolveChild(varChild, getter_AddRefs(accessible)); + * if (FAILED(hr)) { + * return hr; + * } + * + * if (accessible) { + * return accessible->get_accFoo(kVarChildIdSelf, pszName); + * } + * + * // Implementation for CHILDID_SELF case goes here + */ +HRESULT +MsaaAccessible::ResolveChild(const VARIANT& aVarChild, + IAccessible** aOutInterface) { + MOZ_ASSERT(aOutInterface); + *aOutInterface = nullptr; + + if (aVarChild.vt != VT_I4) { + return E_INVALIDARG; + } + + if (!mAcc) { + return CO_E_OBJNOTCONNECTED; + } + + if (aVarChild.lVal == CHILDID_SELF) { + return S_OK; + } + + bool isDefunct = false; + RefPtr<IAccessible> accessible = GetIAccessibleFor(aVarChild, &isDefunct); + if (!accessible) { + return E_INVALIDARG; + } + + if (isDefunct) { + return CO_E_OBJNOTCONNECTED; + } + + accessible.forget(aOutInterface); + return S_OK; +} + +static Accessible* GetAccessibleInSubtree(DocAccessible* aDoc, uint32_t aID) { + Accessible* child = MsaaDocAccessible::GetFrom(aDoc)->GetAccessibleByID(aID); + if (child) return child; + + uint32_t childDocCount = aDoc->ChildDocumentCount(); + for (uint32_t i = 0; i < childDocCount; i++) { + child = GetAccessibleInSubtree(aDoc->GetChildDocumentAt(i), aID); + if (child) return child; + } + + return nullptr; +} + +static Accessible* GetAccessibleInSubtree(DocAccessibleParent* aDoc, + uint32_t aID) { + Accessible* child = MsaaDocAccessible::GetFrom(aDoc)->GetAccessibleByID(aID); + if (child) { + return child; + } + + size_t childDocCount = aDoc->ChildDocCount(); + for (size_t i = 0; i < childDocCount; i++) { + child = GetAccessibleInSubtree(aDoc->ChildDocAt(i), aID); + if (child) { + return child; + } + } + + return nullptr; +} + +static bool IsInclusiveDescendantOf(DocAccessible* aAncestor, + DocAccessible* aDescendant) { + for (DocAccessible* doc = aDescendant; doc; doc = doc->ParentDocument()) { + if (doc == aAncestor) { + return true; + } + } + return false; +} + +already_AddRefed<IAccessible> MsaaAccessible::GetIAccessibleFor( + const VARIANT& aVarChild, bool* aIsDefunct) { + if (aVarChild.vt != VT_I4) return nullptr; + + VARIANT varChild = aVarChild; + + MOZ_ASSERT(aIsDefunct); + *aIsDefunct = false; + + RefPtr<IAccessible> result; + + if (!mAcc) { + *aIsDefunct = true; + return nullptr; + } + + if (varChild.lVal == CHILDID_SELF) { + result = this; + return result.forget(); + } + + if (varChild.ulVal != GetExistingID() && nsAccUtils::MustPrune(mAcc)) { + // This accessible should have no subtree in platform, return null for its + // children. + return nullptr; + } + + if (varChild.lVal > 0) { + // Gecko child indices are 0-based in contrast to indices used in MSAA. + Accessible* xpAcc = mAcc->ChildAt(varChild.lVal - 1); + if (!xpAcc) { + return nullptr; + } + MOZ_ASSERT(xpAcc->IsRemote() || !xpAcc->AsLocal()->IsDefunct(), + "Shouldn't get a defunct child"); + result = MsaaAccessible::GetFrom(xpAcc); + return result.forget(); + } + + // If lVal negative then it is treated as child ID and we should look for + // accessible through whole accessible subtree including subdocuments. + Accessible* doc = nullptr; + Accessible* child = nullptr; + auto id = static_cast<uint32_t>(varChild.lVal); + if (LocalAccessible* localAcc = mAcc->AsLocal()) { + DocAccessible* localDoc = localAcc->Document(); + doc = localDoc; + child = GetAccessibleInSubtree(localDoc, id); + if (!child) { + // Search remote documents which are descendants of this local document. + const auto remoteDocs = DocManager::TopLevelRemoteDocs(); + if (!remoteDocs) { + return nullptr; + } + for (DocAccessibleParent* remoteDoc : *remoteDocs) { + LocalAccessible* outerDoc = remoteDoc->OuterDocOfRemoteBrowser(); + if (!outerDoc || + !IsInclusiveDescendantOf(localDoc, outerDoc->Document())) { + continue; + } + child = GetAccessibleInSubtree(remoteDoc, id); + if (child) { + break; + } + } + } + } else { + DocAccessibleParent* remoteDoc = mAcc->AsRemote()->Document(); + doc = remoteDoc; + child = GetAccessibleInSubtree(remoteDoc, id); + } + if (!child) { + return nullptr; + } + + MOZ_ASSERT(child->IsRemote() || !child->AsLocal()->IsDefunct(), + "Shouldn't get a defunct child"); + // If this method is being called on the document we searched, we can just + // return child. + if (mAcc == doc) { + result = MsaaAccessible::GetFrom(child); + return result.forget(); + } + + // Otherwise, this method was called on a descendant, so we searched an + // ancestor. We must check whether child is really a descendant. This is used + // for ARIA documents and popups. + Accessible* parent = child; + while (parent && parent != doc) { + if (parent == mAcc) { + result = MsaaAccessible::GetFrom(child); + return result.forget(); + } + + parent = parent->Parent(); + } + + return nullptr; +} + +IDispatch* MsaaAccessible::NativeAccessible(Accessible* aAccessible) { + if (!aAccessible) { + NS_WARNING("Not passing in an aAccessible"); + return nullptr; + } + + RefPtr<IDispatch> disp; + disp = MsaaAccessible::GetFrom(aAccessible); + IDispatch* rawDisp; + disp.forget(&rawDisp); + return rawDisp; +} + +ITypeInfo* MsaaAccessible::GetTI(LCID lcid) { + if (gTypeInfo) return gTypeInfo; + + ITypeLib* typeLib = nullptr; + HRESULT hr = LoadRegTypeLib(LIBID_Accessibility, 1, 0, lcid, &typeLib); + if (FAILED(hr)) return nullptr; + + hr = typeLib->GetTypeInfoOfGuid(IID_IAccessible, &gTypeInfo); + typeLib->Release(); + + if (FAILED(hr)) return nullptr; + + return gTypeInfo; +} + +/* static */ +MsaaAccessible* MsaaAccessible::GetFrom(Accessible* aAcc) { + if (!aAcc) { + return nullptr; + } + + if (RemoteAccessible* remoteAcc = aAcc->AsRemote()) { + return reinterpret_cast<MsaaAccessible*>(remoteAcc->GetWrapper()); + } + return static_cast<AccessibleWrap*>(aAcc)->GetMsaa(); +} + +/* static */ +Accessible* MsaaAccessible::GetAccessibleFrom(IUnknown* aUnknown) { + RefPtr<MsaaAccessible> msaa; + aUnknown->QueryInterface(IID_MsaaAccessible, getter_AddRefs(msaa)); + if (!msaa) { + return nullptr; + } + return msaa->Acc(); +} + +// IUnknown methods +STDMETHODIMP +MsaaAccessible::QueryInterface(REFIID iid, void** ppv) { + if (!ppv) return E_INVALIDARG; + + *ppv = nullptr; + + if (IID_IClientSecurity == iid) { + // Some code might QI(IID_IClientSecurity) to detect whether or not we are + // a proxy. Right now that can potentially happen off the main thread, so we + // look for this condition immediately so that we don't trigger other code + // that might not be thread-safe. + return E_NOINTERFACE; + } + + // These interfaces are always available. We can support querying to them + // even if the Accessible is dead. + if (IID_IUnknown == iid) { + *ppv = static_cast<IAccessible*>(this); + } else if (IID_MsaaAccessible == iid) { + *ppv = static_cast<MsaaAccessible*>(this); + } else if (IID_IDispatch == iid || IID_IAccessible == iid) { + *ppv = static_cast<IAccessible*>(this); + } else if (IID_IServiceProvider == iid) { + *ppv = new ServiceProvider(this); + } else { + HRESULT hr = ia2Accessible::QueryInterface(iid, ppv); + if (SUCCEEDED(hr)) { + return hr; + } + } + if (*ppv) { + (reinterpret_cast<IUnknown*>(*ppv))->AddRef(); + return S_OK; + } + + // For interfaces below this point, we have to query the Accessible to + // determine if they are available. + if (!mAcc) { + // mscom::Interceptor (and maybe other callers) expects either S_OK or + // E_NOINTERFACE, so don't return CO_E_OBJNOTCONNECTED like we normally + // would for a dead object. + return E_NOINTERFACE; + } + AccessibleWrap* localAcc = LocalAcc(); + if (IID_IEnumVARIANT == iid) { + // We don't support this interface for leaf elements. + if (!mAcc->HasChildren() || nsAccUtils::MustPrune(mAcc)) { + return E_NOINTERFACE; + } + *ppv = static_cast<IEnumVARIANT*>(new ChildrenEnumVariant(this)); + } else if (IID_ISimpleDOMNode == iid) { + if (mAcc->IsDoc() || (localAcc && !localAcc->HasOwnContent())) { + return E_NOINTERFACE; + } + + *ppv = static_cast<ISimpleDOMNode*>(new sdnAccessible(WrapNotNull(this))); + } else if (iid == IID_ISimpleDOMText && localAcc && localAcc->IsTextLeaf()) { + statistics::ISimpleDOMUsed(); + *ppv = static_cast<ISimpleDOMText*>(new sdnTextAccessible(this)); + static_cast<IUnknown*>(*ppv)->AddRef(); + return S_OK; + } + + if (!*ppv && localAcc) { + HRESULT hr = ia2AccessibleComponent::QueryInterface(iid, ppv); + if (SUCCEEDED(hr)) return hr; + } + + if (!*ppv) { + HRESULT hr = ia2AccessibleHyperlink::QueryInterface(iid, ppv); + if (SUCCEEDED(hr)) return hr; + } + + if (!*ppv) { + HRESULT hr = ia2AccessibleValue::QueryInterface(iid, ppv); + if (SUCCEEDED(hr)) return hr; + } + + if (nullptr == *ppv) return E_NOINTERFACE; + + (reinterpret_cast<IUnknown*>(*ppv))->AddRef(); + return S_OK; +} + +// IAccessible methods + +STDMETHODIMP +MsaaAccessible::get_accParent(IDispatch __RPC_FAR* __RPC_FAR* ppdispParent) { + if (!ppdispParent) return E_INVALIDARG; + + *ppdispParent = nullptr; + + if (!mAcc) { + return CO_E_OBJNOTCONNECTED; + } + + Accessible* xpParentAcc = mAcc->Parent(); + if (!xpParentAcc) return S_FALSE; + + *ppdispParent = NativeAccessible(xpParentAcc); + return S_OK; +} + +STDMETHODIMP +MsaaAccessible::get_accChildCount(long __RPC_FAR* pcountChildren) { + if (!pcountChildren) return E_INVALIDARG; + + *pcountChildren = 0; + + if (!mAcc) return CO_E_OBJNOTCONNECTED; + + if (Compatibility::IsA11ySuppressedForClipboardCopy() && mAcc->IsRoot()) { + // Bug 1798098: Windows Suggested Actions (introduced in Windows 11 22H2) + // might walk the entire a11y tree using UIA whenever anything is copied to + // the clipboard. This causes an unacceptable hang, particularly when the + // cache is disabled. We prevent this tree walk by returning a 0 child count + // for the root window, from which Windows might walk. + return S_OK; + } + + if (nsAccUtils::MustPrune(mAcc)) return S_OK; + + *pcountChildren = mAcc->ChildCount(); + return S_OK; +} + +STDMETHODIMP +MsaaAccessible::get_accChild( + /* [in] */ VARIANT varChild, + /* [retval][out] */ IDispatch __RPC_FAR* __RPC_FAR* ppdispChild) { + if (!ppdispChild) return E_INVALIDARG; + + *ppdispChild = nullptr; + if (!mAcc) return CO_E_OBJNOTCONNECTED; + + // IAccessible::accChild is used to return this accessible or child accessible + // at the given index or to get an accessible by child ID in the case of + // document accessible. + // The getting an accessible by child ID is used by + // AccessibleObjectFromEvent() called by AT when AT handles our MSAA event. + bool isDefunct = false; + RefPtr<IAccessible> child = GetIAccessibleFor(varChild, &isDefunct); + if (!child) { + return E_INVALIDARG; + } + + if (isDefunct) { + return CO_E_OBJNOTCONNECTED; + } + + child.forget(ppdispChild); + return S_OK; +} + +STDMETHODIMP +MsaaAccessible::get_accName( + /* [optional][in] */ VARIANT varChild, + /* [retval][out] */ BSTR __RPC_FAR* pszName) { + if (!pszName || varChild.vt != VT_I4) return E_INVALIDARG; + + *pszName = nullptr; + + RefPtr<IAccessible> accessible; + HRESULT hr = ResolveChild(varChild, getter_AddRefs(accessible)); + if (FAILED(hr)) { + return hr; + } + + if (accessible) { + return accessible->get_accName(kVarChildIdSelf, pszName); + } + + nsAutoString name; + Acc()->Name(name); + + if (name.IsVoid()) return S_FALSE; + + *pszName = ::SysAllocStringLen(name.get(), name.Length()); + if (!*pszName) return E_OUTOFMEMORY; + return S_OK; +} + +STDMETHODIMP +MsaaAccessible::get_accValue( + /* [optional][in] */ VARIANT varChild, + /* [retval][out] */ BSTR __RPC_FAR* pszValue) { + if (!pszValue) return E_INVALIDARG; + + *pszValue = nullptr; + + RefPtr<IAccessible> accessible; + HRESULT hr = ResolveChild(varChild, getter_AddRefs(accessible)); + if (FAILED(hr)) { + return hr; + } + + if (accessible) { + return accessible->get_accValue(kVarChildIdSelf, pszValue); + } + + nsAutoString value; + Acc()->Value(value); + + // See bug 438784: need to expose URL on doc's value attribute. For this, + // reverting part of fix for bug 425693 to make this MSAA method behave + // IAccessible2-style. + if (value.IsEmpty()) return S_FALSE; + + *pszValue = ::SysAllocStringLen(value.get(), value.Length()); + if (!*pszValue) return E_OUTOFMEMORY; + return S_OK; +} + +STDMETHODIMP +MsaaAccessible::get_accDescription(VARIANT varChild, + BSTR __RPC_FAR* pszDescription) { + if (!pszDescription) return E_INVALIDARG; + + *pszDescription = nullptr; + + RefPtr<IAccessible> accessible; + HRESULT hr = ResolveChild(varChild, getter_AddRefs(accessible)); + if (FAILED(hr)) { + return hr; + } + + if (accessible) { + return accessible->get_accDescription(kVarChildIdSelf, pszDescription); + } + + nsAutoString description; + Acc()->Description(description); + + *pszDescription = + ::SysAllocStringLen(description.get(), description.Length()); + return *pszDescription ? S_OK : E_OUTOFMEMORY; +} + +STDMETHODIMP +MsaaAccessible::get_accRole( + /* [optional][in] */ VARIANT varChild, + /* [retval][out] */ VARIANT __RPC_FAR* pvarRole) { + if (!pvarRole) return E_INVALIDARG; + + VariantInit(pvarRole); + + RefPtr<IAccessible> accessible; + HRESULT hr = ResolveChild(varChild, getter_AddRefs(accessible)); + if (FAILED(hr)) { + return hr; + } + + if (accessible) { + return accessible->get_accRole(kVarChildIdSelf, pvarRole); + } + + a11y::role geckoRole; +#ifdef DEBUG + if (mAcc->IsLocal()) { + NS_ASSERTION(nsAccUtils::IsTextInterfaceSupportCorrect(mAcc->AsLocal()), + "Does not support Text when it should"); + } +#endif + geckoRole = mAcc->Role(); + + uint32_t msaaRole = 0; + +#define ROLE(_geckoRole, stringRole, ariaRole, atkRole, macRole, macSubrole, \ + _msaaRole, ia2Role, androidClass, nameRule) \ + case roles::_geckoRole: \ + msaaRole = _msaaRole; \ + break; + + switch (geckoRole) { +#include "RoleMap.h" + default: + MOZ_CRASH("Unknown role."); + } + +#undef ROLE + + // Special case, if there is a ROLE_ROW inside of a ROLE_TREE_TABLE, then call + // the MSAA role a ROLE_OUTLINEITEM for consistency and compatibility. We need + // this because ARIA has a role of "row" for both grid and treegrid + if (geckoRole == roles::ROW) { + Accessible* xpParent = mAcc->Parent(); + if (xpParent && xpParent->Role() == roles::TREE_TABLE) + msaaRole = ROLE_SYSTEM_OUTLINEITEM; + } + + pvarRole->vt = VT_I4; + pvarRole->lVal = msaaRole; + return S_OK; +} + +STDMETHODIMP +MsaaAccessible::get_accState( + /* [optional][in] */ VARIANT varChild, + /* [retval][out] */ VARIANT __RPC_FAR* pvarState) { + if (!pvarState) return E_INVALIDARG; + + VariantInit(pvarState); + pvarState->vt = VT_I4; + pvarState->lVal = 0; + + RefPtr<IAccessible> accessible; + HRESULT hr = ResolveChild(varChild, getter_AddRefs(accessible)); + if (FAILED(hr)) { + return hr; + } + + if (accessible) { + return accessible->get_accState(kVarChildIdSelf, pvarState); + } + + // MSAA only has 31 states and the lowest 31 bits of our state bit mask + // are the same states as MSAA. + // Note: we map the following Gecko states to different MSAA states: + // REQUIRED -> ALERT_LOW + // ALERT -> ALERT_MEDIUM + // INVALID -> ALERT_HIGH + // CHECKABLE -> MARQUEED + + uint64_t state = Acc()->State(); + + uint32_t msaaState = 0; + nsAccUtils::To32States(state, &msaaState, nullptr); + pvarState->lVal = msaaState; + return S_OK; +} + +STDMETHODIMP +MsaaAccessible::get_accHelp( + /* [optional][in] */ VARIANT varChild, + /* [retval][out] */ BSTR __RPC_FAR* pszHelp) { + if (!pszHelp) return E_INVALIDARG; + + *pszHelp = nullptr; + return S_FALSE; +} + +STDMETHODIMP +MsaaAccessible::get_accHelpTopic( + /* [out] */ BSTR __RPC_FAR* pszHelpFile, + /* [optional][in] */ VARIANT varChild, + /* [retval][out] */ long __RPC_FAR* pidTopic) { + if (!pszHelpFile || !pidTopic) return E_INVALIDARG; + + *pszHelpFile = nullptr; + *pidTopic = 0; + return S_FALSE; +} + +STDMETHODIMP +MsaaAccessible::get_accKeyboardShortcut( + /* [optional][in] */ VARIANT varChild, + /* [retval][out] */ BSTR __RPC_FAR* pszKeyboardShortcut) { + if (!pszKeyboardShortcut) return E_INVALIDARG; + *pszKeyboardShortcut = nullptr; + + RefPtr<IAccessible> accessible; + HRESULT hr = ResolveChild(varChild, getter_AddRefs(accessible)); + if (FAILED(hr)) { + return hr; + } + + if (accessible) { + return accessible->get_accKeyboardShortcut(kVarChildIdSelf, + pszKeyboardShortcut); + } + + KeyBinding keyBinding = mAcc->AccessKey(); + if (keyBinding.IsEmpty()) { + if (LocalAccessible* localAcc = mAcc->AsLocal()) { + keyBinding = localAcc->KeyboardShortcut(); + } + } + + nsAutoString shortcut; + keyBinding.ToString(shortcut); + + *pszKeyboardShortcut = ::SysAllocStringLen(shortcut.get(), shortcut.Length()); + return *pszKeyboardShortcut ? S_OK : E_OUTOFMEMORY; +} + +STDMETHODIMP +MsaaAccessible::get_accFocus( + /* [retval][out] */ VARIANT __RPC_FAR* pvarChild) { + if (!pvarChild) return E_INVALIDARG; + + VariantInit(pvarChild); + + // clang-format off + // VT_EMPTY: None. This object does not have the keyboard focus itself + // and does not contain a child that has the keyboard focus. + // VT_I4: lVal is CHILDID_SELF. The object itself has the keyboard focus. + // VT_I4: lVal contains the child ID of the child element with the keyboard focus. + // VT_DISPATCH: pdispVal member is the address of the IDispatch interface + // for the child object with the keyboard focus. + // clang-format on + if (!mAcc) { + return CO_E_OBJNOTCONNECTED; + } + // Return the current IAccessible child that has focus + Accessible* focusedAccessible = mAcc->FocusedChild(); + if (focusedAccessible == mAcc) { + pvarChild->vt = VT_I4; + pvarChild->lVal = CHILDID_SELF; + } else if (focusedAccessible) { + pvarChild->vt = VT_DISPATCH; + pvarChild->pdispVal = NativeAccessible(focusedAccessible); + } else { + pvarChild->vt = VT_EMPTY; // No focus or focus is not a child + } + + return S_OK; +} + +/** + * This helper class implements IEnumVARIANT for a nsTArray containing + * accessible objects. + */ +class AccessibleEnumerator final : public IEnumVARIANT { + public: + explicit AccessibleEnumerator(const nsTArray<Accessible*>& aArray) + : mArray(aArray.Clone()), mCurIndex(0) {} + AccessibleEnumerator(const AccessibleEnumerator& toCopy) + : mArray(toCopy.mArray.Clone()), mCurIndex(toCopy.mCurIndex) {} + ~AccessibleEnumerator() {} + + // IUnknown + DECL_IUNKNOWN + + // IEnumVARIANT + STDMETHODIMP Next(unsigned long celt, VARIANT FAR* rgvar, + unsigned long FAR* pceltFetched); + STDMETHODIMP Skip(unsigned long celt); + STDMETHODIMP Reset() { + mCurIndex = 0; + return S_OK; + } + STDMETHODIMP Clone(IEnumVARIANT FAR* FAR* ppenum); + + private: + nsTArray<Accessible*> mArray; + uint32_t mCurIndex; +}; + +STDMETHODIMP +AccessibleEnumerator::QueryInterface(REFIID iid, void** ppvObject) { + if (iid == IID_IEnumVARIANT) { + *ppvObject = static_cast<IEnumVARIANT*>(this); + AddRef(); + return S_OK; + } + if (iid == IID_IUnknown) { + *ppvObject = static_cast<IUnknown*>(this); + AddRef(); + return S_OK; + } + + *ppvObject = nullptr; + return E_NOINTERFACE; +} + +STDMETHODIMP +AccessibleEnumerator::Next(unsigned long celt, VARIANT FAR* rgvar, + unsigned long FAR* pceltFetched) { + uint32_t length = mArray.Length(); + HRESULT hr = S_OK; + + // Can't get more elements than there are... + if (celt > length - mCurIndex) { + hr = S_FALSE; + celt = length - mCurIndex; + } + + // Copy the elements of the array into rgvar. + for (uint32_t i = 0; i < celt; ++i, ++mCurIndex) { + rgvar[i].vt = VT_DISPATCH; + rgvar[i].pdispVal = MsaaAccessible::NativeAccessible(mArray[mCurIndex]); + } + + if (pceltFetched) *pceltFetched = celt; + + return hr; +} + +STDMETHODIMP +AccessibleEnumerator::Clone(IEnumVARIANT FAR* FAR* ppenum) { + *ppenum = new AccessibleEnumerator(*this); + NS_ADDREF(*ppenum); + return S_OK; +} + +STDMETHODIMP +AccessibleEnumerator::Skip(unsigned long celt) { + uint32_t length = mArray.Length(); + // Check if we can skip the requested number of elements + if (celt > length - mCurIndex) { + mCurIndex = length; + return S_FALSE; + } + mCurIndex += celt; + return S_OK; +} + +/** + * This method is called when a client wants to know which children of a node + * are selected. Note that this method can only find selected children for + * accessible object which implement SelectAccessible. + * + * The VARIANT return value arguement is expected to either contain a single + * IAccessible or an IEnumVARIANT of IAccessibles. We return the IEnumVARIANT + * regardless of the number of children selected, unless there are none selected + * in which case we return an empty VARIANT. + * + * We get the selected options from the select's accessible object and wrap + * those in an AccessibleEnumerator which we then put in the return VARIANT. + * + * returns a VT_EMPTY VARIANT if: + * - there are no selected children for this object + * - the object is not the type that can have children selected + */ +STDMETHODIMP +MsaaAccessible::get_accSelection(VARIANT __RPC_FAR* pvarChildren) { + if (!pvarChildren) return E_INVALIDARG; + + VariantInit(pvarChildren); + pvarChildren->vt = VT_EMPTY; + + if (!mAcc) { + return CO_E_OBJNOTCONNECTED; + } + Accessible* acc = Acc(); + + if (!acc->IsSelect()) { + return S_OK; + } + + AutoTArray<Accessible*, 10> selectedItems; + acc->SelectedItems(&selectedItems); + uint32_t count = selectedItems.Length(); + if (count == 1) { + pvarChildren->vt = VT_DISPATCH; + pvarChildren->pdispVal = NativeAccessible(selectedItems[0]); + } else if (count > 1) { + RefPtr<AccessibleEnumerator> pEnum = + new AccessibleEnumerator(selectedItems); + pvarChildren->vt = + VT_UNKNOWN; // this must be VT_UNKNOWN for an IEnumVARIANT + NS_ADDREF(pvarChildren->punkVal = pEnum); + } + // If count == 0, vt is already VT_EMPTY, so there's nothing else to do. + + return S_OK; +} + +STDMETHODIMP +MsaaAccessible::get_accDefaultAction( + /* [optional][in] */ VARIANT varChild, + /* [retval][out] */ BSTR __RPC_FAR* pszDefaultAction) { + if (!pszDefaultAction) return E_INVALIDARG; + + *pszDefaultAction = nullptr; + + RefPtr<IAccessible> accessible; + HRESULT hr = ResolveChild(varChild, getter_AddRefs(accessible)); + if (FAILED(hr)) { + return hr; + } + + if (accessible) { + return accessible->get_accDefaultAction(kVarChildIdSelf, pszDefaultAction); + } + + nsAutoString defaultAction; + mAcc->ActionNameAt(0, defaultAction); + + *pszDefaultAction = + ::SysAllocStringLen(defaultAction.get(), defaultAction.Length()); + return *pszDefaultAction ? S_OK : E_OUTOFMEMORY; +} + +STDMETHODIMP +MsaaAccessible::accSelect( + /* [in] */ long flagsSelect, + /* [optional][in] */ VARIANT varChild) { + RefPtr<IAccessible> accessible; + HRESULT hr = ResolveChild(varChild, getter_AddRefs(accessible)); + if (FAILED(hr)) { + return hr; + } + + if (accessible) { + return accessible->accSelect(flagsSelect, kVarChildIdSelf); + } + + if (flagsSelect & SELFLAG_TAKEFOCUS) { + mAcc->TakeFocus(); + return S_OK; + } + + if (flagsSelect & SELFLAG_TAKESELECTION) { + mAcc->TakeSelection(); + return S_OK; + } + + if (flagsSelect & SELFLAG_ADDSELECTION) { + mAcc->SetSelected(true); + return S_OK; + } + + if (flagsSelect & SELFLAG_REMOVESELECTION) { + mAcc->SetSelected(false); + return S_OK; + } + + return E_FAIL; +} + +STDMETHODIMP +MsaaAccessible::accLocation( + /* [out] */ long __RPC_FAR* pxLeft, + /* [out] */ long __RPC_FAR* pyTop, + /* [out] */ long __RPC_FAR* pcxWidth, + /* [out] */ long __RPC_FAR* pcyHeight, + /* [optional][in] */ VARIANT varChild) { + if (!pxLeft || !pyTop || !pcxWidth || !pcyHeight) return E_INVALIDARG; + + *pxLeft = 0; + *pyTop = 0; + *pcxWidth = 0; + *pcyHeight = 0; + + RefPtr<IAccessible> accessible; + HRESULT hr = ResolveChild(varChild, getter_AddRefs(accessible)); + if (FAILED(hr)) { + return hr; + } + + if (accessible) { + return accessible->accLocation(pxLeft, pyTop, pcxWidth, pcyHeight, + kVarChildIdSelf); + } + + LayoutDeviceIntRect rect = Acc()->Bounds(); + *pxLeft = rect.X(); + *pyTop = rect.Y(); + *pcxWidth = rect.Width(); + *pcyHeight = rect.Height(); + return S_OK; +} + +STDMETHODIMP +MsaaAccessible::accNavigate( + /* [in] */ long navDir, + /* [optional][in] */ VARIANT varStart, + /* [retval][out] */ VARIANT __RPC_FAR* pvarEndUpAt) { + if (!pvarEndUpAt) return E_INVALIDARG; + + VariantInit(pvarEndUpAt); + + RefPtr<IAccessible> accessible; + HRESULT hr = ResolveChild(varStart, getter_AddRefs(accessible)); + if (FAILED(hr)) { + return hr; + } + + if (accessible) { + return accessible->accNavigate(navDir, kVarChildIdSelf, pvarEndUpAt); + } + + Accessible* navAccessible = nullptr; + Maybe<RelationType> xpRelation; + +#define RELATIONTYPE(geckoType, stringType, atkType, msaaType, ia2Type) \ + case msaaType: \ + xpRelation.emplace(RelationType::geckoType); \ + break; + + switch (navDir) { + case NAVDIR_FIRSTCHILD: + if (!nsAccUtils::MustPrune(mAcc)) { + navAccessible = mAcc->FirstChild(); + } + break; + case NAVDIR_LASTCHILD: + if (!nsAccUtils::MustPrune(mAcc)) { + navAccessible = mAcc->LastChild(); + } + break; + case NAVDIR_NEXT: + navAccessible = mAcc->NextSibling(); + break; + case NAVDIR_PREVIOUS: + navAccessible = mAcc->PrevSibling(); + break; + case NAVDIR_DOWN: + case NAVDIR_LEFT: + case NAVDIR_RIGHT: + case NAVDIR_UP: + return E_NOTIMPL; + + // MSAA relationship extensions to accNavigate +#include "RelationTypeMap.h" + + default: + return E_INVALIDARG; + } + +#undef RELATIONTYPE + + pvarEndUpAt->vt = VT_EMPTY; + + if (xpRelation) { + Relation rel = mAcc->RelationByType(*xpRelation); + navAccessible = rel.Next(); + } + + if (!navAccessible) return E_FAIL; + + pvarEndUpAt->pdispVal = NativeAccessible(navAccessible); + pvarEndUpAt->vt = VT_DISPATCH; + return S_OK; +} + +STDMETHODIMP +MsaaAccessible::accHitTest( + /* [in] */ long xLeft, + /* [in] */ long yTop, + /* [retval][out] */ VARIANT __RPC_FAR* pvarChild) { + if (!pvarChild) return E_INVALIDARG; + + VariantInit(pvarChild); + + if (!mAcc) { + return CO_E_OBJNOTCONNECTED; + } + + // The MSAA documentation says accHitTest should return a child. However, + // clients call AccessibleObjectFromPoint, which ends up walking the + // descendants calling accHitTest on each one. Since clients want the + // deepest descendant anyway, it's faster and probably more accurate to + // just do this ourselves. + Accessible* accessible = mAcc->ChildAtPoint( + xLeft, yTop, Accessible::EWhichChildAtPoint::DeepestChild); + + // if we got a child + if (accessible) { + if (accessible != mAcc && accessible->IsTextLeaf()) { + Accessible* parent = accessible->Parent(); + if (parent != mAcc && parent->Role() == roles::LINK) { + // Bug 1843832: The UI Automation -> IAccessible2 proxy barfs if we + // return the text leaf child of a link when hit testing an ancestor of + // the link. Therefore, we return the link instead. MSAA clients which + // call AccessibleObjectFromPoint will still get to the text leaf, since + // AccessibleObjectFromPoint keeps calling accHitTest until it can't + // descend any further. We should remove this tragic hack once we have + // a native UIA implementation. + accessible = parent; + } + } + if (accessible == mAcc) { + pvarChild->vt = VT_I4; + pvarChild->lVal = CHILDID_SELF; + } else { + pvarChild->vt = VT_DISPATCH; + pvarChild->pdispVal = NativeAccessible(accessible); + } + } else { + // no child at that point + pvarChild->vt = VT_EMPTY; + return S_FALSE; + } + return S_OK; +} + +STDMETHODIMP +MsaaAccessible::accDoDefaultAction( + /* [optional][in] */ VARIANT varChild) { + RefPtr<IAccessible> accessible; + HRESULT hr = ResolveChild(varChild, getter_AddRefs(accessible)); + if (FAILED(hr)) { + return hr; + } + + if (accessible) { + return accessible->accDoDefaultAction(kVarChildIdSelf); + } + + return mAcc->DoAction(0) ? S_OK : E_INVALIDARG; +} + +STDMETHODIMP +MsaaAccessible::put_accName( + /* [optional][in] */ VARIANT varChild, + /* [in] */ BSTR szName) { + return E_NOTIMPL; +} + +STDMETHODIMP +MsaaAccessible::put_accValue( + /* [optional][in] */ VARIANT varChild, + /* [in] */ BSTR szValue) { + RefPtr<IAccessible> accessible; + HRESULT hr = ResolveChild(varChild, getter_AddRefs(accessible)); + if (FAILED(hr)) { + return hr; + } + + if (accessible) { + return accessible->put_accValue(kVarChildIdSelf, szValue); + } + + HyperTextAccessibleBase* ht = mAcc->AsHyperTextBase(); + if (!ht) { + return E_NOTIMPL; + } + + uint32_t length = ::SysStringLen(szValue); + nsAutoString text(szValue, length); + ht->ReplaceText(text); + return S_OK; +} + +// IDispatch methods + +STDMETHODIMP +MsaaAccessible::GetTypeInfoCount(UINT* pctinfo) { + if (!pctinfo) return E_INVALIDARG; + + *pctinfo = 1; + return S_OK; +} + +STDMETHODIMP +MsaaAccessible::GetTypeInfo(UINT iTInfo, LCID lcid, ITypeInfo** ppTInfo) { + if (!ppTInfo) return E_INVALIDARG; + + *ppTInfo = nullptr; + + if (iTInfo != 0) return DISP_E_BADINDEX; + + ITypeInfo* typeInfo = GetTI(lcid); + if (!typeInfo) return E_FAIL; + + typeInfo->AddRef(); + *ppTInfo = typeInfo; + + return S_OK; +} + +STDMETHODIMP +MsaaAccessible::GetIDsOfNames(REFIID riid, LPOLESTR* rgszNames, UINT cNames, + LCID lcid, DISPID* rgDispId) { + ITypeInfo* typeInfo = GetTI(lcid); + if (!typeInfo) return E_FAIL; + + HRESULT hr = DispGetIDsOfNames(typeInfo, rgszNames, cNames, rgDispId); + return hr; +} + +STDMETHODIMP +MsaaAccessible::Invoke(DISPID dispIdMember, REFIID riid, LCID lcid, WORD wFlags, + DISPPARAMS* pDispParams, VARIANT* pVarResult, + EXCEPINFO* pExcepInfo, UINT* puArgErr) { + ITypeInfo* typeInfo = GetTI(lcid); + if (!typeInfo) return E_FAIL; + + return typeInfo->Invoke(static_cast<IAccessible*>(this), dispIdMember, wFlags, + pDispParams, pVarResult, pExcepInfo, puArgErr); +} |