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Diffstat (limited to 'accessible/windows/msaa/MsaaAccessible.cpp')
| -rw-r--r-- | accessible/windows/msaa/MsaaAccessible.cpp | 1793 |
1 files changed, 1793 insertions, 0 deletions
diff --git a/accessible/windows/msaa/MsaaAccessible.cpp b/accessible/windows/msaa/MsaaAccessible.cpp new file mode 100644 index 0000000000..851edbb6c3 --- /dev/null +++ b/accessible/windows/msaa/MsaaAccessible.cpp @@ -0,0 +1,1793 @@ +/* -*- 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 "mozilla/a11y/AccessibleWrap.h" +#include "mozilla/a11y/Compatibility.h" +#include "mozilla/a11y/DocAccessibleParent.h" +#include "mozilla/dom/BrowserBridgeChild.h" +#include "mozilla/dom/BrowserBridgeParent.h" +#include "mozilla/dom/BrowserParent.h" +#include "mozilla/mscom/Interceptor.h" +#include "mozilla/StaticPrefs_accessibility.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" + +using namespace mozilla; +using namespace mozilla::a11y; + +const uint32_t USE_ROLE_STRING = 0; +static const VARIANT kVarChildIdSelf = {{{VT_I4}}}; + +MsaaIdGenerator MsaaAccessible::sIDGen; +ITypeInfo* MsaaAccessible::gTypeInfo = nullptr; + +/* static */ +MsaaAccessible* MsaaAccessible::Create(Accessible* aAcc) { + // If the cache is enabled, this should only ever be called in the parent + // process. + MOZ_ASSERT(!StaticPrefs::accessibility_cache_enabled_AtStartup() || + XRE_IsParentProcess()); + if (!StaticPrefs::accessibility_cache_enabled_AtStartup() && + aAcc->IsRemote()) { + // MsaaAccessible is just a stub to hold the id in this case. + return new MsaaAccessible(aAcc); + } + // 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. + LocalAccessible* localAcc = aAcc->AsLocal(); + if (localAcc && aAcc->IsRoot()) { + 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 (localAcc) { + // XXX These classes don't support RemoteAccessible yet. + if (aAcc->IsApplication()) { + return new ia2AccessibleApplication(aAcc); + } + if (aAcc->IsImage()) { + return new ia2AccessibleImage(aAcc); + } + 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 (!StaticPrefs::accessibility_cache_enabled_AtStartup() && + mAcc->IsRemote()) { + // This MsaaAccessible is just a stub. We just need to clear mAcc. + mAcc = nullptr; + return; + } + + if (mID != kNoID) { + auto doc = MsaaDocAccessible::GetFromOwned(mAcc); + MOZ_ASSERT(doc); + doc->RemoveID(mID); + } + + if (XRE_IsContentProcess()) { + // Bug 1434822: To improve performance for cross-process COM, we disable COM + // garbage collection. However, this means we never receive Release calls + // from clients, so defunct accessibles can never be deleted. Since we + // know when an accessible is shutting down, we can work around this by + // forcing COM to disconnect this object from all of its remote clients, + // which will cause associated references to be released. + IUnknown* unk = static_cast<IAccessible*>(this); + mscom::Interceptor::DisconnectRemotesForTarget(unk); + // If an accessible was retrieved via IAccessibleHypertext::hyperlink*, + // it will have a different Interceptor that won't be matched by the above + // call, even though it's the same object. Therefore, call it again with + // the IAccessibleHyperlink pointer. We can remove this horrible hack once + // bug 1440267 is fixed. + unk = static_cast<IAccessibleHyperlink*>(this); + mscom::Interceptor::DisconnectRemotesForTarget(unk); + for (auto& assocUnk : mAssociatedCOMObjectsForDisconnection) { + mscom::Interceptor::DisconnectRemotesForTarget(assocUnk); + } + mAssociatedCOMObjectsForDisconnection.Clear(); + } + + mAcc = nullptr; +} + +void MsaaAccessible::SetID(uint32_t aID) { + MOZ_ASSERT(XRE_IsParentProcess() && mAcc && + !StaticPrefs::accessibility_cache_enabled_AtStartup()); + mID = aID; +} + +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; + } + + // If the cache is disabled, chrome should use mID which has been generated by + // the content process. + if (!StaticPrefs::accessibility_cache_enabled_AtStartup() && + aAccessible->IsRemote()) { + const uint32_t id = MsaaAccessible::GetFrom(aAccessible)->mID; + MOZ_ASSERT(id != kNoID); + return id; + } + + 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 */ +uint32_t MsaaAccessible::GetContentProcessIdFor( + dom::ContentParentId aIPCContentId) { + if (StaticPrefs::accessibility_cache_enabled_AtStartup()) { + return 0; + } + return sIDGen.GetContentProcessIDFor(aIPCContentId); +} + +/* static */ +void MsaaAccessible::ReleaseContentProcessIdFor( + dom::ContentParentId aIPCContentId) { + sIDGen.ReleaseContentProcessIDFor(aIPCContentId); +} + +/* 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()); +} + +static bool IsHandlerInvalidationNeeded(uint32_t aEvent) { + // We want to return true for any events that would indicate that something + // in the handler cache is out of date. + switch (aEvent) { + case EVENT_OBJECT_STATECHANGE: + case EVENT_OBJECT_LOCATIONCHANGE: + case EVENT_OBJECT_NAMECHANGE: + case EVENT_OBJECT_DESCRIPTIONCHANGE: + case EVENT_OBJECT_VALUECHANGE: + case EVENT_OBJECT_FOCUS: + case IA2_EVENT_ACTION_CHANGED: + case IA2_EVENT_DOCUMENT_LOAD_COMPLETE: + case IA2_EVENT_DOCUMENT_LOAD_STOPPED: + case IA2_EVENT_DOCUMENT_ATTRIBUTE_CHANGED: + case IA2_EVENT_DOCUMENT_CONTENT_CHANGED: + case IA2_EVENT_PAGE_CHANGED: + case IA2_EVENT_TEXT_ATTRIBUTE_CHANGED: + case IA2_EVENT_TEXT_CHANGED: + case IA2_EVENT_TEXT_INSERTED: + case IA2_EVENT_TEXT_REMOVED: + case IA2_EVENT_TEXT_UPDATED: + case IA2_EVENT_OBJECT_ATTRIBUTE_CHANGED: + return true; + default: + return false; + } +} + +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"); + + NS_ASSERTION(aEventType > 0 && aEventType < ArrayLength(gWinEventMap), + "invalid event type"); + + 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; + } + + if (IsHandlerInvalidationNeeded(winEvent)) { + AccessibleWrap::InvalidateHandlers(); + } + + // 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; +} + +/** + * If this is an OOP iframe in a content process, return the COM proxy for the + * child document. + * This will only ever return something when the cache is disabled. When the + * cache is enabled, traversing to OOP iframe documents is handled in the + * parent process via the RemoteAccessible hierarchy. + */ +static already_AddRefed<IDispatch> MaybeGetOOPIframeDocCOMProxy( + Accessible* aAcc) { + if (!XRE_IsContentProcess() || !aAcc->IsOuterDoc()) { + return nullptr; + } + MOZ_ASSERT(!StaticPrefs::accessibility_cache_enabled_AtStartup()); + LocalAccessible* outerDoc = aAcc->AsLocal(); + auto bridge = dom::BrowserBridgeChild::GetFrom(outerDoc->GetContent()); + if (!bridge) { + // This isn't an OOP iframe. + return nullptr; + } + return bridge->GetEmbeddedDocAccessible(); +} + +/** + * 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; + } + + if (aVarChild.lVal == 1 && RefPtr{MaybeGetOOPIframeDocCOMProxy(mAcc)}) { + // We can't access an OOP iframe document. + return E_FAIL; + } + + 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 already_AddRefed<IDispatch> GetProxiedAccessibleInSubtree( + DocAccessibleParent* aDoc, const VARIANT& aVarChild) { + MOZ_ASSERT(!StaticPrefs::accessibility_cache_enabled_AtStartup()); + RefPtr<IAccessible> comProxy; + int32_t docWrapperChildId = MsaaAccessible::GetChildIDFor(aDoc); + // Only document accessible proxies at the top level of their content process + // are created with a pointer to their COM proxy. + if (aDoc->IsTopLevelInContentProcess()) { + aDoc->GetCOMInterface(getter_AddRefs(comProxy)); + } else { + auto tab = static_cast<dom::BrowserParent*>(aDoc->Manager()); + MOZ_ASSERT(tab); + DocAccessibleParent* topLevelDoc = tab->GetTopLevelDocAccessible(); + MOZ_ASSERT(topLevelDoc && topLevelDoc->IsTopLevelInContentProcess()); + VARIANT docId = {{{VT_I4}}}; + docId.lVal = docWrapperChildId; + RefPtr<IDispatch> disp = GetProxiedAccessibleInSubtree(topLevelDoc, docId); + if (!disp) { + return nullptr; + } + + DebugOnly<HRESULT> hr = + disp->QueryInterface(IID_IAccessible, getter_AddRefs(comProxy)); + MOZ_ASSERT(SUCCEEDED(hr)); + } + + MOZ_ASSERT(comProxy); + if (!comProxy) { + return nullptr; + } + + if (docWrapperChildId == aVarChild.lVal) { + return comProxy.forget(); + } + + RefPtr<IDispatch> disp; + if (FAILED(comProxy->get_accChild(aVarChild, getter_AddRefs(disp)))) { + return nullptr; + } + + return disp.forget(); +} + +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; + } + + AccessibleWrap* localAcc = static_cast<AccessibleWrap*>(mAcc->AsLocal()); + if (varChild.lVal == CHILDID_SELF) { + MOZ_ASSERT(localAcc || + StaticPrefs::accessibility_cache_enabled_AtStartup()); + 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 the MSAA ID is not a chrome id then we already know that we won't + // find it here and should look remotely instead. This handles the case when + // accessible is part of the chrome process and is part of the xul browser + // window and the child id points in the content documents. + // Bug 1422674: We must only handle remote ids here (< 0), not child indices. + // Child indices (> 0) are handled below for both local and remote children. + if (XRE_IsParentProcess() && localAcc && varChild.lVal < 0 && + !sIDGen.IsChromeID(varChild.lVal)) { + MOZ_ASSERT(!StaticPrefs::accessibility_cache_enabled_AtStartup()); + if (!localAcc->IsRootForHWND()) { + // Bug 1422201, 1424657: accChild with a remote id is only valid on the + // root accessible for an HWND. + // Otherwise, we might return remote accessibles which aren't descendants + // of this accessible. This would confuse clients which use accChild to + // check whether something is a descendant of a document. + return nullptr; + } + return GetRemoteIAccessibleFor(varChild); + } + + if (varChild.lVal > 0) { + // Gecko child indices are 0-based in contrast to indices used in MSAA. + if (varChild.lVal == 1) { + RefPtr<IDispatch> disp = MaybeGetOOPIframeDocCOMProxy(localAcc); + if (disp) { + // We need to return an IAccessible here, but + // MaybeGetOOPIframeDocCOMProxy returns an IDispatch. We know this + // IDispatch is also an IAccessible, so this code is safe, albeit ugly. + disp.forget((void**)getter_AddRefs(result)); + return result.forget(); + } + } + Accessible* xpAcc = mAcc->ChildAt(varChild.lVal - 1); + if (!xpAcc) { + return nullptr; + } + MOZ_ASSERT(xpAcc->IsRemote() || !xpAcc->AsLocal()->IsDefunct(), + "Shouldn't get a defunct child"); + if (!StaticPrefs::accessibility_cache_enabled_AtStartup() && localAcc && + xpAcc->IsRemote()) { + // We're crossing from a local OuterDoc to a remote document and caching + // isn't enabled. We must return the COM proxy. + MOZ_ASSERT(localAcc->IsOuterDoc()); + xpAcc->AsRemote()->GetCOMInterface(getter_AddRefs(result)); + return result.forget(); + } + 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. + // First see about the case that both this accessible and the target one are + // RemoteAccessibles and the cache is disabled. + if (!localAcc && !StaticPrefs::accessibility_cache_enabled_AtStartup()) { + DocAccessibleParent* proxyDoc = mAcc->AsRemote()->Document(); + RefPtr<IDispatch> disp = GetProxiedAccessibleInSubtree(proxyDoc, varChild); + if (!disp) { + return nullptr; + } + + MOZ_ASSERT(mscom::IsProxy(disp)); + DebugOnly<HRESULT> hr = + disp->QueryInterface(IID_IAccessible, getter_AddRefs(result)); + MOZ_ASSERT(SUCCEEDED(hr)); + return result.forget(); + } + + Accessible* doc = nullptr; + Accessible* child = nullptr; + auto id = static_cast<uint32_t>(varChild.lVal); + if (localAcc) { + DocAccessible* localDoc = localAcc->Document(); + doc = localDoc; + child = GetAccessibleInSubtree(localDoc, id); + if (!child && StaticPrefs::accessibility_cache_enabled_AtStartup()) { + // 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 if (StaticPrefs::accessibility_cache_enabled_AtStartup()) { + DocAccessibleParent* remoteDoc = mAcc->AsRemote()->Document(); + doc = remoteDoc; + child = GetAccessibleInSubtree(remoteDoc, id); + } + if (!child) { + return nullptr; + } + + MOZ_ASSERT(child->IsLocal() || + StaticPrefs::accessibility_cache_enabled_AtStartup()); + 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; +} + +/** + * Visit DocAccessibleParent descendants of `aBrowser` that are at the top + * level of their content process. + * That is, IsTopLevelInContentProcess() will be true for each visited actor. + * Each visited actor will be an embedded document in a different content + * process to its embedder. + * The DocAccessibleParent for `aBrowser` itself is excluded. + * `aCallback` will be called for each DocAccessibleParent. + * The callback should return true to continue traversal, false to cease. + */ +template <typename Callback> +static bool VisitDocAccessibleParentDescendantsAtTopLevelInContentProcess( + dom::BrowserParent* aBrowser, Callback aCallback) { + // We can't use BrowserBridgeParent::VisitAllDescendants because it doesn't + // provide a way to stop the search. + const auto& bridges = aBrowser->ManagedPBrowserBridgeParent(); + return std::all_of(bridges.cbegin(), bridges.cend(), [&](const auto& key) { + auto* bridge = static_cast<dom::BrowserBridgeParent*>(key); + dom::BrowserParent* childBrowser = bridge->GetBrowserParent(); + DocAccessibleParent* childDocAcc = childBrowser->GetTopLevelDocAccessible(); + if (!childDocAcc || childDocAcc->IsShutdown()) { + return true; + } + if (!aCallback(childDocAcc)) { + return false; // Stop traversal. + } + if (!VisitDocAccessibleParentDescendantsAtTopLevelInContentProcess( + childBrowser, aCallback)) { + return false; // Stop traversal. + } + return true; // Continue traversal. + }); +} + +already_AddRefed<IAccessible> MsaaAccessible::GetRemoteIAccessibleFor( + const VARIANT& aVarChild) { + a11y::RootAccessible* root = LocalAcc()->RootAccessible(); + const nsTArray<DocAccessibleParent*>* rawRemoteDocs = + DocManager::TopLevelRemoteDocs(); + if (!rawRemoteDocs) { + return nullptr; + } + nsTArray<RefPtr<DocAccessibleParent>> remoteDocs(rawRemoteDocs->Length()); + for (auto rawRemoteDoc : *rawRemoteDocs) { + remoteDocs.AppendElement(rawRemoteDoc); + } + + RefPtr<IAccessible> result; + + for (auto topRemoteDoc : remoteDocs) { + if (topRemoteDoc->IsShutdown()) { + continue; + } + LocalAccessible* outerDoc = topRemoteDoc->OuterDocOfRemoteBrowser(); + if (!outerDoc) { + continue; + } + + if (outerDoc->RootAccessible() != root) { + continue; + } + + RefPtr<IDispatch> disp; + auto checkDoc = [&aVarChild, + &disp](DocAccessibleParent* aRemoteDoc) -> bool { + uint32_t remoteDocMsaaId = + MsaaAccessible::GetFrom(aRemoteDoc)->GetExistingID(); + if (!sIDGen.IsSameContentProcessFor(aVarChild.lVal, remoteDocMsaaId)) { + return true; // Continue the search. + } + if ((disp = GetProxiedAccessibleInSubtree(aRemoteDoc, aVarChild))) { + return false; // Found it! Stop traversal! + } + return true; // Continue the search. + }; + + // Check the top level document for this id. + checkDoc(topRemoteDoc); + if (!disp) { + // The top level document doesn't contain this id. Recursively check any + // out-of-process iframe documents it embeds. + VisitDocAccessibleParentDescendantsAtTopLevelInContentProcess( + static_cast<dom::BrowserParent*>(topRemoteDoc->Manager()), checkDoc); + } + + if (!disp) { + continue; + } + + DebugOnly<HRESULT> hr = + disp->QueryInterface(IID_IAccessible, getter_AddRefs(result)); + // QI can fail on rare occasions if the LocalAccessible dies after we + // fetched disp but before we QI. + NS_WARNING_ASSERTION(SUCCEEDED(hr), "QI failed on remote IDispatch"); + return result.forget(); + } + + return nullptr; +} + +IDispatch* MsaaAccessible::NativeAccessible(Accessible* aAccessible) { + if (!aAccessible) { + NS_WARNING("Not passing in an aAccessible"); + return nullptr; + } + + RefPtr<IDispatch> disp; + if (!StaticPrefs::accessibility_cache_enabled_AtStartup() && + aAccessible->IsRemote()) { + // This is a RemoteAccessible and caching isn't enabled. We must return + // the COM proxy. + aAccessible->AsRemote()->GetCOMInterface(getter_AddRefs(disp)); + } else { + 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(); +} + +// 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_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) { + if ( + // Don't support this interface for leaf elements. + !mAcc->HasChildren() || nsAccUtils::MustPrune(mAcc) || + // We also don't support this for local OuterDocAccessibles with remote + // document children when the cache is disabled. Handling this is tricky + // and there's no benefit to IEnumVARIANT when there's only one child + // anyway. + (localAcc && localAcc->IsOuterDoc() && + !StaticPrefs::accessibility_cache_enabled_AtStartup() && + localAcc->FirstChild()->IsRemote())) { + 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 (!*ppv && iid == IID_IGeckoCustom) { + MOZ_ASSERT(XRE_IsContentProcess() && + !StaticPrefs::accessibility_cache_enabled_AtStartup()); + RefPtr<GeckoCustom> gkCrap = new GeckoCustom(this); + gkCrap.forget(ppv); + return S_OK; + } + + 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; + MOZ_ASSERT(StaticPrefs::accessibility_cache_enabled_AtStartup() || + xpParentAcc->IsLocal()); + + *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(); + if (*pcountChildren == 0 && RefPtr{MaybeGetOOPIframeDocCOMProxy(mAcc)}) { + *pcountChildren = 1; + } + 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, 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; + } + + // -- Try enumerated role + if (msaaRole != USE_ROLE_STRING) { + pvarRole->vt = VT_I4; + pvarRole->lVal = msaaRole; // Normal enumerated role + return S_OK; + } + + // -- Try BSTR role + // Could not map to known enumerated MSAA role like ROLE_BUTTON + // Use BSTR role to expose role attribute or tag name + namespace + // XXX We should remove this hack and map to standard MSAA roles, even though + // they're lossy. See bug 798492. + if (mAcc->IsRemote()) { + // We don't support unknown or multiple ARIA roles for RemoteAccessible + // here, nor can we support namespaces. No one should be relying on this + // anyway, so this is fine. We just want to avoid returning a failure here. + nsAtom* val = nullptr; + const nsRoleMapEntry* roleMap = mAcc->ARIARoleMap(); + if (roleMap && roleMap->roleAtom != nsGkAtoms::_empty) { + val = roleMap->roleAtom; + } else { + val = mAcc->TagName(); + } + if (!val) { + return E_FAIL; + } + pvarRole->vt = VT_BSTR; + pvarRole->bstrVal = ::SysAllocString(val->GetUTF16String()); + return S_OK; + } + + LocalAccessible* localAcc = mAcc->AsLocal(); + MOZ_ASSERT(localAcc); + nsIContent* content = localAcc->GetContent(); + if (!content) return E_FAIL; + + if (content->IsElement()) { + nsAutoString roleString; + // Try the role attribute. + nsAccUtils::GetARIAAttr(content->AsElement(), nsGkAtoms::role, roleString); + + if (roleString.IsEmpty()) { + // No role attribute (or it is an empty string). + // Use the tag name. + dom::Document* document = content->GetUncomposedDoc(); + if (!document) return E_FAIL; + + dom::NodeInfo* nodeInfo = content->NodeInfo(); + nodeInfo->GetName(roleString); + + // Only append name space if different from that of current document. + if (!nodeInfo->NamespaceEquals(document->GetDefaultNamespaceID())) { + nsAutoString nameSpaceURI; + nodeInfo->GetNamespaceURI(nameSpaceURI); + roleString += u", "_ns + nameSpaceURI; + } + } + + if (!roleString.IsEmpty()) { + pvarRole->vt = VT_BSTR; + pvarRole->bstrVal = ::SysAllocString(roleString.get()); + return S_OK; + } + } + + return E_FAIL; +} + +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); + AssociateCOMObjectForDisconnection(pEnum); + 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) { + if (XRE_IsContentProcess()) { + // In this case we might have been invoked while the IPC MessageChannel is + // waiting on a sync reply. We cannot dispatch additional IPC while that + // is happening, so we dispatch TakeFocus from the main thread to + // guarantee that we are outside any IPC. + MOZ_ASSERT(mAcc->IsLocal(), + "Content process should only have local accessibles"); + nsCOMPtr<nsIRunnable> runnable = mozilla::NewRunnableMethod( + "LocalAccessible::TakeFocus", mAcc->AsLocal(), + &LocalAccessible::TakeFocus); + NS_DispatchToMainThread(runnable, NS_DISPATCH_NORMAL); + return S_OK; + } + 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); + } + // This should never be called on a RemoteAccessible if the cache is disabled. + MOZ_ASSERT(mAcc->IsLocal() || + StaticPrefs::accessibility_cache_enabled_AtStartup()); + + 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 (RefPtr<IDispatch> disp = MaybeGetOOPIframeDocCOMProxy(mAcc)) { + pvarEndUpAt->vt = VT_DISPATCH; + disp.forget(&pvarEndUpAt->pdispVal); + return S_OK; + } else if (!nsAccUtils::MustPrune(mAcc)) { + navAccessible = mAcc->FirstChild(); + } + break; + case NAVDIR_LASTCHILD: + if (RefPtr<IDispatch> disp = MaybeGetOOPIframeDocCOMProxy(mAcc)) { + pvarEndUpAt->vt = VT_DISPATCH; + disp.forget(&pvarEndUpAt->pdispVal); + return S_OK; + } else 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; + } + + Accessible* accessible = mAcc->ChildAtPoint( + xLeft, yTop, + // 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. For now, we keep this behind the cache pref. + StaticPrefs::accessibility_cache_enabled_AtStartup() + ? Accessible::EWhichChildAtPoint::DeepestChild + : Accessible::EWhichChildAtPoint::DirectChild); + + // if we got a child + if (accessible) { + 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 + if (RefPtr<IDispatch> disp = MaybeGetOOPIframeDocCOMProxy(mAcc)) { + // This is an OOP iframe. ChildAtPoint can't traverse inside it. If the + // coordinates are inside this iframe, return the COM proxy for the + // OOP document. + LayoutDeviceIntRect docRect = mAcc->AsLocal()->Bounds(); + if (docRect.Contains(xLeft, yTop)) { + pvarChild->vt = VT_DISPATCH; + disp.forget(&pvarChild->pdispVal); + return S_OK; + } + } + 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); + } + if (mAcc->IsRemote()) { + return E_NOTIMPL; // XXX Not supported for RemoteAccessible yet. + } + + HyperTextAccessible* ht = LocalAcc()->AsHyperText(); + 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); +} |