1 files changed, 289 insertions, 0 deletions
diff --git a/accessible/windows/msaa/AccessibleWrap.cpp b/accessible/windows/msaa/AccessibleWrap.cpp
new file mode 100644
index 0000000000..679a3221ca
--- /dev/null
+++ b/accessible/windows/msaa/AccessibleWrap.cpp
@@ -0,0 +1,289 @@
+/* -*- 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 "AccessibleWrap.h"
+
+#include "mozilla/a11y/DocAccessibleParent.h"
+#include "AccEvent.h"
+#include "GeckoCustom.h"
+#include "nsAccUtils.h"
+#include "nsIAccessibleEvent.h"
+#include "nsIWidget.h"
+#include "nsWindowsHelpers.h"
+#include "mozilla/a11y/HyperTextAccessible.h"
+#include "mozilla/a11y/RemoteAccessible.h"
+#include "ServiceProvider.h"
+#include "sdnAccessible.h"
+
+#include "mozilla/mscom/AsyncInvoker.h"
+#include "mozilla/StaticPrefs_accessibility.h"
+
+using namespace mozilla;
+using namespace mozilla::a11y;
+
+/* For documentation of the accessibility architecture,
+ * see http://lxr.mozilla.org/seamonkey/source/accessible/accessible-docs.html
+ */
+
+StaticAutoPtr<nsTArray<AccessibleWrap::HandlerControllerData>>
+    AccessibleWrap::sHandlerControllers;
+
+////////////////////////////////////////////////////////////////////////////////
+// AccessibleWrap
+////////////////////////////////////////////////////////////////////////////////
+AccessibleWrap::AccessibleWrap(nsIContent* aContent, DocAccessible* aDoc)
+    : LocalAccessible(aContent, aDoc) {}
+
+NS_IMPL_ISUPPORTS_INHERITED0(AccessibleWrap, LocalAccessible)
+
+void AccessibleWrap::Shutdown() {
+  if (mMsaa) {
+    mMsaa->MsaaShutdown();
+    // Don't release mMsaa here because this will cause its id to be released
+    // immediately, which will result in immediate reuse, causing problems
+    // for clients. Instead, we release it in the destructor.
+  }
+  LocalAccessible::Shutdown();
+}
+
+//-----------------------------------------------------
+// IUnknown interface methods - see iunknown.h for documentation
+//-----------------------------------------------------
+
+MsaaAccessible* AccessibleWrap::GetMsaa() {
+  if (!mMsaa) {
+    mMsaa = MsaaAccessible::Create(this);
+  }
+  return mMsaa;
+}
+
+void AccessibleWrap::GetNativeInterface(void** aOutAccessible) {
+  RefPtr<IAccessible> result = GetMsaa();
+  return result.forget(aOutAccessible);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// LocalAccessible
+
+nsresult AccessibleWrap::HandleAccEvent(AccEvent* aEvent) {
+  nsresult rv = LocalAccessible::HandleAccEvent(aEvent);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (IPCAccessibilityActive()) {
+    return NS_OK;
+  }
+
+  uint32_t eventType = aEvent->GetEventType();
+
+  // Means we're not active.
+  NS_ENSURE_TRUE(!IsDefunct(), NS_ERROR_FAILURE);
+
+  LocalAccessible* accessible = aEvent->GetAccessible();
+  if (!accessible) return NS_OK;
+
+  if (eventType == nsIAccessibleEvent::EVENT_TEXT_CARET_MOVED ||
+      eventType == nsIAccessibleEvent::EVENT_FOCUS) {
+    UpdateSystemCaretFor(accessible);
+  }
+
+  MsaaAccessible::FireWinEvent(accessible, eventType);
+
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// AccessibleWrap
+
+//------- Helper methods ---------
+
+bool AccessibleWrap::IsRootForHWND() {
+  if (IsRoot()) {
+    return true;
+  }
+  HWND thisHwnd = MsaaAccessible::GetHWNDFor(this);
+  AccessibleWrap* parent = static_cast<AccessibleWrap*>(LocalParent());
+  MOZ_ASSERT(parent);
+  HWND parentHwnd = MsaaAccessible::GetHWNDFor(parent);
+  return thisHwnd != parentHwnd;
+}
+
+void AccessibleWrap::UpdateSystemCaretFor(LocalAccessible* aAccessible) {
+  // Move the system caret so that Windows Tablet Edition and tradional ATs with
+  // off-screen model can follow the caret
+  ::DestroyCaret();
+
+  HyperTextAccessible* text = aAccessible->AsHyperText();
+  if (!text) return;
+
+  nsIWidget* widget = nullptr;
+  LayoutDeviceIntRect caretRect = text->GetCaretRect(&widget);
+
+  if (!widget) {
+    return;
+  }
+
+  HWND caretWnd =
+      reinterpret_cast<HWND>(widget->GetNativeData(NS_NATIVE_WINDOW));
+  UpdateSystemCaretFor(caretWnd, caretRect);
+}
+
+/* static */
+void AccessibleWrap::UpdateSystemCaretFor(
+    RemoteAccessible* aProxy, const LayoutDeviceIntRect& aCaretRect) {
+  ::DestroyCaret();
+
+  // The HWND should be the real widget HWND, not an emulated HWND.
+  // We get the HWND from the proxy's outer doc to bypass window emulation.
+  LocalAccessible* outerDoc = aProxy->OuterDocOfRemoteBrowser();
+  UpdateSystemCaretFor(MsaaAccessible::GetHWNDFor(outerDoc), aCaretRect);
+}
+
+/* static */
+void AccessibleWrap::UpdateSystemCaretFor(
+    HWND aCaretWnd, const LayoutDeviceIntRect& aCaretRect) {
+  if (!aCaretWnd || aCaretRect.IsEmpty()) {
+    return;
+  }
+
+  // Create invisible bitmap for caret, otherwise its appearance interferes
+  // with Gecko caret
+  nsAutoBitmap caretBitMap(CreateBitmap(1, aCaretRect.Height(), 1, 1, nullptr));
+  if (::CreateCaret(aCaretWnd, caretBitMap, 1,
+                    aCaretRect.Height())) {  // Also destroys the last caret
+    ::ShowCaret(aCaretWnd);
+    RECT windowRect;
+    ::GetWindowRect(aCaretWnd, &windowRect);
+    ::SetCaretPos(aCaretRect.X() - windowRect.left,
+                  aCaretRect.Y() - windowRect.top);
+  }
+}
+
+/* static */
+void AccessibleWrap::SetHandlerControl(DWORD aPid,
+                                       RefPtr<IHandlerControl> aCtrl) {
+  MOZ_ASSERT(XRE_IsParentProcess() && NS_IsMainThread());
+
+  if (!sHandlerControllers) {
+    sHandlerControllers = new nsTArray<HandlerControllerData>();
+    ClearOnShutdown(&sHandlerControllers);
+  }
+
+  HandlerControllerData ctrlData(aPid, std::move(aCtrl));
+  if (sHandlerControllers->Contains(ctrlData)) {
+    return;
+  }
+
+  sHandlerControllers->AppendElement(std::move(ctrlData));
+}
+
+/* static */
+void AccessibleWrap::InvalidateHandlers() {
+  static const HRESULT kErrorServerDied =
+      HRESULT_FROM_WIN32(RPC_S_SERVER_UNAVAILABLE);
+
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!sHandlerControllers || sHandlerControllers->IsEmpty()) {
+    return;
+  }
+
+  // We iterate in reverse so that we may safely remove defunct elements while
+  // executing the loop.
+  for (auto& controller : Reversed(*sHandlerControllers)) {
+    MOZ_ASSERT(controller.mPid);
+    MOZ_ASSERT(controller.mCtrl);
+
+    ASYNC_INVOKER_FOR(IHandlerControl)
+    invoker(controller.mCtrl, Some(controller.mIsProxy));
+
+    HRESULT hr = ASYNC_INVOKE(invoker, Invalidate);
+
+    if (hr == CO_E_OBJNOTCONNECTED || hr == kErrorServerDied) {
+      sHandlerControllers->RemoveElement(controller);
+    } else {
+      Unused << NS_WARN_IF(FAILED(hr));
+    }
+  }
+}
+
+/* static */
+bool AccessibleWrap::DispatchTextChangeToHandler(Accessible* aAcc,
+                                                 bool aIsInsert,
+                                                 const nsAString& aText,
+                                                 int32_t aStart,
+                                                 uint32_t aLen) {
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!StaticPrefs::accessibility_cache_enabled_AtStartup());
+
+  if (!sHandlerControllers || sHandlerControllers->IsEmpty()) {
+    return false;
+  }
+
+  HWND hwnd = MsaaAccessible::GetHWNDFor(aAcc);
+  MOZ_ASSERT(hwnd);
+  if (!hwnd) {
+    return false;
+  }
+
+  long msaaId = MsaaAccessible::GetChildIDFor(aAcc);
+
+  DWORD ourPid = ::GetCurrentProcessId();
+
+  // The handler ends up calling NotifyWinEvent, which should only be done once
+  // since it broadcasts the same event to every process who is subscribed.
+  // OTOH, if our chrome process contains a handler, we should prefer to
+  // broadcast the event from that process, as we want any DLLs injected by ATs
+  // to receive the event synchronously. Otherwise we simply choose the first
+  // handler in the list, for the lack of a better heuristic.
+
+  nsTArray<HandlerControllerData>::index_type ctrlIndex =
+      sHandlerControllers->IndexOf(ourPid);
+
+  if (ctrlIndex == nsTArray<HandlerControllerData>::NoIndex) {
+    ctrlIndex = 0;
+  }
+
+  HandlerControllerData& controller = sHandlerControllers->ElementAt(ctrlIndex);
+  MOZ_ASSERT(controller.mPid);
+  MOZ_ASSERT(controller.mCtrl);
+
+  VARIANT_BOOL isInsert = aIsInsert ? VARIANT_TRUE : VARIANT_FALSE;
+
+  IA2TextSegment textSegment{
+      ::SysAllocStringLen(
+          reinterpret_cast<const wchar_t*>(aText.BeginReading()),
+          aText.Length()),
+      aStart, aStart + static_cast<long>(aLen)};
+
+  ASYNC_INVOKER_FOR(IHandlerControl)
+  invoker(controller.mCtrl, Some(controller.mIsProxy));
+
+  HRESULT hr = ASYNC_INVOKE(invoker, OnTextChange, PtrToLong(hwnd), msaaId,
+                            isInsert, &textSegment);
+
+  ::SysFreeString(textSegment.text);
+
+  return SUCCEEDED(hr);
+}
+
+/* static */
+void AccessibleWrap::SuppressHandlerA11yForClipboardCopy() {
+  if (!sHandlerControllers || sHandlerControllers->IsEmpty()) {
+    return;
+  }
+  // The original intent was that AccessibleHandler would be used in any
+  // process that wanted to access Gecko a11y. That didn't work out for various
+  // reasons. In practice, there is only a single AccessibleHandlerControl which
+  // is for our own parent process, used for in-process client calls. That also
+  // means we don't need to worry about async invokation here.
+  auto& controller = sHandlerControllers->ElementAt(0);
+  MOZ_ASSERT(controller.mPid == ::GetCurrentProcessId() &&
+             !controller.mIsProxy);
+  DebugOnly<HRESULT> hr = controller.mCtrl->SuppressA11yForClipboardCopy();
+  MOZ_ASSERT(SUCCEEDED(hr));
+}