1 files changed, 181 insertions, 0 deletions
diff --git a/accessible/windows/msaa/Compatibility.cpp b/accessible/windows/msaa/Compatibility.cpp
new file mode 100644
index 0000000000..440f327520
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+++ b/accessible/windows/msaa/Compatibility.cpp
@@ -0,0 +1,181 @@
+/* -*- 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 "Compatibility.h"
+
+#include "mozilla/WindowsVersion.h"
+#include "mozilla/WinHeaderOnlyUtils.h"
+#include "mozilla/StaticPrefs_accessibility.h"
+#include "nsExceptionHandler.h"
+#include "nsIXULRuntime.h"
+#include "nsPrintfCString.h"
+#include "nsUnicharUtils.h"
+#include "nsWinUtils.h"
+#include "Statistics.h"
+#include "AccessibleWrap.h"
+
+#include "mozilla/Preferences.h"
+
+#include <shlobj.h>
+
+using namespace mozilla;
+using namespace mozilla::a11y;
+
+/**
+ * String versions of consumer flags. See GetHumanReadableConsumersStr.
+ */
+static const wchar_t* ConsumerStringMap[CONSUMERS_ENUM_LEN + 1] = {
+    L"NVDA",    L"JAWS",         L"OLDJAWS",       L"WE",       L"DOLPHIN",
+    L"SEROTEK", L"COBRA",        L"ZOOMTEXT",      L"KAZAGURU", L"YOUDAO",
+    L"UNKNOWN", L"UIAUTOMATION", L"VISPEROSHARED", L"\0"};
+
+bool Compatibility::IsModuleVersionLessThan(HMODULE aModuleHandle,
+                                            unsigned long long aVersion) {
+  LauncherResult<ModuleVersion> version = GetModuleVersion(aModuleHandle);
+  if (version.isErr()) {
+    return true;
+  }
+
+  return version.unwrap() < aVersion;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Compatibility
+////////////////////////////////////////////////////////////////////////////////
+
+uint32_t Compatibility::sConsumers = Compatibility::UNKNOWN;
+
+/**
+ * This function is safe to call multiple times.
+ */
+/* static */
+void Compatibility::InitConsumers() {
+  HMODULE jawsHandle = ::GetModuleHandleW(L"jhook");
+  if (jawsHandle) {
+    sConsumers |=
+        IsModuleVersionLessThan(jawsHandle, MAKE_FILE_VERSION(19, 0, 0, 0))
+            ? OLDJAWS
+            : JAWS;
+  }
+
+  if (::GetModuleHandleW(L"gwm32inc")) sConsumers |= WE;
+
+  if (::GetModuleHandleW(L"dolwinhk")) sConsumers |= DOLPHIN;
+
+  if (::GetModuleHandleW(L"STSA32")) sConsumers |= SEROTEK;
+
+  if (::GetModuleHandleW(L"nvdaHelperRemote")) sConsumers |= NVDA;
+
+  if (::GetModuleHandleW(L"OsmHooks") || ::GetModuleHandleW(L"OsmHks64"))
+    sConsumers |= COBRA;
+
+  if (::GetModuleHandleW(L"WebFinderRemote")) sConsumers |= ZOOMTEXT;
+
+  if (::GetModuleHandleW(L"Kazahook")) sConsumers |= KAZAGURU;
+
+  if (::GetModuleHandleW(L"TextExtractorImpl32") ||
+      ::GetModuleHandleW(L"TextExtractorImpl64"))
+    sConsumers |= YOUDAO;
+
+  if (::GetModuleHandleW(L"uiautomation") ||
+      ::GetModuleHandleW(L"uiautomationcore"))
+    sConsumers |= UIAUTOMATION;
+
+  if (::GetModuleHandleW(L"AccEventCache")) {
+    sConsumers |= VISPEROSHARED;
+  }
+
+  // If we have a known consumer remove the unknown bit.
+  if (sConsumers != Compatibility::UNKNOWN)
+    sConsumers &= ~Compatibility::UNKNOWN;
+}
+
+/* static */
+bool Compatibility::HasKnownNonUiaConsumer() {
+  InitConsumers();
+  return sConsumers & ~(Compatibility::UNKNOWN | UIAUTOMATION);
+}
+
+void Compatibility::Init() {
+  // Note we collect some AT statistics/telemetry here for convenience.
+  InitConsumers();
+
+  CrashReporter::AnnotateCrashReport(
+      CrashReporter::Annotation::AccessibilityInProcClient,
+      nsPrintfCString("0x%X", sConsumers));
+
+  // Gather telemetry
+  uint32_t temp = sConsumers;
+  for (int i = 0; temp; i++) {
+    if (temp & 0x1) statistics::A11yConsumers(i);
+
+    temp >>= 1;
+  }
+
+  // Turn off new tab switching for Jaws and WE.
+  if (sConsumers & (JAWS | OLDJAWS | WE)) {
+    // Check to see if the pref for disallowing CtrlTab is already set. If so,
+    // bail out (respect the user settings). If not, set it.
+    if (!Preferences::HasUserValue("browser.ctrlTab.disallowForScreenReaders"))
+      Preferences::SetBool("browser.ctrlTab.disallowForScreenReaders", true);
+  }
+}
+
+// static
+void Compatibility::GetHumanReadableConsumersStr(nsAString& aResult) {
+  bool appened = false;
+  uint32_t index = 0;
+  for (uint32_t consumers = sConsumers; consumers; consumers = consumers >> 1) {
+    if (consumers & 0x1) {
+      if (appened) {
+        aResult.AppendLiteral(",");
+      }
+      aResult.Append(ConsumerStringMap[index]);
+      appened = true;
+    }
+    if (++index > CONSUMERS_ENUM_LEN) {
+      break;
+    }
+  }
+}
+
+// Time when SuppressA11yForClipboardCopy() was called, as returned by
+// ::GetTickCount().
+static DWORD sA11yClipboardCopySuppressionStartTime = 0;
+
+/* static */
+void Compatibility::SuppressA11yForClipboardCopy() {
+  // Bug 1774285: Windows Suggested Actions (introduced in Windows 11 22H2)
+  // might walk the a11y tree using UIA whenever anything is copied to the
+  // clipboard. This causes an unacceptable hang, particularly when the cache
+  // is disabled.
+  bool doSuppress = [&] {
+    switch (
+        StaticPrefs::accessibility_windows_suppress_after_clipboard_copy()) {
+      case 0:
+        return false;
+      case 1:
+        return true;
+      default:
+        // Our workaround for Suggested Actions is needed from Windows 11 22H2
+        return IsWin1122H2OrLater();
+    }
+  }();
+
+  if (doSuppress) {
+    sA11yClipboardCopySuppressionStartTime = ::GetTickCount();
+  }
+}
+
+/* static */
+bool Compatibility::IsA11ySuppressedForClipboardCopy() {
+  constexpr DWORD kSuppressTimeout = 1500;  // ms
+  if (!sA11yClipboardCopySuppressionStartTime) {
+    return false;
+  }
+  return ::GetTickCount() - sA11yClipboardCopySuppressionStartTime <
+         kSuppressTimeout;
+}