Source code
Revision control
Copy as Markdown
Other Tools
/* -*- 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
#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::RecordAnnotationNSCString(
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;
}
}
}
struct SuppressionTimer {
constexpr SuppressionTimer() = default;
void Start() { mStart = ::GetTickCount(); }
bool IsActive(DWORD aTickCount) const {
return mStart && aTickCount - mStart < kSuppressTimeout;
}
// Last time Start() was called, as returned by ::GetTickCount().
DWORD mStart = 0;
static constexpr DWORD kSuppressTimeout = 1500; // ms
};
static SuppressionTimer sClipboardSuppressionTimer;
static SuppressionTimer sSnapLayoutsSuppressionTimer;
/* static */
void Compatibility::SuppressA11yForClipboardCopy() {
// 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) {
sClipboardSuppressionTimer.Start();
}
}
/* static */
void Compatibility::SuppressA11yForSnapLayouts() {
// position.
bool doSuppress = [&] {
switch (StaticPrefs::accessibility_windows_suppress_for_snap_layout()) {
case 0:
return false;
case 1:
return true;
default:
// Our workaround for Snap Layouts is needed from Windows 11 22H2
return IsWin1122H2OrLater();
}
}();
if (doSuppress) {
sSnapLayoutsSuppressionTimer.Start();
}
}
/* static */
SuppressionReasons Compatibility::A11ySuppressionReasons() {
const auto now = ::GetTickCount();
auto reasons = SuppressionReasons::None;
if (sClipboardSuppressionTimer.IsActive(now)) {
reasons |= SuppressionReasons::Clipboard;
}
if (sSnapLayoutsSuppressionTimer.IsActive(now)) {
reasons |= SuppressionReasons::SnapLayouts;
}
return reasons;
}