gecko-dev/accessible/windows/msaa/Platform.cpp

/* -*- 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 "Platform.h"

#include "AccEvent.h"
#include "Compatibility.h"
#include "HyperTextAccessibleWrap.h"
#include "ia2AccessibleText.h"
#include "nsIWindowsRegKey.h"
#include "nsIXULRuntime.h"
#include "nsWinUtils.h"
#include "mozilla/a11y/ProxyAccessible.h"
#include "mozilla/mscom/ActivationContext.h"
#include "mozilla/mscom/InterceptorLog.h"
#include "mozilla/mscom/Registration.h"
#include "mozilla/mscom/Utils.h"
#include "mozilla/StaticPtr.h"
#include "mozilla/WindowsVersion.h"
#include "nsDirectoryServiceDefs.h"
#include "nsDirectoryServiceUtils.h"
#include "ProxyWrappers.h"

using namespace mozilla;
using namespace mozilla::a11y;
using namespace mozilla::mscom;

static StaticAutoPtr<RegisteredProxy> gRegCustomProxy;
static StaticAutoPtr<RegisteredProxy> gRegProxy;
static StaticAutoPtr<RegisteredProxy> gRegAccTlb;
static StaticAutoPtr<RegisteredProxy> gRegMiscTlb;
static nsString* gInstantiator = nullptr;

void
a11y::PlatformInit()
{
  nsWinUtils::MaybeStartWindowEmulation();
  ia2AccessibleText::InitTextChangeData();

  mscom::InterceptorLog::Init();
  UniquePtr<RegisteredProxy> regCustomProxy(
      mscom::RegisterProxy());
  gRegCustomProxy = regCustomProxy.release();
  UniquePtr<RegisteredProxy> regProxy(
      mscom::RegisterProxy(L"ia2marshal.dll"));
  gRegProxy = regProxy.release();
  UniquePtr<RegisteredProxy> regAccTlb(
      mscom::RegisterTypelib(L"oleacc.dll",
                             RegistrationFlags::eUseSystemDirectory));
  gRegAccTlb = regAccTlb.release();
  UniquePtr<RegisteredProxy> regMiscTlb(
      mscom::RegisterTypelib(L"Accessible.tlb"));
  gRegMiscTlb = regMiscTlb.release();
}

void
a11y::PlatformShutdown()
{
  ::DestroyCaret();

  nsWinUtils::ShutdownWindowEmulation();
  gRegCustomProxy = nullptr;
  gRegProxy = nullptr;
  gRegAccTlb = nullptr;
  gRegMiscTlb = nullptr;

  if (gInstantiator) {
    delete gInstantiator;
    gInstantiator = nullptr;
  }
}

void
a11y::ProxyCreated(ProxyAccessible* aProxy, uint32_t aInterfaces)
{
  AccessibleWrap* wrapper = nullptr;
  if (aInterfaces & Interfaces::DOCUMENT) {
    wrapper = new DocProxyAccessibleWrap(aProxy);
  } else if (aInterfaces & Interfaces::HYPERTEXT) {
    wrapper = new HyperTextProxyAccessibleWrap(aProxy);
  } else {
    wrapper = new ProxyAccessibleWrap(aProxy);
  }

  wrapper->SetProxyInterfaces(aInterfaces);
  wrapper->AddRef();
  aProxy->SetWrapper(reinterpret_cast<uintptr_t>(wrapper));
}

void
a11y::ProxyDestroyed(ProxyAccessible* aProxy)
{
  AccessibleWrap* wrapper =
    reinterpret_cast<AccessibleWrap*>(aProxy->GetWrapper());

  // If aProxy is a document that was created, but
  // RecvPDocAccessibleConstructor failed then aProxy->GetWrapper() will be
  // null.
  if (!wrapper)
    return;

  if (aProxy->IsDoc() && nsWinUtils::IsWindowEmulationStarted()) {
    aProxy->AsDoc()->SetEmulatedWindowHandle(nullptr);
  }

  wrapper->Shutdown();
  aProxy->SetWrapper(0);
  wrapper->Release();
}

void
a11y::ProxyEvent(ProxyAccessible* aTarget, uint32_t aEventType)
{
  AccessibleWrap::FireWinEvent(WrapperFor(aTarget), aEventType);
}

void
a11y::ProxyStateChangeEvent(ProxyAccessible* aTarget, uint64_t, bool)
{
  AccessibleWrap::FireWinEvent(WrapperFor(aTarget),
                               nsIAccessibleEvent::EVENT_STATE_CHANGE);
}

void
a11y::ProxyFocusEvent(ProxyAccessible* aTarget,
                      const LayoutDeviceIntRect& aCaretRect)
{
  AccessibleWrap::UpdateSystemCaretFor(aTarget, aCaretRect);
  AccessibleWrap::FireWinEvent(WrapperFor(aTarget),
                               nsIAccessibleEvent::EVENT_FOCUS);
}

void
a11y::ProxyCaretMoveEvent(ProxyAccessible* aTarget,
                          const LayoutDeviceIntRect& aCaretRect)
{
  AccessibleWrap::UpdateSystemCaretFor(aTarget, aCaretRect);
  AccessibleWrap::FireWinEvent(WrapperFor(aTarget),
                               nsIAccessibleEvent::EVENT_TEXT_CARET_MOVED);
}

void
a11y::ProxyTextChangeEvent(ProxyAccessible* aText, const nsString& aStr,
                           int32_t aStart, uint32_t aLen, bool aInsert, bool)
{
  AccessibleWrap* wrapper = WrapperFor(aText);
  MOZ_ASSERT(wrapper);
  if (!wrapper) {
    return;
  }

  static const bool useHandler =
    Preferences::GetBool("accessibility.handler.enabled", false) &&
    IsHandlerRegistered();

  if (useHandler) {
    wrapper->DispatchTextChangeToHandler(aInsert, aStr, aStart, aLen);
    return;
  }

  auto text = static_cast<HyperTextAccessibleWrap*>(wrapper->AsHyperText());
  if (text) {
    ia2AccessibleText::UpdateTextChangeData(text, aInsert, aStr, aStart, aLen);
  }

  uint32_t eventType = aInsert ? nsIAccessibleEvent::EVENT_TEXT_INSERTED :
    nsIAccessibleEvent::EVENT_TEXT_REMOVED;
  AccessibleWrap::FireWinEvent(wrapper, eventType);
}

void
a11y::ProxyShowHideEvent(ProxyAccessible* aTarget, ProxyAccessible*, bool aInsert, bool)
{
  uint32_t event = aInsert ? nsIAccessibleEvent::EVENT_SHOW :
    nsIAccessibleEvent::EVENT_HIDE;
  AccessibleWrap* wrapper = WrapperFor(aTarget);
  AccessibleWrap::FireWinEvent(wrapper, event);
}

void
a11y::ProxySelectionEvent(ProxyAccessible* aTarget, ProxyAccessible*, uint32_t aType)
{
  AccessibleWrap* wrapper = WrapperFor(aTarget);
  AccessibleWrap::FireWinEvent(wrapper, aType);
}

bool
a11y::IsHandlerRegistered()
{
  nsresult rv;
  nsCOMPtr<nsIWindowsRegKey> regKey =
    do_CreateInstance("@mozilla.org/windows-registry-key;1", &rv);
  if (NS_FAILED(rv)) {
    return false;
  }

  nsAutoString clsid;
  GUIDToString(CLSID_AccessibleHandler, clsid);

  nsAutoString subKey;
  subKey.AppendLiteral(u"SOFTWARE\\Classes\\CLSID\\");
  subKey.Append(clsid);
  subKey.AppendLiteral(u"\\InprocHandler32");

  rv = regKey->Open(nsIWindowsRegKey::ROOT_KEY_LOCAL_MACHINE, subKey,
                    nsIWindowsRegKey::ACCESS_READ);
  if (NS_FAILED(rv)) {
    return false;
  }

  nsAutoString handlerPath;
  rv = regKey->ReadStringValue(nsAutoString(), handlerPath);
  if (NS_FAILED(rv)) {
    return false;
  }

  nsCOMPtr<nsIFile> actualHandler;
  rv = NS_NewLocalFile(handlerPath, false, getter_AddRefs(actualHandler));
  if (NS_FAILED(rv)) {
    return false;
  }

  nsCOMPtr<nsIFile> expectedHandler;
  rv = NS_GetSpecialDirectory(NS_GRE_DIR, getter_AddRefs(expectedHandler));
  if (NS_FAILED(rv)) {
    return false;
  }

  rv = expectedHandler->Append(NS_LITERAL_STRING("AccessibleHandler.dll"));
  if (NS_FAILED(rv)) {
    return false;
  }

  bool equal;
  rv = expectedHandler->Equals(actualHandler, &equal);
  return NS_SUCCEEDED(rv) && equal;
}

void
a11y::SetInstantiator(const nsAString& aInstantiator)
{
  if (!gInstantiator) {
    gInstantiator = new nsString();
  }

  gInstantiator->Assign(aInstantiator);
}

bool
a11y::GetInstantiator(nsAString& aInstantiator)
{
  if (!gInstantiator) {
    return false;
  }

  aInstantiator.Assign(*gInstantiator);
  return true;
}