nsBaseWidget.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=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 "mozilla/ArrayUtils.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/TextEventDispatcher.h"
#include "mozilla/TextEventDispatcherListener.h"

#include "mozilla/layers/CompositorBridgeChild.h"
#include "mozilla/layers/CompositorBridgeParent.h"
#include "mozilla/layers/PLayerTransactionChild.h"
#include "mozilla/layers/ImageBridgeChild.h"
#include "LiveResizeListener.h"
#include "nsBaseWidget.h"
#include "nsDeviceContext.h"
#include "nsCOMPtr.h"
#include "nsGfxCIID.h"
#include "nsWidgetsCID.h"
#include "nsServiceManagerUtils.h"
#include "nsIKeyEventInPluginCallback.h"
#include "nsIScreenManager.h"
#include "nsAppDirectoryServiceDefs.h"
#include "nsISimpleEnumerator.h"
#include "nsIContent.h"
#include "nsIDocument.h"
#include "nsIPresShell.h"
#include "nsIServiceManager.h"
#include "mozilla/Preferences.h"
#include "BasicLayers.h"
#include "ClientLayerManager.h"
#include "mozilla/layers/Compositor.h"
#include "nsIXULRuntime.h"
#include "nsIXULWindow.h"
#include "nsIBaseWindow.h"
#include "nsXULPopupManager.h"
#include "nsXBLWindowKeyHandler.h"
#include "nsIWidgetListener.h"
#include "nsIGfxInfo.h"
#include "npapi.h"
#include "X11UndefineNone.h"
#include "base/thread.h"
#include "prdtoa.h"
#include "prenv.h"
#include "mozilla/Attributes.h"
#include "mozilla/Unused.h"
#include "nsContentUtils.h"
#include "gfxPrefs.h"
#include "mozilla/gfx/2D.h"
#include "mozilla/MouseEvents.h"
#include "GLConsts.h"
#include "mozilla/Unused.h"
#include "mozilla/IMEStateManager.h"
#include "mozilla/VsyncDispatcher.h"
#include "mozilla/layers/IAPZCTreeManager.h"
#include "mozilla/layers/APZEventState.h"
#include "mozilla/layers/APZInputBridge.h"
#include "mozilla/layers/APZThreadUtils.h"
#include "mozilla/layers/ChromeProcessController.h"
#include "mozilla/layers/CompositorOptions.h"
#include "mozilla/layers/InputAPZContext.h"
#include "mozilla/layers/APZCCallbackHelper.h"
#include "mozilla/layers/WebRenderLayerManager.h"
#include "mozilla/dom/ContentChild.h"
#include "mozilla/dom/TabParent.h"
#include "mozilla/gfx/GPUProcessManager.h"
#include "mozilla/gfx/gfxVars.h"
#include "mozilla/Move.h"
#include "mozilla/Services.h"
#include "mozilla/Sprintf.h"
#include "mozilla/webrender/WebRenderTypes.h"
#include "nsRefPtrHashtable.h"
#include "TouchEvents.h"
#include "WritingModes.h"
#include "InputData.h"
#include "FrameLayerBuilder.h"
#ifdef ACCESSIBILITY
#include "nsAccessibilityService.h"
#endif
#include "gfxConfig.h"
#include "mozilla/layers/CompositorSession.h"
#include "VRManagerChild.h"
#include "gfxConfig.h"
#include "nsView.h"
#include "nsViewManager.h"

#ifdef DEBUG
#include "nsIObserver.h"

static void debug_RegisterPrefCallbacks();

#endif

#ifdef NOISY_WIDGET_LEAKS
static int32_t gNumWidgets;
#endif

#ifdef XP_MACOSX
#include "nsCocoaFeatures.h"
#endif

#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
static nsRefPtrHashtable<nsVoidPtrHashKey, nsIWidget>* sPluginWidgetList;
#endif

nsIRollupListener* nsBaseWidget::gRollupListener = nullptr;

using namespace mozilla::dom;
using namespace mozilla::layers;
using namespace mozilla::ipc;
using namespace mozilla::widget;
using namespace mozilla;
using base::Thread;

// Global user preference for disabling native theme. Used
// in NativeWindowTheme.
bool            gDisableNativeTheme               = false;

// Async pump timer during injected long touch taps
#define TOUCH_INJECT_PUMP_TIMER_MSEC 50
#define TOUCH_INJECT_LONG_TAP_DEFAULT_MSEC 1500
int32_t nsIWidget::sPointerIdCounter = 0;

// Some statics from nsIWidget.h
/*static*/ uint64_t AutoObserverNotifier::sObserverId = 0;
/*static*/ nsDataHashtable<nsUint64HashKey, nsCOMPtr<nsIObserver>> AutoObserverNotifier::sSavedObservers;

// The maximum amount of time to let the EnableDragDrop runnable wait in the
// idle queue before timing out and moving it to the regular queue. Value is in
// milliseconds.
const uint32_t kAsyncDragDropTimeout = 1000;

namespace mozilla {
namespace widget {

void
IMENotification::SelectionChangeDataBase::SetWritingMode(
                                        const WritingMode& aWritingMode)
{
  mWritingMode = aWritingMode.mWritingMode;
}

WritingMode
IMENotification::SelectionChangeDataBase::GetWritingMode() const
{
  return WritingMode(mWritingMode);
}

} // namespace widget
} // namespace mozilla

NS_IMPL_ISUPPORTS(nsBaseWidget, nsIWidget, nsISupportsWeakReference)

//-------------------------------------------------------------------------
//
// nsBaseWidget constructor
//
//-------------------------------------------------------------------------

nsBaseWidget::nsBaseWidget()
: mWidgetListener(nullptr)
, mAttachedWidgetListener(nullptr)
, mPreviouslyAttachedWidgetListener(nullptr)
, mLayerManager(nullptr)
, mCompositorVsyncDispatcher(nullptr)
, mCursor(eCursor_standard)
, mBorderStyle(eBorderStyle_none)
, mBounds(0,0,0,0)
, mOriginalBounds(nullptr)
, mClipRectCount(0)
, mSizeMode(nsSizeMode_Normal)
, mPopupLevel(ePopupLevelTop)
, mPopupType(ePopupTypeAny)
, mHasRemoteContent(false)
, mUpdateCursor(true)
, mUseAttachedEvents(false)
, mIMEHasFocus(false)
, mIsFullyOccluded(false)
{
#ifdef NOISY_WIDGET_LEAKS
  gNumWidgets++;
  printf("WIDGETS+ = %d\n", gNumWidgets);
#endif

#ifdef DEBUG
  debug_RegisterPrefCallbacks();
#endif

#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
  if (!sPluginWidgetList) {
    sPluginWidgetList = new nsRefPtrHashtable<nsVoidPtrHashKey, nsIWidget>();
  }
#endif
  mShutdownObserver = new WidgetShutdownObserver(this);
}

NS_IMPL_ISUPPORTS(WidgetShutdownObserver, nsIObserver)

WidgetShutdownObserver::WidgetShutdownObserver(nsBaseWidget* aWidget) :
  mWidget(aWidget),
  mRegistered(false)
{
  Register();
}

WidgetShutdownObserver::~WidgetShutdownObserver()
{
  // No need to call Unregister(), we can't be destroyed until nsBaseWidget
  // gets torn down. The observer service and nsBaseWidget have a ref on us
  // so nsBaseWidget has to call Unregister and then clear its ref.
}

NS_IMETHODIMP
WidgetShutdownObserver::Observe(nsISupports *aSubject,
                                const char *aTopic,
                                const char16_t *aData)
{
  if (mWidget && !strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
    RefPtr<nsBaseWidget> widget(mWidget);
    widget->Shutdown();
  }
  return NS_OK;
}

void
WidgetShutdownObserver::Register()
{
  if (!mRegistered) {
    mRegistered = true;
    nsContentUtils::RegisterShutdownObserver(this);
  }
}

void
WidgetShutdownObserver::Unregister()
{
  if (mRegistered) {
    mWidget = nullptr;
    nsContentUtils::UnregisterShutdownObserver(this);
    mRegistered = false;
  }
}

void
nsBaseWidget::Shutdown()
{
  NotifyLiveResizeStopped();
  RevokeTransactionIdAllocator();
  DestroyCompositor();
  FreeShutdownObserver();
#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
  if (sPluginWidgetList) {
    delete sPluginWidgetList;
    sPluginWidgetList = nullptr;
  }
#endif
}

void nsBaseWidget::DestroyCompositor()
{
  // We release this before releasing the compositor, since it may hold the
  // last reference to our ClientLayerManager. ClientLayerManager's dtor can
  // trigger a paint, creating a new compositor, and we don't want to re-use
  // the old vsync dispatcher.
  if (mCompositorVsyncDispatcher) {
    MOZ_ASSERT(mCompositorVsyncDispatcherLock.get());

    MutexAutoLock lock(*mCompositorVsyncDispatcherLock.get());
    mCompositorVsyncDispatcher->Shutdown();
    mCompositorVsyncDispatcher = nullptr;
  }

  // The compositor shutdown sequence looks like this:
  //  1. CompositorSession calls CompositorBridgeChild::Destroy.
  //  2. CompositorBridgeChild synchronously sends WillClose.
  //  3. CompositorBridgeParent releases some resources (such as the layer
  //     manager, compositor, and widget).
  //  4. CompositorBridgeChild::Destroy returns.
  //  5. Asynchronously, CompositorBridgeParent::ActorDestroy will fire on the
  //     compositor thread when the I/O thread closes the IPC channel.
  //  6. Step 5 will schedule DeferredDestroy on the compositor thread, which
  //     releases the reference CompositorBridgeParent holds to itself.
  //
  // When CompositorSession::Shutdown returns, we assume the compositor is gone
  // or will be gone very soon.
  if (mCompositorSession) {
    ReleaseContentController();
    mAPZC = nullptr;
    SetCompositorWidgetDelegate(nullptr);
    mCompositorBridgeChild = nullptr;

    // XXX CompositorBridgeChild and CompositorBridgeParent might be re-created in
    // ClientLayerManager destructor. See bug 1133426.
    RefPtr<CompositorSession> session = mCompositorSession.forget();
    session->Shutdown();
  }
}

// This prevents the layer manager from starting a new transaction during
// shutdown.
void
nsBaseWidget::RevokeTransactionIdAllocator()
{
  if (!mLayerManager) {
    return;
  }
  mLayerManager->SetTransactionIdAllocator(nullptr);
}

void nsBaseWidget::ReleaseContentController()
{
  if (mRootContentController) {
    mRootContentController->Destroy();
    mRootContentController = nullptr;
  }
}

void nsBaseWidget::DestroyLayerManager()
{
  if (mLayerManager) {
    mLayerManager->Destroy();
    mLayerManager = nullptr;
  }
  DestroyCompositor();
}

void
nsBaseWidget::OnRenderingDeviceReset()
{
  DestroyLayerManager();
}

void
nsBaseWidget::FreeShutdownObserver()
{
  if (mShutdownObserver) {
    mShutdownObserver->Unregister();
  }
  mShutdownObserver = nullptr;
}

//-------------------------------------------------------------------------
//
// nsBaseWidget destructor
//
//-------------------------------------------------------------------------

nsBaseWidget::~nsBaseWidget()
{
  IMEStateManager::WidgetDestroyed(this);

  if (mLayerManager) {
    if (BasicLayerManager* mgr = mLayerManager->AsBasicLayerManager()) {
      mgr->ClearRetainerWidget();
    }
  }

  FreeShutdownObserver();
  RevokeTransactionIdAllocator();
  DestroyLayerManager();

#ifdef NOISY_WIDGET_LEAKS
  gNumWidgets--;
  printf("WIDGETS- = %d\n", gNumWidgets);
#endif

  delete mOriginalBounds;
}

//-------------------------------------------------------------------------
//
// Basic create.
//
//-------------------------------------------------------------------------
void nsBaseWidget::BaseCreate(nsIWidget* aParent,
                              nsWidgetInitData* aInitData)
{
  static bool gDisableNativeThemeCached = false;
  if (!gDisableNativeThemeCached) {
    Preferences::AddBoolVarCache(&gDisableNativeTheme,
                                 "mozilla.widget.disable-native-theme",
                                 gDisableNativeTheme);
    gDisableNativeThemeCached = true;
  }

  // keep a reference to the device context
  if (nullptr != aInitData) {
    mWindowType = aInitData->mWindowType;
    mBorderStyle = aInitData->mBorderStyle;
    mPopupLevel = aInitData->mPopupLevel;
    mPopupType = aInitData->mPopupHint;
    mHasRemoteContent = aInitData->mHasRemoteContent;
  }

  if (aParent) {
    aParent->AddChild(this);
  }
}

//-------------------------------------------------------------------------
//
// Accessor functions to get/set the client data
//
//-------------------------------------------------------------------------

nsIWidgetListener* nsBaseWidget::GetWidgetListener()
{
  return mWidgetListener;
}

void nsBaseWidget::SetWidgetListener(nsIWidgetListener* aWidgetListener)
{
  mWidgetListener = aWidgetListener;
}

already_AddRefed<nsIWidget>
nsBaseWidget::CreateChild(const LayoutDeviceIntRect& aRect,
                          nsWidgetInitData* aInitData,
                          bool aForceUseIWidgetParent)
{
  nsIWidget* parent = this;
  nsNativeWidget nativeParent = nullptr;

  if (!aForceUseIWidgetParent) {
    // Use only either parent or nativeParent, not both, to match
    // existing code.  Eventually Create() should be divested of its
    // nativeWidget parameter.
    nativeParent = parent ? parent->GetNativeData(NS_NATIVE_WIDGET) : nullptr;
    parent = nativeParent ? nullptr : parent;
    MOZ_ASSERT(!parent || !nativeParent, "messed up logic");
  }

  nsCOMPtr<nsIWidget> widget;
  if (aInitData && aInitData->mWindowType == eWindowType_popup) {
    widget = AllocateChildPopupWidget();
  } else {
    widget = nsIWidget::CreateChildWindow();
  }

  if (widget &&
      NS_SUCCEEDED(widget->Create(parent, nativeParent, aRect, aInitData))) {
    return widget.forget();
  }

  return nullptr;
}

// Attach a view to our widget which we'll send events to.
void
nsBaseWidget::AttachViewToTopLevel(bool aUseAttachedEvents)
{
  NS_ASSERTION((mWindowType == eWindowType_toplevel ||
                mWindowType == eWindowType_dialog ||
                mWindowType == eWindowType_invisible ||
                mWindowType == eWindowType_child),
               "Can't attach to window of that type");

  mUseAttachedEvents = aUseAttachedEvents;
}

nsIWidgetListener* nsBaseWidget::GetAttachedWidgetListener()
 {
   return mAttachedWidgetListener;
 }

nsIWidgetListener* nsBaseWidget::GetPreviouslyAttachedWidgetListener()
 {
   return mPreviouslyAttachedWidgetListener;
 }

void nsBaseWidget::SetPreviouslyAttachedWidgetListener(nsIWidgetListener* aListener)
 {
   mPreviouslyAttachedWidgetListener = aListener;
 }

void nsBaseWidget::SetAttachedWidgetListener(nsIWidgetListener* aListener)
 {
   mAttachedWidgetListener = aListener;
 }

//-------------------------------------------------------------------------
//
// Close this nsBaseWidget
//
//-------------------------------------------------------------------------
void nsBaseWidget::Destroy()
{
  // Just in case our parent is the only ref to us
  nsCOMPtr<nsIWidget> kungFuDeathGrip(this);
  // disconnect from the parent
  nsIWidget *parent = GetParent();
  if (parent) {
    parent->RemoveChild(this);
  }

#if defined(XP_WIN)
  // Allow our scroll capture container to be cleaned up, if we have one.
  mScrollCaptureContainer = nullptr;
#endif
}

//-------------------------------------------------------------------------
//
// Get this nsBaseWidget parent
//
//-------------------------------------------------------------------------
nsIWidget* nsBaseWidget::GetParent(void)
{
  return nullptr;
}

//-------------------------------------------------------------------------
//
// Get this nsBaseWidget top level widget
//
//-------------------------------------------------------------------------
nsIWidget* nsBaseWidget::GetTopLevelWidget()
{
  nsIWidget *topLevelWidget = nullptr, *widget = this;
  while (widget) {
    topLevelWidget = widget;
    widget = widget->GetParent();
  }
  return topLevelWidget;
}

//-------------------------------------------------------------------------
//
// Get this nsBaseWidget's top (non-sheet) parent (if it's a sheet)
//
//-------------------------------------------------------------------------
nsIWidget* nsBaseWidget::GetSheetWindowParent(void)
{
  return nullptr;
}

float nsBaseWidget::GetDPI()
{
  return 96.0f;
}

CSSToLayoutDeviceScale nsIWidget::GetDefaultScale()
{
  double devPixelsPerCSSPixel = DefaultScaleOverride();

  if (devPixelsPerCSSPixel <= 0.0) {
    devPixelsPerCSSPixel = GetDefaultScaleInternal();
  }

  return CSSToLayoutDeviceScale(devPixelsPerCSSPixel);
}

/* static */
double nsIWidget::DefaultScaleOverride()
{
  // The number of device pixels per CSS pixel. A value <= 0 means choose
  // automatically based on the DPI. A positive value is used as-is. This effectively
  // controls the size of a CSS "px".
  static float devPixelsPerCSSPixel = -1.0f;

  static bool valueCached = false;
  if (!valueCached) {
    Preferences::AddFloatVarCache(&devPixelsPerCSSPixel,
                                  "layout.css.devPixelsPerPx", -1.0f);
    valueCached = true;
  }

  return devPixelsPerCSSPixel;
}

//-------------------------------------------------------------------------
//
// Add a child to the list of children
//
//-------------------------------------------------------------------------
void nsBaseWidget::AddChild(nsIWidget* aChild)
{
  MOZ_ASSERT(!aChild->GetNextSibling() && !aChild->GetPrevSibling(),
             "aChild not properly removed from its old child list");

  if (!mFirstChild) {
    mFirstChild = mLastChild = aChild;
  } else {
    // append to the list
    MOZ_ASSERT(mLastChild);
    MOZ_ASSERT(!mLastChild->GetNextSibling());
    mLastChild->SetNextSibling(aChild);
    aChild->SetPrevSibling(mLastChild);
    mLastChild = aChild;
  }
}


//-------------------------------------------------------------------------
//
// Remove a child from the list of children
//
//-------------------------------------------------------------------------
void nsBaseWidget::RemoveChild(nsIWidget* aChild)
{
#ifdef DEBUG
#ifdef XP_MACOSX
  // nsCocoaWindow doesn't implement GetParent, so in that case parent will be
  // null and we'll just have to do without this assertion.
  nsIWidget* parent = aChild->GetParent();
  NS_ASSERTION(!parent || parent == this, "Not one of our kids!");
#else
  MOZ_RELEASE_ASSERT(aChild->GetParent() == this, "Not one of our kids!");
#endif
#endif

  if (mLastChild == aChild) {
    mLastChild = mLastChild->GetPrevSibling();
  }
  if (mFirstChild == aChild) {
    mFirstChild = mFirstChild->GetNextSibling();
  }

  // Now remove from the list.  Make sure that we pass ownership of the tail
  // of the list correctly before we have aChild let go of it.
  nsIWidget* prev = aChild->GetPrevSibling();
  nsIWidget* next = aChild->GetNextSibling();
  if (prev) {
    prev->SetNextSibling(next);
  }
  if (next) {
    next->SetPrevSibling(prev);
  }

  aChild->SetNextSibling(nullptr);
  aChild->SetPrevSibling(nullptr);
}


//-------------------------------------------------------------------------
//
// Sets widget's position within its parent's child list.
//
//-------------------------------------------------------------------------
void nsBaseWidget::SetZIndex(int32_t aZIndex)
{
  // Hold a ref to ourselves just in case, since we're going to remove
  // from our parent.
  nsCOMPtr<nsIWidget> kungFuDeathGrip(this);

  mZIndex = aZIndex;

  // reorder this child in its parent's list.
  auto* parent = static_cast<nsBaseWidget*>(GetParent());
  if (parent) {
    parent->RemoveChild(this);
    // Scope sib outside the for loop so we can check it afterward
    nsIWidget* sib = parent->GetFirstChild();
    for ( ; sib; sib = sib->GetNextSibling()) {
      int32_t childZIndex = GetZIndex();
      if (aZIndex < childZIndex) {
        // Insert ourselves before sib
        nsIWidget* prev = sib->GetPrevSibling();
        mNextSibling = sib;
        mPrevSibling = prev;
        sib->SetPrevSibling(this);
        if (prev) {
          prev->SetNextSibling(this);
        } else {
          NS_ASSERTION(sib == parent->mFirstChild, "Broken child list");
          // We've taken ownership of sib, so it's safe to have parent let
          // go of it
          parent->mFirstChild = this;
        }
        PlaceBehind(eZPlacementBelow, sib, false);
        break;
      }
    }
    // were we added to the list?
    if (!sib) {
      parent->AddChild(this);
    }
  }
}

//-------------------------------------------------------------------------
//
// Maximize, minimize or restore the window. The BaseWidget implementation
// merely stores the state.
//
//-------------------------------------------------------------------------
void
nsBaseWidget::SetSizeMode(nsSizeMode aMode)
{
  MOZ_ASSERT(aMode == nsSizeMode_Normal ||
             aMode == nsSizeMode_Minimized ||
             aMode == nsSizeMode_Maximized ||
             aMode == nsSizeMode_Fullscreen);
  mSizeMode = aMode;
}

//-------------------------------------------------------------------------
//
// Get this component cursor
//
//-------------------------------------------------------------------------

void
nsBaseWidget::SetCursor(nsCursor aCursor)
{
  mCursor = aCursor;
}

nsresult
nsBaseWidget::SetCursor(imgIContainer* aCursor,
                        uint32_t aHotspotX, uint32_t aHotspotY)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

//-------------------------------------------------------------------------
//
// Window transparency methods
//
//-------------------------------------------------------------------------

void nsBaseWidget::SetTransparencyMode(nsTransparencyMode aMode) {
}

nsTransparencyMode nsBaseWidget::GetTransparencyMode() {
  return eTransparencyOpaque;
}

bool
nsBaseWidget::IsWindowClipRegionEqual(const nsTArray<LayoutDeviceIntRect>& aRects)
{
  return mClipRects &&
         mClipRectCount == aRects.Length() &&
         memcmp(mClipRects.get(), aRects.Elements(), sizeof(LayoutDeviceIntRect)*mClipRectCount) == 0;
}

void
nsBaseWidget::StoreWindowClipRegion(const nsTArray<LayoutDeviceIntRect>& aRects)
{
  mClipRectCount = aRects.Length();
  mClipRects = MakeUnique<LayoutDeviceIntRect[]>(mClipRectCount);
  if (mClipRects) {
    memcpy(mClipRects.get(), aRects.Elements(), sizeof(LayoutDeviceIntRect)*mClipRectCount);
  }
}

void
nsBaseWidget::GetWindowClipRegion(nsTArray<LayoutDeviceIntRect>* aRects)
{
  if (mClipRects) {
    aRects->AppendElements(mClipRects.get(), mClipRectCount);
  } else {
    aRects->AppendElement(LayoutDeviceIntRect(0, 0, mBounds.Width(), mBounds.Height()));
  }
}

const LayoutDeviceIntRegion
nsBaseWidget::RegionFromArray(const nsTArray<LayoutDeviceIntRect>& aRects)
{
  LayoutDeviceIntRegion region;
  for (uint32_t i = 0; i < aRects.Length(); ++i) {
    region.Or(region, aRects[i]);
  }
  return region;
}

void
nsBaseWidget::ArrayFromRegion(const LayoutDeviceIntRegion& aRegion,
                              nsTArray<LayoutDeviceIntRect>& aRects)
{
  for (auto iter = aRegion.RectIter(); !iter.Done(); iter.Next()) {
    aRects.AppendElement(iter.Get());
  }
}

nsresult
nsBaseWidget::SetWindowClipRegion(const nsTArray<LayoutDeviceIntRect>& aRects,
                                  bool aIntersectWithExisting)
{
  if (!aIntersectWithExisting) {
    StoreWindowClipRegion(aRects);
  } else {
    // get current rects
    nsTArray<LayoutDeviceIntRect> currentRects;
    GetWindowClipRegion(&currentRects);
    // create region from them
    LayoutDeviceIntRegion currentRegion = RegionFromArray(currentRects);
    // create region from new rects
    LayoutDeviceIntRegion newRegion = RegionFromArray(aRects);
    // intersect regions
    LayoutDeviceIntRegion intersection;
    intersection.And(currentRegion, newRegion);
    // create int rect array from intersection
    nsTArray<LayoutDeviceIntRect> rects;
    ArrayFromRegion(intersection, rects);
    // store
    StoreWindowClipRegion(rects);
  }
  return NS_OK;
}

/* virtual */ void
nsBaseWidget::PerformFullscreenTransition(FullscreenTransitionStage aStage,
                                          uint16_t aDuration,
                                          nsISupports* aData,
                                          nsIRunnable* aCallback)
{
  MOZ_ASSERT_UNREACHABLE(
    "Should never call PerformFullscreenTransition on nsBaseWidget");
}

//-------------------------------------------------------------------------
//
// Put the window into full-screen mode
//
//-------------------------------------------------------------------------
void
nsBaseWidget::InfallibleMakeFullScreen(bool aFullScreen, nsIScreen* aScreen)
{
  HideWindowChrome(aFullScreen);

  if (aFullScreen) {
    if (!mOriginalBounds) {
      mOriginalBounds = new LayoutDeviceIntRect();
    }
    *mOriginalBounds = GetScreenBounds();

    // Move to top-left corner of screen and size to the screen dimensions
    nsCOMPtr<nsIScreen> screen = aScreen;
    if (!screen) {
      screen = GetWidgetScreen();
    }
    if (screen) {
      int32_t left, top, width, height;
      if (NS_SUCCEEDED(screen->GetRectDisplayPix(&left, &top, &width, &height))) {
        Resize(left, top, width, height, true);
      }
    }
  } else if (mOriginalBounds) {
    if (BoundsUseDesktopPixels()) {
      DesktopRect deskRect = *mOriginalBounds / GetDesktopToDeviceScale();
      Resize(deskRect.X(), deskRect.Y(),
	     deskRect.Width(), deskRect.Height(), true);
    } else {
      Resize(mOriginalBounds->X(), mOriginalBounds->Y(),
	     mOriginalBounds->Width(), mOriginalBounds->Height(), true);
    }
  }
}

nsresult
nsBaseWidget::MakeFullScreen(bool aFullScreen, nsIScreen* aScreen)
{
  InfallibleMakeFullScreen(aFullScreen, aScreen);
  return NS_OK;
}

nsBaseWidget::AutoLayerManagerSetup::AutoLayerManagerSetup(
    nsBaseWidget* aWidget, gfxContext* aTarget,
    BufferMode aDoubleBuffering, ScreenRotation aRotation)
  : mWidget(aWidget)
{
  LayerManager* lm = mWidget->GetLayerManager();
  NS_ASSERTION(!lm || lm->GetBackendType() == LayersBackend::LAYERS_BASIC,
    "AutoLayerManagerSetup instantiated for non-basic layer backend!");
  if (lm) {
    mLayerManager = lm->AsBasicLayerManager();
    if (mLayerManager) {
      mLayerManager->SetDefaultTarget(aTarget);
      mLayerManager->SetDefaultTargetConfiguration(aDoubleBuffering, aRotation);
    }
  }
}

nsBaseWidget::AutoLayerManagerSetup::~AutoLayerManagerSetup()
{
  if (mLayerManager) {
    mLayerManager->SetDefaultTarget(nullptr);
    mLayerManager->SetDefaultTargetConfiguration(mozilla::layers::BufferMode::BUFFER_NONE, ROTATION_0);
  }
}

bool nsBaseWidget::IsSmallPopup() const
{
  return mWindowType == eWindowType_popup && mPopupType != ePopupTypePanel;
}

bool
nsBaseWidget::ComputeShouldAccelerate()
{
  if (gfx::gfxVars::UseWebRender() && !AllowWebRenderForThisWindow()) {
    // If WebRender is enabled, non-WebRender widgets use the basic compositor
    // (at least for now), even though they would get an accelerated compositor
    // if WebRender wasn't enabled.
    return false;
  }
  return gfx::gfxConfig::IsEnabled(gfx::Feature::HW_COMPOSITING) &&
         WidgetTypeSupportsAcceleration();
}

bool
nsBaseWidget::UseAPZ()
{
  return (gfxPlatform::AsyncPanZoomEnabled() &&
          (WindowType() == eWindowType_toplevel ||
           WindowType() == eWindowType_child ||
           (WindowType() == eWindowType_popup && HasRemoteContent() &&
            gfxPrefs::APZPopupsEnabled())));
}

bool
nsBaseWidget::AllowWebRenderForThisWindow()
{
  return WindowType() == eWindowType_toplevel ||
         WindowType() == eWindowType_child ||
         WindowType() == eWindowType_dialog ||
         (WindowType() == eWindowType_popup && HasRemoteContent());
}

void nsBaseWidget::CreateCompositor()
{
  LayoutDeviceIntRect rect = GetBounds();
  CreateCompositor(rect.Width(), rect.Height());
}

already_AddRefed<GeckoContentController>
nsBaseWidget::CreateRootContentController()
{
  RefPtr<GeckoContentController> controller = new ChromeProcessController(this, mAPZEventState, mAPZC);
  return controller.forget();
}

void nsBaseWidget::ConfigureAPZCTreeManager()
{
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(mAPZC);

  ConfigureAPZControllerThread();

  float dpi = GetDPI();
  // On Android the main thread is not the controller thread
  APZThreadUtils::RunOnControllerThread(NewRunnableMethod<float>(
      "layers::IAPZCTreeManager::SetDPI",
      mAPZC,
      &IAPZCTreeManager::SetDPI,
      dpi));

  if (gfxPrefs::APZKeyboardEnabled()) {
    KeyboardMap map = nsXBLWindowKeyHandler::CollectKeyboardShortcuts();
    // On Android the main thread is not the controller thread
    APZThreadUtils::RunOnControllerThread(NewRunnableMethod<KeyboardMap>(
        "layers::IAPZCTreeManager::SetKeyboardMap",
        mAPZC,
        &IAPZCTreeManager::SetKeyboardMap,
        map));
  }

  RefPtr<IAPZCTreeManager> treeManager = mAPZC;  // for capture by the lambdas

  ContentReceivedInputBlockCallback callback(
      [treeManager](const ScrollableLayerGuid& aGuid,
                    uint64_t aInputBlockId,
                    bool aPreventDefault)
      {
        MOZ_ASSERT(NS_IsMainThread());
        APZThreadUtils::RunOnControllerThread(NewRunnableMethod<uint64_t, bool>(
          "layers::IAPZCTreeManager::ContentReceivedInputBlock",
          treeManager,
          &IAPZCTreeManager::ContentReceivedInputBlock,
          aInputBlockId,
          aPreventDefault));
      });
  mAPZEventState = new APZEventState(this, std::move(callback));

  mSetAllowedTouchBehaviorCallback = [treeManager](uint64_t aInputBlockId,
                                                   const nsTArray<TouchBehaviorFlags>& aFlags)
  {
    MOZ_ASSERT(NS_IsMainThread());
    APZThreadUtils::RunOnControllerThread(
      NewRunnableMethod<uint64_t,
                        StoreCopyPassByLRef<nsTArray<TouchBehaviorFlags>>>(
        "layers::IAPZCTreeManager::SetAllowedTouchBehavior",
        treeManager,
        &IAPZCTreeManager::SetAllowedTouchBehavior,
        aInputBlockId,
        aFlags));
  };

  mRootContentController = CreateRootContentController();
  if (mRootContentController) {
    mCompositorSession->SetContentController(mRootContentController);
  }

  // When APZ is enabled, we can actually enable raw touch events because we
  // have code that can deal with them properly. If APZ is not enabled, this
  // function doesn't get called.
  if (Preferences::GetInt("dom.w3c_touch_events.enabled", 0) ||
      Preferences::GetBool("dom.w3c_pointer_events.enabled", false)) {
    RegisterTouchWindow();
  }
}

void nsBaseWidget::ConfigureAPZControllerThread()
{
  // By default the controller thread is the main thread.
  APZThreadUtils::SetControllerThread(MessageLoop::current());
}

void
nsBaseWidget::SetConfirmedTargetAPZC(uint64_t aInputBlockId,
                                     const nsTArray<ScrollableLayerGuid>& aTargets) const
{
  APZThreadUtils::RunOnControllerThread(
    NewRunnableMethod<uint64_t,
                      StoreCopyPassByRRef<nsTArray<ScrollableLayerGuid>>>(
      "layers::IAPZCTreeManager::SetTargetAPZC",
      mAPZC,
      &IAPZCTreeManager::SetTargetAPZC,
      aInputBlockId,
      aTargets));
}

void
nsBaseWidget::UpdateZoomConstraints(const uint32_t& aPresShellId,
                                    const ScrollableLayerGuid::ViewID& aViewId,
                                    const Maybe<ZoomConstraints>& aConstraints)
{
  if (!mCompositorSession || !mAPZC) {
    if (mInitialZoomConstraints) {
      MOZ_ASSERT(mInitialZoomConstraints->mPresShellID == aPresShellId);
      MOZ_ASSERT(mInitialZoomConstraints->mViewID == aViewId);
      if (!aConstraints) {
        mInitialZoomConstraints.reset();
      }
    }

    if (aConstraints) {
      // We have some constraints, but the compositor and APZC aren't created yet.
      // Save these so we can use them later.
      mInitialZoomConstraints = Some(InitialZoomConstraints(aPresShellId, aViewId, aConstraints.ref()));
    }
    return;
  }
  LayersId layersId = mCompositorSession->RootLayerTreeId();
  mAPZC->UpdateZoomConstraints(ScrollableLayerGuid(layersId, aPresShellId, aViewId),
                               aConstraints);
}

bool
nsBaseWidget::AsyncPanZoomEnabled() const
{
  return !!mAPZC;
}

nsEventStatus
nsBaseWidget::ProcessUntransformedAPZEvent(WidgetInputEvent* aEvent,
                                           const ScrollableLayerGuid& aGuid,
                                           uint64_t aInputBlockId,
                                           nsEventStatus aApzResponse)
{
  MOZ_ASSERT(NS_IsMainThread());
  InputAPZContext context(aGuid, aInputBlockId, aApzResponse);

  // If this is an event that the APZ has targeted to an APZC in the root
  // process, apply that APZC's callback-transform before dispatching the
  // event. If the event is instead targeted to an APZC in the child process,
  // the transform will be applied in the child process before dispatching
  // the event there (see e.g. TabChild::RecvRealTouchEvent()).
  if (aGuid.mLayersId == mCompositorSession->RootLayerTreeId()) {
    APZCCallbackHelper::ApplyCallbackTransform(*aEvent, aGuid,
        GetDefaultScale());
  }

  // Make a copy of the original event for the APZCCallbackHelper helpers that
  // we call later, because the event passed to DispatchEvent can get mutated in
  // ways that we don't want (i.e. touch points can get stripped out).
  nsEventStatus status;
  UniquePtr<WidgetEvent> original(aEvent->Duplicate());
  DispatchEvent(aEvent, status);

  if (mAPZC && !InputAPZContext::WasRoutedToChildProcess() && aInputBlockId) {
    // EventStateManager did not route the event into the child process.
    // It's safe to communicate to APZ that the event has been processed.
    UniquePtr<DisplayportSetListener> postLayerization;
    if (WidgetTouchEvent* touchEvent = aEvent->AsTouchEvent()) {
      if (touchEvent->mMessage == eTouchStart) {
        if (gfxPrefs::TouchActionEnabled()) {
          APZCCallbackHelper::SendSetAllowedTouchBehaviorNotification(this,
              GetDocument(), *(original->AsTouchEvent()), aInputBlockId,
              mSetAllowedTouchBehaviorCallback);
        }
        postLayerization = APZCCallbackHelper::SendSetTargetAPZCNotification(this, GetDocument(),
            *(original->AsTouchEvent()), aGuid, aInputBlockId);
      }
      mAPZEventState->ProcessTouchEvent(*touchEvent, aGuid, aInputBlockId,
          aApzResponse, status);
    } else if (WidgetWheelEvent* wheelEvent = aEvent->AsWheelEvent()) {
      MOZ_ASSERT(wheelEvent->mFlags.mHandledByAPZ);
      postLayerization = APZCCallbackHelper::SendSetTargetAPZCNotification(this, GetDocument(),
          *(original->AsWheelEvent()), aGuid, aInputBlockId);
      if (wheelEvent->mCanTriggerSwipe) {
        ReportSwipeStarted(aInputBlockId, wheelEvent->TriggersSwipe());
      }
      mAPZEventState->ProcessWheelEvent(*wheelEvent, aGuid, aInputBlockId);
    } else if (WidgetMouseEvent* mouseEvent = aEvent->AsMouseEvent()) {
      MOZ_ASSERT(mouseEvent->mFlags.mHandledByAPZ);
      postLayerization = APZCCallbackHelper::SendSetTargetAPZCNotification(this, GetDocument(),
          *(original->AsMouseEvent()), aGuid, aInputBlockId);
      mAPZEventState->ProcessMouseEvent(*mouseEvent, aGuid, aInputBlockId);
    }
    if (postLayerization && postLayerization->Register()) {
      Unused << postLayerization.release();
    }
  }

  return status;
}

class DispatchWheelEventOnMainThread : public Runnable
{
public:
  DispatchWheelEventOnMainThread(const ScrollWheelInput& aWheelInput,
                                 nsBaseWidget* aWidget,
                                 nsEventStatus aAPZResult,
                                 uint64_t aInputBlockId,
                                 ScrollableLayerGuid aGuid)
    : mozilla::Runnable("DispatchWheelEventOnMainThread")
    , mWheelInput(aWheelInput)
    , mWidget(aWidget)
    , mAPZResult(aAPZResult)
    , mInputBlockId(aInputBlockId)
    , mGuid(aGuid)
  {
  }

  NS_IMETHOD Run() override
  {
    WidgetWheelEvent wheelEvent = mWheelInput.ToWidgetWheelEvent(mWidget);
    mWidget->ProcessUntransformedAPZEvent(&wheelEvent, mGuid, mInputBlockId, mAPZResult);
    return NS_OK;
  }

private:
  ScrollWheelInput mWheelInput;
  nsBaseWidget* mWidget;
  nsEventStatus mAPZResult;
  uint64_t mInputBlockId;
  ScrollableLayerGuid mGuid;
};

class DispatchWheelInputOnControllerThread : public Runnable
{
public:
  DispatchWheelInputOnControllerThread(const WidgetWheelEvent& aWheelEvent,
                                       IAPZCTreeManager* aAPZC,
                                       nsBaseWidget* aWidget)
    : mozilla::Runnable("DispatchWheelInputOnControllerThread")
    , mMainMessageLoop(MessageLoop::current())
    , mWheelInput(aWheelEvent)
    , mAPZC(aAPZC)
    , mWidget(aWidget)
    , mInputBlockId(0)
  {
  }

  NS_IMETHOD Run() override
  {
    nsEventStatus result = mAPZC->InputBridge()->ReceiveInputEvent(mWheelInput, &mGuid, &mInputBlockId);
    if (result == nsEventStatus_eConsumeNoDefault) {
      return NS_OK;
    }
    RefPtr<Runnable> r = new DispatchWheelEventOnMainThread(mWheelInput, mWidget, result, mInputBlockId, mGuid);
    mMainMessageLoop->PostTask(r.forget());
    return NS_OK;
  }

private:
  MessageLoop* mMainMessageLoop;
  ScrollWheelInput mWheelInput;
  RefPtr<IAPZCTreeManager> mAPZC;
  nsBaseWidget* mWidget;
  uint64_t mInputBlockId;
  ScrollableLayerGuid mGuid;
};

void
nsBaseWidget::DispatchTouchInput(MultiTouchInput& aInput)
{
  MOZ_ASSERT(NS_IsMainThread());
  if (mAPZC) {
    MOZ_ASSERT(APZThreadUtils::IsControllerThread());
    uint64_t inputBlockId = 0;
    ScrollableLayerGuid guid;

    nsEventStatus result = mAPZC->InputBridge()->ReceiveInputEvent(aInput, &guid, &inputBlockId);
    if (result == nsEventStatus_eConsumeNoDefault) {
      return;
    }

    WidgetTouchEvent event = aInput.ToWidgetTouchEvent(this);
    ProcessUntransformedAPZEvent(&event, guid, inputBlockId, result);
  } else {
    WidgetTouchEvent event = aInput.ToWidgetTouchEvent(this);

    nsEventStatus status;
    DispatchEvent(&event, status);
  }
}

nsEventStatus
nsBaseWidget::DispatchInputEvent(WidgetInputEvent* aEvent)
{
  MOZ_ASSERT(NS_IsMainThread());
  if (mAPZC) {
    if (APZThreadUtils::IsControllerThread()) {
      uint64_t inputBlockId = 0;
      ScrollableLayerGuid guid;

      nsEventStatus result =
        mAPZC->InputBridge()->ReceiveInputEvent(*aEvent, &guid, &inputBlockId);
      if (result == nsEventStatus_eConsumeNoDefault) {
        return result;
      }
      return ProcessUntransformedAPZEvent(aEvent, guid, inputBlockId, result);
    }
    WidgetWheelEvent* wheelEvent = aEvent->AsWheelEvent();
    if (wheelEvent) {
      RefPtr<Runnable> r =
        new DispatchWheelInputOnControllerThread(*wheelEvent, mAPZC, this);
      APZThreadUtils::RunOnControllerThread(r.forget());
      return nsEventStatus_eConsumeDoDefault;
    }
    // Allow dispatching keyboard events on Gecko thread.
    MOZ_ASSERT(aEvent->AsKeyboardEvent());
  }

  nsEventStatus status;
  DispatchEvent(aEvent, status);
  return status;
}

void
nsBaseWidget::DispatchEventToAPZOnly(mozilla::WidgetInputEvent* aEvent)
{
  MOZ_ASSERT(NS_IsMainThread());
  if (mAPZC) {
    MOZ_ASSERT(APZThreadUtils::IsControllerThread());
    uint64_t inputBlockId = 0;
    ScrollableLayerGuid guid;
    mAPZC->InputBridge()->ReceiveInputEvent(*aEvent, &guid, &inputBlockId);
  }
}

// static
bool
nsBaseWidget::ShowContextMenuAfterMouseUp()
{
  static bool gContextMenuAfterMouseUp = false;
  static bool gContextMenuAfterMouseUpCached = false;
  if (!gContextMenuAfterMouseUpCached) {
    Preferences::AddBoolVarCache(&gContextMenuAfterMouseUp,
                                 "ui.context_menus.after_mouseup",
                                 false);

    gContextMenuAfterMouseUpCached = true;
  }
  return gContextMenuAfterMouseUp;
}

nsIDocument*
nsBaseWidget::GetDocument() const
{
  if (mWidgetListener) {
    if (nsIPresShell* presShell = mWidgetListener->GetPresShell()) {
      return presShell->GetDocument();
    }
  }
  return nullptr;
}

void nsBaseWidget::CreateCompositorVsyncDispatcher()
{
  // Parent directly listens to the vsync source whereas
  // child process communicate via IPC
  // Should be called AFTER gfxPlatform is initialized
  if (XRE_IsParentProcess()) {
    if (!mCompositorVsyncDispatcherLock) {
      mCompositorVsyncDispatcherLock = MakeUnique<Mutex>("mCompositorVsyncDispatcherLock");
    }
    MutexAutoLock lock(*mCompositorVsyncDispatcherLock.get());
    mCompositorVsyncDispatcher = new CompositorVsyncDispatcher();
  }
}

already_AddRefed<CompositorVsyncDispatcher>
nsBaseWidget::GetCompositorVsyncDispatcher()
{
  MOZ_ASSERT(mCompositorVsyncDispatcherLock.get());

  MutexAutoLock lock(*mCompositorVsyncDispatcherLock.get());
  RefPtr<CompositorVsyncDispatcher> dispatcher = mCompositorVsyncDispatcher;
  return dispatcher.forget();
}

already_AddRefed<LayerManager>
nsBaseWidget::CreateCompositorSession(int aWidth,
                                      int aHeight,
                                      CompositorOptions* aOptionsOut)
{
  MOZ_ASSERT(aOptionsOut);

  do {
    CreateCompositorVsyncDispatcher();

    gfx::GPUProcessManager* gpu = gfx::GPUProcessManager::Get();
    // Make sure GPU process is ready for use.
    // If it failed to connect to GPU process, GPU process usage is disabled in EnsureGPUReady().
    // It could update gfxVars and gfxConfigs.
    gpu->EnsureGPUReady();

    // If widget type does not supports acceleration, we use ClientLayerManager
    // even when gfxVars::UseWebRender() is true. WebRender could coexist only
    // with BasicCompositor.
    bool enableWR = gfx::gfxVars::UseWebRender() && WidgetTypeSupportsAcceleration()
      && AllowWebRenderForThisWindow();
    bool enableAPZ = UseAPZ();
    CompositorOptions options(enableAPZ, enableWR);

    bool enableAL = gfx::gfxConfig::IsEnabled(gfx::Feature::ADVANCED_LAYERS);
    options.SetUseAdvancedLayers(enableAL);

#ifdef MOZ_WIDGET_ANDROID
    if (!GetNativeData(NS_JAVA_SURFACE)) {
      options.SetInitiallyPaused(true);
    }
#endif

    RefPtr<LayerManager> lm;
    if (options.UseWebRender()) {
      lm = new WebRenderLayerManager(this);
    } else {
      lm = new ClientLayerManager(this);
    }

    bool retry = false;
    mCompositorSession = gpu->CreateTopLevelCompositor(
      this,
      lm,
      GetDefaultScale(),
      options,
      UseExternalCompositingSurface(),
      gfx::IntSize(aWidth, aHeight),
      &retry);

    if (lm->AsWebRenderLayerManager() && mCompositorSession) {
      TextureFactoryIdentifier textureFactoryIdentifier;
      lm->AsWebRenderLayerManager()->Initialize(mCompositorSession->GetCompositorBridgeChild(),
                                                wr::AsPipelineId(mCompositorSession->RootLayerTreeId()),
                                                &textureFactoryIdentifier);
      if (textureFactoryIdentifier.mParentBackend != LayersBackend::LAYERS_WR) {
        retry = true;
        DestroyCompositor();
        gfx::GPUProcessManager::Get()->DisableWebRender(wr::WebRenderError::INITIALIZE);
      }
    }

    // We need to retry in a loop because the act of failing to create the
    // compositor can change our state (e.g. disable WebRender).
    if (mCompositorSession || !retry) {
      *aOptionsOut = options;
      return lm.forget();
    }
  } while (true);
}

void nsBaseWidget::CreateCompositor(int aWidth, int aHeight)
{
  // This makes sure that gfxPlatforms gets initialized if it hasn't by now.
  gfxPlatform::GetPlatform();

  MOZ_ASSERT(gfxPlatform::UsesOffMainThreadCompositing(),
             "This function assumes OMTC");

  MOZ_ASSERT(!mCompositorSession && !mCompositorBridgeChild,
    "Should have properly cleaned up the previous PCompositor pair beforehand");

  if (mCompositorBridgeChild) {
    mCompositorBridgeChild->Destroy();
  }

  // Recreating this is tricky, as we may still have an old and we need
  // to make sure it's properly destroyed by calling DestroyCompositor!

  // If we've already received a shutdown notification, don't try
  // create a new compositor.
  if (!mShutdownObserver) {
    return;
  }

  CompositorOptions options;
  RefPtr<LayerManager> lm =
    CreateCompositorSession(aWidth, aHeight, &options);
  if (!lm) {
    return;
  }

  MOZ_ASSERT(mCompositorSession);
  mCompositorBridgeChild = mCompositorSession->GetCompositorBridgeChild();
  SetCompositorWidgetDelegate(mCompositorSession->GetCompositorWidgetDelegate());

  if (options.UseAPZ()) {
    mAPZC = mCompositorSession->GetAPZCTreeManager();
    ConfigureAPZCTreeManager();
  } else {
    mAPZC = nullptr;
  }

  if (mInitialZoomConstraints) {
    UpdateZoomConstraints(mInitialZoomConstraints->mPresShellID,
                          mInitialZoomConstraints->mViewID,
                          Some(mInitialZoomConstraints->mConstraints));
    mInitialZoomConstraints.reset();
  }

  if (lm->AsWebRenderLayerManager()) {
    TextureFactoryIdentifier textureFactoryIdentifier = lm->GetTextureFactoryIdentifier();
    MOZ_ASSERT(textureFactoryIdentifier.mParentBackend == LayersBackend::LAYERS_WR);
    ImageBridgeChild::IdentifyCompositorTextureHost(textureFactoryIdentifier);
    gfx::VRManagerChild::IdentifyTextureHost(textureFactoryIdentifier);
  }

  ShadowLayerForwarder* lf = lm->AsShadowForwarder();
  if (lf) {
    // lf is non-null if we are creating a ClientLayerManager above
    TextureFactoryIdentifier textureFactoryIdentifier;
    PLayerTransactionChild* shadowManager = nullptr;

    nsTArray<LayersBackend> backendHints;
    gfxPlatform::GetPlatform()->GetCompositorBackends(ComputeShouldAccelerate(), backendHints);

    bool success = false;
    if (!backendHints.IsEmpty()) {
      shadowManager =
        mCompositorBridgeChild->SendPLayerTransactionConstructor(backendHints, LayersId{0});
      if (shadowManager->SendGetTextureFactoryIdentifier(&textureFactoryIdentifier) &&
          textureFactoryIdentifier.mParentBackend != LayersBackend::LAYERS_NONE)
      {
        success = true;
      }
    }

    if (!success) {
      NS_WARNING("Failed to create an OMT compositor.");
      DestroyCompositor();
      mLayerManager = nullptr;
      return;
    }

    lf->SetShadowManager(shadowManager);
    lm->UpdateTextureFactoryIdentifier(textureFactoryIdentifier);
    // Some popup or transparent widgets may use a different backend than the
    // compositors used with ImageBridge and VR (and more generally web content).
    if (WidgetTypeSupportsAcceleration()) {
      ImageBridgeChild::IdentifyCompositorTextureHost(textureFactoryIdentifier);
      gfx::VRManagerChild::IdentifyTextureHost(textureFactoryIdentifier);
    }
  }

  WindowUsesOMTC();

  mLayerManager = lm.forget();

  // Only track compositors for top-level windows, since other window types
  // may use the basic compositor.  Except on the OS X - see bug 1306383
#if defined(XP_MACOSX)
  bool getCompositorFromThisWindow = true;
#else
  bool getCompositorFromThisWindow = (mWindowType == eWindowType_toplevel);
#endif

  if (getCompositorFromThisWindow) {
    gfxPlatform::GetPlatform()->NotifyCompositorCreated(mLayerManager->GetCompositorBackendType());
  }
}

void nsBaseWidget::NotifyCompositorSessionLost(CompositorSession* aSession)
{
  MOZ_ASSERT(aSession == mCompositorSession);
  DestroyLayerManager();
}

bool nsBaseWidget::ShouldUseOffMainThreadCompositing()
{
  return gfxPlatform::UsesOffMainThreadCompositing();
}

LayerManager* nsBaseWidget::GetLayerManager(PLayerTransactionChild* aShadowManager,
                                            LayersBackend aBackendHint,
                                            LayerManagerPersistence aPersistence)
{
  if (!mLayerManager) {
    if (!mShutdownObserver) {
      // We are shutting down, do not try to re-create a LayerManager
      return nullptr;
    }
    // Try to use an async compositor first, if possible
    if (ShouldUseOffMainThreadCompositing()) {
      // e10s uses the parameter to pass in the shadow manager from the TabChild
      // so we don't expect to see it there since this doesn't support e10s.
      NS_ASSERTION(aShadowManager == nullptr, "Async Compositor not supported with e10s");
      CreateCompositor();
    }

    if (!mLayerManager) {
      mLayerManager = CreateBasicLayerManager();
    }
  }
  return mLayerManager;
}

LayerManager* nsBaseWidget::CreateBasicLayerManager()
{
  return new BasicLayerManager(this);
}

CompositorBridgeChild* nsBaseWidget::GetRemoteRenderer()
{
  return mCompositorBridgeChild;
}

already_AddRefed<gfx::DrawTarget>
nsBaseWidget::StartRemoteDrawing()
{
  if (recordreplay::IsRecordingOrReplaying()) {
    return recordreplay::child::DrawTargetForRemoteDrawing(mBounds.Size());
  }
  return nullptr;
}

uint32_t
nsBaseWidget::GetGLFrameBufferFormat()
{
  return LOCAL_GL_RGBA;
}

//-------------------------------------------------------------------------
//
// Destroy the window
//
//-------------------------------------------------------------------------
void nsBaseWidget::OnDestroy()
{
  if (mTextEventDispatcher) {
    mTextEventDispatcher->OnDestroyWidget();
    // Don't release it until this widget actually released because after this
    // is called, TextEventDispatcher() may create it again.
  }

  // If this widget is being destroyed, let the APZ code know to drop references
  // to this widget. Callers of this function all should be holding a deathgrip
  // on this widget already.
  ReleaseContentController();
}

void
nsBaseWidget::MoveClient(double aX, double aY)
{
  LayoutDeviceIntPoint clientOffset(GetClientOffset());

  // GetClientOffset returns device pixels; scale back to desktop pixels
  // if that's what this widget uses for the Move/Resize APIs
  if (BoundsUseDesktopPixels()) {
    DesktopPoint desktopOffset = clientOffset / GetDesktopToDeviceScale();
    Move(aX - desktopOffset.x, aY - desktopOffset.y);
  } else {
    Move(aX - clientOffset.x, aY - clientOffset.y);
  }
}

void
nsBaseWidget::ResizeClient(double aWidth, double aHeight, bool aRepaint)
{
  NS_ASSERTION((aWidth >=0) , "Negative width passed to ResizeClient");
  NS_ASSERTION((aHeight >=0), "Negative height passed to ResizeClient");

  LayoutDeviceIntRect clientBounds = GetClientBounds();

  // GetClientBounds and mBounds are device pixels; scale back to desktop pixels
  // if that's what this widget uses for the Move/Resize APIs
  if (BoundsUseDesktopPixels()) {
    DesktopSize desktopDelta =
      (LayoutDeviceIntSize(mBounds.Width(), mBounds.Height()) -
       clientBounds.Size()) / GetDesktopToDeviceScale();
    Resize(aWidth + desktopDelta.width, aHeight + desktopDelta.height,
           aRepaint);
  } else {
    Resize(mBounds.Width() + (aWidth - clientBounds.Width()),
           mBounds.Height() + (aHeight - clientBounds.Height()), aRepaint);
  }
}

void
nsBaseWidget::ResizeClient(double aX,
                           double aY,
                           double aWidth,
                           double aHeight,
                           bool aRepaint)
{
  NS_ASSERTION((aWidth >=0) , "Negative width passed to ResizeClient");
  NS_ASSERTION((aHeight >=0), "Negative height passed to ResizeClient");

  LayoutDeviceIntRect clientBounds = GetClientBounds();
  LayoutDeviceIntPoint clientOffset = GetClientOffset();

  if (BoundsUseDesktopPixels()) {
    DesktopToLayoutDeviceScale scale = GetDesktopToDeviceScale();
    DesktopPoint desktopOffset = clientOffset / scale;
    DesktopSize desktopDelta =
      (LayoutDeviceIntSize(mBounds.Width(), mBounds.Height()) -
       clientBounds.Size()) / scale;
    Resize(aX - desktopOffset.x, aY - desktopOffset.y,
           aWidth + desktopDelta.width, aHeight + desktopDelta.height,
           aRepaint);
  } else {
    Resize(aX - clientOffset.x, aY - clientOffset.y,
           aWidth + mBounds.Width() - clientBounds.Width(),
           aHeight + mBounds.Height() - clientBounds.Height(),
           aRepaint);
  }
}

//-------------------------------------------------------------------------
//
// Bounds
//
//-------------------------------------------------------------------------

/**
* If the implementation of nsWindow supports borders this method MUST be overridden
*
**/
LayoutDeviceIntRect
nsBaseWidget::GetClientBounds()
{
  return GetBounds();
}

/**
* If the implementation of nsWindow supports borders this method MUST be overridden
*
**/
LayoutDeviceIntRect
nsBaseWidget::GetBounds()
{
  return mBounds;
}

/**
* If the implementation of nsWindow uses a local coordinate system within the window,
* this method must be overridden
*
**/
LayoutDeviceIntRect
nsBaseWidget::GetScreenBounds()
{
  return GetBounds();
}

nsresult
nsBaseWidget::GetRestoredBounds(LayoutDeviceIntRect& aRect)
{
  if (SizeMode() != nsSizeMode_Normal) {
    return NS_ERROR_FAILURE;
  }
  aRect = GetScreenBounds();
  return NS_OK;
}

LayoutDeviceIntPoint
nsBaseWidget::GetClientOffset()
{
  return LayoutDeviceIntPoint(0, 0);
}

nsresult
nsBaseWidget::SetNonClientMargins(LayoutDeviceIntMargin &margins)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

uint32_t nsBaseWidget::GetMaxTouchPoints() const
{
  return 0;
}

bool
nsBaseWidget::HasPendingInputEvent()
{
  return false;
}

bool
nsBaseWidget::ShowsResizeIndicator(LayoutDeviceIntRect* aResizerRect)
{
  return false;
}

/**
 * Modifies aFile to point at an icon file with the given name and suffix.  The
 * suffix may correspond to a file extension with leading '.' if appropriate.
 * Returns true if the icon file exists and can be read.
 */
static bool
ResolveIconNameHelper(nsIFile *aFile,
                      const nsAString &aIconName,
                      const nsAString &aIconSuffix)
{
  aFile->Append(NS_LITERAL_STRING("icons"));
  aFile->Append(NS_LITERAL_STRING("default"));
  aFile->Append(aIconName + aIconSuffix);

  bool readable;
  return NS_SUCCEEDED(aFile->IsReadable(&readable)) && readable;
}

/**
 * Resolve the given icon name into a local file object.  This method is
 * intended to be called by subclasses of nsBaseWidget.  aIconSuffix is a
 * platform specific icon file suffix (e.g., ".ico" under Win32).
 *
 * If no file is found matching the given parameters, then null is returned.
 */
void
nsBaseWidget::ResolveIconName(const nsAString &aIconName,
                              const nsAString &aIconSuffix,
                              nsIFile **aResult)
{
  *aResult = nullptr;

  nsCOMPtr<nsIProperties> dirSvc = do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID);
  if (!dirSvc)
    return;

  // first check auxilary chrome directories

  nsCOMPtr<nsISimpleEnumerator> dirs;
  dirSvc->Get(NS_APP_CHROME_DIR_LIST, NS_GET_IID(nsISimpleEnumerator),
              getter_AddRefs(dirs));
  if (dirs) {
    bool hasMore;
    while (NS_SUCCEEDED(dirs->HasMoreElements(&hasMore)) && hasMore) {
      nsCOMPtr<nsISupports> element;
      dirs->GetNext(getter_AddRefs(element));
      if (!element)
        continue;
      nsCOMPtr<nsIFile> file = do_QueryInterface(element);
      if (!file)
        continue;
      if (ResolveIconNameHelper(file, aIconName, aIconSuffix)) {
        NS_ADDREF(*aResult = file);
        return;
      }
    }
  }

  // then check the main app chrome directory

  nsCOMPtr<nsIFile> file;
  dirSvc->Get(NS_APP_CHROME_DIR, NS_GET_IID(nsIFile),
              getter_AddRefs(file));
  if (file && ResolveIconNameHelper(file, aIconName, aIconSuffix))
    NS_ADDREF(*aResult = file);
}

void nsBaseWidget::SetSizeConstraints(const SizeConstraints& aConstraints)
{
  mSizeConstraints = aConstraints;

  // Popups are constrained during layout, and we don't want to synchronously
  // paint from reflow, so bail out... This is not great, but it's no worse than
  // what we used to do.
  //
  // The right fix here is probably making constraint changes go through the
  // view manager and such.
  if (mWindowType == eWindowType_popup) {
    return;
  }

  // If the current size doesn't meet the new constraints, trigger a
  // resize to apply it. Note that, we don't want to invoke Resize if
  // the new constraints don't affect the current size, because Resize
  // implementation on some platforms may touch other geometry even if
  // the size don't need to change.
  LayoutDeviceIntSize curSize = mBounds.Size();
  LayoutDeviceIntSize clampedSize =
    Max(aConstraints.mMinSize, Min(aConstraints.mMaxSize, curSize));
  if (clampedSize != curSize) {
    gfx::Size size;
    if (BoundsUseDesktopPixels()) {
      DesktopSize desktopSize = clampedSize / GetDesktopToDeviceScale();
      size = desktopSize.ToUnknownSize();
    } else {
      size = gfx::Size(clampedSize.ToUnknownSize());
    }
    Resize(size.width, size.height, true);
  }
}

const widget::SizeConstraints nsBaseWidget::GetSizeConstraints()
{
  return mSizeConstraints;
}

// static
nsIRollupListener*
nsBaseWidget::GetActiveRollupListener()
{
  // If set, then this is likely an <html:select> dropdown.
  if (gRollupListener)
    return gRollupListener;

  return nsXULPopupManager::GetInstance();
}

void
nsBaseWidget::NotifyWindowDestroyed()
{
  if (!mWidgetListener)
    return;

  nsCOMPtr<nsIXULWindow> window = mWidgetListener->GetXULWindow();
  nsCOMPtr<nsIBaseWindow> xulWindow(do_QueryInterface(window));
  if (xulWindow) {
    xulWindow->Destroy();
  }
}

void
nsBaseWidget::NotifyWindowMoved(int32_t aX, int32_t aY)
{
  if (mWidgetListener) {
    mWidgetListener->WindowMoved(this, aX, aY);
  }

  if (mIMEHasFocus && IMENotificationRequestsRef().WantPositionChanged()) {
    NotifyIME(IMENotification(IMEMessage::NOTIFY_IME_OF_POSITION_CHANGE));
  }
}

void
nsBaseWidget::NotifyPresShell(NotificationFunc aNotificationFunc)
{
  if (!mWidgetListener) {
    return;
  }

  nsIPresShell* presShell = mWidgetListener->GetPresShell();
  if (presShell) {
    (presShell->*aNotificationFunc)();
  }
}

void
nsBaseWidget::NotifySizeMoveDone()
{
  NotifyPresShell(&nsIPresShell::WindowSizeMoveDone);
}

void
nsBaseWidget::NotifySysColorChanged()
{
  NotifyPresShell(&nsIPresShell::SysColorChanged);
}

void
nsBaseWidget::NotifyThemeChanged()
{
  NotifyPresShell(&nsIPresShell::ThemeChanged);
}

void
nsBaseWidget::NotifyUIStateChanged(UIStateChangeType aShowAccelerators,
                                   UIStateChangeType aShowFocusRings)
{
  if (nsIDocument* doc = GetDocument()) {
    nsPIDOMWindowOuter* win = doc->GetWindow();
    if (win) {
      win->SetKeyboardIndicators(aShowAccelerators, aShowFocusRings);
    }
  }
}

nsresult
nsBaseWidget::NotifyIME(const IMENotification& aIMENotification)
{
  switch (aIMENotification.mMessage) {
    case REQUEST_TO_COMMIT_COMPOSITION:
    case REQUEST_TO_CANCEL_COMPOSITION:
      // We should send request to IME only when there is a TextEventDispatcher
      // instance (this means that this widget has dispatched at least one
      // composition event or keyboard event) and the it has composition.
      // Otherwise, there is nothing to do.
      // Note that if current input transaction is for native input events,
      // TextEventDispatcher::NotifyIME() will call
      // TextEventDispatcherListener::NotifyIME().
      if (mTextEventDispatcher && mTextEventDispatcher->IsComposing()) {
        return mTextEventDispatcher->NotifyIME(aIMENotification);
      }
      return NS_OK;
    default: {
      if (aIMENotification.mMessage == NOTIFY_IME_OF_FOCUS) {
        mIMEHasFocus = true;
      }
      EnsureTextEventDispatcher();
      // TextEventDispatcher::NotifyIME() will always call
      // TextEventDispatcherListener::NotifyIME().  I.e., even if current
      // input transaction is for synthesized events for automated tests,
      // notifications will be sent to native IME.
      nsresult rv = mTextEventDispatcher->NotifyIME(aIMENotification);
      if (aIMENotification.mMessage == NOTIFY_IME_OF_BLUR) {
        mIMEHasFocus = false;
      }
      return rv;
    }
  }
}

void
nsBaseWidget::EnsureTextEventDispatcher()
{
  if (mTextEventDispatcher) {
    return;
  }
  mTextEventDispatcher = new TextEventDispatcher(this);
}

nsIWidget::NativeIMEContext
nsBaseWidget::GetNativeIMEContext()
{
  if (mTextEventDispatcher && mTextEventDispatcher->GetPseudoIMEContext()) {
    // If we already have a TextEventDispatcher and it's working with
    // a TextInputProcessor, we need to return pseudo IME context since
    // TextCompositionArray::IndexOf(nsIWidget*) should return a composition
    // on the pseudo IME context in such case.
    NativeIMEContext pseudoIMEContext;
    pseudoIMEContext.InitWithRawNativeIMEContext(
                       mTextEventDispatcher->GetPseudoIMEContext());
    return pseudoIMEContext;
  }
  return NativeIMEContext(this);
}

nsIWidget::TextEventDispatcher*
nsBaseWidget::GetTextEventDispatcher()
{
  EnsureTextEventDispatcher();
  return mTextEventDispatcher;
}

void*
nsBaseWidget::GetPseudoIMEContext()
{
  TextEventDispatcher* dispatcher = GetTextEventDispatcher();
  if (!dispatcher) {
    return nullptr;
  }
  return dispatcher->GetPseudoIMEContext();
}

TextEventDispatcherListener*
nsBaseWidget::GetNativeTextEventDispatcherListener()
{
  // TODO: If all platforms supported use of TextEventDispatcher for handling
  //       native IME and keyboard events, this method should be removed since
  //       in such case, this is overridden by all the subclasses.
  return nullptr;
}

void
nsBaseWidget::ZoomToRect(const uint32_t& aPresShellId,
                         const ScrollableLayerGuid::ViewID& aViewId,
                         const CSSRect& aRect,
                         const uint32_t& aFlags)
{
  if (!mCompositorSession || !mAPZC) {
    return;
  }
  LayersId layerId = mCompositorSession->RootLayerTreeId();
  APZThreadUtils::RunOnControllerThread(
    NewRunnableMethod<ScrollableLayerGuid, CSSRect, uint32_t>(
      "layers::IAPZCTreeManager::ZoomToRect",
      mAPZC,
      &IAPZCTreeManager::ZoomToRect,
      ScrollableLayerGuid(layerId, aPresShellId, aViewId),
      aRect,
      aFlags));
}

#ifdef ACCESSIBILITY

a11y::Accessible*
nsBaseWidget::GetRootAccessible()
{
  NS_ENSURE_TRUE(mWidgetListener, nullptr);

  nsIPresShell* presShell = mWidgetListener->GetPresShell();
  NS_ENSURE_TRUE(presShell, nullptr);

  // If container is null then the presshell is not active. This often happens
  // when a preshell is being held onto for fastback.
  nsPresContext* presContext = presShell->GetPresContext();
  NS_ENSURE_TRUE(presContext->GetContainerWeak(), nullptr);

  // Accessible creation might be not safe so use IsSafeToRunScript to
  // make sure it's not created at unsafe times.
  nsAccessibilityService* accService = GetOrCreateAccService();
  if (accService) {
    return accService->GetRootDocumentAccessible(presShell, nsContentUtils::IsSafeToRunScript());
  }

  return nullptr;
}

#endif // ACCESSIBILITY

void
nsBaseWidget::StartAsyncScrollbarDrag(const AsyncDragMetrics& aDragMetrics)
{
  if (!AsyncPanZoomEnabled()) {
    return;
  }

  MOZ_ASSERT(XRE_IsParentProcess() && mCompositorSession);

  LayersId layersId = mCompositorSession->RootLayerTreeId();
  ScrollableLayerGuid guid(layersId, aDragMetrics.mPresShellId, aDragMetrics.mViewId);

  APZThreadUtils::RunOnControllerThread(
    NewRunnableMethod<ScrollableLayerGuid, AsyncDragMetrics>(
      "layers::IAPZCTreeManager::StartScrollbarDrag",
      mAPZC,
      &IAPZCTreeManager::StartScrollbarDrag,
      guid,
      aDragMetrics));
}

bool
nsBaseWidget::StartAsyncAutoscroll(const ScreenPoint& aAnchorLocation,
                                   const ScrollableLayerGuid& aGuid)
{
  MOZ_ASSERT(XRE_IsParentProcess() && AsyncPanZoomEnabled());

  return mAPZC->StartAutoscroll(aGuid, aAnchorLocation);
}

void
nsBaseWidget::StopAsyncAutoscroll(const ScrollableLayerGuid& aGuid)
{
  MOZ_ASSERT(XRE_IsParentProcess() && AsyncPanZoomEnabled());

  mAPZC->StopAutoscroll(aGuid);
}


already_AddRefed<nsIScreen>
nsBaseWidget::GetWidgetScreen()
{
  nsCOMPtr<nsIScreenManager> screenManager;
  screenManager = do_GetService("@mozilla.org/gfx/screenmanager;1");
  if (!screenManager) {
    return nullptr;
  }

  LayoutDeviceIntRect bounds = GetScreenBounds();
  DesktopIntRect deskBounds = RoundedToInt(bounds / GetDesktopToDeviceScale());
  nsCOMPtr<nsIScreen> screen;
  screenManager->ScreenForRect(deskBounds.X(), deskBounds.Y(),
                               deskBounds.Width(), deskBounds.Height(),
                               getter_AddRefs(screen));
  return screen.forget();
}

mozilla::DesktopToLayoutDeviceScale
nsBaseWidget::GetDesktopToDeviceScaleByScreen()
{
  return (nsView::GetViewFor(this)->GetViewManager()->GetDeviceContext())->GetDesktopToDeviceScale();
}

nsresult
nsIWidget::SynthesizeNativeTouchTap(LayoutDeviceIntPoint aPoint, bool aLongTap,
                                    nsIObserver* aObserver)
{
  AutoObserverNotifier notifier(aObserver, "touchtap");

  if (sPointerIdCounter > TOUCH_INJECT_MAX_POINTS) {
    sPointerIdCounter = 0;
  }
  int pointerId = sPointerIdCounter;
  sPointerIdCounter++;
  nsresult rv = SynthesizeNativeTouchPoint(pointerId, TOUCH_CONTACT,
                                           aPoint, 1.0, 90, nullptr);
  if (NS_FAILED(rv)) {
    return rv;
  }

  if (!aLongTap) {
    return SynthesizeNativeTouchPoint(pointerId, TOUCH_REMOVE,
                                      aPoint, 0, 0, nullptr);
  }

  // initiate a long tap
  int elapse = Preferences::GetInt("ui.click_hold_context_menus.delay",
                                   TOUCH_INJECT_LONG_TAP_DEFAULT_MSEC);
  if (!mLongTapTimer) {
    mLongTapTimer = NS_NewTimer();
    if (!mLongTapTimer) {
      SynthesizeNativeTouchPoint(pointerId, TOUCH_CANCEL,
                                 aPoint, 0, 0, nullptr);
      return NS_ERROR_UNEXPECTED;
    }
    // Windows requires recuring events, so we set this to a smaller window
    // than the pref value.
    int timeout = elapse;
    if (timeout > TOUCH_INJECT_PUMP_TIMER_MSEC) {
      timeout = TOUCH_INJECT_PUMP_TIMER_MSEC;
    }
    mLongTapTimer->InitWithNamedFuncCallback(
      OnLongTapTimerCallback,
      this,
      timeout,
      nsITimer::TYPE_REPEATING_SLACK,
      "nsIWidget::SynthesizeNativeTouchTap");
  }

  // If we already have a long tap pending, cancel it. We only allow one long
  // tap to be active at a time.
  if (mLongTapTouchPoint) {
    SynthesizeNativeTouchPoint(mLongTapTouchPoint->mPointerId, TOUCH_CANCEL,
                               mLongTapTouchPoint->mPosition, 0, 0, nullptr);
  }

  mLongTapTouchPoint =
    MakeUnique<LongTapInfo>(pointerId, aPoint,
                            TimeDuration::FromMilliseconds(elapse),
                            aObserver);
  notifier.SkipNotification();  // we'll do it in the long-tap callback
  return NS_OK;
}

// static
void
nsIWidget::OnLongTapTimerCallback(nsITimer* aTimer, void* aClosure)
{
  auto *self = static_cast<nsIWidget *>(aClosure);

  if ((self->mLongTapTouchPoint->mStamp + self->mLongTapTouchPoint->mDuration) >
      TimeStamp::Now()) {
#ifdef XP_WIN
    // Windows needs us to keep pumping feedback to the digitizer, so update
    // the pointer id with the same position.
    self->SynthesizeNativeTouchPoint(self->mLongTapTouchPoint->mPointerId,
                                     TOUCH_CONTACT,
                                     self->mLongTapTouchPoint->mPosition,
                                     1.0, 90, nullptr);
#endif
    return;
  }

  AutoObserverNotifier notifier(self->mLongTapTouchPoint->mObserver, "touchtap");

  // finished, remove the touch point
  self->mLongTapTimer->Cancel();
  self->mLongTapTimer = nullptr;
  self->SynthesizeNativeTouchPoint(self->mLongTapTouchPoint->mPointerId,
                                   TOUCH_REMOVE,
                                   self->mLongTapTouchPoint->mPosition,
                                   0, 0, nullptr);
  self->mLongTapTouchPoint = nullptr;
}

nsresult
nsIWidget::ClearNativeTouchSequence(nsIObserver* aObserver)
{
  AutoObserverNotifier notifier(aObserver, "cleartouch");

  if (!mLongTapTimer) {
    return NS_OK;
  }
  mLongTapTimer->Cancel();
  mLongTapTimer = nullptr;
  SynthesizeNativeTouchPoint(mLongTapTouchPoint->mPointerId, TOUCH_CANCEL,
                             mLongTapTouchPoint->mPosition, 0, 0, nullptr);
  mLongTapTouchPoint = nullptr;
  return NS_OK;
}

MultiTouchInput
nsBaseWidget::UpdateSynthesizedTouchState(MultiTouchInput* aState,
                                          uint32_t aTime,
                                          mozilla::TimeStamp aTimeStamp,
                                          uint32_t aPointerId,
                                          TouchPointerState aPointerState,
                                          LayoutDeviceIntPoint aPoint,
                                          double aPointerPressure,
                                          uint32_t aPointerOrientation)
{
  ScreenIntPoint pointerScreenPoint = ViewAs<ScreenPixel>(aPoint,
      PixelCastJustification::LayoutDeviceIsScreenForBounds);

  // We can't dispatch *aState directly because (a) dispatching
  // it might inadvertently modify it and (b) in the case of touchend or
  // touchcancel events aState will hold the touches that are
  // still down whereas the input dispatched needs to hold the removed
  // touch(es). We use |inputToDispatch| for this purpose.
  MultiTouchInput inputToDispatch;
  inputToDispatch.mInputType = MULTITOUCH_INPUT;
  inputToDispatch.mTime = aTime;
  inputToDispatch.mTimeStamp = aTimeStamp;

  int32_t index = aState->IndexOfTouch((int32_t)aPointerId);
  if (aPointerState == TOUCH_CONTACT) {
    if (index >= 0) {
      // found an existing touch point, update it
      SingleTouchData& point = aState->mTouches[index];
      point.mScreenPoint = pointerScreenPoint;
      point.mRotationAngle = (float)aPointerOrientation;
      point.mForce = (float)aPointerPressure;
      inputToDispatch.mType = MultiTouchInput::MULTITOUCH_MOVE;
    } else {
      // new touch point, add it
      aState->mTouches.AppendElement(SingleTouchData(
          (int32_t)aPointerId,
          pointerScreenPoint,
          ScreenSize(0, 0),
          (float)aPointerOrientation,
          (float)aPointerPressure));
      inputToDispatch.mType = MultiTouchInput::MULTITOUCH_START;
    }
    inputToDispatch.mTouches = aState->mTouches;
  } else {
    MOZ_ASSERT(aPointerState == TOUCH_REMOVE || aPointerState == TOUCH_CANCEL);
    // a touch point is being lifted, so remove it from the stored list
    if (index >= 0) {
      aState->mTouches.RemoveElementAt(index);
    }
    inputToDispatch.mType = (aPointerState == TOUCH_REMOVE
        ? MultiTouchInput::MULTITOUCH_END
        : MultiTouchInput::MULTITOUCH_CANCEL);
    inputToDispatch.mTouches.AppendElement(SingleTouchData(
        (int32_t)aPointerId,
        pointerScreenPoint,
        ScreenSize(0, 0),
        (float)aPointerOrientation,
        (float)aPointerPressure));
  }

  return inputToDispatch;
}

void
nsBaseWidget::NotifyLiveResizeStarted()
{
  // If we have mLiveResizeListeners already non-empty, we should notify those
  // listeners that the resize stopped before starting anew. In theory this
  // should never happen because we shouldn't get nested live resize actions.
  NotifyLiveResizeStopped();
  MOZ_ASSERT(mLiveResizeListeners.IsEmpty());

  // If we can get the active tab parent for the current widget, suppress
  // the displayport on it during the live resize.
  if (!mWidgetListener) {
    return;
  }
  nsCOMPtr<nsIXULWindow> xulWindow = mWidgetListener->GetXULWindow();
  if (!xulWindow) {
    return;
  }
  mLiveResizeListeners = xulWindow->GetLiveResizeListeners();
  for (uint32_t i = 0; i < mLiveResizeListeners.Length(); i++) {
    mLiveResizeListeners[i]->LiveResizeStarted();
  }
}

void
nsBaseWidget::NotifyLiveResizeStopped()
{
  if (!mLiveResizeListeners.IsEmpty()) {
    for (uint32_t i = 0; i < mLiveResizeListeners.Length(); i++) {
      mLiveResizeListeners[i]->LiveResizeStopped();
    }
    mLiveResizeListeners.Clear();
  }
}

void
nsBaseWidget::RegisterPluginWindowForRemoteUpdates()
{
#if !defined(XP_WIN) && !defined(MOZ_WIDGET_GTK)
  MOZ_ASSERT_UNREACHABLE("nsBaseWidget::RegisterPluginWindowForRemoteUpdates "
                         "not implemented!");
  return;
#else
  MOZ_ASSERT(NS_IsMainThread());
  void* id = GetNativeData(NS_NATIVE_PLUGIN_ID);
  if (!id) {
    NS_WARNING("This is not a valid native widget!");
    return;
  }
  MOZ_ASSERT(sPluginWidgetList);
  sPluginWidgetList->Put(id, this);
#endif
}

void
nsBaseWidget::UnregisterPluginWindowForRemoteUpdates()
{
#if !defined(XP_WIN) && !defined(MOZ_WIDGET_GTK)
  MOZ_ASSERT_UNREACHABLE("nsBaseWidget::UnregisterPluginWindowForRemoteUpdates "
                         "not implemented!");
  return;
#else
  MOZ_ASSERT(NS_IsMainThread());
  void* id = GetNativeData(NS_NATIVE_PLUGIN_ID);
  if (!id) {
    NS_WARNING("This is not a valid native widget!");
    return;
  }
  MOZ_ASSERT(sPluginWidgetList);
  sPluginWidgetList->Remove(id);
#endif
}

nsresult
nsBaseWidget::AsyncEnableDragDrop(bool aEnable)
{
  RefPtr<nsBaseWidget> kungFuDeathGrip = this;
  return NS_IdleDispatchToCurrentThread(
    NS_NewRunnableFunction("AsyncEnableDragDropFn",
                           [this, aEnable, kungFuDeathGrip]() {
                             EnableDragDrop(aEnable);
                           }),
    kAsyncDragDropTimeout);
}

// static
nsIWidget*
nsIWidget::LookupRegisteredPluginWindow(uintptr_t aWindowID)
{
#if !defined(XP_WIN) && !defined(MOZ_WIDGET_GTK)
  MOZ_ASSERT_UNREACHABLE("nsBaseWidget::LookupRegisteredPluginWindow "
                         "not implemented!");
  return nullptr;
#else
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(sPluginWidgetList);
  return sPluginWidgetList->GetWeak((void*)aWindowID);
#endif
}

// static
void
nsIWidget::UpdateRegisteredPluginWindowVisibility(uintptr_t aOwnerWidget,
                                                  nsTArray<uintptr_t>& aPluginIds)
{
#if !defined(XP_WIN) && !defined(MOZ_WIDGET_GTK)
  MOZ_ASSERT_UNREACHABLE("nsBaseWidget::UpdateRegisteredPluginWindowVisibility"
                         " not implemented!");
  return;
#else
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(sPluginWidgetList);

  // Our visible list is associated with a compositor which is associated with
  // a specific top level window. We use the parent widget during iteration
  // to skip the plugin widgets owned by other top level windows.
  for (auto iter = sPluginWidgetList->Iter(); !iter.Done(); iter.Next()) {
    const void* windowId = iter.Key();
    nsIWidget* widget = iter.UserData();

    MOZ_ASSERT(windowId);
    MOZ_ASSERT(widget);

    if (!widget->Destroyed()) {
      if ((uintptr_t)widget->GetParent() == aOwnerWidget) {
        widget->Show(aPluginIds.Contains((uintptr_t)windowId));
      }
    }
  }
#endif
}

#if defined(XP_WIN)
// static
void
nsIWidget::CaptureRegisteredPlugins(uintptr_t aOwnerWidget)
{
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(sPluginWidgetList);

  // Our visible list is associated with a compositor which is associated with
  // a specific top level window. We use the parent widget during iteration
  // to skip the plugin widgets owned by other top level windows.
  for (auto iter = sPluginWidgetList->Iter(); !iter.Done(); iter.Next()) {
    DebugOnly<const void*> windowId = iter.Key();
    nsIWidget* widget = iter.UserData();

    MOZ_ASSERT(windowId);
    MOZ_ASSERT(widget);

    if (!widget->Destroyed() && widget->IsVisible()) {
      if ((uintptr_t)widget->GetParent() == aOwnerWidget) {
        widget->UpdateScrollCapture();
      }
    }
  }
}

uint64_t
nsBaseWidget::CreateScrollCaptureContainer()
{
  mScrollCaptureContainer =
    LayerManager::CreateImageContainer(ImageContainer::ASYNCHRONOUS);
  if (!mScrollCaptureContainer) {
    NS_WARNING("Failed to create ImageContainer for widget image capture.");
    return ImageContainer::sInvalidAsyncContainerId;
  }

  return mScrollCaptureContainer->GetAsyncContainerHandle().Value();
}

void
nsBaseWidget::UpdateScrollCapture()
{
  // Don't capture if no container or no size.
  if (!mScrollCaptureContainer || mBounds.IsEmpty()) {
    return;
  }

  // If the derived class cannot take a snapshot, for example due to clipping,
  // then it is responsible for creating a fallback. If null is returned, this
  // means that we want to keep the existing snapshot.
  RefPtr<gfx::SourceSurface> snapshot = CreateScrollSnapshot();
  if (!snapshot) {
    return;
  }

  ImageContainer::NonOwningImage holder(new SourceSurfaceImage(snapshot));

  AutoTArray<ImageContainer::NonOwningImage, 1> imageList;
  imageList.AppendElement(holder);

  mScrollCaptureContainer->SetCurrentImages(imageList);
}

void
nsBaseWidget::DefaultFillScrollCapture(DrawTarget* aSnapshotDrawTarget)
{
  gfx::IntSize dtSize = aSnapshotDrawTarget->GetSize();
  aSnapshotDrawTarget->FillRect(
    gfx::Rect(0, 0, dtSize.width, dtSize.height),
    gfx::ColorPattern(gfx::Color::FromABGR(kScrollCaptureFillColor)),
    gfx::DrawOptions(1.f, gfx::CompositionOp::OP_SOURCE));
  aSnapshotDrawTarget->Flush();
}
#endif

const IMENotificationRequests&
nsIWidget::IMENotificationRequestsRef()
{
  TextEventDispatcher* dispatcher = GetTextEventDispatcher();
  return dispatcher->IMENotificationRequestsRef();
}

nsresult
nsIWidget::OnWindowedPluginKeyEvent(const NativeEventData& aKeyEventData,
                                    nsIKeyEventInPluginCallback* aCallback)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

void
nsIWidget::PostHandleKeyEvent(mozilla::WidgetKeyboardEvent* aEvent)
{
}

void
nsIWidget::GetEditCommands(nsIWidget::NativeKeyBindingsType aType,
                           const WidgetKeyboardEvent& aEvent,
                           nsTArray<CommandInt>& aCommands)
{
  MOZ_ASSERT(aEvent.IsTrusted());
  MOZ_ASSERT(aCommands.IsEmpty());
}

already_AddRefed<nsIBidiKeyboard>
nsIWidget::CreateBidiKeyboard()
{
  if (XRE_IsContentProcess()) {
    return CreateBidiKeyboardContentProcess();
  }
  return CreateBidiKeyboardInner();
}

#ifdef ANDROID
already_AddRefed<nsIBidiKeyboard>
nsIWidget::CreateBidiKeyboardInner()
{
  // no bidi keyboard implementation
  return nullptr;
}
#endif

namespace mozilla {
namespace widget {

const char*
ToChar(InputContext::Origin aOrigin)
{
  switch (aOrigin) {
    case InputContext::ORIGIN_MAIN:
      return "ORIGIN_MAIN";
    case InputContext::ORIGIN_CONTENT:
      return "ORIGIN_CONTENT";
    default:
      return "Unexpected value";
  }
}

const char*
ToChar(IMEMessage aIMEMessage)
{
  switch (aIMEMessage) {
    case NOTIFY_IME_OF_NOTHING:
      return "NOTIFY_IME_OF_NOTHING";
    case NOTIFY_IME_OF_FOCUS:
      return "NOTIFY_IME_OF_FOCUS";
    case NOTIFY_IME_OF_BLUR:
      return "NOTIFY_IME_OF_BLUR";
    case NOTIFY_IME_OF_SELECTION_CHANGE:
      return "NOTIFY_IME_OF_SELECTION_CHANGE";
    case NOTIFY_IME_OF_TEXT_CHANGE:
      return "NOTIFY_IME_OF_TEXT_CHANGE";
    case NOTIFY_IME_OF_COMPOSITION_EVENT_HANDLED:
      return "NOTIFY_IME_OF_COMPOSITION_EVENT_HANDLED";
    case NOTIFY_IME_OF_POSITION_CHANGE:
      return "NOTIFY_IME_OF_POSITION_CHANGE";
    case NOTIFY_IME_OF_MOUSE_BUTTON_EVENT:
      return "NOTIFY_IME_OF_MOUSE_BUTTON_EVENT";
    case REQUEST_TO_COMMIT_COMPOSITION:
      return "REQUEST_TO_COMMIT_COMPOSITION";
    case REQUEST_TO_CANCEL_COMPOSITION:
      return "REQUEST_TO_CANCEL_COMPOSITION";
    default:
      return "Unexpected value";
  }
}

void
NativeIMEContext::Init(nsIWidget* aWidget)
{
  if (!aWidget) {
    mRawNativeIMEContext = reinterpret_cast<uintptr_t>(nullptr);
    mOriginProcessID = static_cast<uint64_t>(-1);
    return;
  }
  if (!XRE_IsContentProcess()) {
    mRawNativeIMEContext = reinterpret_cast<uintptr_t>(
      aWidget->GetNativeData(NS_RAW_NATIVE_IME_CONTEXT));
    mOriginProcessID = 0;
    return;
  }
  // If this is created in a child process, aWidget is an instance of
  // PuppetWidget which doesn't support NS_RAW_NATIVE_IME_CONTEXT.
  // Instead of that PuppetWidget::GetNativeIMEContext() returns cached
  // native IME context of the parent process.
  *this = aWidget->GetNativeIMEContext();
}

void
NativeIMEContext::InitWithRawNativeIMEContext(void* aRawNativeIMEContext)
{
  if (NS_WARN_IF(!aRawNativeIMEContext)) {
    mRawNativeIMEContext = reinterpret_cast<uintptr_t>(nullptr);
    mOriginProcessID = static_cast<uint64_t>(-1);
    return;
  }
  mRawNativeIMEContext = reinterpret_cast<uintptr_t>(aRawNativeIMEContext);
  mOriginProcessID =
    XRE_IsContentProcess() ? ContentChild::GetSingleton()->GetID() : 0;
}

void
IMENotification::TextChangeDataBase::MergeWith(
                   const IMENotification::TextChangeDataBase& aOther)
{
  MOZ_ASSERT(aOther.IsValid(),
             "Merging data must store valid data");
  MOZ_ASSERT(aOther.mStartOffset <= aOther.mRemovedEndOffset,
             "end of removed text must be same or larger than start");
  MOZ_ASSERT(aOther.mStartOffset <= aOther.mAddedEndOffset,
             "end of added text must be same or larger than start");

  if (!IsValid()) {
    *this = aOther;
    return;
  }

  // |mStartOffset| and |mRemovedEndOffset| represent all replaced or removed
  // text ranges.  I.e., mStartOffset should be the smallest offset of all
  // modified text ranges in old text.  |mRemovedEndOffset| should be the
  // largest end offset in old text of all modified text ranges.
  // |mAddedEndOffset| represents the end offset of all inserted text ranges.
  // I.e., only this is an offset in new text.
  // In other words, between mStartOffset and |mRemovedEndOffset| of the
  // premodified text was already removed.  And some text whose length is
  // |mAddedEndOffset - mStartOffset| is inserted to |mStartOffset|.  I.e.,
  // this allows IME to mark dirty the modified text range with |mStartOffset|
  // and |mRemovedEndOffset| if IME stores all text of the focused editor and
  // to compute new text length with |mAddedEndOffset| and |mRemovedEndOffset|.
  // Additionally, IME can retrieve only the text between |mStartOffset| and
  // |mAddedEndOffset| for updating stored text.

  // For comparing new and old |mStartOffset|/|mRemovedEndOffset| values, they
  // should be adjusted to be in same text. The |newData.mStartOffset| and
  // |newData.mRemovedEndOffset| should be computed as in old text because
  // |mStartOffset| and |mRemovedEndOffset| represent the modified text range
  // in the old text but even if some text before the values of the newData
  // has already been modified, the values don't include the changes.

  // For comparing new and old |mAddedEndOffset| values, they should be
  // adjusted to be in same text.  The |oldData.mAddedEndOffset| should be
  // computed as in the new text because |mAddedEndOffset| indicates the end
  // offset of inserted text in the new text but |oldData.mAddedEndOffset|
  // doesn't include any changes of the text before |newData.mAddedEndOffset|.

  const TextChangeDataBase& newData = aOther;
  const TextChangeDataBase oldData = *this;

  // mCausedOnlyByComposition should be true only when all changes are caused
  // by composition.
  mCausedOnlyByComposition =
    newData.mCausedOnlyByComposition && oldData.mCausedOnlyByComposition;

  // mIncludingChangesWithoutComposition should be true if at least one of
  // merged changes occurred without composition.
  mIncludingChangesWithoutComposition =
    newData.mIncludingChangesWithoutComposition ||
      oldData.mIncludingChangesWithoutComposition;

  // mIncludingChangesDuringComposition should be true when at least one of
  // the merged non-composition changes occurred during the latest composition.
  if (!newData.mCausedOnlyByComposition &&
      !newData.mIncludingChangesDuringComposition) {
    MOZ_ASSERT(newData.mIncludingChangesWithoutComposition);
    MOZ_ASSERT(mIncludingChangesWithoutComposition);
    // If new change is neither caused by composition nor occurred during
    // composition, set mIncludingChangesDuringComposition to false because
    // IME doesn't want outdated text changes as text change during current
    // composition.
    mIncludingChangesDuringComposition = false;
  } else {
    // Otherwise, set mIncludingChangesDuringComposition to true if either
    // oldData or newData includes changes during composition.
    mIncludingChangesDuringComposition =
      newData.mIncludingChangesDuringComposition ||
        oldData.mIncludingChangesDuringComposition;
  }

  if (newData.mStartOffset >= oldData.mAddedEndOffset) {
    // Case 1:
    // If new start is after old end offset of added text, it means that text
    // after the modified range is modified.  Like:
    // added range of old change:             +----------+
    // removed range of new change:                           +----------+
    // So, the old start offset is always the smaller offset.
    mStartOffset = oldData.mStartOffset;
    // The new end offset of removed text is moved by the old change and we
    // need to cancel the move of the old change for comparing the offsets in
    // same text because it doesn't make sensce to compare offsets in different
    // text.
    uint32_t newRemovedEndOffsetInOldText =
      newData.mRemovedEndOffset - oldData.Difference();
    mRemovedEndOffset =
      std::max(newRemovedEndOffsetInOldText, oldData.mRemovedEndOffset);
    // The new end offset of added text is always the larger offset.
    mAddedEndOffset = newData.mAddedEndOffset;
    return;
  }

  if (newData.mStartOffset >= oldData.mStartOffset) {
    // If new start is in the modified range, it means that new data changes
    // a part or all of the range.
    mStartOffset = oldData.mStartOffset;
    if (newData.mRemovedEndOffset >= oldData.mAddedEndOffset) {
      // Case 2:
      // If new end of removed text is greater than old end of added text, it
      // means that all or a part of modified range modified again and text
      // after the modified range is also modified.  Like:
      // added range of old change:             +----------+
      // removed range of new change:                   +----------+
      // So, the new removed end offset is moved by the old change and we need
      // to cancel the move of the old change for comparing the offsets in the
      // same text because it doesn't make sense to compare the offsets in
      // different text.
      uint32_t newRemovedEndOffsetInOldText =
        newData.mRemovedEndOffset - oldData.Difference();
      mRemovedEndOffset =
        std::max(newRemovedEndOffsetInOldText, oldData.mRemovedEndOffset);
      // The old end of added text is replaced by new change. So, it should be
      // same as the new start.  On the other hand, the new added end offset is
      // always same or larger.  Therefore, the merged end offset of added
      // text should be the new end offset of added text.
      mAddedEndOffset = newData.mAddedEndOffset;
      return;
    }

    // Case 3:
    // If new end of removed text is less than old end of added text, it means
    // that only a part of the modified range is modified again.  Like:
    // added range of old change:             +------------+
    // removed range of new change:               +-----+
    // So, the new end offset of removed text should be same as the old end
    // offset of removed text.  Therefore, the merged end offset of removed
    // text should be the old text change's |mRemovedEndOffset|.
    mRemovedEndOffset = oldData.mRemovedEndOffset;
    // The old end of added text is moved by new change.  So, we need to cancel
    // the move of the new change for comparing the offsets in same text.
    uint32_t oldAddedEndOffsetInNewText =
      oldData.mAddedEndOffset + newData.Difference();
    mAddedEndOffset =
      std::max(newData.mAddedEndOffset, oldAddedEndOffsetInNewText);
    return;
  }

  if (newData.mRemovedEndOffset >= oldData.mStartOffset) {
    // If new end of removed text is greater than old start (and new start is
    // less than old start), it means that a part of modified range is modified
    // again and some new text before the modified range is also modified.
    MOZ_ASSERT(newData.mStartOffset < oldData.mStartOffset,
      "new start offset should be less than old one here");
    mStartOffset = newData.mStartOffset;
    if (newData.mRemovedEndOffset >= oldData.mAddedEndOffset) {
      // Case 4:
      // If new end of removed text is greater than old end of added text, it
      // means that all modified text and text after the modified range is
      // modified.  Like:
      // added range of old change:             +----------+
      // removed range of new change:        +------------------+
      // So, the new end of removed text is moved by the old change.  Therefore,
      // we need to cancel the move of the old change for comparing the offsets
      // in same text because it doesn't make sense to compare the offsets in
      // different text.
      uint32_t newRemovedEndOffsetInOldText =
        newData.mRemovedEndOffset - oldData.Difference();
      mRemovedEndOffset =
        std::max(newRemovedEndOffsetInOldText, oldData.mRemovedEndOffset);
      // The old end of added text is replaced by new change.  So, the old end
      // offset of added text is same as new text change's start offset.  Then,
      // new change's end offset of added text is always same or larger than
      // it.  Therefore, merged end offset of added text is always the new end
      // offset of added text.
      mAddedEndOffset = newData.mAddedEndOffset;
      return;
    }

    // Case 5:
    // If new end of removed text is less than old end of added text, it
    // means that only a part of the modified range is modified again.  Like:
    // added range of old change:             +----------+
    // removed range of new change:      +----------+
    // So, the new end of removed text should be same as old end of removed
    // text for preventing end of removed text to be modified.  Therefore,
    // merged end offset of removed text is always the old end offset of removed
    // text.
    mRemovedEndOffset = oldData.mRemovedEndOffset;
    // The old end of added text is moved by this change.  So, we need to
    // cancel the move of the new change for comparing the offsets in same text
    // because it doesn't make sense to compare the offsets in different text.
    uint32_t oldAddedEndOffsetInNewText =
      oldData.mAddedEndOffset + newData.Difference();
    mAddedEndOffset =
      std::max(newData.mAddedEndOffset, oldAddedEndOffsetInNewText);
    return;
  }

  // Case 6:
  // Otherwise, i.e., both new end of added text and new start are less than
  // old start, text before the modified range is modified.  Like:
  // added range of old change:                  +----------+
  // removed range of new change: +----------+
  MOZ_ASSERT(newData.mStartOffset < oldData.mStartOffset,
    "new start offset should be less than old one here");
  mStartOffset = newData.mStartOffset;
  MOZ_ASSERT(newData.mRemovedEndOffset < oldData.mRemovedEndOffset,
     "new removed end offset should be less than old one here");
  mRemovedEndOffset = oldData.mRemovedEndOffset;
  // The end of added text should be adjusted with the new difference.
  uint32_t oldAddedEndOffsetInNewText =
    oldData.mAddedEndOffset + newData.Difference();
  mAddedEndOffset =
    std::max(newData.mAddedEndOffset, oldAddedEndOffsetInNewText);
}

#ifdef DEBUG

// Let's test the code of merging multiple text change data in debug build
// and crash if one of them fails because this feature is very complex but
// cannot be tested with mochitest.
void
IMENotification::TextChangeDataBase::Test()
{
  static bool gTestTextChangeEvent = true;
  if (!gTestTextChangeEvent) {
    return;
  }
  gTestTextChangeEvent = false;

  /****************************************************************************
   * Case 1
   ****************************************************************************/

  // Appending text
  MergeWith(TextChangeData(10, 10, 20, false, false));
  MergeWith(TextChangeData(20, 20, 35, false, false));
  MOZ_ASSERT(mStartOffset == 10,
    "Test 1-1-1: mStartOffset should be the first offset");
  MOZ_ASSERT(mRemovedEndOffset == 10, // 20 - (20 - 10)
    "Test 1-1-2: mRemovedEndOffset should be the first end of removed text");
  MOZ_ASSERT(mAddedEndOffset == 35,
    "Test 1-1-3: mAddedEndOffset should be the last end of added text");
  Clear();

  // Removing text (longer line -> shorter line)
  MergeWith(TextChangeData(10, 20, 10, false, false));
  MergeWith(TextChangeData(10, 30, 10, false, false));
  MOZ_ASSERT(mStartOffset == 10,
    "Test 1-2-1: mStartOffset should be the first offset");
  MOZ_ASSERT(mRemovedEndOffset == 40, // 30 + (10 - 20)
    "Test 1-2-2: mRemovedEndOffset should be the the last end of removed text "
    "with already removed length");
  MOZ_ASSERT(mAddedEndOffset == 10,
    "Test 1-2-3: mAddedEndOffset should be the last end of added text");
  Clear();

  // Removing text (shorter line -> longer line)
  MergeWith(TextChangeData(10, 20, 10, false, false));
  MergeWith(TextChangeData(10, 15, 10, false, false));
  MOZ_ASSERT(mStartOffset == 10,
    "Test 1-3-1: mStartOffset should be the first offset");
  MOZ_ASSERT(mRemovedEndOffset == 25, // 15 + (10 - 20)
    "Test 1-3-2: mRemovedEndOffset should be the the last end of removed text "
    "with already removed length");
  MOZ_ASSERT(mAddedEndOffset == 10,
    "Test 1-3-3: mAddedEndOffset should be the last end of added text");
  Clear();

  // Appending text at different point (not sure if actually occurs)
  MergeWith(TextChangeData(10, 10, 20, false, false));
  MergeWith(TextChangeData(55, 55, 60, false, false));
  MOZ_ASSERT(mStartOffset == 10,
    "Test 1-4-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 45, // 55 - (10 - 20)
    "Test 1-4-2: mRemovedEndOffset should be the the largest end of removed "
    "text without already added length");
  MOZ_ASSERT(mAddedEndOffset == 60,
    "Test 1-4-3: mAddedEndOffset should be the last end of added text");
  Clear();

  // Removing text at different point (not sure if actually occurs)
  MergeWith(TextChangeData(10, 20, 10, false, false));
  MergeWith(TextChangeData(55, 68, 55, false, false));
  MOZ_ASSERT(mStartOffset == 10,
    "Test 1-5-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 78, // 68 - (10 - 20)
    "Test 1-5-2: mRemovedEndOffset should be the the largest end of removed "
    "text with already removed length");
  MOZ_ASSERT(mAddedEndOffset == 55,
    "Test 1-5-3: mAddedEndOffset should be the largest end of added text");
  Clear();

  // Replacing text and append text (becomes longer)
  MergeWith(TextChangeData(30, 35, 32, false, false));
  MergeWith(TextChangeData(32, 32, 40, false, false));
  MOZ_ASSERT(mStartOffset == 30,
    "Test 1-6-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 35, // 32 - (32 - 35)
    "Test 1-6-2: mRemovedEndOffset should be the the first end of removed "
    "text");
  MOZ_ASSERT(mAddedEndOffset == 40,
    "Test 1-6-3: mAddedEndOffset should be the last end of added text");
  Clear();

  // Replacing text and append text (becomes shorter)
  MergeWith(TextChangeData(30, 35, 32, false, false));
  MergeWith(TextChangeData(32, 32, 33, false, false));
  MOZ_ASSERT(mStartOffset == 30,
    "Test 1-7-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 35, // 32 - (32 - 35)
    "Test 1-7-2: mRemovedEndOffset should be the the first end of removed "
    "text");
  MOZ_ASSERT(mAddedEndOffset == 33,
    "Test 1-7-3: mAddedEndOffset should be the last end of added text");
  Clear();

  // Removing text and replacing text after first range (not sure if actually
  // occurs)
  MergeWith(TextChangeData(30, 35, 30, false, false));
  MergeWith(TextChangeData(32, 34, 48, false, false));
  MOZ_ASSERT(mStartOffset == 30,
    "Test 1-8-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 39, // 34 - (30 - 35)
    "Test 1-8-2: mRemovedEndOffset should be the the first end of removed text "
    "without already removed text");
  MOZ_ASSERT(mAddedEndOffset == 48,
    "Test 1-8-3: mAddedEndOffset should be the last end of added text");
  Clear();

  // Removing text and replacing text after first range (not sure if actually
  // occurs)
  MergeWith(TextChangeData(30, 35, 30, false, false));
  MergeWith(TextChangeData(32, 38, 36, false, false));
  MOZ_ASSERT(mStartOffset == 30,
    "Test 1-9-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 43, // 38 - (30 - 35)
    "Test 1-9-2: mRemovedEndOffset should be the the first end of removed text "
    "without already removed text");
  MOZ_ASSERT(mAddedEndOffset == 36,
    "Test 1-9-3: mAddedEndOffset should be the last end of added text");
  Clear();

  /****************************************************************************
   * Case 2
   ****************************************************************************/

  // Replacing text in around end of added text (becomes shorter) (not sure
  // if actually occurs)
  MergeWith(TextChangeData(50, 50, 55, false, false));
  MergeWith(TextChangeData(53, 60, 54, false, false));
  MOZ_ASSERT(mStartOffset == 50,
    "Test 2-1-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 55, // 60 - (55 - 50)
    "Test 2-1-2: mRemovedEndOffset should be the the last end of removed text "
    "without already added text length");
  MOZ_ASSERT(mAddedEndOffset == 54,
    "Test 2-1-3: mAddedEndOffset should be the last end of added text");
  Clear();

  // Replacing text around end of added text (becomes longer) (not sure
  // if actually occurs)
  MergeWith(TextChangeData(50, 50, 55, false, false));
  MergeWith(TextChangeData(54, 62, 68, false, false));
  MOZ_ASSERT(mStartOffset == 50,
    "Test 2-2-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 57, // 62 - (55 - 50)
    "Test 2-2-2: mRemovedEndOffset should be the the last end of removed text "
    "without already added text length");
  MOZ_ASSERT(mAddedEndOffset == 68,
    "Test 2-2-3: mAddedEndOffset should be the last end of added text");
  Clear();

  // Replacing text around end of replaced text (became shorter) (not sure if
  // actually occurs)
  MergeWith(TextChangeData(36, 48, 45, false, false));
  MergeWith(TextChangeData(43, 50, 49, false, false));
  MOZ_ASSERT(mStartOffset == 36,
    "Test 2-3-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 53, // 50 - (45 - 48)
    "Test 2-3-2: mRemovedEndOffset should be the the last end of removed text "
    "without already removed text length");
  MOZ_ASSERT(mAddedEndOffset == 49,
    "Test 2-3-3: mAddedEndOffset should be the last end of added text");
  Clear();

  // Replacing text around end of replaced text (became longer) (not sure if
  // actually occurs)
  MergeWith(TextChangeData(36, 52, 53, false, false));
  MergeWith(TextChangeData(43, 68, 61, false, false));
  MOZ_ASSERT(mStartOffset == 36,
    "Test 2-4-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 67, // 68 - (53 - 52)
    "Test 2-4-2: mRemovedEndOffset should be the the last end of removed text "
    "without already added text length");
  MOZ_ASSERT(mAddedEndOffset == 61,
    "Test 2-4-3: mAddedEndOffset should be the last end of added text");
  Clear();

  /****************************************************************************
   * Case 3
   ****************************************************************************/

  // Appending text in already added text (not sure if actually occurs)
  MergeWith(TextChangeData(10, 10, 20, false, false));
  MergeWith(TextChangeData(15, 15, 30, false, false));
  MOZ_ASSERT(mStartOffset == 10,
    "Test 3-1-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 10,
    "Test 3-1-2: mRemovedEndOffset should be the the first end of removed text");
  MOZ_ASSERT(mAddedEndOffset == 35, // 20 + (30 - 15)
    "Test 3-1-3: mAddedEndOffset should be the first end of added text with "
    "added text length by the new change");
  Clear();

  // Replacing text in added text (not sure if actually occurs)
  MergeWith(TextChangeData(50, 50, 55, false, false));
  MergeWith(TextChangeData(52, 53, 56, false, false));
  MOZ_ASSERT(mStartOffset == 50,
    "Test 3-2-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 50,
    "Test 3-2-2: mRemovedEndOffset should be the the first end of removed text");
  MOZ_ASSERT(mAddedEndOffset == 58, // 55 + (56 - 53)
    "Test 3-2-3: mAddedEndOffset should be the first end of added text with "
    "added text length by the new change");
  Clear();

  // Replacing text in replaced text (became shorter) (not sure if actually
  // occurs)
  MergeWith(TextChangeData(36, 48, 45, false, false));
  MergeWith(TextChangeData(37, 38, 50, false, false));
  MOZ_ASSERT(mStartOffset == 36,
    "Test 3-3-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 48,
    "Test 3-3-2: mRemovedEndOffset should be the the first end of removed text");
  MOZ_ASSERT(mAddedEndOffset == 57, // 45 + (50 - 38)
    "Test 3-3-3: mAddedEndOffset should be the first end of added text with "
    "added text length by the new change");
  Clear();

  // Replacing text in replaced text (became longer) (not sure if actually
  // occurs)
  MergeWith(TextChangeData(32, 48, 53, false, false));
  MergeWith(TextChangeData(43, 50, 52, false, false));
  MOZ_ASSERT(mStartOffset == 32,
    "Test 3-4-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 48,
    "Test 3-4-2: mRemovedEndOffset should be the the last end of removed text "
    "without already added text length");
  MOZ_ASSERT(mAddedEndOffset == 55, // 53 + (52 - 50)
    "Test 3-4-3: mAddedEndOffset should be the first end of added text with "
    "added text length by the new change");
  Clear();

  // Replacing text in replaced text (became shorter) (not sure if actually
  // occurs)
  MergeWith(TextChangeData(36, 48, 50, false, false));
  MergeWith(TextChangeData(37, 49, 47, false, false));
  MOZ_ASSERT(mStartOffset == 36,
    "Test 3-5-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 48,
    "Test 3-5-2: mRemovedEndOffset should be the the first end of removed "
    "text");
  MOZ_ASSERT(mAddedEndOffset == 48, // 50 + (47 - 49)
    "Test 3-5-3: mAddedEndOffset should be the first end of added text without "
    "removed text length by the new change");
  Clear();

  // Replacing text in replaced text (became longer) (not sure if actually
  // occurs)
  MergeWith(TextChangeData(32, 48, 53, false, false));
  MergeWith(TextChangeData(43, 50, 47, false, false));
  MOZ_ASSERT(mStartOffset == 32,
    "Test 3-6-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 48,
    "Test 3-6-2: mRemovedEndOffset should be the the last end of removed text "
    "without already added text length");
  MOZ_ASSERT(mAddedEndOffset == 50, // 53 + (47 - 50)
    "Test 3-6-3: mAddedEndOffset should be the first end of added text without "
    "removed text length by the new change");
  Clear();

  /****************************************************************************
   * Case 4
   ****************************************************************************/

  // Replacing text all of already append text (not sure if actually occurs)
  MergeWith(TextChangeData(50, 50, 55, false, false));
  MergeWith(TextChangeData(44, 66, 68, false, false));
  MOZ_ASSERT(mStartOffset == 44,
    "Test 4-1-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 61, // 66 - (55 - 50)
    "Test 4-1-2: mRemovedEndOffset should be the the last end of removed text "
    "without already added text length");
  MOZ_ASSERT(mAddedEndOffset == 68,
    "Test 4-1-3: mAddedEndOffset should be the last end of added text");
  Clear();

  // Replacing text around a point in which text was removed (not sure if
  // actually occurs)
  MergeWith(TextChangeData(50, 62, 50, false, false));
  MergeWith(TextChangeData(44, 66, 68, false, false));
  MOZ_ASSERT(mStartOffset == 44,
    "Test 4-2-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 78, // 66 - (50 - 62)
    "Test 4-2-2: mRemovedEndOffset should be the the last end of removed text "
    "without already removed text length");
  MOZ_ASSERT(mAddedEndOffset == 68,
    "Test 4-2-3: mAddedEndOffset should be the last end of added text");
  Clear();

  // Replacing text all replaced text (became shorter) (not sure if actually
  // occurs)
  MergeWith(TextChangeData(50, 62, 60, false, false));
  MergeWith(TextChangeData(49, 128, 130, false, false));
  MOZ_ASSERT(mStartOffset == 49,
    "Test 4-3-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 130, // 128 - (60 - 62)
    "Test 4-3-2: mRemovedEndOffset should be the the last end of removed text "
    "without already removed text length");
  MOZ_ASSERT(mAddedEndOffset == 130,
    "Test 4-3-3: mAddedEndOffset should be the last end of added text");
  Clear();

  // Replacing text all replaced text (became longer) (not sure if actually
  // occurs)
  MergeWith(TextChangeData(50, 61, 73, false, false));
  MergeWith(TextChangeData(44, 100, 50, false, false));
  MOZ_ASSERT(mStartOffset == 44,
    "Test 4-4-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 88, // 100 - (73 - 61)
    "Test 4-4-2: mRemovedEndOffset should be the the last end of removed text "
    "with already added text length");
  MOZ_ASSERT(mAddedEndOffset == 50,
    "Test 4-4-3: mAddedEndOffset should be the last end of added text");
  Clear();

  /****************************************************************************
   * Case 5
   ****************************************************************************/

  // Replacing text around start of added text (not sure if actually occurs)
  MergeWith(TextChangeData(50, 50, 55, false, false));
  MergeWith(TextChangeData(48, 52, 49, false, false));
  MOZ_ASSERT(mStartOffset == 48,
    "Test 5-1-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 50,
    "Test 5-1-2: mRemovedEndOffset should be the the first end of removed "
    "text");
  MOZ_ASSERT(mAddedEndOffset == 52, // 55 + (52 - 49)
    "Test 5-1-3: mAddedEndOffset should be the first end of added text with "
    "added text length by the new change");
  Clear();

  // Replacing text around start of replaced text (became shorter) (not sure if
  // actually occurs)
  MergeWith(TextChangeData(50, 60, 58, false, false));
  MergeWith(TextChangeData(43, 50, 48, false, false));
  MOZ_ASSERT(mStartOffset == 43,
    "Test 5-2-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 60,
    "Test 5-2-2: mRemovedEndOffset should be the the first end of removed "
    "text");
  MOZ_ASSERT(mAddedEndOffset == 56, // 58 + (48 - 50)
    "Test 5-2-3: mAddedEndOffset should be the first end of added text without "
    "removed text length by the new change");
  Clear();

  // Replacing text around start of replaced text (became longer) (not sure if
  // actually occurs)
  MergeWith(TextChangeData(50, 60, 68, false, false));
  MergeWith(TextChangeData(43, 55, 53, false, false));
  MOZ_ASSERT(mStartOffset == 43,
    "Test 5-3-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 60,
    "Test 5-3-2: mRemovedEndOffset should be the the first end of removed "
    "text");
  MOZ_ASSERT(mAddedEndOffset == 66, // 68 + (53 - 55)
    "Test 5-3-3: mAddedEndOffset should be the first end of added text without "
    "removed text length by the new change");
  Clear();

  // Replacing text around start of replaced text (became shorter) (not sure if
  // actually occurs)
  MergeWith(TextChangeData(50, 60, 58, false, false));
  MergeWith(TextChangeData(43, 50, 128, false, false));
  MOZ_ASSERT(mStartOffset == 43,
    "Test 5-4-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 60,
    "Test 5-4-2: mRemovedEndOffset should be the the first end of removed "
    "text");
  MOZ_ASSERT(mAddedEndOffset == 136, // 58 + (128 - 50)
    "Test 5-4-3: mAddedEndOffset should be the first end of added text with "
    "added text length by the new change");
  Clear();

  // Replacing text around start of replaced text (became longer) (not sure if
  // actually occurs)
  MergeWith(TextChangeData(50, 60, 68, false, false));
  MergeWith(TextChangeData(43, 55, 65, false, false));
  MOZ_ASSERT(mStartOffset == 43,
    "Test 5-5-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 60,
    "Test 5-5-2: mRemovedEndOffset should be the the first end of removed "
    "text");
  MOZ_ASSERT(mAddedEndOffset == 78, // 68 + (65 - 55)
    "Test 5-5-3: mAddedEndOffset should be the first end of added text with "
    "added text length by the new change");
  Clear();

  /****************************************************************************
   * Case 6
   ****************************************************************************/

  // Appending text before already added text (not sure if actually occurs)
  MergeWith(TextChangeData(30, 30, 45, false, false));
  MergeWith(TextChangeData(10, 10, 20, false, false));
  MOZ_ASSERT(mStartOffset == 10,
    "Test 6-1-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 30,
    "Test 6-1-2: mRemovedEndOffset should be the the largest end of removed "
    "text");
  MOZ_ASSERT(mAddedEndOffset == 55, // 45 + (20 - 10)
    "Test 6-1-3: mAddedEndOffset should be the first end of added text with "
    "added text length by the new change");
  Clear();

  // Removing text before already removed text (not sure if actually occurs)
  MergeWith(TextChangeData(30, 35, 30, false, false));
  MergeWith(TextChangeData(10, 25, 10, false, false));
  MOZ_ASSERT(mStartOffset == 10,
    "Test 6-2-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 35,
    "Test 6-2-2: mRemovedEndOffset should be the the largest end of removed "
    "text");
  MOZ_ASSERT(mAddedEndOffset == 15, // 30 - (25 - 10)
    "Test 6-2-3: mAddedEndOffset should be the first end of added text with "
    "removed text length by the new change");
  Clear();

  // Replacing text before already replaced text (not sure if actually occurs)
  MergeWith(TextChangeData(50, 65, 70, false, false));
  MergeWith(TextChangeData(13, 24, 15, false, false));
  MOZ_ASSERT(mStartOffset == 13,
    "Test 6-3-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 65,
    "Test 6-3-2: mRemovedEndOffset should be the the largest end of removed "
    "text");
  MOZ_ASSERT(mAddedEndOffset == 61, // 70 + (15 - 24)
    "Test 6-3-3: mAddedEndOffset should be the first end of added text without "
    "removed text length by the new change");
  Clear();

  // Replacing text before already replaced text (not sure if actually occurs)
  MergeWith(TextChangeData(50, 65, 70, false, false));
  MergeWith(TextChangeData(13, 24, 36, false, false));
  MOZ_ASSERT(mStartOffset == 13,
    "Test 6-4-1: mStartOffset should be the smallest offset");
  MOZ_ASSERT(mRemovedEndOffset == 65,
    "Test 6-4-2: mRemovedEndOffset should be the the largest end of removed "
    "text");
  MOZ_ASSERT(mAddedEndOffset == 82, // 70 + (36 - 24)
    "Test 6-4-3: mAddedEndOffset should be the first end of added text without "
    "removed text length by the new change");
  Clear();
}

#endif // #ifdef DEBUG

} // namespace widget
} // namespace mozilla

#ifdef DEBUG
//////////////////////////////////////////////////////////////
//
// Convert a GUI event message code to a string.
// Makes it a lot easier to debug events.
//
// See gtk/nsWidget.cpp and windows/nsWindow.cpp
// for a DebugPrintEvent() function that uses
// this.
//
//////////////////////////////////////////////////////////////
/* static */ nsAutoString
nsBaseWidget::debug_GuiEventToString(WidgetGUIEvent* aGuiEvent)
{
  NS_ASSERTION(nullptr != aGuiEvent,"cmon, null gui event.");

  nsAutoString eventName(NS_LITERAL_STRING("UNKNOWN"));

#define _ASSIGN_eventName(_value,_name)\
case _value: eventName.AssignLiteral(_name) ; break

  switch(aGuiEvent->mMessage)
  {
    _ASSIGN_eventName(eBlur,"eBlur");
    _ASSIGN_eventName(eDrop,"eDrop");
    _ASSIGN_eventName(eDragEnter,"eDragEnter");
    _ASSIGN_eventName(eDragExit,"eDragExit");
    _ASSIGN_eventName(eDragOver,"eDragOver");
    _ASSIGN_eventName(eEditorInput,"eEditorInput");
    _ASSIGN_eventName(eFocus,"eFocus");
    _ASSIGN_eventName(eFocusIn,"eFocusIn");
    _ASSIGN_eventName(eFocusOut,"eFocusOut");
    _ASSIGN_eventName(eFormSelect,"eFormSelect");
    _ASSIGN_eventName(eFormChange,"eFormChange");
    _ASSIGN_eventName(eFormReset,"eFormReset");
    _ASSIGN_eventName(eFormSubmit,"eFormSubmit");
    _ASSIGN_eventName(eImageAbort,"eImageAbort");
    _ASSIGN_eventName(eLoadError,"eLoadError");
    _ASSIGN_eventName(eKeyDown,"eKeyDown");
    _ASSIGN_eventName(eKeyPress,"eKeyPress");
    _ASSIGN_eventName(eKeyUp,"eKeyUp");
    _ASSIGN_eventName(eMouseEnterIntoWidget,"eMouseEnterIntoWidget");
    _ASSIGN_eventName(eMouseExitFromWidget,"eMouseExitFromWidget");
    _ASSIGN_eventName(eMouseDown,"eMouseDown");
    _ASSIGN_eventName(eMouseUp,"eMouseUp");
    _ASSIGN_eventName(eMouseClick,"eMouseClick");
    _ASSIGN_eventName(eMouseAuxClick,"eMouseAuxClick");
    _ASSIGN_eventName(eMouseDoubleClick,"eMouseDoubleClick");
    _ASSIGN_eventName(eMouseMove,"eMouseMove");
    _ASSIGN_eventName(eLoad,"eLoad");
    _ASSIGN_eventName(ePopState,"ePopState");
    _ASSIGN_eventName(eBeforeScriptExecute,"eBeforeScriptExecute");
    _ASSIGN_eventName(eAfterScriptExecute,"eAfterScriptExecute");
    _ASSIGN_eventName(eUnload,"eUnload");
    _ASSIGN_eventName(eHashChange,"eHashChange");
    _ASSIGN_eventName(eReadyStateChange,"eReadyStateChange");
    _ASSIGN_eventName(eXULBroadcast, "eXULBroadcast");
    _ASSIGN_eventName(eXULCommandUpdate, "eXULCommandUpdate");

#undef _ASSIGN_eventName

  default:
    {
    eventName.AssignLiteral("UNKNOWN: ");
    eventName.AppendInt(aGuiEvent->mMessage);
    }
    break;
  }

  return nsAutoString(eventName);
}
//////////////////////////////////////////////////////////////
//
// Code to deal with paint and event debug prefs.
//
//////////////////////////////////////////////////////////////
struct PrefPair
{
  const char * name;
  bool value;
};

static PrefPair debug_PrefValues[] =
{
  { "nglayout.debug.crossing_event_dumping", false },
  { "nglayout.debug.event_dumping", false },
  { "nglayout.debug.invalidate_dumping", false },
  { "nglayout.debug.motion_event_dumping", false },
  { "nglayout.debug.paint_dumping", false },
  { "nglayout.debug.paint_flashing", false }
};

//////////////////////////////////////////////////////////////
bool
nsBaseWidget::debug_GetCachedBoolPref(const char * aPrefName)
{
  NS_ASSERTION(nullptr != aPrefName,"cmon, pref name is null.");

  for (uint32_t i = 0; i < ArrayLength(debug_PrefValues); i++)
  {
    if (strcmp(debug_PrefValues[i].name, aPrefName) == 0)
    {
      return debug_PrefValues[i].value;
    }
  }

  return false;
}
//////////////////////////////////////////////////////////////
static void debug_SetCachedBoolPref(const char * aPrefName,bool aValue)
{
  NS_ASSERTION(nullptr != aPrefName,"cmon, pref name is null.");

  for (uint32_t i = 0; i < ArrayLength(debug_PrefValues); i++)
  {
    if (strcmp(debug_PrefValues[i].name, aPrefName) == 0)
    {
      debug_PrefValues[i].value = aValue;

      return;
    }
  }

  NS_ASSERTION(false, "cmon, this code is not reached dude.");
}

//////////////////////////////////////////////////////////////
class Debug_PrefObserver final : public nsIObserver {
    ~Debug_PrefObserver() {}

  public:
    NS_DECL_ISUPPORTS
    NS_DECL_NSIOBSERVER
};

NS_IMPL_ISUPPORTS(Debug_PrefObserver, nsIObserver)

NS_IMETHODIMP
Debug_PrefObserver::Observe(nsISupports* subject, const char* topic,
                            const char16_t* data)
{
  NS_ConvertUTF16toUTF8 prefName(data);

  bool value = Preferences::GetBool(prefName.get(), false);
  debug_SetCachedBoolPref(prefName.get(), value);
  return NS_OK;
}

//////////////////////////////////////////////////////////////
/* static */ void
debug_RegisterPrefCallbacks()
{
  static bool once = true;

  if (!once) {
    return;
  }

  once = false;

  nsCOMPtr<nsIObserver> obs(new Debug_PrefObserver());
  for (uint32_t i = 0; i < ArrayLength(debug_PrefValues); i++) {
    // Initialize the pref values
    debug_PrefValues[i].value =
      Preferences::GetBool(debug_PrefValues[i].name, false);

    if (obs) {
      // Register callbacks for when these change
      nsCString name;
      name.AssignLiteral(debug_PrefValues[i].name,
                         strlen(debug_PrefValues[i].name));
      Preferences::AddStrongObserver(obs, name);
    }
  }
}
//////////////////////////////////////////////////////////////
static int32_t
_GetPrintCount()
{
  static int32_t sCount = 0;

  return ++sCount;
}
//////////////////////////////////////////////////////////////
/* static */ bool
nsBaseWidget::debug_WantPaintFlashing()
{
  return debug_GetCachedBoolPref("nglayout.debug.paint_flashing");
}
//////////////////////////////////////////////////////////////
/* static */ void
nsBaseWidget::debug_DumpEvent(FILE *                aFileOut,
                              nsIWidget *           aWidget,
                              WidgetGUIEvent*       aGuiEvent,
                              const char*           aWidgetName,
                              int32_t               aWindowID)
{
  if (aGuiEvent->mMessage == eMouseMove) {
    if (!debug_GetCachedBoolPref("nglayout.debug.motion_event_dumping"))
      return;
  }

  if (aGuiEvent->mMessage == eMouseEnterIntoWidget ||
      aGuiEvent->mMessage == eMouseExitFromWidget) {
    if (!debug_GetCachedBoolPref("nglayout.debug.crossing_event_dumping"))
      return;
  }

  if (!debug_GetCachedBoolPref("nglayout.debug.event_dumping"))
    return;

  NS_LossyConvertUTF16toASCII tempString(debug_GuiEventToString(aGuiEvent).get());

  fprintf(aFileOut,
          "%4d %-26s widget=%-8p name=%-12s id=0x%-6x refpt=%d,%d\n",
          _GetPrintCount(),
          tempString.get(),
          (void *) aWidget,
          aWidgetName,
          aWindowID,
          aGuiEvent->mRefPoint.x,
          aGuiEvent->mRefPoint.y);
}
//////////////////////////////////////////////////////////////
/* static */ void
nsBaseWidget::debug_DumpPaintEvent(FILE *                aFileOut,
                                   nsIWidget *           aWidget,
                                   const nsIntRegion &   aRegion,
                                   const char *          aWidgetName,
                                   int32_t               aWindowID)
{
  NS_ASSERTION(nullptr != aFileOut,"cmon, null output FILE");
  NS_ASSERTION(nullptr != aWidget,"cmon, the widget is null");

  if (!debug_GetCachedBoolPref("nglayout.debug.paint_dumping"))
    return;

  nsIntRect rect = aRegion.GetBounds();
  fprintf(aFileOut,
          "%4d PAINT      widget=%p name=%-12s id=0x%-6x bounds-rect=%3d,%-3d %3d,%-3d",
          _GetPrintCount(),
          (void *) aWidget,
          aWidgetName,
          aWindowID,
          rect.X(), rect.Y(), rect.Width(), rect.Height()
    );

  fprintf(aFileOut,"\n");
}
//////////////////////////////////////////////////////////////
/* static */ void
nsBaseWidget::debug_DumpInvalidate(FILE* aFileOut,
                                   nsIWidget* aWidget,
                                   const LayoutDeviceIntRect* aRect,
                                   const char* aWidgetName,
                                   int32_t aWindowID)
{
  if (!debug_GetCachedBoolPref("nglayout.debug.invalidate_dumping"))
    return;

  NS_ASSERTION(nullptr != aFileOut,"cmon, null output FILE");
  NS_ASSERTION(nullptr != aWidget,"cmon, the widget is null");

  fprintf(aFileOut,
          "%4d Invalidate widget=%p name=%-12s id=0x%-6x",
          _GetPrintCount(),
          (void *) aWidget,
          aWidgetName,
          aWindowID);

  if (aRect) {
    fprintf(aFileOut,
            " rect=%3d,%-3d %3d,%-3d",
            aRect->X(), aRect->Y(), aRect->Width(), aRect->Height());
  } else {
    fprintf(aFileOut,
            " rect=%-15s",
            "none");
  }

  fprintf(aFileOut, "\n");
}
//////////////////////////////////////////////////////////////

#endif // DEBUG