widget/nsBaseWidget.h
author Dorel Luca <dluca@mozilla.com>
Mon, 04 Dec 2017 18:01:09 +0200
changeset 394844 58fec9a96e269a57cc6f84bfe3a6dc6800acd955
parent 392781 f540f9e801cb2e0be5259baea13dfce953ccb520
child 396793 4309d6abe27f88b9dcc90b59a69b469df6da959e
permissions -rw-r--r--
Backed out 7 changesets (bug 1377007) for failing build bustage on Linux pgo and faling Cpp's jsapi-tests r=backout on a CLOSED TREE Backed out changeset 9428a4ed7dec (bug 1377007) Backed out changeset 4407b43a8aff (bug 1377007) Backed out changeset 65a37a7f78a5 (bug 1377007) Backed out changeset 276fe6d9b716 (bug 1377007) Backed out changeset 1de46e60ffba (bug 1377007) Backed out changeset 893e303e17ec (bug 1377007) Backed out changeset 081a241e25d4 (bug 1377007)

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
#ifndef nsBaseWidget_h__
#define nsBaseWidget_h__

#include "InputData.h"
#include "mozilla/EventForwards.h"
#include "mozilla/RefPtr.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/WidgetUtils.h"
#include "mozilla/layers/APZCCallbackHelper.h"
#include "mozilla/layers/CompositorOptions.h"
#include "nsRect.h"
#include "nsIWidget.h"
#include "nsWidgetsCID.h"
#include "nsIFile.h"
#include "nsString.h"
#include "nsCOMPtr.h"
#include "nsIRollupListener.h"
#include "nsIObserver.h"
#include "nsIWidgetListener.h"
#include "nsPIDOMWindow.h"
#include "nsWeakReference.h"
#include <algorithm>

#if defined(XP_WIN)
// Scroll capture constants
const uint32_t kScrollCaptureFillColor = 0xFFa0a0a0; // gray
const mozilla::gfx::SurfaceFormat kScrollCaptureFormat =
  mozilla::gfx::SurfaceFormat::X8R8G8B8_UINT32;
#endif

class nsIContent;
class gfxContext;

namespace mozilla {
class CompositorVsyncDispatcher;
class LiveResizeListener;

#ifdef ACCESSIBILITY
namespace a11y {
class Accessible;
}
#endif

namespace gfx {
class DrawTarget;
class SourceSurface;
} // namespace gfx

namespace layers {
class BasicLayerManager;
class CompositorBridgeChild;
class CompositorBridgeParent;
class IAPZCTreeManager;
class GeckoContentController;
class APZEventState;
class CompositorSession;
class ImageContainer;
struct ScrollableLayerGuid;
class RemoteCompositorSession;
} // namespace layers

namespace widget {
class CompositorWidgetDelegate;
class InProcessCompositorWidget;
class WidgetRenderingContext;
} // namespace widget

class CompositorVsyncDispatcher;
} // namespace mozilla

namespace base {
class Thread;
} // namespace base

// Windows specific constant indicating the maximum number of touch points the
// inject api will allow. This also sets the maximum numerical value for touch
// ids we can use when injecting touch points on Windows.
#define TOUCH_INJECT_MAX_POINTS 256

class nsBaseWidget;

// Helper class used in shutting down gfx related code.
class WidgetShutdownObserver final : public nsIObserver
{
  ~WidgetShutdownObserver();

public:
  explicit WidgetShutdownObserver(nsBaseWidget* aWidget);

  NS_DECL_ISUPPORTS
  NS_DECL_NSIOBSERVER

  void Register();
  void Unregister();

  nsBaseWidget *mWidget;
  bool mRegistered;
};

/**
 * Common widget implementation used as base class for native
 * or crossplatform implementations of Widgets.
 * All cross-platform behavior that all widgets need to implement
 * should be placed in this class.
 * (Note: widget implementations are not required to use this
 * class, but it gives them a head start.)
 */

class nsBaseWidget : public nsIWidget, public nsSupportsWeakReference
{
  friend class DispatchWheelEventOnMainThread;
  friend class mozilla::widget::InProcessCompositorWidget;
  friend class mozilla::layers::RemoteCompositorSession;

protected:
  typedef base::Thread Thread;
  typedef mozilla::gfx::DrawTarget DrawTarget;
  typedef mozilla::gfx::SourceSurface SourceSurface;
  typedef mozilla::layers::BasicLayerManager BasicLayerManager;
  typedef mozilla::layers::BufferMode BufferMode;
  typedef mozilla::layers::CompositorBridgeChild CompositorBridgeChild;
  typedef mozilla::layers::CompositorBridgeParent CompositorBridgeParent;
  typedef mozilla::layers::IAPZCTreeManager IAPZCTreeManager;
  typedef mozilla::layers::GeckoContentController GeckoContentController;
  typedef mozilla::layers::ScrollableLayerGuid ScrollableLayerGuid;
  typedef mozilla::layers::APZEventState APZEventState;
  typedef mozilla::layers::SetAllowedTouchBehaviorCallback SetAllowedTouchBehaviorCallback;
  typedef mozilla::CSSIntRect CSSIntRect;
  typedef mozilla::CSSRect CSSRect;
  typedef mozilla::ScreenRotation ScreenRotation;
  typedef mozilla::widget::CompositorWidgetDelegate CompositorWidgetDelegate;
  typedef mozilla::layers::CompositorSession CompositorSession;
  typedef mozilla::layers::ImageContainer ImageContainer;

  virtual ~nsBaseWidget();

public:
  nsBaseWidget();

  NS_DECL_ISUPPORTS

  // nsIWidget interface
  virtual void            CaptureMouse(bool aCapture) override {}
  virtual void            CaptureRollupEvents(nsIRollupListener* aListener,
                                              bool aDoCapture) override {}
  virtual nsIWidgetListener*  GetWidgetListener() override;
  virtual void            SetWidgetListener(nsIWidgetListener* alistener) override;
  virtual void            Destroy() override;
  virtual void            SetParent(nsIWidget* aNewParent) override {};
  virtual nsIWidget*      GetParent(void) override;
  virtual nsIWidget*      GetTopLevelWidget() override;
  virtual nsIWidget*      GetSheetWindowParent(void) override;
  virtual float           GetDPI() override;
  virtual void            AddChild(nsIWidget* aChild) override;
  virtual void            RemoveChild(nsIWidget* aChild) override;

  void                    SetZIndex(int32_t aZIndex) override;
  virtual void            PlaceBehind(nsTopLevelWidgetZPlacement aPlacement,
                                      nsIWidget *aWidget, bool aActivate)
                                      override {}

  virtual void            SetSizeMode(nsSizeMode aMode) override;
  virtual nsSizeMode      SizeMode() override
  {
    return mSizeMode;
  }

  virtual bool            IsFullyOccluded() const override
  {
    return mIsFullyOccluded;
  }

  virtual void            SetCursor(nsCursor aCursor) override;
  virtual nsresult        SetCursor(imgIContainer* aCursor,
                                    uint32_t aHotspotX, uint32_t aHotspotY) override;
  virtual void            ClearCachedCursor() override { mUpdateCursor = true; }
  virtual void            SetTransparencyMode(nsTransparencyMode aMode) override;
  virtual nsTransparencyMode GetTransparencyMode() override;
  virtual void            GetWindowClipRegion(nsTArray<LayoutDeviceIntRect>* aRects) override;
  virtual void            SetWindowShadowStyle(int32_t aStyle) override {}
  virtual void            SetShowsToolbarButton(bool aShow) override {}
  virtual void            SetShowsFullScreenButton(bool aShow) override {}
  virtual void            SetWindowAnimationType(WindowAnimationType aType) override {}
  virtual void            HideWindowChrome(bool aShouldHide) override {}
  virtual bool PrepareForFullscreenTransition(nsISupports** aData) override { return false; }
  virtual void PerformFullscreenTransition(FullscreenTransitionStage aStage,
                                           uint16_t aDuration,
                                           nsISupports* aData,
                                           nsIRunnable* aCallback) override;
  virtual already_AddRefed<nsIScreen> GetWidgetScreen() override;
  virtual nsresult        MakeFullScreen(bool aFullScreen,
                                         nsIScreen* aScreen = nullptr) override;
  void                    InfallibleMakeFullScreen(bool aFullScreen,
                                                   nsIScreen* aScreen = nullptr);

  virtual LayerManager*   GetLayerManager(PLayerTransactionChild* aShadowManager = nullptr,
                                          LayersBackend aBackendHint = mozilla::layers::LayersBackend::LAYERS_NONE,
                                          LayerManagerPersistence aPersistence = LAYER_MANAGER_CURRENT) override;

  // A remote compositor session tied to this window has been lost and IPC
  // messages will no longer work. The widget must clean up any lingering
  // resources and possibly schedule another paint.
  //
  // A reference to the session object is held until this function has
  // returned.
  void NotifyCompositorSessionLost(mozilla::layers::CompositorSession* aSession);

  mozilla::CompositorVsyncDispatcher* GetCompositorVsyncDispatcher();
  void            CreateCompositorVsyncDispatcher();
  virtual void            CreateCompositor();
  virtual void            CreateCompositor(int aWidth, int aHeight);
  virtual void            SetCompositorWidgetDelegate(CompositorWidgetDelegate* delegate) {}
  virtual void            PrepareWindowEffects() override {}
  virtual void            UpdateThemeGeometries(const nsTArray<ThemeGeometry>& aThemeGeometries) override {}
  virtual void            SetModal(bool aModal) override {}
  virtual uint32_t        GetMaxTouchPoints() const override;
  virtual void            SetWindowClass(const nsAString& xulWinType)
                            override {}
  virtual nsresult        SetWindowClipRegion(const nsTArray<LayoutDeviceIntRect>& aRects, bool aIntersectWithExisting) override;
  // Return whether this widget interprets parameters to Move and Resize APIs
  // as "desktop pixels" rather than "device pixels", and therefore
  // applies its GetDefaultScale() value to them before using them as mBounds
  // etc (which are always stored in device pixels).
  // Note that APIs that -get- the widget's position/size/bounds, rather than
  // -setting- them (i.e. moving or resizing the widget) will always return
  // values in the widget's device pixels.
  bool                    BoundsUseDesktopPixels() const {
    return mWindowType <= eWindowType_popup;
  }
  // Default implementation, to be overridden by platforms where desktop coords
  // are virtualized and may not correspond to device pixels on the screen.
  mozilla::DesktopToLayoutDeviceScale GetDesktopToDeviceScale() override {
    return mozilla::DesktopToLayoutDeviceScale(1.0);
  }
  virtual void            ConstrainPosition(bool aAllowSlop,
                                            int32_t *aX,
                                            int32_t *aY) override {}
  virtual void            MoveClient(double aX, double aY) override;
  virtual void            ResizeClient(double aWidth, double aHeight, bool aRepaint) override;
  virtual void            ResizeClient(double aX, double aY, double aWidth, double aHeight, bool aRepaint) override;
  virtual LayoutDeviceIntRect GetBounds() override;
  virtual LayoutDeviceIntRect GetClientBounds() override;
  virtual LayoutDeviceIntRect GetScreenBounds() override;
  virtual MOZ_MUST_USE nsresult GetRestoredBounds(LayoutDeviceIntRect& aRect) override;
  virtual nsresult        SetNonClientMargins(LayoutDeviceIntMargin& aMargins) override;
  virtual LayoutDeviceIntPoint GetClientOffset() override;
  virtual void            EnableDragDrop(bool aEnable) override {};
  virtual nsresult        AsyncEnableDragDrop(bool aEnable) override;
  virtual MOZ_MUST_USE nsresult
                          GetAttention(int32_t aCycleCount) override
                          { return NS_OK; }
  virtual bool            HasPendingInputEvent() override;
  virtual void            SetIcon(const nsAString &aIconSpec) override {}
  virtual void            SetWindowTitlebarColor(nscolor aColor, bool aActive)
                            override {}
  virtual void            SetDrawsInTitlebar(bool aState) override {}
  virtual bool            ShowsResizeIndicator(LayoutDeviceIntRect* aResizerRect) override;
  virtual void            FreeNativeData(void * data, uint32_t aDataType) override {}
  virtual MOZ_MUST_USE nsresult
                          BeginResizeDrag(mozilla::WidgetGUIEvent* aEvent,
                                          int32_t aHorizontal,
                                          int32_t aVertical) override
                          { return NS_ERROR_NOT_IMPLEMENTED; }
  virtual MOZ_MUST_USE nsresult
                          BeginMoveDrag(mozilla::WidgetMouseEvent* aEvent) override
                          { return NS_ERROR_NOT_IMPLEMENTED; }
  virtual nsresult        ActivateNativeMenuItemAt(const nsAString& indexString) override { return NS_ERROR_NOT_IMPLEMENTED; }
  virtual nsresult        ForceUpdateNativeMenuAt(const nsAString& indexString) override { return NS_ERROR_NOT_IMPLEMENTED; }
  virtual nsresult        NotifyIME(const IMENotification& aIMENotification)
                            override final;
  virtual MOZ_MUST_USE nsresult
                          StartPluginIME(const mozilla::WidgetKeyboardEvent& aKeyboardEvent,
                                         int32_t aPanelX, int32_t aPanelY,
                                         nsString& aCommitted) override
                          { return NS_ERROR_NOT_IMPLEMENTED; }
  virtual void            SetPluginFocused(bool& aFocused) override {}
  virtual void            SetCandidateWindowForPlugin(
                            const mozilla::widget::CandidateWindowPosition&
                              aPosition) override
                          { }
  virtual void            DefaultProcOfPluginEvent(
                            const mozilla::WidgetPluginEvent& aEvent) override
                          { }
  virtual MOZ_MUST_USE nsresult AttachNativeKeyEvent(mozilla::WidgetKeyboardEvent& aEvent) override { return NS_ERROR_NOT_IMPLEMENTED; }
  bool                    ComputeShouldAccelerate();
  virtual bool            WidgetTypeSupportsAcceleration() { return true; }
  virtual MOZ_MUST_USE nsresult OnDefaultButtonLoaded(const LayoutDeviceIntRect& aButtonRect) override { return NS_ERROR_NOT_IMPLEMENTED; }
  virtual already_AddRefed<nsIWidget>
  CreateChild(const LayoutDeviceIntRect& aRect,
              nsWidgetInitData* aInitData = nullptr,
              bool aForceUseIWidgetParent = false) override;
  virtual void            AttachViewToTopLevel(bool aUseAttachedEvents) override;
  virtual nsIWidgetListener* GetAttachedWidgetListener() override;
  virtual void               SetAttachedWidgetListener(nsIWidgetListener* aListener) override;
  virtual nsIWidgetListener* GetPreviouslyAttachedWidgetListener() override;
  virtual void               SetPreviouslyAttachedWidgetListener(nsIWidgetListener* aListener) override;
  virtual TextEventDispatcher* GetTextEventDispatcher() override final;
  virtual TextEventDispatcherListener*
    GetNativeTextEventDispatcherListener() override;
  virtual void ZoomToRect(const uint32_t& aPresShellId,
                          const FrameMetrics::ViewID& aViewId,
                          const CSSRect& aRect,
                          const uint32_t& aFlags) override;
  // Dispatch an event that must be first be routed through APZ.
  nsEventStatus DispatchInputEvent(mozilla::WidgetInputEvent* aEvent) override;
  void DispatchEventToAPZOnly(mozilla::WidgetInputEvent* aEvent) override;

  void SetConfirmedTargetAPZC(uint64_t aInputBlockId,
                              const nsTArray<ScrollableLayerGuid>& aTargets) const override;

  void UpdateZoomConstraints(const uint32_t& aPresShellId,
                             const FrameMetrics::ViewID& aViewId,
                             const mozilla::Maybe<ZoomConstraints>& aConstraints) override;

  bool AsyncPanZoomEnabled() const override;

  void NotifyWindowDestroyed();
  void NotifySizeMoveDone();
  void NotifyWindowMoved(int32_t aX, int32_t aY);

  // Register plugin windows for remote updates from the compositor
  virtual void RegisterPluginWindowForRemoteUpdates() override;
  virtual void UnregisterPluginWindowForRemoteUpdates() override;

  virtual void SetNativeData(uint32_t aDataType, uintptr_t aVal) override {};

  // Should be called by derived implementations to notify on system color and
  // theme changes.
  void NotifySysColorChanged();
  void NotifyThemeChanged();
  void NotifyUIStateChanged(UIStateChangeType aShowAccelerators,
                            UIStateChangeType aShowFocusRings);

#ifdef ACCESSIBILITY
  // Get the accessible for the window.
  mozilla::a11y::Accessible* GetRootAccessible();
#endif

  // Return true if this is a simple widget (that is typically not worth
  // accelerating)
  bool IsSmallPopup() const;

  nsPopupLevel PopupLevel() { return mPopupLevel; }

  virtual LayoutDeviceIntSize
  ClientToWindowSize(const LayoutDeviceIntSize& aClientSize) override
  {
    return aClientSize;
  }

  // return true if this is a popup widget with a native titlebar
  bool IsPopupWithTitleBar() const
  {
    return (mWindowType == eWindowType_popup &&
            mBorderStyle != eBorderStyle_default &&
            mBorderStyle & eBorderStyle_title);
  }

  virtual void ReparentNativeWidget(nsIWidget* aNewParent) override {}

  virtual const SizeConstraints GetSizeConstraints() override;
  virtual void SetSizeConstraints(const SizeConstraints& aConstraints) override;

  virtual void StartAsyncScrollbarDrag(const AsyncDragMetrics& aDragMetrics) override;

  virtual bool StartAsyncAutoscroll(const ScreenPoint& aAnchorLocation,
                                    const ScrollableLayerGuid& aGuid) override;

  virtual void StopAsyncAutoscroll(const ScrollableLayerGuid& aGuid) override;

  /**
   * Use this when GetLayerManager() returns a BasicLayerManager
   * (nsBaseWidget::GetLayerManager() does). This sets up the widget's
   * layer manager to temporarily render into aTarget.
   *
   * |aNaturalWidgetBounds| is the un-rotated bounds of |aWidget|.
   * |aRotation| is the "virtual rotation" to apply when rendering to
   * the target.  When |aRotation| is ROTATION_0,
   * |aNaturalWidgetBounds| is not used.
   */
  class AutoLayerManagerSetup {
  public:
    AutoLayerManagerSetup(nsBaseWidget* aWidget, gfxContext* aTarget,
                          BufferMode aDoubleBuffering,
                          ScreenRotation aRotation = mozilla::ROTATION_0);
    ~AutoLayerManagerSetup();
  private:
    nsBaseWidget* mWidget;
    RefPtr<BasicLayerManager> mLayerManager;
  };
  friend class AutoLayerManagerSetup;

  virtual bool            ShouldUseOffMainThreadCompositing();

  static nsIRollupListener* GetActiveRollupListener();

  void Shutdown();

#if defined(XP_WIN)
  uint64_t CreateScrollCaptureContainer() override;
#endif

  // These functions should be called at the start and end of a "live" widget
  // resize (i.e. when the window contents are repainting during the resize,
  // such as when the user drags a window border). It will suppress the
  // displayport during the live resize to avoid unneccessary overpainting.
  void NotifyLiveResizeStarted();
  void NotifyLiveResizeStopped();

#if defined(MOZ_WIDGET_ANDROID)
  void RecvToolbarAnimatorMessageFromCompositor(int32_t) override {};
  void UpdateRootFrameMetrics(const ScreenPoint& aScrollOffset, const CSSToScreenScale& aZoom) override {};
  void RecvScreenPixels(mozilla::ipc::Shmem&& aMem, const ScreenIntSize& aSize) override {};
#endif

  /**
   * Whether context menus should only appear on mouseup instead of mousedown,
   * on OSes where they normally appear on mousedown (macOS, *nix).
   */
  static bool ShowContextMenuAfterMouseUp();

protected:
  // These are methods for CompositorWidgetWrapper, and should only be
  // accessed from that class. Derived widgets can choose which methods to
  // implement, or none if supporting out-of-process compositing.
  virtual bool PreRender(mozilla::widget::WidgetRenderingContext* aContext) {
    return true;
  }
  virtual void PostRender(mozilla::widget::WidgetRenderingContext* aContext)
  {}
  virtual void DrawWindowUnderlay(mozilla::widget::WidgetRenderingContext* aContext,
                                  LayoutDeviceIntRect aRect)
  {}
  virtual void DrawWindowOverlay(mozilla::widget::WidgetRenderingContext* aContext,
                                 LayoutDeviceIntRect aRect)
  {}
  virtual already_AddRefed<DrawTarget> StartRemoteDrawing();
  virtual already_AddRefed<DrawTarget>
  StartRemoteDrawingInRegion(LayoutDeviceIntRegion& aInvalidRegion, BufferMode* aBufferMode)
  {
    return StartRemoteDrawing();
  }
  virtual void EndRemoteDrawing()
  {}
  virtual void EndRemoteDrawingInRegion(DrawTarget* aDrawTarget,
                                        LayoutDeviceIntRegion& aInvalidRegion)
  {
    EndRemoteDrawing();
  }
  virtual void CleanupRemoteDrawing()
  {}
  virtual void CleanupWindowEffects()
  {}
  virtual bool InitCompositor(mozilla::layers::Compositor* aCompositor) {
    return true;
  }
  virtual uint32_t GetGLFrameBufferFormat();

protected:
  void            ResolveIconName(const nsAString &aIconName,
                                  const nsAString &aIconSuffix,
                                  nsIFile **aResult);
  virtual void    OnDestroy();
  void            BaseCreate(nsIWidget *aParent,
                             nsWidgetInitData* aInitData);

  virtual void ConfigureAPZCTreeManager();
  virtual void ConfigureAPZControllerThread();
  virtual already_AddRefed<GeckoContentController> CreateRootContentController();

  // Dispatch an event that has already been routed through APZ.
  nsEventStatus ProcessUntransformedAPZEvent(mozilla::WidgetInputEvent* aEvent,
                                             const ScrollableLayerGuid& aGuid,
                                             uint64_t aInputBlockId,
                                             nsEventStatus aApzResponse);

  const LayoutDeviceIntRegion RegionFromArray(const nsTArray<LayoutDeviceIntRect>& aRects);
  void ArrayFromRegion(const LayoutDeviceIntRegion& aRegion,
                       nsTArray<LayoutDeviceIntRect>& aRects);

  virtual nsresult SynthesizeNativeKeyEvent(int32_t aNativeKeyboardLayout,
                                            int32_t aNativeKeyCode,
                                            uint32_t aModifierFlags,
                                            const nsAString& aCharacters,
                                            const nsAString& aUnmodifiedCharacters,
                                            nsIObserver* aObserver) override
  {
    mozilla::widget::AutoObserverNotifier notifier(aObserver, "keyevent");
    return NS_ERROR_UNEXPECTED;
  }

  virtual nsresult SynthesizeNativeMouseEvent(LayoutDeviceIntPoint aPoint,
                                              uint32_t aNativeMessage,
                                              uint32_t aModifierFlags,
                                              nsIObserver* aObserver) override
  {
    mozilla::widget::AutoObserverNotifier notifier(aObserver, "mouseevent");
    return NS_ERROR_UNEXPECTED;
  }

  virtual nsresult SynthesizeNativeMouseMove(LayoutDeviceIntPoint aPoint,
                                             nsIObserver* aObserver) override
  {
    mozilla::widget::AutoObserverNotifier notifier(aObserver, "mouseevent");
    return NS_ERROR_UNEXPECTED;
  }

  virtual nsresult SynthesizeNativeMouseScrollEvent(LayoutDeviceIntPoint aPoint,
                                                    uint32_t aNativeMessage,
                                                    double aDeltaX,
                                                    double aDeltaY,
                                                    double aDeltaZ,
                                                    uint32_t aModifierFlags,
                                                    uint32_t aAdditionalFlags,
                                                    nsIObserver* aObserver) override
  {
    mozilla::widget::AutoObserverNotifier notifier(aObserver, "mousescrollevent");
    return NS_ERROR_UNEXPECTED;
  }

  virtual nsresult SynthesizeNativeTouchPoint(uint32_t aPointerId,
                                              TouchPointerState aPointerState,
                                              LayoutDeviceIntPoint aPoint,
                                              double aPointerPressure,
                                              uint32_t aPointerOrientation,
                                              nsIObserver* aObserver) override
  {
    mozilla::widget::AutoObserverNotifier notifier(aObserver, "touchpoint");
    return NS_ERROR_UNEXPECTED;
  }

  /**
   * GetPseudoIMEContext() returns pseudo IME context when TextEventDispatcher
   * has non-native input transaction.  Otherwise, returns nullptr.
   */
  void* GetPseudoIMEContext();

protected:
  // Utility to check if an array of clip rects is equal to our
  // internally stored clip rect array mClipRects.
  bool IsWindowClipRegionEqual(const nsTArray<LayoutDeviceIntRect>& aRects);

  // Stores the clip rectangles in aRects into mClipRects.
  void StoreWindowClipRegion(const nsTArray<LayoutDeviceIntRect>& aRects);

  virtual already_AddRefed<nsIWidget>
  AllocateChildPopupWidget()
  {
    static NS_DEFINE_IID(kCPopUpCID, NS_CHILD_CID);
    nsCOMPtr<nsIWidget> widget = do_CreateInstance(kCPopUpCID);
    return widget.forget();
  }

  LayerManager* CreateBasicLayerManager();

  nsPopupType PopupType() const { return mPopupType; }

  bool HasRemoteContent() const { return mHasRemoteContent; }

  void NotifyRollupGeometryChange()
  {
    // XULPopupManager isn't interested in this notification, so only
    // send it if gRollupListener is set.
    if (gRollupListener) {
      gRollupListener->NotifyGeometryChange();
    }
  }

  /**
   * Apply the current size constraints to the given size.
   *
   * @param aWidth width to constrain
   * @param aHeight height to constrain
   */
  void ConstrainSize(int32_t* aWidth, int32_t* aHeight)
  {
    SizeConstraints c = GetSizeConstraints();
    *aWidth = std::max(c.mMinSize.width,
                       std::min(c.mMaxSize.width, *aWidth));
    *aHeight = std::max(c.mMinSize.height,
                        std::min(c.mMaxSize.height, *aHeight));
  }

  virtual CompositorBridgeChild* GetRemoteRenderer() override;

  /**
   * Notify the widget that this window is being used with OMTC.
   */
  virtual void WindowUsesOMTC() {}
  virtual void RegisterTouchWindow() {}

  nsIDocument* GetDocument() const;

  void EnsureTextEventDispatcher();

  // Notify the compositor that a device reset has occurred.
  void OnRenderingDeviceReset();

  bool UseAPZ();

  /**
   * For widgets that support synthesizing native touch events, this function
   * can be used to manage the current state of synthetic pointers. Each widget
   * must maintain its own MultiTouchInput instance and pass it in as the state,
   * along with the desired parameters for the changes. This function returns
   * a new MultiTouchInput object that is ready to be dispatched.
   */
  mozilla::MultiTouchInput
  UpdateSynthesizedTouchState(mozilla::MultiTouchInput* aState,
                              uint32_t aTime,
                              mozilla::TimeStamp aTimeStamp,
                              uint32_t aPointerId,
                              TouchPointerState aPointerState,
                              LayoutDeviceIntPoint aPoint,
                              double aPointerPressure,
                              uint32_t aPointerOrientation);

  /**
   * Dispatch the given MultiTouchInput through APZ to Gecko (if APZ is enabled)
   * or directly to gecko (if APZ is not enabled). This function must only
   * be called from the main thread, and if APZ is enabled, that must also be
   * the APZ controller thread.
   */
  void DispatchTouchInput(mozilla::MultiTouchInput& aInput);

#if defined(XP_WIN)
  void UpdateScrollCapture() override;

  /**
   * To be overridden by derived classes to return a snapshot that can be used
   * during scrolling. Returning null means we won't update the container.
   * @return an already AddRefed SourceSurface containing the snapshot
   */
  virtual already_AddRefed<SourceSurface> CreateScrollSnapshot()
  {
    return nullptr;
  };

  /**
   * Used by derived classes to create a fallback scroll image.
   * @param aSnapshotDrawTarget DrawTarget to fill with fallback image.
   */
  void DefaultFillScrollCapture(DrawTarget* aSnapshotDrawTarget);

  RefPtr<ImageContainer> mScrollCaptureContainer;
#endif

protected:
  // Returns whether compositing should use an external surface size.
  virtual bool UseExternalCompositingSurface() const {
    return false;
  }

  /**
   * Starts the OMTC compositor destruction sequence.
   *
   * When this function returns, the compositor should not be
   * able to access the opengl context anymore.
   * It is safe to call it several times if platform implementations
   * require the compositor to be destroyed before ~nsBaseWidget is
   * reached (This is the case with gtk2 for instance).
   */
  virtual void DestroyCompositor();
  void DestroyLayerManager();
  void ReleaseContentController();
  void RevokeTransactionIdAllocator();

  void FreeShutdownObserver();

  nsIWidgetListener* mWidgetListener;
  nsIWidgetListener* mAttachedWidgetListener;
  nsIWidgetListener* mPreviouslyAttachedWidgetListener;
  RefPtr<LayerManager> mLayerManager;
  RefPtr<CompositorSession> mCompositorSession;
  RefPtr<CompositorBridgeChild> mCompositorBridgeChild;
  RefPtr<mozilla::CompositorVsyncDispatcher> mCompositorVsyncDispatcher;
  RefPtr<IAPZCTreeManager> mAPZC;
  RefPtr<GeckoContentController> mRootContentController;
  RefPtr<APZEventState> mAPZEventState;
  SetAllowedTouchBehaviorCallback mSetAllowedTouchBehaviorCallback;
  RefPtr<WidgetShutdownObserver> mShutdownObserver;
  RefPtr<TextEventDispatcher> mTextEventDispatcher;
  nsCursor          mCursor;
  nsBorderStyle     mBorderStyle;
  LayoutDeviceIntRect mBounds;
  LayoutDeviceIntRect* mOriginalBounds;
  // When this pointer is null, the widget is not clipped
  mozilla::UniquePtr<LayoutDeviceIntRect[]> mClipRects;
  uint32_t          mClipRectCount;
  nsSizeMode        mSizeMode;
  nsPopupLevel      mPopupLevel;
  nsPopupType       mPopupType;
  SizeConstraints   mSizeConstraints;
  bool              mHasRemoteContent;

  bool              mUpdateCursor;
  bool              mUseAttachedEvents;
  bool              mIMEHasFocus;
  bool              mIsFullyOccluded;
  static nsIRollupListener* gRollupListener;

  struct InitialZoomConstraints {
    InitialZoomConstraints(const uint32_t& aPresShellID,
                           const FrameMetrics::ViewID& aViewID,
                           const ZoomConstraints& aConstraints)
      : mPresShellID(aPresShellID), mViewID(aViewID), mConstraints(aConstraints)
    {
    }

    uint32_t mPresShellID;
    FrameMetrics::ViewID mViewID;
    ZoomConstraints mConstraints;
  };

  mozilla::Maybe<InitialZoomConstraints> mInitialZoomConstraints;

  // This points to the resize listeners who have been notified that a live
  // resize is in progress. This should always be empty when a live-resize is
  // not in progress.
  nsTArray<RefPtr<mozilla::LiveResizeListener>> mLiveResizeListeners;

#ifdef DEBUG
protected:
  static nsAutoString debug_GuiEventToString(mozilla::WidgetGUIEvent* aGuiEvent);
  static bool debug_WantPaintFlashing();

  static void debug_DumpInvalidate(FILE* aFileOut,
                                   nsIWidget* aWidget,
                                   const LayoutDeviceIntRect* aRect,
                                   const char* aWidgetName,
                                   int32_t aWindowID);

  static void debug_DumpEvent(FILE* aFileOut,
                              nsIWidget* aWidget,
                              mozilla::WidgetGUIEvent* aGuiEvent,
                              const char* aWidgetName,
                              int32_t aWindowID);

  static void debug_DumpPaintEvent(FILE *                aFileOut,
                                   nsIWidget *           aWidget,
                                   const nsIntRegion &   aPaintEvent,
                                   const char *          aWidgetName,
                                   int32_t               aWindowID);

  static bool debug_GetCachedBoolPref(const char* aPrefName);
#endif

private:
  already_AddRefed<LayerManager>
  CreateCompositorSession(int aWidth, int aHeight,
                          mozilla::layers::CompositorOptions* aOptionsOut);
};

#endif // nsBaseWidget_h__