xref: /dports/www/firefox/firefox-99.0/dom/interfaces/base/nsIDOMWindowUtils.idl

/* -*- Mode: IDL; 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/. */

#include "nsISupports.idl"
#include "domstubs.idl"

/**
 * nsIDOMWindowUtils is intended for infrequently-used methods related
 * to the current nsIDOMWindow.  Some of the methods may require
 * elevated privileges; the method implementations should contain the
 * necessary security checks.  Access this interface by calling
 * getInterface on a DOMWindow.
 *
 * WARNING: Do not use 'out jsval' parameters in this file.
 *          SpecialPowers, which is used to access nsIDOMWindowUtils
 *          in plain mochitests, does not know how to handle them.
 *          (Use 'jsval' return values instead.)
 */

%{C++
#include "nsColor.h"
class gfxContext;
struct nsRect;
%}

[ref] native nsConstRect(const nsRect);
native nscolor(nscolor);
[ptr] native gfxContext(gfxContext);

interface nsIArray;
interface nsICycleCollectorListener;
interface nsIPreloadedStyleSheet;
interface nsITransferable;
interface nsIQueryContentEventResult;
interface nsIDOMWindow;
interface nsIFile;
interface nsIURI;
interface nsIRunnable;
interface nsITranslationNodeList;
interface nsIJSRAIIHelper;
interface nsIContentPermissionRequest;
interface nsIObserver;

webidl Animation;
webidl DOMRect;
webidl Element;
webidl EventTarget;
webidl Event;
webidl Node;
webidl NodeList;
webidl Storage;

[builtinclass, scriptable, uuid(4d6732ca-9da7-4176-b8a1-8dde15cd0bf9)]
interface nsIDOMWindowUtils : nsISupports {

  /**
   * Image animation mode of the window. When this attribute's value
   * is changed, the implementation should set all images in the window
   * to the given value. That is, when set to kDontAnimMode, all images
   * will stop animating. The attribute's value must be one of the
   * animationMode values from imgIContainer.
   * @note Images may individually override the window's setting after
   *       the window's mode is set. Therefore images given different modes
   *       since the last setting of the window's mode may behave
   *       out of line with the window's overall mode.
   * @note The attribute's value is the window's overall mode. It may
   *       for example continue to report kDontAnimMode after all images
   *       have subsequently been individually animated.
   * @note Only images immediately in this window are affected;
   *       this is not recursive to subwindows.
   * @see imgIContainer
   */
  attribute unsigned short imageAnimationMode;

  /**
   * Whether the charset of the window's current document has been forced by
   * the user.
   * Cannot be accessed from unprivileged context (not content-accessible)
   */
  readonly attribute boolean docCharsetIsForced;

  /**
   * Return the conversion of a physical millimeter in CSS pixels.
   */
  readonly attribute float physicalMillimeterInCSSPixels;

  /**
   * Function to get metadata associated with the window's current document
   * @param aName the name of the metadata.  This should be all lowercase.
   * @return the value of the metadata, or the empty string if it's not set
   *
   * Will throw a DOM security error if called without chrome privileges.
   */
  AString getDocumentMetadata(in AString aName);

  /**
   * Force a synchronous layer transaction for this window if necessary.
   */
  [can_run_script]
  void updateLayerTree();

  /**
   * Get the last used layer transaction id for this window's refresh driver.
   */
  readonly attribute unsigned long long lastTransactionId;

  /**
   * Information retrieved from the <meta name="viewport"> tag.
   * See Document::GetViewportInfo for more information.
   */
  void getViewportInfo(in uint32_t aDisplayWidth, in uint32_t aDisplayHeight,
                       out double aDefaultZoom, out boolean aAllowZoom,
                       out double aMinZoom, out double aMaxZoom,
                       out uint32_t aWidth, out uint32_t aHeight,
                       out boolean aAutoSize);
  /*
   * Information retrieved from the viewport-fit value of <meta name="viewport">
   * element.
   */
  AString getViewportFitInfo();

  /**
   * Information about the window size in device pixels.
   */
  void getContentViewerSize(out uint32_t aDisplayWidth, out uint32_t aDisplayHeight);

  /**
   * For any scrollable element, this allows you to override the default
   * scroll behaviour and force autodir (which allows a mousewheel to
   * horizontally scroll regions that only scroll on that one axis).
   *
   * See the documentation for mousewheel.autodir.enabled and
   * mousewheel.autodir.honourroot for a more thorough explanation of
   * what these behaviours do.
   */
  void setMousewheelAutodir(in Element aElement, in boolean aEnabled, in boolean aHonourRoot);

  /**
   * For any scrollable element, this allows you to override the
   * visible region and draw more than what is visible, which is
   * useful for asynchronous drawing. The "displayport" will be
   * <xPx, yPx, widthPx, heightPx> in units of CSS pixels,
   * regardless of the size of the enclosing container.  This
   * will *not* trigger reflow.
   *
   * For the root scroll area, pass in the root document element.
   * For scrollable elements, pass in the container element (for
   * instance, the element with overflow: scroll).
   *
   * <x, y> is relative to the top-left of what would normally be
   * the visible area of the element. This means that the pixels
   * rendered to the displayport take scrolling into account,
   * for example.
   *
   * It's legal to set a displayport that extends beyond the overflow
   * area in any direction (left/right/top/bottom).
   *
   * It's also legal to set a displayport that extends beyond the
   * area's bounds.  No pixels are rendered outside the area bounds.
   *
   * The caller of this method must have chrome privileges.
   *
   * Calling this will always force a recomposite, so it should be
   * avoided if at all possible. Client code should do checks before
   * calling this so that duplicate sets are not made with the same
   * displayport.
   *
   * aPriority is recorded along with the displayport rectangle. If this
   * method is called with a lower priority than the current priority, the
   * call is ignored.
   */
  void setDisplayPortForElement(in float aXPx, in float aYPx,
                                in float aWidthPx, in float aHeightPx,
                                in Element aElement,
                                in uint32_t aPriority);
  /**
   * An alternate way to represent a displayport rect as a set of margins and a
   * base rect to apply those margins to. A consumer of pixels may ask for as
   * many extra pixels as it would like in each direction. Layout then sets
   * the base rect to the "visible rect" of the element, which is just the
   * subrect of the element that is drawn (it does not take in account content
   * covering the element).
   *
   * If both a displayport rect and displayport margins with corresponding base
   * rect are set with the same priority then the margins will take precendence.
   *
   * Specifying an alignment value will ensure that after the base rect has
   * been expanded by the displayport margins, it will be further expanded so
   * that each edge is located at a multiple of the "alignment" value.
   *
   * Note that both the margin values and alignment are treated as values in
   * ScreenPixels. Refer to layout/base/Units.h for a description of this unit.
   * The base rect values are in app units.
   */
  void setDisplayPortMarginsForElement(in float aLeftMargin,
                                       in float aTopMargin,
                                       in float aRightMargin,
                                       in float aBottomMargin,
                                       in Element aElement,
                                       in uint32_t aPriority);

  void setDisplayPortBaseForElement(in int32_t aX,
                                    in int32_t aY,
                                    in int32_t aWidth,
                                    in int32_t aHeight,
                                    in Element aElement);

  /**
   * If |aElement| is a scroll container, returns the amount of layout
   * space taken up by its scrollbars (that is, the width of the vertical
   * scrollbar and the height of the horizontal scrollbar) in CSS pixels;
   * otherwise returns zero.
   *
   * Note that on some platforms, scrollbars don't take up layout space
   * ("overlay scrollbars"). On such platforms, the returned sizes are
   * always zero.
   *
   * Layout scrollbars that normally take up space but were only shown to
   * scroll the visual viewport inside the layout viewport (the layout viewport
   * cannot be scrolled) do not take up space but they still return their size
   * from this function.
   */
  void getScrollbarSizes(in Element aElement,
                         out uint32_t aVerticalScrollbarWidth,
                         out uint32_t aHorizontalScrollbarHeight);

  /**
   * Get/set the resolution at which rescalable web content is drawn for
   * testing purposes.
   *
   * Setting a new resolution does *not* trigger reflow.  This API is
   * entirely separate from textZoom and fullZoom; a resolution scale
   * can be applied together with both textZoom and fullZoom.
   *
   * The effect of this API is for gfx code to allocate more or fewer
   * pixels for rescalable content by a factor of |resolution| in
   * both dimensions.
   *
   * In addition, the content is scaled by the amount of the resolution,
   * so that it is displayed at a correspondingly larger or smaller size,
   * without the need for the caller to set an additional transform.
   *
   * The purpose of this API is to allow tests to simulate many of the effects
   * a non-reflowing scale-zoom, e.g. for pinch-zoom on mobile platforms, and
   * should be only used for testing purposes.
   *
   * The caller of this method must have chrome privileges.
   *
   * This is intended to be used by test code only!
   */
  void setResolutionAndScaleTo(in float aResolution);

  float getResolution();

  /**
   * Set a resolution on the presShell which is the "restored" from history.
   * The display dimensions are compared to their current values and used
   * to scale the resolution value if necessary, e.g. if the device was
   * rotated between saving and restoring of the session data.
   * This resolution should be used when painting for the first time. Calling
   * this too late may have no effect.
   */
  void setRestoreResolution(in float aResolution,
                            in uint32_t aDisplayWidth,
                            in uint32_t aDisplayHeight);

  /**
   * Whether the next paint should be flagged as the first paint for a document.
   * This gives a way to track the next paint that occurs after the flag is
   * set. The flag gets cleared after the next paint.
   *
   * Can only be accessed with chrome privileges.
   */
  attribute boolean isFirstPaint;

  uint32_t getPresShellId();

  /**
   * Returns whether a given header and value is a CORS-safelisted request
   * header per https://fetch.spec.whatwg.org/#cors-safelisted-request-header
   */
  boolean isCORSSafelistedRequestHeader(in ACString name, in ACString value);

  /**
   * Following modifiers are for sent*Event() except sendNative*Event().
   * NOTE: MODIFIER_ALT, MODIFIER_CONTROL, MODIFIER_SHIFT and MODIFIER_META
   *       are must be same values as Event_Binding::*_MASK for backward
   *       compatibility.
   */
  const long MODIFIER_ALT        = 0x0001;
  const long MODIFIER_CONTROL    = 0x0002;
  const long MODIFIER_SHIFT      = 0x0004;
  const long MODIFIER_META       = 0x0008;
  const long MODIFIER_ALTGRAPH   = 0x0010;
  const long MODIFIER_CAPSLOCK   = 0x0020;
  const long MODIFIER_FN         = 0x0040;
  const long MODIFIER_FNLOCK     = 0x0080;
  const long MODIFIER_NUMLOCK    = 0x0100;
  const long MODIFIER_SCROLLLOCK = 0x0200;
  const long MODIFIER_SYMBOL     = 0x0400;
  const long MODIFIER_SYMBOLLOCK = 0x0800;
  const long MODIFIER_OS         = 0x1000;

  /** Synthesize a mouse event. The event types supported are:
   *    mousedown, mouseup, mousemove, mouseover, mouseout, mousecancel,
   *    contextmenu, MozMouseHittest
   *
   * Events are sent in coordinates offset by aX and aY from the window.
   *
   * Note that additional events may be fired as a result of this call. For
   * instance, typically a click event will be fired as a result of a
   * mousedown and mouseup in sequence.
   *
   * Normally at this level of events, the mouseover and mouseout events are
   * only fired when the window is entered or exited. For inter-element
   * mouseover and mouseout events, a movemove event fired on the new element
   * should be sufficient to generate the correct over and out events as well.
   *
   * Cannot be accessed from unprivileged context (not content-accessible)
   * Will throw a DOM security error if called without chrome privileges.
   *
   * The event is dispatched via the toplevel window, so it could go to any
   * window under the toplevel window, in some cases it could never reach this
   * window at all.
   *
   * NOTE: mousecancel is used to represent the vanishing of an input device
   * such as a pen leaving its digitizer by synthesizing a WidgetMouseEvent,
   * whose mMessage is eMouseExitFromWidget and mExitFrom is
   * WidgetMouseEvent::eTopLevel.
   *
   * @param aType event type
   * @param aX x offset in CSS pixels
   * @param aY y offset in CSS pixels
   * @param aButton button to synthesize
   * @param aClickCount number of clicks that have been performed
   * @param aModifiers modifiers pressed, using constants defined as MODIFIER_*
   * @param aIgnoreRootScrollFrame whether the event should ignore viewport bounds
   *                           during dispatch
   * @param aPressure touch input pressure: 0.0 -> 1.0
   * @param aInputSourceArg input source, see MouseEvent for values,
   *        defaults to mouse input.
   * @param aIsDOMEventSynthesized controls Event.isSynthesized value
   *                               that helps identifying test related events,
   *                               defaults to true
   * @param aIsWidgetEventSynthesized controls WidgetMouseEvent.mReason value
   *                                  defaults to false (WidgetMouseEvent::eReal)
   * @param aIdentifier A unique identifier for the pointer causing the event,
   *                    defaulting to nsIDOMWindowUtils::DEFAULT_MOUSE_POINTER_ID.
   *
   * returns true if the page called prevent default on this event
   */
  [optional_argc, can_run_script]
  boolean sendMouseEvent(in AString aType,
                         in float aX,
                         in float aY,
                         in long aButton,
                         in long aClickCount,
                         in long aModifiers,
                         [optional] in boolean aIgnoreRootScrollFrame,
                         [optional] in float aPressure,
                         [optional] in unsigned short aInputSourceArg,
                         [optional] in boolean aIsDOMEventSynthesized,
                         [optional] in boolean aIsWidgetEventSynthesized,
                         [optional] in long aButtons,
                         [optional] in unsigned long aIdentifier);

  /** Synthesize a touch event. The event types supported are:
   *    touchstart, touchend, touchmove, and touchcancel
   *
   * Events are sent in coordinates offset by aX and aY from the window.
   *
   * Cannot be accessed from unprivileged context (not content-accessible)
   * Will throw a DOM security error if called without chrome privileges.
   *
   * The event is dispatched via the toplevel window, so it could go to any
   * window under the toplevel window, in some cases it could never reach this
   * window at all.
   *
   * @param aType event type
   * @param xs array of offsets in CSS pixels for each touch to be sent
   * @param ys array of offsets in CSS pixels for each touch to be sent
   * @param rxs array of radii in CSS pixels for each touch to be sent
   * @param rys array of radii in CSS pixels for each touch to be sent
   * @param rotationAngles array of angles in degrees for each touch to be sent
   * @param forces array of forces (floats from 0 to 1) for each touch to be sent
   * @param count number of touches in this set
   * @param aModifiers modifiers pressed, using constants defined as MODIFIER_*
   * @param aIgnoreRootScrollFrame whether the event should ignore viewport bounds
   *                           during dispatch
   *
   * returns true if the page called prevent default on this touch event
   */
  [can_run_script]
  boolean sendTouchEvent(in AString aType,
                         in Array<uint32_t> aIdentifiers,
                         in Array<int32_t> aXs,
                         in Array<int32_t> aYs,
                         in Array<uint32_t> aRxs,
                         in Array<uint32_t> aRys,
                         in Array<float> aRotationAngles,
                         in Array<float> aForces,
                         in long aModifiers,
                         [optional] in boolean aIgnoreRootScrollFrame);

  /** The same as sendMouseEvent but ensures that the event is dispatched to
   *  this DOM window or one of its children.
   */
  [optional_argc, can_run_script]
  void sendMouseEventToWindow(in AString aType,
                              in float aX,
                              in float aY,
                              in long aButton,
                              in long aClickCount,
                              in long aModifiers,
                              [optional] in boolean aIgnoreRootScrollFrame,
                              [optional] in float aPressure,
                              [optional] in unsigned short aInputSourceArg,
                              [optional] in boolean aIsDOMEventSynthesized,
                              [optional] in boolean aIsWidgetEventSynthesized,
                              [optional] in long aButtons,
                              [optional] in unsigned long aIdentifier);

  /** The same as sendTouchEvent but ensures that the event is dispatched to
   *  this DOM window or one of its children.
   */
  [can_run_script]
  boolean sendTouchEventToWindow(in AString aType,
                                 in Array<uint32_t> aIdentifiers,
                                 in Array<int32_t> aXs,
                                 in Array<int32_t> aYs,
                                 in Array<uint32_t> aRxs,
                                 in Array<uint32_t> aRys,
                                 in Array<float> aRotationAngles,
                                 in Array<float> aForces,
                                 in long aModifiers,
                                 [optional] in boolean aIgnoreRootScrollFrame);

  /** Synthesize a wheel event for a window. The event types supported is only
   *  wheel.
   *
   * Events are sent in coordinates offset by aX and aY from the window.
   *
   * Cannot be accessed from unprivileged context (not content-accessible)
   * Will throw a DOM security error if called without chrome privileges.
   *
   * @param aX                 x offset in CSS pixels
   * @param aY                 y offset in CSS pixels
   * @param aDeltaX            deltaX value.
   * @param aDeltaY            deltaY value.
   * @param aDeltaZ            deltaZ value.
   * @param aDeltaMode         deltaMode value which must be one of the
   *                           WheelEvent DOM_DELTA_* constants.
   * @param aModifiers         modifiers pressed, using constants defined as
   *                           MODIFIER_*
   * @param aLineOrPageDeltaX  If you set this value non-zero for
   *                           DOM_DELTA_PIXEL event, EventStateManager will
   *                           dispatch NS_MOUSE_SCROLL event for horizontal
   *                           scroll.
   * @param aLineOrPageDeltaY  If you set this value non-zero for
   *                           DOM_DELTA_PIXEL event, EventStateManager will
   *                           dispatch NS_MOUSE_SCROLL event for vertical
   *                           scroll.
   * @param aOptions           Set following flags.
   */
  const unsigned long WHEEL_EVENT_CAUSED_BY_NO_LINE_OR_PAGE_DELTA_DEVICE = 0x0001;
  const unsigned long WHEEL_EVENT_CAUSED_BY_MOMENTUM                     = 0x0002;
  const unsigned long WHEEL_EVENT_CUSTOMIZED_BY_USER_PREFS               = 0x0004;
  // If any of the following flags is specified this method will throw an
  // exception in case the relevant overflowDelta has an unexpected value.
  const unsigned long WHEEL_EVENT_EXPECTED_OVERFLOW_DELTA_X_ZERO      = 0x0010;
  const unsigned long WHEEL_EVENT_EXPECTED_OVERFLOW_DELTA_X_POSITIVE  = 0x0020;
  const unsigned long WHEEL_EVENT_EXPECTED_OVERFLOW_DELTA_X_NEGATIVE  = 0x0040;
  const unsigned long WHEEL_EVENT_EXPECTED_OVERFLOW_DELTA_Y_ZERO      = 0x0100;
  const unsigned long WHEEL_EVENT_EXPECTED_OVERFLOW_DELTA_Y_POSITIVE  = 0x0200;
  const unsigned long WHEEL_EVENT_EXPECTED_OVERFLOW_DELTA_Y_NEGATIVE  = 0x0400;
  void sendWheelEvent(in float aX,
                      in float aY,
                      in double aDeltaX,
                      in double aDeltaY,
                      in double aDeltaZ,
                      in unsigned long aDeltaMode,
                      in long aModifiers,
                      in long aLineOrPageDeltaX,
                      in long aLineOrPageDeltaY,
                      in unsigned long aOptions);

  /**
   * Native modifiers for sendNativeKeyEvent and sendNativeMouseEvent.
   * TODO: The other sendNative*Event should take these values instead.
   */
  const unsigned long NATIVE_MODIFIER_CAPS_LOCK       = 0x00000001;
  const unsigned long NATIVE_MODIFIER_NUM_LOCK        = 0x00000002;
  const unsigned long NATIVE_MODIFIER_SHIFT_LEFT      = 0x00000100;
  const unsigned long NATIVE_MODIFIER_SHIFT_RIGHT     = 0x00000200;
  const unsigned long NATIVE_MODIFIER_CONTROL_LEFT    = 0x00000400;
  const unsigned long NATIVE_MODIFIER_CONTROL_RIGHT   = 0x00000800;
  const unsigned long NATIVE_MODIFIER_ALT_LEFT        = 0x00001000;
  const unsigned long NATIVE_MODIFIER_ALT_RIGHT       = 0x00002000;
  const unsigned long NATIVE_MODIFIER_COMMAND_LEFT    = 0x00004000;
  const unsigned long NATIVE_MODIFIER_COMMAND_RIGHT   = 0x00008000;
  const unsigned long NATIVE_MODIFIER_HELP            = 0x00010000;
  // On Windows, AltGraph key emulates the AltRight key on specific keyboard
  // layouts.  Therefore, this shouldn't be used without `synthesizeNativeKey`.
  const unsigned long NATIVE_MODIFIER_ALT_GRAPH       = 0x00020000;
  // Available only on macOS.
  const unsigned long NATIVE_MODIFIER_FUNCTION        = 0x00100000;
  // Available only on macOS.  When pressing a key in numeric key pad, this
  // must be included.
  const unsigned long NATIVE_MODIFIER_NUMERIC_KEY_PAD = 0x01000000;

  /**
   * See nsIWidget::SynthesizeNativeKeyEvent
   *
   * Cannot be accessed from unprivileged context (not content-accessible)
   * Will throw a DOM security error if called without chrome privileges.
   *
   * When you use this for tests, use the constants defined in NativeKeyCodes.js
   *
   * NOTE: The synthesized native event will be fired asynchronously, and upon
   * completion the observer, if provided, will be notified with a "keyevent"
   * topic.
   */
  void sendNativeKeyEvent(in long aNativeKeyboardLayout,
                          in long aNativeKeyCode,
                          in unsigned long aModifierFlags,
                          in AString aCharacters,
                          in AString aUnmodifiedCharacters,
                          [optional] in nsIObserver aObserver);

  /**
   * See nsIWidget::SynthesizeNativeMouseEvent
   *
   * Will be called on the widget that contains aElement.
   * Cannot be accessed from unprivileged context (not content-accessible)
   * Will throw a DOM security error if called without chrome privileges.
   *
   * @param aScreenX    X offset in the screen in device pixels.
   * @param aScreenY    Y offset in the screen in derive pixels.
   * @param aNativeMessage      One of NATIVE_MOUSE_MESSAGE_*
   * @param aButton     Same as `MouseEvent.button` value.
   * @param aModifierFlags      See nsIWidget's native modifier flags.
   * @param aElementOnWidget    An element which is on a widget.
   * @param aObserver   The synthesized native event will be fired
   *                    asynchronously, and upon completion the observer, if
   *                    provided, will be notified with a "mouseevent" topic.
   */
  const unsigned long NATIVE_MOUSE_MESSAGE_BUTTON_DOWN  = 0x00000001;
  const unsigned long NATIVE_MOUSE_MESSAGE_BUTTON_UP    = 0x00000002;
  const unsigned long NATIVE_MOUSE_MESSAGE_MOVE         = 0x00000003;
  const unsigned long NATIVE_MOUSE_MESSAGE_ENTER_WINDOW = 0x00000004;
  const unsigned long NATIVE_MOUSE_MESSAGE_LEAVE_WINDOW = 0x00000005;
  void sendNativeMouseEvent(in long aScreenX,
                            in long aScreenY,
                            in unsigned long aNativeMessage,
                            in short aButton,
                            in unsigned long aModifierFlags,
                            in Element aElementOnWidget,
                            [optional] in nsIObserver aObserver);

  /**
   * Suppress animations that are applied to a window by OS when
   * resizing, moving, changing size mode, ...
   */
  void suppressAnimation(in boolean aSuppress);

  /**
   * The values for sendNativeMouseScrollEvent's aAdditionalFlags.
   */

  /**
   * If MOUSESCROLL_PREFER_WIDGET_AT_POINT is set, widget will dispatch
   * the event to a widget which is under the cursor.  Otherwise, dispatch to
   * a default target on the platform.  E.g., on Windows, it's focused window.
   */
  const unsigned long MOUSESCROLL_PREFER_WIDGET_AT_POINT = 0x00000001;

  /**
   * Interpret the scroll delta values as lines rather than pixels.
   */
  const unsigned long MOUSESCROLL_SCROLL_LINES = 0x00000002;

  /**
   * The platform specific values of aAdditionalFlags.  Must be over 0x00010000.
   */

  /**
   * If MOUSESCROLL_WIN_SCROLL_LPARAM_NOT_NULL is set and aNativeMessage is
   * WM_VSCROLL or WM_HSCROLL, widget will set the window handle to the lParam
   * instead of NULL.
   */
  const unsigned long MOUSESCROLL_WIN_SCROLL_LPARAM_NOT_NULL = 0x00010000;

  /**
   * See nsIWidget::SynthesizeNativeMouseScrollEvent
   *
   * Will be called on the widget that contains aElement.
   * Cannot be accessed from unprivileged context (not content-accessible)
   * Will throw a DOM security error if called without chrome privileges.
   *
   * NOTE: The synthesized native event will be fired asynchronously, and upon
   * completion the observer, if provided, will be notified with a
   * "mousescrollevent" topic.
   *
   * @param aNativeMessage
   *   On Windows:  WM_MOUSEWHEEL (0x020A), WM_MOUSEHWHEEL(0x020E),
   *                WM_VSCROLL (0x0115) or WM_HSCROLL (0x114).
   */
  void sendNativeMouseScrollEvent(in long aScreenX,
                                  in long aScreenY,
                                  in unsigned long aNativeMessage,
                                  in double aDeltaX,
                                  in double aDeltaY,
                                  in double aDeltaZ,
                                  in unsigned long aModifierFlags,
                                  in unsigned long aAdditionalFlags,
                                  in Element aElement,
                                  [optional] in nsIObserver aObserver);

  /**
   * Touch states for sendNativeTouchPoint. These values match
   * nsIWidget's TouchPointerState.
   */

  // The pointer is in a hover state above the digitizer
  const long TOUCH_HOVER   = 0x01;
  // The pointer is in contact with the digitizer
  const long TOUCH_CONTACT = 0x02;
  // The pointer has been removed from the digitizer detection area
  const long TOUCH_REMOVE  = 0x04;
  // The pointer has been canceled. Will cancel any pending os level
  // gestures that would be triggered as a result of completion of the
  // input sequence. This may not cancel moz platform related events
  // that might get tirggered by input already delivered.
  const long TOUCH_CANCEL  = 0x08;

  /**
   * Phase states for sendNativeTouchPadPinch.
   */
  const long PHASE_BEGIN = 0;
  const long PHASE_UPDATE = 1;
  const long PHASE_END  = 2;

  /**
   * Create a new or update an existing touch point on the digitizer.
   * To trigger os level gestures, individual touch points should
   * transition through a complete set of touch states which should be
   * sent as individual calls. For example:
   * tap - msg1:TOUCH_CONTACT, msg2:TOUCH_REMOVE
   * drag - msg1-n:TOUCH_CONTACT (moving), msgn+1:TOUCH_REMOVE
   * hover drag - msg1-n:TOUCH_HOVER (moving), msgn+1:TOUCH_REMOVE
   *
   * Widget support: Windows 8.0+, Winrt/Win32. Other widgets will throw.
   *
   * NOTE: The synthesized native event will be fired asynchronously, and upon
   * completion the observer, if provided, will be notified with a "touchpoint"
   * topic.
   *
   * @param aPointerId The touch point id to create or update.
   * @param aTouchState one or more of the touch states listed above
   * @param aScreenX, aScreenY screen coords of this event
   * @param aPressure 0.0 -> 1.0 float val indicating pressure
   * @param aOrientation 0 -> 359 degree value indicating the
   * orientation of the pointer. Use 90 for normal taps.
   */
  void sendNativeTouchPoint(in unsigned long aPointerId,
                            in unsigned long aTouchState,
                            in long aScreenX,
                            in long aScreenY,
                            in double aPressure,
                            in unsigned long aOrientation,
                            [optional] in nsIObserver aObserver);
  /**
   * These values indicate touchpad pinch phase states :
   * PHASE_BEGIN
   * PHASE_UPDATE
   * PHASE_END
   * Widget support: Linux GTK 3.18+.
   * @param aEventPhase The touchpad pinch phase using states listed above.
   * @param aScale Events with PHASE_UPDATE will change the zoom level by
   * the ratio between the scale of the current event and the scale of the last event.
   * @param aScreenX, aScreenY screen coords of the focus point of this event.
   * @param aModifierFlags is expected to contain native modifier values.
   */
  void sendNativeTouchpadPinch(in unsigned long aEventPhase,
                               in float aScale,
                               in long aScreenX,
                               in long aScreenY,
                               in long aModifierFlags);

  /**
   * Simulates native touch based taps on the input digitizer. Events
   * triggered by this call are injected at the os level. Events do not
   * bypass widget level input processing and as such can be used to
   * test widget event logic and async pan-zoom controller functionality.
   * Cannot be accessed from an unprivileged context.
   *
   * Long taps (based on the aLongTap parameter) will be completed
   * asynchrnously after the call returns. Long tap delay is based on
   * the ui.click_hold_context_menus.delay pref or 1500 msec if pref
   * is not set.
   *
   * Widget support: Windows 8.0+, Winrt/Win32. Other widgets will
   * throw.
   *
   * NOTE: The synthesized native event will be fired asynchronously, and upon
   * completion the observer, if provided, will be notified, with a "touchtap"
   * topic.
   *
   * @param aScreenX, aScreenY screen coords of this event
   * @param aLongTap true if the tap should be long, false for a short
   * tap.
   */
  void sendNativeTouchTap(in long aScreenX,
                          in long aScreenY,
                          in boolean aLongTap,
                          [optional] in nsIObserver aObserver);

  /**
   * Create a new or update an existing pen input on the digitizer.
   *
   * Widget support: Windows 10 1809+. Other widgets will throw.
   *
   * NOTE: The synthesized native event will be fired asynchronously, and upon
   * completion the observer, if provided, will be notified with a "peninput"
   * topic.
   *
   * @param aPointerId The touch point id to create or update.
   * @param aPointerState one or more of the TOUCH_* listed above
   * @param aScreenX x screen coord of this event
   * @param aScreenY y screen coord of this event
   * @param aPressure 0.0 -> 1.0 float val indicating pressure
   * @param aRotation 0 -> 359 degree value indicating the rotation of the
   * pointer. Use 0 for normal taps.
   * @param aTiltX -90 -> 90 degree value indicating the tilt along the x-axis
   * of the pointer. Use 0 for normal taps.
   * @param aTiltY -90 -> 90 degree value indicating the tilt along the y-axis
   * of the pointer. Use 0 for normal taps.
   * @param aButton Same as MouseEvent::button.
   */
  void sendNativePenInput(in unsigned long aPointerId,
                          in unsigned long aPointerState,
                          in long aScreenX,
                          in long aScreenY,
                          in double aPressure,
                          in unsigned long aRotation,
                          in long aTiltX,
                          in long aTiltY,
                          in long aButton,
                          [optional] in nsIObserver aObserver);

  /**
   * Cancel any existing touch points or long tap delays. Calling this is safe
   * even if you're sure there aren't any pointers recorded. You should call
   * this when tests shut down to reset the digitizer driver. Not doing so can
   * leave the digitizer in an undetermined state which can screw up subsequent
   * tests and native input.
   *
   * NOTE: The synthesized native event will be fired asynchronously, and upon
   * completion the observer, if provided, will be notified with a "cleartouch"
   * topic.
   */
  void clearNativeTouchSequence([optional] in nsIObserver aObserver);

  /**
   * Send a native event as if the user double tapped the touchpad with two
   * fingers.
   *
   * Widget support: macOS.
   * @param aScreenX, aScreenY screen coords of the focus point of this event.
   * @param aModifierFlags is expected to contain native modifier values.
   */
  void sendNativeTouchpadDoubleTap(in long aScreenX,
                                   in long aScreenY,
                                   in long aModifierFlags);

  /**
   * Send a native event as if the user panned on the touchpad with two
   * fingers.
   *
   * Widget support: Windows.
   * @param aScreenX, aScreenY screen coords of the focus point of this event.
   * @param aDeltaX, aDeltaY the amount of delta in the pan.
   * @param aModifierFlags is expected to contain native modifier values.
   */
  void sendNativeTouchpadPan(in unsigned long aEventPhase,
                             in long aScreenX,
                             in long aScreenY,
                             in double aDeltaX,
                             in double aDeltaY,
                             in long aModifierFlags);

  /**
   * Clears the SharedStyleSheetCache.
   */
  void clearSharedStyleSheetCache();

  /**
   * Returns the number of stylesheets that have been parsed on this document.
   * Useful to test caching.
   */
  readonly attribute unsigned long parsedStyleSheets;

  /**
   * See nsIWidget::ActivateNativeMenuItemAt
   *
   * Cannot be accessed from unprivileged context (not content-accessible)
   * Will throw a DOM security error if called without chrome privileges.
   */
  void activateNativeMenuItemAt(in AString indexString);

  /**
   * See nsIWidget::ForceUpdateNativeMenuAt
   *
   * Cannot be accessed from unprivileged context (not content-accessible)
   * Will throw a DOM security error if called without chrome privileges.
   */
  void forceUpdateNativeMenuAt(in AString indexString);

  /**
   * Returns the current selection as plaintext. Note that the result may be
   * different from the result of sendQueryContentEvent(QUERY_SELECTED_TEXT).
   * This result is computed by native API with transferable data. In other
   * words, when the OS treats the selection as plaintext, it treats current
   * selection as this result.
   */
  AString GetSelectionAsPlaintext();

  /**
   * Force a garbage collection followed by a cycle collection.
   *
   * Will throw a DOM security error if called without chrome privileges in
   * non-debug builds. Available to all callers in debug builds.
   *
   * @param aListener listener that receives information about the CC graph
   */
  void garbageCollect([optional] in nsICycleCollectorListener aListener);

  /**
   * Force a cycle collection without garbage collection.
   *
   * Will throw a DOM security error if called without chrome privileges in
   * non-debug builds. Available to all callers in debug builds.
   *
   * @param aListener listener that receives information about the CC graph
   */
  void cycleCollect([optional] in nsICycleCollectorListener aListener);

  /**
   * Trigger whichever GC or CC timer is currently active and waiting to fire.
   * Don't do this too much for initiating heavy actions, like the start of a IGC.
   *
   * @param aReason the reason for the GC, from js/public/GCAPI.h. Defaults to
   * DOM_WINDOW_UTILS.
   */
  void runNextCollectorTimer([optional] in ACString aReason);

  /**
   * "Poke" the GC: set a timer to run a GC soon (usually 4 seconds), unless
   * another GC timer has already been set. This is used for testing.
   *
   * @param aReason the reason for the GC, from js/public/GCAPI.h. Defaults to
   * DOM_WINDOW_UTILS.
   */
  void pokeGC([optional] in ACString aReason);

  /** Synthesize a simple gesture event for a window. The event types
   *  supported are: MozSwipeGestureMayStart, MozSwipeGestureStart,
   *  MozSwipeGestureUpdate, MozSwipeGestureEnd, MozSwipeGesture,
   *  MozMagnifyGestureStart, MozMagnifyGestureUpdate, MozMagnifyGesture,
   *  MozRotateGestureStart, MozRotateGestureUpdate, MozRotateGesture,
   *  MozPressTapGesture, MozTapGesture, and MozEdgeUIGesture.
   *
   * Cannot be accessed from unprivileged context (not
   * content-accessible) Will throw a DOM security error if called
   * without chrome privileges.
   *
   * @param aType event type
   * @param aX x offset in CSS pixels
   * @param aY y offset in CSS pixels
   * @param aDirection direction, using constants defined in SimpleGestureEvent.webidl
   * @param aDelta  amount of magnification or rotation for magnify and rotation events
   * @param aModifiers modifiers pressed, using constants defined in Event.webidl
   * @param aClickCount For tap gestures, the number of taps.
   */
  void sendSimpleGestureEvent(in AString aType,
                              in float aX,
                              in float aY,
                              in unsigned long aDirection,
                              in double aDelta,
                              in long aModifiers,
                              [optional] in unsigned long aClickCount);

  /**
   * Retrieve the element at point aX, aY in the window's document.
   *
   * @param aIgnoreRootScrollFrame whether or not to ignore the root scroll
   *        frame when retrieving the element. If false, this method returns
   *        null for coordinates outside of the viewport.
   * @param aFlushLayout flushes layout if true. Otherwise, no flush occurs.
   */
  Element elementFromPoint(in float aX,
                           in float aY,
                           in boolean aIgnoreRootScrollFrame,
                           in boolean aFlushLayout);

  /**
   * Retrieve all nodes that intersect a rect in the window's document.
   *
   * @param aX x reference for the rectangle in CSS pixels
   * @param aY y reference for the rectangle in CSS pixels
   * @param aTopSize How much to expand up the rectangle
   * @param aRightSize How much to expand right the rectangle
   * @param aBottomSize How much to expand down the rectangle
   * @param aLeftSize How much to expand left the rectangle
   * @param aIgnoreRootScrollFrame whether or not to ignore the root scroll
   *        frame when retrieving the element. If false, this method returns
   *        null for coordinates outside of the viewport.
   * @param aFlushLayout flushes layout if true. Otherwise, no flush occurs.
   * @param aOnlyVisible Set to true if you only want nodes that pass a visibility
   *        hit test.
   * @param aTransparencyThreshold Only has an effect if aOnlyVisible is true.
   *        Returns what amount of transparency is considered "opaque enough"
   *        to consider elements "not visible". The default is effectively "1"
   *        (so, only opaque elements will stop an element from being
   *        "visible").
   */
  NodeList nodesFromRect(in float aX,
                         in float aY,
                         in float aTopSize,
                         in float aRightSize,
                         in float aBottomSize,
                         in float aLeftSize,
                         in boolean aIgnoreRootScrollFrame,
                         in boolean aFlushLayout,
                         in boolean aOnlyVisible,
                         [optional] in float aTransparencyThreshold);


  /**
   * Get a list of nodes that have meaningful textual content to
   * be translated. The implementation of this algorithm is in flux
   * as we experiment and refine which approach works best.
   *
   * This method requires chrome privileges.
   */
  nsITranslationNodeList getTranslationNodes(in Node aRoot);

  /**
   * Compare the two canvases, returning the number of differing pixels and
   * the maximum difference in a channel.  This will throw an error if
   * the dimensions of the two canvases are different.
   *
   * This method requires chrome privileges.
   */
  uint32_t compareCanvases(in nsISupports aCanvas1,
                           in nsISupports aCanvas2,
                           out unsigned long aMaxDifference);

  /**
   * Returns true if a MozAfterPaint event has been queued but not yet
   * fired.
   */
  readonly attribute boolean isMozAfterPaintPending;

  /**
   * Returns true if the InputTaskManager is suspended.
   */
  readonly attribute boolean isInputTaskManagerSuspended;

  /**
   * Suppresses/unsuppresses user initiated event handling in window's document
   * and subdocuments.
   *
   * @throw NS_ERROR_DOM_SECURITY_ERR if called without chrome privileges and
   *        NS_ERROR_FAILURE if window doesn't have a document.
   */
  void suppressEventHandling(in boolean aSuppress);

  /**
   * Disable or enable non synthetic test mouse events on *all* windows.
   *
   * Cannot be accessed from unprivileged context (not content-accessible).
   * Will throw a DOM security error if called without chrome privileges.
   *
   * @param aDisable  If true, disable all non synthetic test mouse events
   *               on all windows.  Otherwise, enable them.
   */
  void disableNonTestMouseEvents(in boolean aDisable);

  /**
   * Returns the scroll position of the window's currently loaded document.
   *
   * @param aFlushLayout flushes layout if true. Otherwise, no flush occurs.
   * @see nsIDOMWindow::scrollX/Y
   */
  void getScrollXY(in boolean aFlushLayout, out long aScrollX, out long aScrollY);

  /**
   * Returns the scroll position of the window's currently loaded document.
   *
   * @param aFlushLayout flushes layout if true. Otherwise, no flush occurs.
   * @see nsIDOMWindow::scrollX/Y
   */
  void getScrollXYFloat(in boolean aFlushLayout, out float aScrollX, out float aScrollY);

  /**
   * Returns the scrollbar width of the window's scroll frame.
   *
   * @param aFlushLayout flushes layout if true. Otherwise, no flush occurs.
   */
  void getScrollbarSize(in boolean aFlushLayout, out long aWidth, out long aHeight);

  /**
   * Returns the given element's bounds without flushing pending layout changes.
   */
  DOMRect getBoundsWithoutFlushing(in Element aElement);

  /**
   * Scroll the visual viewport to the given coordinates, relative to the
   * document origin.
   * Only applicable to the window associated with the root content document.
   * Note: this does not take effect right away. Rather, the visual scroll
   *       request is sent to APZ with the next transaction, and will be
   *       reflected in the main thread with the subsequent APZ repaint request.
   * Please see the caveats mentioned at PresShell::ScrollToVisual(), and
   * request APZ review if adding a new call to this.
   */
  const long UPDATE_TYPE_RESTORE = 0;
  const long UPDATE_TYPE_MAIN_THREAD = 1;
  const long SCROLL_MODE_INSTANT = 0;
  const long SCROLL_MODE_SMOOTH = 1;
  void scrollToVisual(in float aOffsetX, in float aOffsetY,
                      in long aUpdateType, in long aScrollMode);

  /**
   * Returns the offset of the window's visual viewport relative to the
   * layout viewport.
   */
  void getVisualViewportOffsetRelativeToLayoutViewport(out float aOffsetX,
                                                       out float aOffsetY);

  /**
   * Returns the scroll position of the window's visual viewport.
   */
  void getVisualViewportOffset(out long aOffsetX, out long aOffsetY);

  /**
   * Transforms the passed in rect from layout relative coords (relative to
   * this document) to be is visual coords.
   */
  DOMRect transformRectLayoutToVisual(in float aX, in float aY,
                                      in float aWidth, in float aHeight);

  /**
   * Transform a rectangle given in coordinates relative to this document
   * into CSS coordinates relative to the screen.
   */
  DOMRect toScreenRectInCSSUnits(in float aX, in float aY,
                                 in float aWidth, in float aHeight);

  /**
   * Transform a rectangle given in coordinates relative to this document
   * to the screen.
   */
  DOMRect toScreenRect(in float aX, in float aY,
                       in float aWidth, in float aHeight);

  /**
   * Transform a rectangle given in coordinates relative to the top level
   * parent process widget to the local widget. This window should be in a
   * child process.
   */
  DOMRect convertFromParentProcessWidgetToLocal(in float aX,
                                                in float aY,
                                                in float aWidth,
                                                in float aHeight);

  /**
   * Sets the maximum height of the dynamic toolbar in Screen pixel units.
   */
  [can_run_script]
  void setDynamicToolbarMaxHeight(in uint32_t aHeightInScreen);

  const long FLUSH_NONE = -1;
  const long FLUSH_STYLE = 0;
  const long FLUSH_LAYOUT = 1;
  const long FLUSH_DISPLAY = 2;

  /**
   * Returns true if a flush of the given type is needed.
   */
  bool needsFlush(in long aFlushtype);

  /**
   * Flush pending layout-type notification without flushing throttled
   * animations.
   */
  void flushLayoutWithoutThrottledAnimations();

  /**
   * Returns the bounds of the window's currently loaded document. This will
   * generally be (0, 0, pageWidth, pageHeight) but in some cases (e.g. RTL
   * documents) may have a negative left value.
   */
  DOMRect getRootBounds();

  /**
   * Get IME open state. TRUE means 'Open', otherwise, 'Close'.
   * This property works only when IMEEnabled is IME_STATUS_ENABLED.
   */
  readonly attribute boolean IMEIsOpen;

  /**
   * WARNING: These values must be same as nsIWidget's values.
   */

  /**
   * DISABLED means users cannot use IME completely.
   * Note that this state is *not* same as |ime-mode: disabled;|.
   */
  const unsigned long IME_STATUS_DISABLED = 0;

  /**
   * ENABLED means users can use all functions of IME. This state is same as
   * |ime-mode: normal;|.
   */
  const unsigned long IME_STATUS_ENABLED  = 1;

  /**
   * PASSWORD means users cannot use most functions of IME. But on GTK2,
   * users can use "Simple IM" which only supports dead key inputting.
   * The behavior is same as the behavior of the native password field.
   * This state is same as |ime-mode: disabled;|.
   */
  const unsigned long IME_STATUS_PASSWORD = 2;

  /**
   * Get IME status, see above IME_STATUS_* definitions.
   */
  readonly attribute unsigned long IMEStatus;

  /**
   * Get whether current input context (including IME status) in the widget
   * is set by content or not.
   */
  const unsigned long INPUT_CONTEXT_ORIGIN_MAIN = 0;
  const unsigned long INPUT_CONTEXT_ORIGIN_CONTENT = 1;
  readonly attribute unsigned long inputContextOrigin;

  /**
   * Get a root node which is observed by IMEContentObserver.
   */
  readonly attribute Node nodeObservedByIMEContentObserver;

  /**
   * Get the number of screen pixels per CSS pixel,
   * not taking into account any override of the device pixel scale
   * that's imposed by Responsive Design Mode.
   *
   * This is needed to e.g. correctly translate "window.mozInnerScreenX/Y"
   * into device pixels even when "window" is the window of a document
   * inside an RDM pane.
   */
  readonly attribute float screenPixelsPerCSSPixelNoOverride;

  /**
   * Get the current zoom factor.
   * This is _approximately_ the same as nsIContentViewer.fullZoom,
   * but takes into account Gecko's quantization of the zoom factor, which is
   * implemented by adjusting the (integer) number of appUnits per devPixel.
   */
  readonly attribute float fullZoom;

  /**
   * Dispatches aEvent as a synthesized trusted event for tests via the
   * PresShell object of the window's document.
   * The event is dispatched to aTarget, which should be an object
   * which implements nsIContent interface (#element, #text, etc).
   *
   * Cannot be accessed from unprivileged context (not
   * content-accessible) Will throw a DOM security error if called
   * without chrome privileges.
   *
   * @note Event handlers won't get aEvent as parameter, but a similar event.
   *       Also, aEvent should not be reused.
   */
  [can_run_script]
  boolean dispatchDOMEventViaPresShellForTesting(in Node aTarget,
                                                 in Event aEvent);

  /**
   * Sets WidgetEvent::mFlags::mOnlyChromeDispatch to true to ensure that
   * the event is propagated only to chrome.
   * Event's .target property will be aTarget.
   * Returns the same value as what EventTarget.dispatchEvent does.
   */
  boolean dispatchEventToChromeOnly(in EventTarget aTarget,
                                    in Event aEvent);

  /**
   * Returns the real classname (possibly of the mostly-transparent security
   * wrapper) of aObj.
   */
  [implicit_jscontext] string getClassName(in jsval aObject);

  /**
   * Generate a content command event.
   *
   * Cannot be accessed from unprivileged context (not content-accessible)
   * Will throw a DOM security error if called without chrome privileges.
   *
   * @param aType Type of command content event to send.  Can be one of "cut",
   *        "copy", "paste", "delete", "undo", "redo", "insertText" or
   *        "pasteTransferable".
   * @param aTransferable an instance of nsITransferable when aType is
   *        "pasteTransferable"
   * @param aString The string to be inserted into focused editor when aType is
   *        "insertText"
   */
  void sendContentCommandEvent(in AString aType,
                               [optional] in nsITransferable aTransferable,
                               [optional] in AString aString);

  /**
   * If sendQueryContentEvent()'s aAdditionalFlags argument is
   * QUERY_CONTENT_FLAG_USE_XP_LINE_BREAK, plain text generated from content
   * is created with "\n".
   * Otherwise, platform dependent.  E.g., on Windows, "\r\n" is used.
   * aOffset and aLength are offset and length in/of the plain text content.
   * This flag also affects the result values such as offset, length and string.
   */
  const unsigned long QUERY_CONTENT_FLAG_USE_NATIVE_LINE_BREAK = 0x0000;
  const unsigned long QUERY_CONTENT_FLAG_USE_XP_LINE_BREAK     = 0x0001;

  /**
   * sendQueryContentEvent()'s aAdditionalFlags may have one of following
   * flags when aType is QUERY_SELECTED_TEXT.  If one of them is set,
   * the result is the first range of the selection type.  See also
   * nsISelectionController::SELECTION_*.
   */
  const unsigned long QUERY_CONTENT_FLAG_SELECTION_SPELLCHECK          = 0x0002;
  const unsigned long QUERY_CONTENT_FLAG_SELECTION_IME_RAWINPUT        = 0x0004;
  const unsigned long QUERY_CONTENT_FLAG_SELECTION_IME_SELECTEDRAWTEXT = 0x0008;
  const unsigned long QUERY_CONTENT_FLAG_SELECTION_IME_CONVERTEDTEXT   = 0x0010;
  const unsigned long QUERY_CONTENT_FLAG_SELECTION_IME_SELECTEDCONVERTEDTEXT =
                                                                         0x0020;
  const unsigned long QUERY_CONTENT_FLAG_SELECTION_ACCESSIBILITY       = 0x0040;
  const unsigned long QUERY_CONTENT_FLAG_SELECTION_FIND                = 0x0080;
  const unsigned long QUERY_CONTENT_FLAG_SELECTION_URLSECONDARY        = 0x0100;
  const unsigned long QUERY_CONTENT_FLAG_SELECTION_URLSTRIKEOUT        = 0x0200;

  /**
   * One of sendQueryContentEvent()'s aAdditionalFlags.  If this is specified,
   * aOffset is relative to start of selection or composition.
   * Note that this is supported only when QUERY_CONTENT_FLAG_USE_XP_LINE_BREAK
   * is not specified for now.
   */
  const unsigned long QUERY_CONTENT_FLAG_OFFSET_RELATIVE_TO_INSERTION_POINT =
                                                                         0x0400;

  /**
   * Synthesize a query content event. Note that the result value returned here
   * is in LayoutDevice pixels rather than CSS pixels.
   *
   * @param aType  One of the following const values.  And see also each comment
   *               for the other parameters and the result.
   * @param aAdditionalFlags See the description of QUERY_CONTENT_FLAG_*.
   */
  nsIQueryContentEventResult sendQueryContentEvent(
                               in unsigned long aType,
                               in long long aOffset,
                               in unsigned long aLength,
                               in long aX,
                               in long aY,
                               [optional] in unsigned long aAdditionalFlags);

  /**
   * QUERY_SELECTED_TEXT queries the first selection range's information.
   *
   * @param aOffset   Not used.
   * @param aLength   Not used.
   * @param aX        Not used.
   * @param aY        Not used.
   *
   * @return offset, reversed and text properties of the result are available.
   */
  const unsigned long QUERY_SELECTED_TEXT                       = 3200;

  /**
   * QUERY_TEXT_CONTENT queries the text at the specified range.
   *
   * @param aOffset   The first character's offset.  0 is the first character.
   * @param aLength   The length of getting text.  If the aLength is too long,
   *                  the result text is shorter than this value.
   * @param aX        Not used.
   * @param aY        Not used.
   *
   * @return text property of the result is available.
   */
  const unsigned long QUERY_TEXT_CONTENT                        = 3201;

  /**
   * QUERY_CARET_RECT queries the (collapsed) caret rect of the offset.
   * If the actual caret is there at the specified offset, this returns the
   * actual caret rect.  Otherwise, this guesses the caret rect from the
   * metrics of the text.
   *
   * @param aOffset   The caret offset.  0 is the left side of the first
   *                  caracter in LTR text.
   * @param aLength   Not used.
   * @param aX        Not used.
   * @param aY        Not used.
   *
   * @return left, top, width and height properties of the result are available.
   *         The left and the top properties are offset in the client area of
   *         the DOM window.
   */
  const unsigned long QUERY_CARET_RECT                          = 3203;

  /**
   * QUERY_TEXT_RECT queries the specified text's rect.
   *
   * @param aOffset   The first character's offset.  0 is the first character.
   * @param aLength   The length of getting text.  If the aLength is too long,
   *                  the extra length is ignored.
   * @param aX        Not used.
   * @param aY        Not used.
   *
   * @return left, top, width and height properties of the result are available.
   *         The left and the top properties are offset in the client area of
   *         the DOM window.
   */
  const unsigned long QUERY_TEXT_RECT                           = 3204;

  /**
   * QUERY_TEXT_RECT queries the focused editor's rect.
   *
   * @param aOffset   Not used.
   * @param aLength   Not used.
   * @param aX        Not used.
   * @param aY        Not used.
   *
   * @return left, top, width and height properties of the result are available.
   */
  const unsigned long QUERY_EDITOR_RECT                         = 3205;

  /**
   * QUERY_CHARACTER_AT_POINT queries the character information at the
   * specified point.  The point is offset in the window.
   * NOTE: If there are some panels at the point, this method send the query
   * event to the panel's widget automatically.
   *
   * @param aOffset   Not used.
   * @param aLength   Not used.
   * @param aX        X offset in the widget.
   * @param aY        Y offset in the widget.
   *
   * @return offset, notFound, left, top, width and height properties of the
   *         result are available.
   */
  const unsigned long QUERY_CHARACTER_AT_POINT                  = 3208;

  /**
   * QUERY_TEXT_RECT_ARRAY queries the rects per character
   *
   * @param aOffset   The first character's offset.  0 is the first character.
   * @param aLength   The length of getting text.  If the aLength is too long,
   *                  the extra length is ignored.
   * @param aX        Not used.
   * @param aY        Not used.
   */
  const unsigned long QUERY_TEXT_RECT_ARRAY                     = 3209;

  /**
   * Called when the remote child frame has changed its fullscreen state,
   * when entering fullscreen, and when the origin which is fullscreen changes.
   * aFrameElement is the iframe element which contains the child-process
   * fullscreen document.
   */
  void remoteFrameFullscreenChanged(in Element aFrameElement);

  /**
   * Called when the remote frame has popped all fullscreen elements off its
   * stack, so that the operation can complete on the parent side.
   */
  void remoteFrameFullscreenReverted();

  /**
   * Calls the document to handle any pending fullscreen requests.
   * It is called when the parent document has entered fullscreen, and
   * we want to put the current document into fullscreen as well.
   * The return value indicates whether there is any fullscreen request
   * handled by this call.
   */
  boolean handleFullscreenRequests();

  /**
   * Called when the child frame has fully exit fullscreen, so that the parent
   * process can also fully exit.
   */
  void exitFullscreen();

  /**
   * If sendQueryContentEvent()'s aAdditionalFlags argument is
   * SELECTION_SET_FLAG_USE_NATIVE_LINE_BREAK, aOffset and aLength are offset
   * and length in/of plain text generated from content is created with "\n".
   * Otherwise, platform dependent.  E.g., on Windows, "\r\n" is used.
   */
  const unsigned long SELECTION_SET_FLAG_USE_NATIVE_LINE_BREAK = 0x0000;
  const unsigned long SELECTION_SET_FLAG_USE_XP_LINE_BREAK     = 0x0001;

  /**
   * If SELECTION_SET_FLAG_REVERSE is set, the selection is set from
   * |aOffset + aLength| to |aOffset|.  Otherwise, it's set from |aOffset| to
   * |aOffset + aLength|.
   */
  const unsigned long SELECTION_SET_FLAG_REVERSE               = 0x0002;

  /**
   * Synthesize a selection set event to the window.
   *
   * This sets the selection as the specified information.
   *
   * @param aOffset  The caret offset of the selection start.
   * @param aLength  The length of the selection.  If this is too long, the
   *                 extra length is ignored.
   * @param aAdditionalFlags See the description of SELECTION_SET_FLAG_*.
   * @return True, if succeeded.  Otherwise, false.
   */
  boolean sendSelectionSetEvent(in unsigned long aOffset,
                                in unsigned long aLength,
                                [optional] in unsigned long aAdditionalFlags);

  /* Selection behaviors - mirror nsIFrame's nsSelectionAmount constants */
  const unsigned long SELECT_CHARACTER   = 0;
  const unsigned long SELECT_CLUSTER     = 1;
  const unsigned long SELECT_WORD        = 2;
  const unsigned long SELECT_LINE        = 3;
  const unsigned long SELECT_BEGINLINE   = 4;
  const unsigned long SELECT_ENDLINE     = 5;
  const unsigned long SELECT_PARAGRAPH   = 6;
  const unsigned long SELECT_WORDNOSPACE = 7;

  /**
   * Select content at a client point based on a selection behavior if the
   * underlying content is selectable. Selection will accumulate with any
   * existing selection, callers should clear selection prior if needed.
   * May fire selection changed events. Calls nsFrame's SelectByTypeAtPoint.
   *
   * @param aX, aY The selection point in client coordinates.
   * @param aSelectType The selection behavior requested.
   * @return True if a selection occured, false otherwise.
   * @throw NS_ERROR_DOM_SECURITY_ERR, NS_ERROR_UNEXPECTED for utils
   * issues, and NS_ERROR_INVALID_ARG for coordinates that are outside
   * this window.
   */
  [can_run_script]
  boolean selectAtPoint(in float aX,
                        in float aY,
                        in unsigned long aSelectBehavior);

  /**
   * Perform the equivalent of:
   *   window.getComputedStyle(aElement, aPseudoElement).
   *     getPropertyValue(aPropertyName)
   * except that, when the link whose presence in history is allowed to
   * influence aElement's style is visited, get the value the property
   * would have if allowed all properties to change as a result of
   * :visited selectors (except for cases where getComputedStyle uses
   * data from the frame).
   *
   * This is easier to implement than adding our property restrictions
   * to this API, and is sufficient for the present testing
   * requirements (which are essentially testing 'color').
   */
  AString getVisitedDependentComputedStyle(in Element aElement,
                                           in AString aPseudoElement,
                                           in AString aPropertyName);

  /**
   * Put the window into a state where scripts are frozen and events
   * suppressed, for use when the window has launched a modal prompt.
   */
  void enterModalState();

  /**
   * Resume normal window state, where scripts can run and events are
   * delivered.
   */
  void leaveModalState();

  /**
   * Is the window is in a modal state? [See enterModalState()]
   */
  boolean isInModalState();

  /**
   * Internal desktopMode flag.
   */
  attribute boolean desktopModeViewport;

  /**
   * Suspend/resume timeouts on this window and its descendant windows.
   */
  void suspendTimeouts();
  void resumeTimeouts();

  /**
   * What type of layer manager the widget associated with this window is
   * using. "Basic" is unaccelerated; other types are accelerated. Throws an
   * error if there is no widget associated with this window.
   */
  readonly attribute AString layerManagerType;

  /**
   * True if the layer manager for the widget associated with this window is
   * forwarding layers to a remote compositor, false otherwise. Throws an
   * error if there is no widget associated with this window.
   */
  readonly attribute boolean layerManagerRemote;

  /**
   * True if webrender was requested by the user (via pref or env-var), false
   * otherwise. Note that this doesn't represent whether or not webrender is
   * *actually* enabled, just whether or not it was requested.
   */
  readonly attribute boolean isWebRenderRequested;

  /**
   * Returns the current audio backend as a free-form string.
   */
  readonly attribute AString currentAudioBackend;

  /**
   * Returns the max channel counts of the current audio device.
   */
  readonly attribute unsigned long currentMaxAudioChannels;

  /**
   * Returns the mean round trip latency in seconds for the default input and
   * output device, and the stddev of this latency, as a two element array when
   * the Promise succeeds.
   */
  Promise defaultDevicesRoundTripLatency();

  /**
   * Returns the preferred sample rate of the current audio device.
   */
  readonly attribute unsigned long currentPreferredSampleRate;

  /**
   * Returns all the audio input/output devices.
   */
  const unsigned short AUDIO_INPUT   = 0;
  const unsigned short AUDIO_OUTPUT  = 1;
  nsIArray audioDevices(in unsigned short aSide);

  /**
   * Record (and return) frame-intervals for frames which were presented
   *   between calling StartFrameTimeRecording and StopFrameTimeRecording.
   *
   * - Uses a cyclic buffer and serves concurrent consumers, so if Stop is called too late
   *     (elements were overwritten since Start), result is considered invalid and hence empty.
   * - Buffer is capable of holding 10 seconds @ 60fps (or more if frames were less frequent).
   *     Can be changed (up to 1 hour) via pref: toolkit.framesRecording.bufferSize.
   * - Note: the first frame-interval may be longer than expected because last frame
   *     might have been presented some time before calling StartFrameTimeRecording.
   */

  /**
   * Returns a handle which represents current recording start position.
   */
  void startFrameTimeRecording([retval] out unsigned long startIndex);

  /**
   * Returns array of frame intervals since the time when the given startIndex
   * was handed out from startFrameTimeRecording.
   */
  Array<float> stopFrameTimeRecording(in unsigned long startIndex);

  /**
   * The DPI of the display
   */
  readonly attribute float displayDPI;

  /**
   * advanceTimeAndRefresh allows the caller to take over the refresh
   * driver timing for a window.  A call to advanceTimeAndRefresh does
   * three things:
   *  (1) It marks the refresh driver for this presentation so that it
   *      no longer refreshes on its own, but is instead driven entirely
   *      by the caller (except for the refresh that happens when a
   *      document comes out of the bfcache).
   *  (2) It advances the refresh driver's current refresh time by the
   *      argument given.  Negative advances are permitted.
   *  (3) It does a refresh (i.e., notifies refresh observers) at that
   *      new time.
   *
   * Note that this affects other connected docshells of the same type
   * in the same docshell tree, such as parent frames.
   *
   * When callers have completed their use of advanceTimeAndRefresh,
   * they must call restoreNormalRefresh.
   */
  void advanceTimeAndRefresh(in long long aMilliseconds);

  /**
   * Undoes the effects of advanceTimeAndRefresh.
   */
  void restoreNormalRefresh();

  /**
   * Reports whether the current state is test-controlled refreshes
   * (see advanceTimeAndRefresh and restoreNormalRefresh above).
   */
  readonly attribute bool isTestControllingRefreshes;

  /**
   * Reports whether APZ is enabled on the widget that this window is attached
   * to. If there is no widget it will report the default platform value of
   * whether or not APZ is enabled.
   */
  readonly attribute bool asyncPanZoomEnabled;

  /**
   * Set async scroll offset on an element. The next composite will render
   * with that offset if async scrolling is enabled, and then the offset
   * will be removed. Only call this while test-controlled refreshes is enabled.
   */
  void setAsyncScrollOffset(in Element aElement, in float aX, in float aY);

  /**
   * Set async zoom value. aRootElement should be the document element of our
   * document. The next composite will render with that zoom added to any
   * existing zoom if async scrolling is enabled, and then the zoom will be
   * removed. Only call this while test-controlled refreshes is enabled.
   */
  void setAsyncZoom(in Element aRootElement, in float aValue);

  /**
   * Do a round-trip to the compositor to ensure any pending APZ repaint requests
   * get flushed to the main thread. If the function returns true, the flush was
   * triggered and an "apz-repaints-flushed" notification will be dispatched via
   * the observer service once the flush is complete. If the function returns
   * false, an error occurred or a flush is not needed, and the notification
   * will not fire. This is intended to be used by test code only!
   */
  bool flushApzRepaints();

  /**
   * Sets a flag on the element to forcibly disable APZ on it. This affects
   * the result of nsLayoutUtils::ShouldDisableApzForElement when called on
   * this element. This function also schedules a repaint to ensure that the
   * change takes effect. Note that this is not reversible; it is intended for
   * use by test code only.
   */
  void disableApzForElement(in Element aElement);

  /**
   * Ask APZ to pan and zoom to the focused input element.
   */
  [can_run_script] void zoomToFocusedInput();

  /**
   * Method for testing StyleAnimationValue::ComputeDistance.
   *
   * Returns the distance between the two values as reported by
   * StyleAnimationValue::ComputeDistance for the given element and
   * property.
   */
  double computeAnimationDistance(in Element element,
                                  in AString property,
                                  in AString value1,
                                  in AString value2);

  /**
   * Returns the computed style for the specified property of given pseudo type
   * on the given element after removing styles from declarative animations.
   * @param aElement - A target element
   * @param aPseudoElement - A pseudo type (e.g. '::before' or null)
   * @param aProperty - A longhand CSS property (e.g. 'background-color')
   * @param aFlushType - FLUSH_NONE if any pending styles should not happen,
   *                     FLUSH_STYLE to flush pending styles.
   */
  AString getUnanimatedComputedStyle(in Element aElement,
                                     in AString aPseudoElement,
                                     in AString aProperty,
                                     in long aFlushType);

  /**
   * Returns the effective canvas background color for the window.
   */
  readonly attribute AString canvasBackgroundColor;

  /**
   * Get the type of the currently focused html input, if any.
   */
  readonly attribute AString focusedInputType;

  /**
   * Get the action hint of the currently focused html input, if any.
   */
  readonly attribute AString focusedActionHint;

  /**
   * Get the inputmode of the currently focused editing host, if any.
   */
  readonly attribute AString focusedInputMode;

  /**
   * Get the autocapitalize of the currently focused editing host, if any.
   */
  readonly attribute AString focusedAutocapitalize;

  /**
   * Find the view ID for a given element. This is the reverse of
   * findElementWithViewId().
   */
  nsViewID getViewId(in Element aElement);

  /**
   * Check if any PaintedLayer painting has been done for this element,
   * clears the painted flags if they have.
   */
  boolean checkAndClearPaintedState(in Element aElement);

  /**
   * Check if any display list building has been done for this element,
   * clears the display list flags if they have.
   */
  boolean checkAndClearDisplayListState(in Element aElement);

  /**
   * Check whether all display items of the primary frame of aElement have been
   * assigned to the same single PaintedLayer in the last paint. If that is the
   * case, returns whether that PaintedLayer is opaque; if it's not the case, an
   * exception is thrown.
   */
  boolean isPartOfOpaqueLayer(in Element aElement);

  /**
   * Count the number of different PaintedLayers that the supplied elements have
   * been assigned to in the last paint. Throws an exception if any of the
   * elements doesn't have a primary frame, or if that frame's display items are
   * assigned to any other layers than just a single PaintedLayer per element.
   */
  unsigned long numberOfAssignedPaintedLayers(in Array<Element> aElements);

  /**
   * Get internal id of the stored blob, file or file handle.
   */
  [implicit_jscontext] long long getFileId(in jsval aFile);

  /**
   * Get internal file path of the stored file or file handle.
   *
   * TODO: File handle objects are actually not supported at the moment.
   */
  [implicit_jscontext] AString getFilePath(in jsval aFile);

  /**
   * Get file ref count info for given database and file id.
   *
   */
  [implicit_jscontext]
  boolean getFileReferences(in AString aDatabaseName, in long long aId,
                            [optional] in jsval aOptions,
                            [optional] out long aRefCnt,
                            [optional] out long aDBRefCnt);

  void flushPendingFileDeletions();

  /**
   * Begin opcode-level profiling of all JavaScript execution in the window's
   * runtime.
   */
  [implicit_jscontext]
  void startPCCountProfiling();

  /**
   * Stop opcode-level profiling of JavaScript execution in the runtime, and
   * collect all counts for use by getPCCount methods.
   */
  [implicit_jscontext]
  void stopPCCountProfiling();

  /**
   * Purge collected PC counters.
   */
  [implicit_jscontext]
  void purgePCCounts();

  /**
   * Get the number of scripts with opcode-level profiling information.
   */
  [implicit_jscontext]
  long getPCCountScriptCount();

  /**
   * Get a JSON string for a short summary of a script and the PC counts
   * accumulated for it.
   */
  [implicit_jscontext]
  AString getPCCountScriptSummary(in long script);

  /**
   * Get a JSON string with full information about a profiled script,
   * including the decompilation of the script and placement of decompiled
   * operations within it, and PC counts for each operation.
   */
  [implicit_jscontext]
  AString getPCCountScriptContents(in long script);

  /**
   * Returns true if painting is suppressed for this window and false
   * otherwise.
   */
  readonly attribute boolean paintingSuppressed;

  /**
   * Set the viewport size for the purposes of clamping scroll positions for
   * the root scroll frame of this document to be (aWidth,aHeight) in CSS pixels.
   *
   * The caller of this method must have chrome privileges.
   */
  void setVisualViewportSize(in float aWidth, in float aHeight);

  /**
   * These are used to control whether dialogs (alert, prompt, confirm) are
   * allowed, and to reset the inernal state that controls whether dialogs
   * are currently blocked or not.
   */
  void disableDialogs();
  void enableDialogs();
  bool areDialogsEnabled();
  void resetDialogAbuseState();

  const unsigned long AGENT_SHEET = 0;
  const unsigned long USER_SHEET = 1;
  const unsigned long AUTHOR_SHEET = 2;
  /**
   * Synchronously loads a style sheet from |sheetURI| and adds it to the list
   * of additional style sheets of the document.
   *
   * These additional style sheets are very much like user/agent sheets loaded
   * with loadAndRegisterSheet. The only difference is that they are applied only
   * on the document owned by this window.
   *
   * Sheets added via this API take effect immediately on the document.
   */
  void loadSheet(in nsIURI sheetURI, in unsigned long type);

  /**
   * Same as the above method but allows passing the URI as a string.
   */
  void loadSheetUsingURIString(in ACString sheetURI, in unsigned long type);

  /**
   * Adds a style sheet to the list of additional style sheets of the document.
   *
   * Style sheets can be preloaded with nsIStyleSheetService.preloadSheet.
   *
   * Sheets added via this API take effect immediately on the document.
   */
  void addSheet(in nsIPreloadedStyleSheet sheet, in unsigned long type);

  /**
   * Remove the document style sheet at |sheetURI| from the list of additional
   * style sheets of the document.  The removal takes effect immediately.
   */
  void removeSheet(in nsIURI sheetURI, in unsigned long type);

  /**
   * Same as the above method but allows passing the URI as a string.
   */
  void removeSheetUsingURIString(in ACString sheetURI, in unsigned long type);

  /**
   * Returns true if a user input is being handled.
   *
   * This calls EventStateManager::IsHandlingUserInput().
   */
  readonly attribute boolean isHandlingUserInput;

  /**
   * Returns milliseconds elapsed since last user input was started.
   * Returns -1 if there wasn't any previous user input.
   *
   * This relies on EventStateManager::LatestUserInputStart()
   */
  readonly attribute double millisSinceLastUserInput;

  /**
   * After calling the method, the window for which this DOMWindowUtils
   * was created can be closed using scripts.
   */
  void allowScriptsToClose();

  /**
   * Is the parent window's main widget visible?  If it isn't, we probably
   * don't want to display any dialogs etc it may request.  This corresponds
   * to the visibility check in nsWindowWatcher::OpenWindowInternal().
   *
   * Will throw a DOM security error if called without chrome privileges or
   * NS_ERROR_NOT_AVAILABLE in the unlikely event that the parent window's
   * main widget can't be reached.
   */
  readonly attribute boolean isParentWindowMainWidgetVisible;

  /**
   * In certain cases the event handling of nodes, form controls in practice,
   * may be disabled. Such cases are for example the existence of disabled
   * attribute or -moz-user-input: none.
   */
  boolean isNodeDisabledForEvents(in Node aNode);

  /*
   * Returns the value of a given property animated on the compositor thread.
   * If the property is NOT currently being animated on the compositor thread,
   * returns an empty string.
   * NOTE: Do not use this function for elements that there was another
   * animation running on the compositor before.
   */
  AString getOMTAStyle(in Element aElement, in AString aProperty,
                       [optional] in AString aPseudoElement);

  /*
   * Returns true if the given animation is being tracked by the pending
   * animation tracker for the current document.
   */
  bool isAnimationInPendingTracker(in Animation aAnimation);

  /**
   * If aHandlingInput is true, this informs the event state manager that
   * we're handling user input. Otherwise, this is a no-op (as by default
   * we're not handling user input).
   * Remember to call destruct() on the return value!
   * See also nsIDOMWindowUtils::isHandlingUserInput.
   */
  nsIJSRAIIHelper setHandlingUserInput(in boolean aHandlingInput);

  /**
   * Get the content- and compositor-side APZ test data instances.
   * The return values are of type APZTestData (see APZTestData.webidl).
   */
  [implicit_jscontext] jsval getContentAPZTestData();
  [implicit_jscontext] jsval getCompositorAPZTestData();

  /**
   * Posts an RestyleHint::RESTYLE_SELF restyle event for the given element.
   */
  void postRestyleSelfEvent(in Element aElement);

  /**
   * This method doesn't do anything useful.  It was solely added for the
   * purpose of the test for bug 503926.
   */
  void xpconnectArgument(in nsISupports aObj);

  /**
   * Helper for JS components that need to send permission requests with
   * e10s support properly.
   */
  void askPermission(in nsIContentPermissionRequest aRequest);

  /**
   * Restyle generation for the current document.
   *
   * May throw NS_ERROR_NOT_AVAILABLE.
   */
  readonly attribute unsigned long long restyleGeneration;

  /**
   * Number of frames constructed (excluding breaking) for the curent
   * document.
   *
   * May throw NS_ERROR_NOT_AVAILABLE.
   */
  readonly attribute unsigned long long framesConstructed;

  /**
   * Number of frames reflowed for the curent document.
   *
   * May throw NS_ERROR_NOT_AVAILABLE.
   */
  readonly attribute unsigned long long framesReflowed;

  /**
   * Indicates whether the current frame's refresh driver has a pending tick,
   * as reported by nsRefreshDriver::HasPendingTick.
   *
   * May throw NS_ERROR_NOT_AVAILABLE.
   */
  readonly attribute bool refreshDriverHasPendingTick;

  /**
   * Controls the amount of chrome that should be visible on each side of
   * the window. Works like the chromemargin xul:window attribute.
   * This should only be used with non-XUL windows.
   */
  void setChromeMargin(in int32_t aTop,
                       in int32_t aRight,
                       in int32_t aBottom,
                       in int32_t aLeft);

  /**
   * Controls the amount of space on each edge of the window that can be
   * dragged to resize the window in that direction.
   *
   * @param aResizeMargin  In CSS pixels, will apply to all four window sides.
   */
  void setResizeMargin(in int32_t aResizeMargin);

  /**
   * Returns a JSObject which contains a list of frame uniformities
   * when the pref gfx.vsync.collect-scroll-data is enabled.
   * Every result contains a layer address and a frame uniformity for that layer.
   * A negative frame uniformity value indicates an invalid frame uniformity and an error has occured.
   */
  [implicit_jscontext] jsval getFrameUniformityTestData();

  /*
   * Increase the chaos mode activation level. An equivalent number of
   * calls to leaveChaosMode must be made in order to restore the original
   * chaos mode state. If the activation level is nonzero all chaos mode
   * features are activated.
   */
  void enterChaosMode();

  /**
   * Decrease the chaos mode activation level. See enterChaosMode().
   */
  void leaveChaosMode();

  /**
   * Alerts Gecko of a device reset
   */
  void triggerDeviceReset();

  /**
   * Returns whether the document's style set's rule processor for the
   * specified level of the cascade is shared by multiple style sets.
   * (Used by tests to ensure that certain optimizations do not regress.)
   *
   * @param aSheetType One of the nsIStyleSheetService.*_SHEET constants.
   */
  bool hasRuleProcessorUsedByMultipleStyleSets(in unsigned long aSheetType);

  /**
   * Enable or disable displayport suppression. This is intended to be used by
   * testing code, to provide more deterministic behaviour over the displayport
   * suppression during tests. Note that this updates a flag, so whatever value
   * was last provided is what will be used.
   */
  void respectDisplayPortSuppression(in boolean aEnabled);

  /**
   * Set a flag that forces the next reflow interrupt check to return true. This
   * can be used by tests to force execution of the interrupted reflow codepaths.
   */
  void forceReflowInterrupt();

  /**
   * Terminate the GPU process. Used for testing GPU process restarts.
   */
  void terminateGPUProcess();

  /**
    * Returns the GPU process pid, or -1 if there is no GPU process.
    */
  readonly attribute int32_t gpuProcessPid;

  /**
   * Adds an EventStates bit to the element.
   *
   * The state string must be one of the following:
   *   * (none yet; but for example "higlighted" for NS_EVENT_STATE_HIGHLIGHTED)
   *
   * The supported state strings are defined in kManuallyManagedStates
   * in nsDOMWindowUtils.cpp.
   */
  void addManuallyManagedState(in Element element,
                               in AString state);

  /**
   * Removes the specified EventStates bits from the element.
   *
   * See above for the strings that can be passed for |state|.
   */
  void removeManuallyManagedState(in Element element,
                                  in AString state);

  /**
   * Returns usage data for a given storage object.
   *
   * @param aStorage
   *    The storage object to get usage data for.
   */
  int64_t getStorageUsage(in Storage aStorage);

  /**
   * Returns the directionality of a string using the first-strong character
   * algorithm defined in http://unicode.org/reports/tr9/#P2.
   *
   * @param aString the string to retrieve the direction for.
   * @return one of DIRECTION_LTR, DIRECTION_RTL or DIRECTION_NOT_SET depending
   *         on the first-strong character found in the string.
   */
  long getDirectionFromText(in AString aString);

  /**
   * Calls FrameNeedsReflow on that root frame so that a layout flush
   * will be necessary.
   *
   * This should only be used for testing.
   */
  void ensureDirtyRootFrame();

  /**
   * Capture the contents of the current WebRender frame and
   * save them to a folder relative to the current working directory.
   */
  void wrCapture();

  /**
   * Flag bits for use in |wrStartCaptureSequence|'s |aFlags| argument.
   */
  const uint32_t WR_CAPTURE_SCENE = 0x1;
  const uint32_t WR_CAPTURE_FRAME = 0x2;
  const uint32_t WR_CAPTURE_TILE_CACHE = 0x4;
  const uint32_t WR_CAPTURE_EXTERNAL_RESOURCES = 0x8;

  /**
   * Start capturing each WebRender frame to disk.
   *
   * |aPath| is the name of a new directory to be created to hold the captures.
   * it is relative to:
   * - the |PUBLIC_STORAGE| environment variable, if set, else
   * - the |MOZ_UPLOAD_DIR| environment variable, if set, else
   * - the user's home directory, if known, else
   * the current directory.
   *
   * If there is already a directory with the given name, a numeric suffix is
   * added to ensure a fresh directory is created. This means that you can't
   * be sure your capture directory is actually named |aPath|.
   *
   * |aFlags| is a set of flags from |webrender::render_api::CaptureBits|.
   *
   * If there is already a sequence capture in progress, stop it and start a new
   * one, with the new path and flags.
   */
  void wrStartCaptureSequence(in ACString aPath, in uint32_t aFlags);

  /**
   * Stop a capture begun with |wrStartCaptureSequence|.
   */
  void wrStopCaptureSequence();

  /**
   * Toggle recording of composition on and off.
   *
   * This is equivalent to calling |startCompositionRecorder()| or
   * |stopCompositionRecorder(true)|.
   */
  Promise setCompositionRecording(in boolean aValue);

  /**
   * Start the composition recorder.
   *
   * @return A promise that is resolved to true if the composion recorder was
   *         started successfully.
   */
  Promise startCompositionRecording();

  /**
   * Stop the composition recorder.
   *
   * @param aWriteToDisk Whether or not the frames should be written to disk.
   *                     If false, they will be returned in the promise.
   * @return A promise that resolves when the frames have been collected.
   *         When |aWriteToDisk| is true, the promise will resolve to |undefined|.
   *         Otherwise, the promise will resolve to a |DOMCollectedFrames| dictionary,
   *         which contains the timestamps and contents of the captured frames.
   */
  Promise stopCompositionRecording(in boolean aWriteToDisk);

  /**
   * Returns whether the document we're associated to has recorded a given CSS
   * property via the use counter mechanism.
   *
   * Throws if there's no document or the property is invalid.
   */
  bool isCssPropertyRecordedInUseCounter(in ACString aProperty);

  /**
   * Calls SetInitialViewport on the MobileViewportManager, which effectively
   * causes it to refresh all of its internal state and update things that
   * need updating.
   */
  void resetMobileViewportManager();

  /**
   * NOTE: Currently works only on GTK+.
   */
  attribute ACString systemFont;

  /**
   * Returns the number of times this document for this window has
   * been painted to the screen.
   *
   * Use this instead of window.mozPaintCount
   */
  readonly attribute unsigned long long paintCount;

  // These consts are only for testing purposes.
  const long DEFAULT_MOUSE_POINTER_ID = 0;
  const long DEFAULT_PEN_POINTER_ID   = 1;
  const long DEFAULT_TOUCH_POINTER_ID = 2;

  // Match mozilla::MouseButton.
  const long MOUSE_BUTTON_LEFT_BUTTON   = 0;
  const long MOUSE_BUTTON_MIDDLE_BUTTON = 1;
  const long MOUSE_BUTTON_RIGHT_BUTTON  = 2;

  // Match mozilla::MouseButtonsFlag.
  const long MOUSE_BUTTONS_NO_BUTTON = 0x00;
  const long MOUSE_BUTTONS_LEFT_BUTTON = 0x01;
  const long MOUSE_BUTTONS_RIGHT_BUTTON = 0x02;
  const long MOUSE_BUTTONS_MIDDLE_BUTTON = 0x04;
  // Typically, "back" button being left side of 5-button
  // mice, see "buttons" attribute document of DOM3 Events.
  const long MOUSE_BUTTONS_4TH_BUTTON = 0x08;
  // Typically, "forward" button being right side of 5-button
  // mice, see "buttons" attribute document of DOM3 Events.
  const long MOUSE_BUTTONS_5TH_BUTTON = 0x10;
  // Buttons are not specified, will be calculated from |aButton|.
  const long MOUSE_BUTTONS_NOT_SPECIFIED = -1;

  // Return values for getDirectionFromText().
  const long DIRECTION_LTR = 0;
  const long DIRECTION_RTL = 1;
  const long DIRECTION_NOT_SET = 2;

  void syncFlushCompositor();

  unsigned long long getLayersId();

  // Returns true if we are effectively throttling frame requests.
  readonly attribute bool effectivelyThrottlesFrameRequests;

  // Returns the ID for the underlying window widget, which can
  // be compared against the rawId from a nsIMediaDevice to determine
  // if the window is being shared.
  //
  // Using this only makes sense in the parent process, and the function
  // will intentionally crash any non-parent process that tries to access
  // it.
  readonly attribute AString webrtcRawDeviceId;

  // Used for testing to check the suspend status.
  readonly attribute bool suspendedByBrowsingContextGroup;
};

[scriptable, uuid(c694e359-7227-4392-a138-33c0cc1f15a6)]
interface nsITranslationNodeList : nsISupports {
  readonly attribute unsigned long length;
  Node item(in unsigned long index);

  // A translation root is a block element, or an inline element
  // which its parent is not a translation node.
  boolean isTranslationRootAtIndex(in unsigned long index);
};

/**
 * JS doesn't do RAII very well. We can use this interface to make remembering
 * to destruct an object in a finally clause easier.
 */
[scriptable, uuid(52e5a996-d0a9-4efc-a6fa-24489c532b19)]
interface nsIJSRAIIHelper : nsISupports {
  void destruct();
};