widget/BasicEvents.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef mozilla_BasicEvents_h__
   7 #define mozilla_BasicEvents_h__
   8
   9 #include <stdint.h>
  10 #include <type_traits>
  11
  12 #include "mozilla/EventForwards.h"
  13 #include "mozilla/TimeStamp.h"
  14 #include "mozilla/dom/EventTarget.h"
  15 #include "mozilla/layers/LayersTypes.h"
  16 #include "nsCOMPtr.h"
  17 #include "nsAtom.h"
  18 #include "nsISupportsImpl.h"
  19 #include "nsIWidget.h"
  20 #include "nsString.h"
  21 #include "Units.h"
  22
  23 #ifdef DEBUG
  24 #  include "nsXULAppAPI.h"
  25 #endif  // #ifdef DEBUG
  26
  27 class nsIPrincipal;
  28
  29 namespace IPC {
  30 template <typename T>
  31 struct ParamTraits;
  32 }  // namespace IPC
  33
  34 namespace mozilla {
  35
  36 class EventTargetChainItem;
  37
  38 enum class CrossProcessForwarding {
  39   // eStop prevents the event to be sent to remote process.
  40   eStop,
  41   // eAllow keeps current state of the event whether it's sent to remote
  42   // process.  In other words, eAllow does NOT mean that making the event
  43   // sent to remote process when IsCrossProcessForwardingStopped() returns
  44   // true.
  45   eAllow,
  46 };
  47
  48 /******************************************************************************
  49  * mozilla::BaseEventFlags
  50  *
  51  * BaseEventFlags must be a POD struct for safe to use memcpy (including
  52  * in ParamTraits<BaseEventFlags>).  So don't make virtual methods, constructor,
  53  * destructor and operators.
  54  * This is necessary for VC which is NOT C++0x compiler.
  55  ******************************************************************************/
  56
  57 struct BaseEventFlags {
  58  public:
  59   // If mIsTrusted is true, the event is a trusted event.  Otherwise, it's
  60   // an untrusted event.
  61   bool mIsTrusted : 1;
  62   // If mInBubblingPhase is true, the event is in bubbling phase or target
  63   // phase.
  64   bool mInBubblingPhase : 1;
  65   // If mInCapturePhase is true, the event is in capture phase or target phase.
  66   bool mInCapturePhase : 1;
  67   // If mInSystemGroup is true, the event is being dispatched in system group.
  68   bool mInSystemGroup : 1;
  69   // If mCancelable is true, the event can be consumed.  I.e., calling
  70   // dom::Event::PreventDefault() can prevent the default action.
  71   bool mCancelable : 1;
  72   // If mBubbles is true, the event can bubble.  Otherwise, cannot be handled
  73   // in bubbling phase.
  74   bool mBubbles : 1;
  75   // If mPropagationStopped is true, dom::Event::StopPropagation() or
  76   // dom::Event::StopImmediatePropagation() has been called.
  77   bool mPropagationStopped : 1;
  78   // If mImmediatePropagationStopped is true,
  79   // dom::Event::StopImmediatePropagation() has been called.
  80   // Note that mPropagationStopped must be true when this is true.
  81   bool mImmediatePropagationStopped : 1;
  82   // If mDefaultPrevented is true, the event has been consumed.
  83   // E.g., dom::Event::PreventDefault() has been called or
  84   // the default action has been performed.
  85   bool mDefaultPrevented : 1;
  86   // If mDefaultPreventedByContent is true, the event has been
  87   // consumed by content.
  88   // Note that mDefaultPrevented must be true when this is true.
  89   bool mDefaultPreventedByContent : 1;
  90   // If mDefaultPreventedByChrome is true, the event has been
  91   // consumed by chrome.
  92   // Note that mDefaultPrevented must be true when this is true.
  93   bool mDefaultPreventedByChrome : 1;
  94   // mMultipleActionsPrevented may be used when default handling don't want to
  95   // be prevented, but only one of the event targets should handle the event.
  96   // For example, when a <label> element is in another <label> element and
  97   // the first <label> element is clicked, that one may set this true.
  98   // Then, the second <label> element won't handle the event.
  99   bool mMultipleActionsPrevented : 1;
 100   // Similar to above but expected to be used during PreHandleEvent phase.
 101   bool mMultiplePreActionsPrevented : 1;
 102   // If mIsBeingDispatched is true, the DOM event created from the event is
 103   // dispatching into the DOM tree and not completed.
 104   bool mIsBeingDispatched : 1;
 105   // If mDispatchedAtLeastOnce is true, the event has been dispatched
 106   // as a DOM event and the dispatch has been completed in the process.
 107   // So, this is false even if the event has already been dispatched
 108   // in another process.
 109   bool mDispatchedAtLeastOnce : 1;
 110   // If mIsSynthesizedForTests is true, the event has been synthesized for
 111   // automated tests or something hacky approach of an add-on.
 112   bool mIsSynthesizedForTests : 1;
 113   // If mExceptionWasRaised is true, one of the event handlers has raised an
 114   // exception.
 115   bool mExceptionWasRaised : 1;
 116   // If mRetargetToNonNativeAnonymous is true and the target is in a non-native
 117   // native anonymous subtree, the event target is set to mOriginalTarget.
 118   bool mRetargetToNonNativeAnonymous : 1;
 119   // If mNoContentDispatch is true, the event is never dispatched to the
 120   // event handlers which are added to the contents, onfoo attributes and
 121   // properties.  Note that this flag is ignored when
 122   // EventChainPreVisitor::mForceContentDispatch is set true.  For exapmle,
 123   // window and document object sets it true.  Therefore, web applications
 124   // can handle the event if they add event listeners to the window or the
 125   // document.
 126   // XXX This is an ancient and broken feature, don't use this for new bug
 127   //     as far as possible.
 128   bool mNoContentDispatch : 1;
 129   // If mOnlyChromeDispatch is true, the event is dispatched to only chrome.
 130   bool mOnlyChromeDispatch : 1;
 131   // Indicates if the key combination is reserved by chrome.  This is set by
 132   // MarkAsReservedByChrome().
 133   bool mIsReservedByChrome : 1;
 134   // If mOnlySystemGroupDispatchInContent is true, event listeners added to
 135   // the default group for non-chrome EventTarget won't be called.
 136   // Be aware, if this is true, EventDispatcher needs to check if each event
 137   // listener is added to chrome node, so, don't set this to true for the
 138   // events which are fired a lot of times like eMouseMove.
 139   bool mOnlySystemGroupDispatchInContent : 1;
 140   // If mOnlySystemGroupDispatch is true, the event will be dispatched only to
 141   // event listeners added in the system group.
 142   bool mOnlySystemGroupDispatch : 1;
 143   // The event's action will be handled by APZ. The main thread should not
 144   // perform its associated action.
 145   bool mHandledByAPZ : 1;
 146   // True if the event is currently being handled by an event listener that
 147   // was registered as a passive listener.
 148   bool mInPassiveListener : 1;
 149   // If mComposed is true, the event fired by nodes in shadow DOM can cross the
 150   // boundary of shadow DOM and light DOM.
 151   bool mComposed : 1;
 152   // Similar to mComposed. Set it to true to allow events cross the boundary
 153   // between native non-anonymous content and native anonymouse content
 154   bool mComposedInNativeAnonymousContent : 1;
 155   // Set to true for events which are suppressed or delayed so that later a
 156   // DelayedEvent of it is dispatched. This is used when parent side process
 157   // the key event after content side, and may drop the event if the event
 158   // was suppressed or delayed in contents side.
 159   // It is also set to true for the events (in a DelayedInputEvent), which will
 160   // be dispatched afterwards.
 161   bool mIsSuppressedOrDelayed : 1;
 162   // Certain mouse events can be marked as positionless to return 0 from
 163   // coordinate related getters.
 164   bool mIsPositionless : 1;
 165
 166   // Flags managing state of propagation between processes.
 167   // Note the the following flags shouldn't be referred directly.  Use utility
 168   // methods instead.
 169
 170   // If mNoRemoteProcessDispatch is true, the event is not allowed to be sent
 171   // to remote process.
 172   bool mNoRemoteProcessDispatch : 1;
 173   // If mWantReplyFromContentProcess is true, the event will be redispatched
 174   // in the parent process after the content process has handled it. Useful
 175   // for when the parent process need the know first how the event was used
 176   // by content before handling it itself.
 177   bool mWantReplyFromContentProcess : 1;
 178   // If mPostedToRemoteProcess is true, the event has been posted to the
 179   // remote process (but it's not handled yet if it's not a duplicated event
 180   // instance).
 181   bool mPostedToRemoteProcess : 1;
 182   // If mCameFromAnotherProcess is true, the event came from another process.
 183   bool mCameFromAnotherProcess : 1;
 184
 185   // At lease one of the event in the event path had non privileged click
 186   // listener.
 187   bool mHadNonPrivilegedClickListeners : 1;
 188
 189   // If the event is being handled in target phase, returns true.
 190   inline bool InTargetPhase() const {
 191     return (mInBubblingPhase && mInCapturePhase);
 192   }
 193
 194   /**
 195    * Helper methods for methods of DOM Event.
 196    */
 197   inline void StopPropagation() { mPropagationStopped = true; }
 198   inline void StopImmediatePropagation() {
 199     StopPropagation();
 200     mImmediatePropagationStopped = true;
 201   }
 202   inline void PreventDefault(bool aCalledByDefaultHandler = true) {
 203     if (!mCancelable) {
 204       return;
 205     }
 206     mDefaultPrevented = true;
 207     // Note that even if preventDefault() has already been called by chrome,
 208     // a call of preventDefault() by content needs to overwrite
 209     // mDefaultPreventedByContent to true because in such case, defaultPrevented
 210     // must be true when web apps check it after they call preventDefault().
 211     if (aCalledByDefaultHandler) {
 212       StopCrossProcessForwarding();
 213       mDefaultPreventedByChrome = true;
 214     } else {
 215       mDefaultPreventedByContent = true;
 216     }
 217   }
 218   // This should be used only before dispatching events into the DOM tree.
 219   inline void PreventDefaultBeforeDispatch(
 220       CrossProcessForwarding aCrossProcessForwarding) {
 221     if (!mCancelable) {
 222       return;
 223     }
 224     mDefaultPrevented = true;
 225     if (aCrossProcessForwarding == CrossProcessForwarding::eStop) {
 226       StopCrossProcessForwarding();
 227     }
 228   }
 229   inline bool DefaultPrevented() const { return mDefaultPrevented; }
 230   inline bool DefaultPreventedByContent() const {
 231     MOZ_ASSERT(!mDefaultPreventedByContent || DefaultPrevented());
 232     return mDefaultPreventedByContent;
 233   }
 234   inline bool IsTrusted() const { return mIsTrusted; }
 235   inline bool PropagationStopped() const { return mPropagationStopped; }
 236
 237   // Helper methods to access flags managing state of propagation between
 238   // processes.
 239
 240   /**
 241    * Prevent to be dispatched to remote process.
 242    */
 243   inline void StopCrossProcessForwarding() {
 244     MOZ_ASSERT(!mPostedToRemoteProcess);
 245     mNoRemoteProcessDispatch = true;
 246     mWantReplyFromContentProcess = false;
 247   }
 248   /**
 249    * Return true if the event shouldn't be dispatched to remote process.
 250    */
 251   inline bool IsCrossProcessForwardingStopped() const {
 252     return mNoRemoteProcessDispatch;
 253   }
 254   /**
 255    * Mark the event as waiting reply from remote process.
 256    * If the caller needs to win other keyboard event handlers in chrome,
 257    * the caller should call StopPropagation() too.
 258    * Otherwise, if the caller just needs to know if the event is consumed by
 259    * either content or chrome, it should just call this because the event
 260    * may be reserved by chrome and it needs to be dispatched into the DOM
 261    * tree in chrome for checking if it's reserved before being sent to any
 262    * remote processes.
 263    */
 264   inline void MarkAsWaitingReplyFromRemoteProcess() {
 265     MOZ_ASSERT(!mPostedToRemoteProcess);
 266     mNoRemoteProcessDispatch = false;
 267     mWantReplyFromContentProcess = true;
 268   }
 269   /**
 270    * Reset "waiting reply from remote process" state.  This is useful when
 271    * you dispatch a copy of an event coming from different process.
 272    */
 273   inline void ResetWaitingReplyFromRemoteProcessState() {
 274     if (IsWaitingReplyFromRemoteProcess()) {
 275       // FYI: mWantReplyFromContentProcess is also used for indicating
 276       //      "handled in remote process" state.  Therefore, only when
 277       //      IsWaitingReplyFromRemoteProcess() returns true, this should
 278       //      reset the flag.
 279       mWantReplyFromContentProcess = false;
 280     }
 281   }
 282   /**
 283    * Return true if the event handler should wait reply event.  I.e., if this
 284    * returns true, any event handler should do nothing with the event.
 285    */
 286   inline bool IsWaitingReplyFromRemoteProcess() const {
 287     return !mNoRemoteProcessDispatch && mWantReplyFromContentProcess;
 288   }
 289   /**
 290    * Mark the event as already handled in the remote process.  This should be
 291    * called when initializing reply events.
 292    */
 293   inline void MarkAsHandledInRemoteProcess() {
 294     mNoRemoteProcessDispatch = true;
 295     mWantReplyFromContentProcess = true;
 296     mPostedToRemoteProcess = false;
 297   }
 298   /**
 299    * Return true if the event has already been handled in the remote process.
 300    */
 301   inline bool IsHandledInRemoteProcess() const {
 302     return mNoRemoteProcessDispatch && mWantReplyFromContentProcess;
 303   }
 304   /**
 305    * Return true if the event should be sent back to its parent process.
 306    */
 307   inline bool WantReplyFromContentProcess() const {
 308     MOZ_ASSERT(!XRE_IsParentProcess());
 309     return IsWaitingReplyFromRemoteProcess();
 310   }
 311   /**
 312    * Mark the event has already posted to a remote process.
 313    */
 314   inline void MarkAsPostedToRemoteProcess() {
 315     MOZ_ASSERT(!IsCrossProcessForwardingStopped());
 316     mPostedToRemoteProcess = true;
 317   }
 318   /**
 319    * Reset the cross process dispatching state.  This should be used when a
 320    * process receives the event because the state is in the sender.
 321    */
 322   inline void ResetCrossProcessDispatchingState() {
 323     MOZ_ASSERT(!IsCrossProcessForwardingStopped());
 324     mPostedToRemoteProcess = false;
 325     // Ignore propagation state in the remote process if it's marked as
 326     // "waiting reply from remote process" because the process needs to
 327     // stop propagation in the process until receiving a reply event.
 328     // Note that the propagation stopped flag is important for the reply event
 329     // handler in the main process because it's used for making whether it's
 330     // ignored by the remote process or not.
 331     if (!XRE_IsParentProcess() && IsWaitingReplyFromRemoteProcess()) {
 332       mPropagationStopped = mImmediatePropagationStopped = false;
 333     }
 334     // mDispatchedAtLeastOnce indicates the state in current process.
 335     mDispatchedAtLeastOnce = false;
 336   }
 337   /**
 338    * Return true if the event has been posted to a remote process.
 339    * Note that MarkAsPostedToRemoteProcess() is called by
 340    * ParamTraits<mozilla::WidgetEvent>.  Therefore, it *might* be possible
 341    * that posting the event failed even if this returns true.  But that must
 342    * really rare.  If that'd be problem for you, you should unmark this in
 343    * BrowserParent or somewhere.
 344    */
 345   inline bool HasBeenPostedToRemoteProcess() const {
 346     return mPostedToRemoteProcess;
 347   }
 348   /**
 349    * Return true if the event came from another process.
 350    */
 351   inline bool CameFromAnotherProcess() const { return mCameFromAnotherProcess; }
 352   /**
 353    * Mark the event as coming from another process.
 354    */
 355   inline void MarkAsComingFromAnotherProcess() {
 356     mCameFromAnotherProcess = true;
 357   }
 358   /**
 359    * Mark the event is reserved by chrome.  I.e., shouldn't be dispatched to
 360    * content because it shouldn't be cancelable.
 361    */
 362   inline void MarkAsReservedByChrome() {
 363     MOZ_ASSERT(!mPostedToRemoteProcess);
 364     mIsReservedByChrome = true;
 365     // For reserved commands (such as Open New Tab), we don't need to wait for
 366     // the content to answer, neither to give a chance for content to override
 367     // its behavior.
 368     StopCrossProcessForwarding();
 369     // If the event is reserved by chrome, we shouldn't expose the event to
 370     // web contents because such events shouldn't be cancelable.  So, it's not
 371     // good behavior to fire such events but to ignore the defaultPrevented
 372     // attribute value in chrome.
 373     mOnlySystemGroupDispatchInContent = true;
 374   }
 375   /**
 376    * Return true if the event is reserved by chrome.
 377    */
 378   inline bool IsReservedByChrome() const {
 379     MOZ_ASSERT(!mIsReservedByChrome || (IsCrossProcessForwardingStopped() &&
 380                                         mOnlySystemGroupDispatchInContent));
 381     return mIsReservedByChrome;
 382   }
 383
 384   inline void Clear() { SetRawFlags(0); }
 385   // Get if either the instance's bit or the aOther's bit is true, the
 386   // instance's bit becomes true.  In other words, this works like:
 387   // eventFlags |= aOther;
 388   inline void Union(const BaseEventFlags& aOther) {
 389     RawFlags rawFlags = GetRawFlags() | aOther.GetRawFlags();
 390     SetRawFlags(rawFlags);
 391   }
 392
 393  private:
 394   typedef uint64_t RawFlags;
 395
 396   inline void SetRawFlags(RawFlags aRawFlags) {
 397     static_assert(sizeof(BaseEventFlags) <= sizeof(RawFlags),
 398                   "mozilla::EventFlags must not be bigger than the RawFlags");
 399     memcpy(this, &aRawFlags, sizeof(BaseEventFlags));
 400   }
 401   inline RawFlags GetRawFlags() const {
 402     RawFlags result = 0;
 403     memcpy(&result, this, sizeof(BaseEventFlags));
 404     return result;
 405   }
 406 };
 407
 408 /******************************************************************************
 409  * mozilla::EventFlags
 410  ******************************************************************************/
 411
 412 struct EventFlags : public BaseEventFlags {
 413   EventFlags() { Clear(); }
 414 };
 415
 416 /******************************************************************************
 417  * mozilla::WidgetEventTime
 418  ******************************************************************************/
 419
 420 class WidgetEventTime {
 421  public:
 422   // Elapsed time, in milliseconds, from a platform-specific zero time
 423   // to the time the message was created
 424   uint64_t mTime;
 425   // Timestamp when the message was created. Set in parallel to 'time' until we
 426   // determine if it is safe to drop 'time' (see bug 77992).
 427   TimeStamp mTimeStamp;
 428
 429   WidgetEventTime() : mTime(0), mTimeStamp(TimeStamp::Now()) {}
 430
 431   WidgetEventTime(uint64_t aTime, TimeStamp aTimeStamp)
 432       : mTime(aTime), mTimeStamp(aTimeStamp) {}
 433
 434   void AssignEventTime(const WidgetEventTime& aOther) {
 435     mTime = aOther.mTime;
 436     mTimeStamp = aOther.mTimeStamp;
 437   }
 438 };
 439
 440 /******************************************************************************
 441  * mozilla::WidgetEvent
 442  ******************************************************************************/
 443
 444 class WidgetEvent : public WidgetEventTime {
 445  private:
 446   void SetDefaultCancelableAndBubbles() {
 447     switch (mClass) {
 448       case eEditorInputEventClass:
 449         mFlags.mCancelable = false;
 450         mFlags.mBubbles = mFlags.mIsTrusted;
 451         break;
 452       case eMouseEventClass:
 453         mFlags.mCancelable =
 454             (mMessage != eMouseEnter && mMessage != eMouseLeave);
 455         mFlags.mBubbles = (mMessage != eMouseEnter && mMessage != eMouseLeave);
 456         break;
 457       case ePointerEventClass:
 458         mFlags.mCancelable =
 459             (mMessage != ePointerEnter && mMessage != ePointerLeave &&
 460              mMessage != ePointerCancel && mMessage != ePointerGotCapture &&
 461              mMessage != ePointerLostCapture);
 462         mFlags.mBubbles =
 463             (mMessage != ePointerEnter && mMessage != ePointerLeave);
 464         break;
 465       case eDragEventClass:
 466         mFlags.mCancelable = (mMessage != eDragExit && mMessage != eDragLeave &&
 467                               mMessage != eDragEnd);
 468         mFlags.mBubbles = true;
 469         break;
 470       case eSMILTimeEventClass:
 471         mFlags.mCancelable = false;
 472         mFlags.mBubbles = false;
 473         break;
 474       case eTransitionEventClass:
 475       case eAnimationEventClass:
 476         mFlags.mCancelable = false;
 477         mFlags.mBubbles = true;
 478         break;
 479       case eCompositionEventClass:
 480         // XXX compositionstart is cancelable in draft of DOM3 Events.
 481         //     However, it doesn't make sense for us, we cannot cancel
 482         //     composition when we send compositionstart event.
 483         mFlags.mCancelable = false;
 484         mFlags.mBubbles = true;
 485         break;
 486       default:
 487         if (mMessage == eResize || mMessage == eMozVisualResize ||
 488             mMessage == eMozVisualScroll || mMessage == eEditorInput ||
 489             mMessage == eFormSelect) {
 490           mFlags.mCancelable = false;
 491         } else {
 492           mFlags.mCancelable = true;
 493         }
 494         mFlags.mBubbles = true;
 495         break;
 496     }
 497   }
 498
 499  protected:
 500   WidgetEvent(bool aIsTrusted, EventMessage aMessage,
 501               EventClassID aEventClassID)
 502       : WidgetEventTime(),
 503         mClass(aEventClassID),
 504         mMessage(aMessage),
 505         mRefPoint(0, 0),
 506         mLastRefPoint(0, 0),
 507         mFocusSequenceNumber(0),
 508         mSpecifiedEventType(nullptr),
 509         mPath(nullptr),
 510         mLayersId(layers::LayersId{0}) {
 511     MOZ_COUNT_CTOR(WidgetEvent);
 512     mFlags.Clear();
 513     mFlags.mIsTrusted = aIsTrusted;
 514     SetDefaultCancelableAndBubbles();
 515     SetDefaultComposed();
 516     SetDefaultComposedInNativeAnonymousContent();
 517   }
 518
 519   WidgetEvent() : WidgetEventTime(), mPath(nullptr) {
 520     MOZ_COUNT_CTOR(WidgetEvent);
 521   }
 522
 523  public:
 524   WidgetEvent(bool aIsTrusted, EventMessage aMessage)
 525       : WidgetEvent(aIsTrusted, aMessage, eBasicEventClass) {}
 526
 527   MOZ_COUNTED_DTOR_VIRTUAL(WidgetEvent)
 528
 529   WidgetEvent(const WidgetEvent& aOther) : WidgetEventTime() {
 530     MOZ_COUNT_CTOR(WidgetEvent);
 531     *this = aOther;
 532   }
 533   WidgetEvent& operator=(const WidgetEvent& aOther) = default;
 534
 535   WidgetEvent(WidgetEvent&& aOther)
 536       : WidgetEventTime(std::move(aOther)),
 537         mClass(aOther.mClass),
 538         mMessage(aOther.mMessage),
 539         mRefPoint(std::move(aOther.mRefPoint)),
 540         mLastRefPoint(std::move(aOther.mLastRefPoint)),
 541         mFocusSequenceNumber(aOther.mFocusSequenceNumber),
 542         mFlags(std::move(aOther.mFlags)),
 543         mSpecifiedEventType(std::move(aOther.mSpecifiedEventType)),
 544         mSpecifiedEventTypeString(std::move(aOther.mSpecifiedEventTypeString)),
 545         mTarget(std::move(aOther.mTarget)),
 546         mCurrentTarget(std::move(aOther.mCurrentTarget)),
 547         mOriginalTarget(std::move(aOther.mOriginalTarget)),
 548         mRelatedTarget(std::move(aOther.mRelatedTarget)),
 549         mOriginalRelatedTarget(std::move(aOther.mOriginalRelatedTarget)),
 550         mPath(std::move(aOther.mPath)) {
 551     MOZ_COUNT_CTOR(WidgetEvent);
 552   }
 553   WidgetEvent& operator=(WidgetEvent&& aOther) = default;
 554
 555   virtual WidgetEvent* Duplicate() const {
 556     MOZ_ASSERT(mClass == eBasicEventClass,
 557                "Duplicate() must be overridden by sub class");
 558     WidgetEvent* result = new WidgetEvent(false, mMessage);
 559     result->AssignEventData(*this, true);
 560     result->mFlags = mFlags;
 561     return result;
 562   }
 563
 564   EventClassID mClass;
 565   EventMessage mMessage;
 566   // Relative to the widget of the event, or if there is no widget then it is
 567   // in screen coordinates. Not modified by layout code.
 568   // This is in visual coordinates, i.e. the correct RelativeTo value that
 569   // expresses what this is relative to is `{viewportFrame, Visual}`, where
 570   // `viewportFrame` is the viewport frame of the widget's root document.
 571   LayoutDeviceIntPoint mRefPoint;
 572   // The previous mRefPoint, if known, used to calculate mouse movement deltas.
 573   LayoutDeviceIntPoint mLastRefPoint;
 574   // The sequence number of the last potentially focus changing event handled
 575   // by APZ. This is used to track when that event has been processed by
 576   // content, and focus can be reconfirmed for async keyboard scrolling.
 577   uint64_t mFocusSequenceNumber;
 578   // See BaseEventFlags definition for the detail.
 579   BaseEventFlags mFlags;
 580
 581   // If JS creates an event with unknown event type or known event type but
 582   // for different event interface, the event type is stored to this.
 583   // NOTE: This is always used if the instance is a WidgetCommandEvent instance
 584   //       or "input" event is dispatched with dom::Event class.
 585   RefPtr<nsAtom> mSpecifiedEventType;
 586
 587   // nsAtom isn't available on non-main thread due to unsafe.  Therefore,
 588   // mSpecifiedEventTypeString is used instead of mSpecifiedEventType if
 589   // the event is created in non-main thread.
 590   nsString mSpecifiedEventTypeString;
 591
 592   // Event targets, needed by DOM Events
 593   // Note that when you need event target for DOM event, you should use
 594   // Get*DOMEventTarget() instead of accessing these members directly.
 595   nsCOMPtr<dom::EventTarget> mTarget;
 596   nsCOMPtr<dom::EventTarget> mCurrentTarget;
 597   nsCOMPtr<dom::EventTarget> mOriginalTarget;
 598
 599   /// The possible related target
 600   nsCOMPtr<dom::EventTarget> mRelatedTarget;
 601   nsCOMPtr<dom::EventTarget> mOriginalRelatedTarget;
 602
 603   nsTArray<EventTargetChainItem>* mPath;
 604
 605   // The LayersId of the content process that this event should be
 606   // dispatched to. This field is only used in the chrome process
 607   // and doesn't get remoted to child processes.
 608   layers::LayersId mLayersId;
 609
 610   dom::EventTarget* GetDOMEventTarget() const;
 611   dom::EventTarget* GetCurrentDOMEventTarget() const;
 612   dom::EventTarget* GetOriginalDOMEventTarget() const;
 613
 614   void AssignEventData(const WidgetEvent& aEvent, bool aCopyTargets) {
 615     // mClass should be initialized with the constructor.
 616     // mMessage should be initialized with the constructor.
 617     mRefPoint = aEvent.mRefPoint;
 618     // mLastRefPoint doesn't need to be copied.
 619     mFocusSequenceNumber = aEvent.mFocusSequenceNumber;
 620     // mLayersId intentionally not copied, since it's not used within content
 621     AssignEventTime(aEvent);
 622     // mFlags should be copied manually if it's necessary.
 623     mSpecifiedEventType = aEvent.mSpecifiedEventType;
 624     // mSpecifiedEventTypeString should be copied manually if it's necessary.
 625     mTarget = aCopyTargets ? aEvent.mTarget : nullptr;
 626     mCurrentTarget = aCopyTargets ? aEvent.mCurrentTarget : nullptr;
 627     mOriginalTarget = aCopyTargets ? aEvent.mOriginalTarget : nullptr;
 628     mRelatedTarget = aCopyTargets ? aEvent.mRelatedTarget : nullptr;
 629     mOriginalRelatedTarget =
 630         aCopyTargets ? aEvent.mOriginalRelatedTarget : nullptr;
 631   }
 632
 633   /**
 634    * Helper methods for methods of DOM Event.
 635    */
 636   void StopPropagation() { mFlags.StopPropagation(); }
 637   void StopImmediatePropagation() { mFlags.StopImmediatePropagation(); }
 638   void PreventDefault(bool aCalledByDefaultHandler = true,
 639                       nsIPrincipal* aPrincipal = nullptr);
 640
 641   void PreventDefaultBeforeDispatch(
 642       CrossProcessForwarding aCrossProcessForwarding) {
 643     mFlags.PreventDefaultBeforeDispatch(aCrossProcessForwarding);
 644   }
 645   bool DefaultPrevented() const { return mFlags.DefaultPrevented(); }
 646   bool DefaultPreventedByContent() const {
 647     return mFlags.DefaultPreventedByContent();
 648   }
 649   bool IsTrusted() const { return mFlags.IsTrusted(); }
 650   bool PropagationStopped() const { return mFlags.PropagationStopped(); }
 651
 652   /**
 653    * Prevent to be dispatched to remote process.
 654    */
 655   inline void StopCrossProcessForwarding() {
 656     mFlags.StopCrossProcessForwarding();
 657   }
 658   /**
 659    * Return true if the event shouldn't be dispatched to remote process.
 660    */
 661   inline bool IsCrossProcessForwardingStopped() const {
 662     return mFlags.IsCrossProcessForwardingStopped();
 663   }
 664   /**
 665    * Mark the event as waiting reply from remote process.
 666    * Note that this also stops immediate propagation in current process.
 667    */
 668   inline void MarkAsWaitingReplyFromRemoteProcess() {
 669     mFlags.MarkAsWaitingReplyFromRemoteProcess();
 670   }
 671   /**
 672    * Reset "waiting reply from remote process" state.  This is useful when
 673    * you dispatch a copy of an event coming from different process.
 674    */
 675   inline void ResetWaitingReplyFromRemoteProcessState() {
 676     mFlags.ResetWaitingReplyFromRemoteProcessState();
 677   }
 678   /**
 679    * Return true if the event handler should wait reply event.  I.e., if this
 680    * returns true, any event handler should do nothing with the event.
 681    */
 682   inline bool IsWaitingReplyFromRemoteProcess() const {
 683     return mFlags.IsWaitingReplyFromRemoteProcess();
 684   }
 685   /**
 686    * Mark the event as already handled in the remote process.  This should be
 687    * called when initializing reply events.
 688    */
 689   inline void MarkAsHandledInRemoteProcess() {
 690     mFlags.MarkAsHandledInRemoteProcess();
 691   }
 692   /**
 693    * Return true if the event has already been handled in the remote process.
 694    * I.e., if this returns true, the event is a reply event.
 695    */
 696   inline bool IsHandledInRemoteProcess() const {
 697     return mFlags.IsHandledInRemoteProcess();
 698   }
 699   /**
 700    * Return true if the event should be sent back to its parent process.
 701    * So, usual event handlers shouldn't call this.
 702    */
 703   inline bool WantReplyFromContentProcess() const {
 704     return mFlags.WantReplyFromContentProcess();
 705   }
 706   /**
 707    * Mark the event has already posted to a remote process.
 708    */
 709   inline void MarkAsPostedToRemoteProcess() {
 710     mFlags.MarkAsPostedToRemoteProcess();
 711   }
 712   /**
 713    * Reset the cross process dispatching state.  This should be used when a
 714    * process receives the event because the state is in the sender.
 715    */
 716   inline void ResetCrossProcessDispatchingState() {
 717     mFlags.ResetCrossProcessDispatchingState();
 718   }
 719   /**
 720    * Return true if the event has been posted to a remote process.
 721    */
 722   inline bool HasBeenPostedToRemoteProcess() const {
 723     return mFlags.HasBeenPostedToRemoteProcess();
 724   }
 725   /**
 726    * Return true if the event came from another process.
 727    */
 728   inline bool CameFromAnotherProcess() const {
 729     return mFlags.CameFromAnotherProcess();
 730   }
 731   /**
 732    * Mark the event as coming from another process.
 733    */
 734   inline void MarkAsComingFromAnotherProcess() {
 735     mFlags.MarkAsComingFromAnotherProcess();
 736   }
 737   /**
 738    * Mark the event is reserved by chrome.  I.e., shouldn't be dispatched to
 739    * content because it shouldn't be cancelable.
 740    */
 741   inline void MarkAsReservedByChrome() { mFlags.MarkAsReservedByChrome(); }
 742   /**
 743    * Return true if the event is reserved by chrome.
 744    */
 745   inline bool IsReservedByChrome() const { return mFlags.IsReservedByChrome(); }
 746
 747   /**
 748    * Utils for checking event types
 749    */
 750
 751   /**
 752    * As*Event() returns the pointer of the instance only when the instance is
 753    * the class or one of its derived class.
 754    */
 755 #define NS_ROOT_EVENT_CLASS(aPrefix, aName)
 756 #define NS_EVENT_CLASS(aPrefix, aName) \
 757   virtual aPrefix##aName* As##aName(); \
 758   const aPrefix##aName* As##aName() const;
 759
 760 #include "mozilla/EventClassList.h"
 761
 762 #undef NS_EVENT_CLASS
 763 #undef NS_ROOT_EVENT_CLASS
 764
 765   /**
 766    * Returns true if the event is a query content event.
 767    */
 768   bool IsQueryContentEvent() const;
 769   /**
 770    * Returns true if the event is a selection event.
 771    */
 772   bool IsSelectionEvent() const;
 773   /**
 774    * Returns true if the event is a content command event.
 775    */
 776   bool IsContentCommandEvent() const;
 777
 778   /**
 779    * Returns true if the event mMessage is one of mouse events.
 780    */
 781   bool HasMouseEventMessage() const;
 782   /**
 783    * Returns true if the event mMessage is one of drag events.
 784    */
 785   bool HasDragEventMessage() const;
 786   /**
 787    * Returns true if aMessage or mMessage is one of key events.
 788    */
 789   static bool IsKeyEventMessage(EventMessage aMessage);
 790   bool HasKeyEventMessage() const { return IsKeyEventMessage(mMessage); }
 791   /**
 792    * Returns true if the event mMessage is one of composition events or text
 793    * event.
 794    */
 795   bool HasIMEEventMessage() const;
 796
 797   /**
 798    * Returns true if the event can be sent to remote process.
 799    */
 800   bool CanBeSentToRemoteProcess() const;
 801   /**
 802    * Returns true if the original target is a remote process and the event
 803    * will be posted to the remote process later.
 804    */
 805   bool WillBeSentToRemoteProcess() const;
 806   /**
 807    * Returns true if the event is related to IME handling.  It includes
 808    * IME events, query content events and selection events.
 809    * Be careful when you use this.
 810    */
 811   bool IsIMERelatedEvent() const;
 812
 813   /**
 814    * Whether the event should be handled by the frame of the mouse cursor
 815    * position or not.  When it should be handled there (e.g., the mouse events),
 816    * this returns true.
 817    */
 818   bool IsUsingCoordinates() const;
 819   /**
 820    * Whether the event should be handled by the focused DOM window in the
 821    * same top level window's or not.  E.g., key events, IME related events
 822    * (including the query content events, they are used in IME transaction)
 823    * should be handled by the (last) focused window rather than the dispatched
 824    * window.
 825    *
 826    * NOTE: Even if this returns true, the event isn't going to be handled by the
 827    * application level active DOM window which is on another top level window.
 828    * So, when the event is fired on a deactive window, the event is going to be
 829    * handled by the last focused DOM window in the last focused window.
 830    */
 831   bool IsTargetedAtFocusedWindow() const;
 832   /**
 833    * Whether the event should be handled by the focused content or not.  E.g.,
 834    * key events, IME related events and other input events which are not handled
 835    * by the frame of the mouse cursor position.
 836    *
 837    * NOTE: Even if this returns true, the event isn't going to be handled by the
 838    * application level active DOM window which is on another top level window.
 839    * So, when the event is fired on a deactive window, the event is going to be
 840    * handled by the last focused DOM element of the last focused DOM window in
 841    * the last focused window.
 842    */
 843   bool IsTargetedAtFocusedContent() const;
 844   /**
 845    * Whether the event should cause a DOM event.
 846    */
 847   bool IsAllowedToDispatchDOMEvent() const;
 848   /**
 849    * Whether the event should be dispatched in system group.
 850    */
 851   bool IsAllowedToDispatchInSystemGroup() const;
 852   /**
 853    * Whether the event should be blocked for fingerprinting resistance.
 854    */
 855   bool IsBlockedForFingerprintingResistance() const;
 856   /**
 857    * Initialize mComposed
 858    */
 859   void SetDefaultComposed() {
 860     switch (mClass) {
 861       case eClipboardEventClass:
 862         mFlags.mComposed = true;
 863         break;
 864       case eCompositionEventClass:
 865         mFlags.mComposed =
 866             mMessage == eCompositionStart || mMessage == eCompositionUpdate ||
 867             mMessage == eCompositionChange || mMessage == eCompositionEnd;
 868         break;
 869       case eDragEventClass:
 870         // All drag & drop events are composed
 871         mFlags.mComposed = mMessage == eDrag || mMessage == eDragEnd ||
 872                            mMessage == eDragEnter || mMessage == eDragExit ||
 873                            mMessage == eDragLeave || mMessage == eDragOver ||
 874                            mMessage == eDragStart || mMessage == eDrop;
 875         break;
 876       case eEditorInputEventClass:
 877         mFlags.mComposed =
 878             mMessage == eEditorInput || mMessage == eEditorBeforeInput;
 879         break;
 880       case eFocusEventClass:
 881         mFlags.mComposed = mMessage == eBlur || mMessage == eFocus ||
 882                            mMessage == eFocusOut || mMessage == eFocusIn;
 883         break;
 884       case eKeyboardEventClass:
 885         mFlags.mComposed =
 886             mMessage == eKeyDown || mMessage == eKeyUp || mMessage == eKeyPress;
 887         break;
 888       case eMouseEventClass:
 889         mFlags.mComposed =
 890             mMessage == eMouseClick || mMessage == eMouseDoubleClick ||
 891             mMessage == eMouseAuxClick || mMessage == eMouseDown ||
 892             mMessage == eMouseUp || mMessage == eMouseOver ||
 893             mMessage == eMouseOut || mMessage == eMouseMove ||
 894             mMessage == eContextMenu || mMessage == eXULPopupShowing ||
 895             mMessage == eXULPopupHiding || mMessage == eXULPopupShown ||
 896             mMessage == eXULPopupHidden;
 897         break;
 898       case ePointerEventClass:
 899         // All pointer events are composed
 900         mFlags.mComposed =
 901             mMessage == ePointerDown || mMessage == ePointerMove ||
 902             mMessage == ePointerUp || mMessage == ePointerCancel ||
 903             mMessage == ePointerOver || mMessage == ePointerOut ||
 904             mMessage == ePointerGotCapture || mMessage == ePointerLostCapture;
 905         break;
 906       case eTouchEventClass:
 907         // All touch events are composed
 908         mFlags.mComposed = mMessage == eTouchStart || mMessage == eTouchEnd ||
 909                            mMessage == eTouchMove || mMessage == eTouchCancel;
 910         break;
 911       case eUIEventClass:
 912         mFlags.mComposed = mMessage == eLegacyDOMFocusIn ||
 913                            mMessage == eLegacyDOMFocusOut ||
 914                            mMessage == eLegacyDOMActivate;
 915         break;
 916       case eWheelEventClass:
 917         // All wheel events are composed
 918         mFlags.mComposed = mMessage == eWheel;
 919         break;
 920       case eMouseScrollEventClass:
 921         // Legacy mouse scroll events are composed too, for consistency with
 922         // wheel.
 923         mFlags.mComposed = mMessage == eLegacyMouseLineOrPageScroll ||
 924                            mMessage == eLegacyMousePixelScroll;
 925         break;
 926       default:
 927         mFlags.mComposed = false;
 928         break;
 929     }
 930   }
 931
 932   void SetComposed(const nsAString& aEventTypeArg) {
 933     mFlags.mComposed =  // composition events
 934         aEventTypeArg.EqualsLiteral("compositionstart") ||
 935         aEventTypeArg.EqualsLiteral("compositionupdate") ||
 936         aEventTypeArg.EqualsLiteral("compositionend") ||
 937         aEventTypeArg.EqualsLiteral("text") ||
 938         // drag and drop events
 939         aEventTypeArg.EqualsLiteral("dragstart") ||
 940         aEventTypeArg.EqualsLiteral("drag") ||
 941         aEventTypeArg.EqualsLiteral("dragenter") ||
 942         aEventTypeArg.EqualsLiteral("dragexit") ||
 943         aEventTypeArg.EqualsLiteral("dragleave") ||
 944         aEventTypeArg.EqualsLiteral("dragover") ||
 945         aEventTypeArg.EqualsLiteral("drop") ||
 946         aEventTypeArg.EqualsLiteral("dropend") ||
 947         // editor input events
 948         aEventTypeArg.EqualsLiteral("input") ||
 949         aEventTypeArg.EqualsLiteral("beforeinput") ||
 950         // focus events
 951         aEventTypeArg.EqualsLiteral("blur") ||
 952         aEventTypeArg.EqualsLiteral("focus") ||
 953         aEventTypeArg.EqualsLiteral("focusin") ||
 954         aEventTypeArg.EqualsLiteral("focusout") ||
 955         // keyboard events
 956         aEventTypeArg.EqualsLiteral("keydown") ||
 957         aEventTypeArg.EqualsLiteral("keyup") ||
 958         aEventTypeArg.EqualsLiteral("keypress") ||
 959         // mouse events
 960         aEventTypeArg.EqualsLiteral("click") ||
 961         aEventTypeArg.EqualsLiteral("dblclick") ||
 962         aEventTypeArg.EqualsLiteral("mousedown") ||
 963         aEventTypeArg.EqualsLiteral("mouseup") ||
 964         aEventTypeArg.EqualsLiteral("mouseenter") ||
 965         aEventTypeArg.EqualsLiteral("mouseleave") ||
 966         aEventTypeArg.EqualsLiteral("mouseover") ||
 967         aEventTypeArg.EqualsLiteral("mouseout") ||
 968         aEventTypeArg.EqualsLiteral("mousemove") ||
 969         aEventTypeArg.EqualsLiteral("contextmenu") ||
 970         // pointer events
 971         aEventTypeArg.EqualsLiteral("pointerdown") ||
 972         aEventTypeArg.EqualsLiteral("pointermove") ||
 973         aEventTypeArg.EqualsLiteral("pointerup") ||
 974         aEventTypeArg.EqualsLiteral("pointercancel") ||
 975         aEventTypeArg.EqualsLiteral("pointerover") ||
 976         aEventTypeArg.EqualsLiteral("pointerout") ||
 977         aEventTypeArg.EqualsLiteral("pointerenter") ||
 978         aEventTypeArg.EqualsLiteral("pointerleave") ||
 979         aEventTypeArg.EqualsLiteral("gotpointercapture") ||
 980         aEventTypeArg.EqualsLiteral("lostpointercapture") ||
 981         // touch events
 982         aEventTypeArg.EqualsLiteral("touchstart") ||
 983         aEventTypeArg.EqualsLiteral("touchend") ||
 984         aEventTypeArg.EqualsLiteral("touchmove") ||
 985         aEventTypeArg.EqualsLiteral("touchcancel") ||
 986         // UI legacy events
 987         aEventTypeArg.EqualsLiteral("DOMFocusIn") ||
 988         aEventTypeArg.EqualsLiteral("DOMFocusOut") ||
 989         aEventTypeArg.EqualsLiteral("DOMActivate") ||
 990         // wheel events
 991         aEventTypeArg.EqualsLiteral("wheel");
 992   }
 993
 994   void SetComposed(bool aComposed) { mFlags.mComposed = aComposed; }
 995
 996   void SetDefaultComposedInNativeAnonymousContent() {
 997     // For compatibility concerns, we set mComposedInNativeAnonymousContent to
 998     // false for those events we want to stop propagation.
 999     //
1000     // nsVideoFrame may create anonymous image element which fires eLoad,
1001     // eLoadStart, eLoadEnd, eLoadError. We don't want these events cross
1002     // the boundary of NAC
1003     mFlags.mComposedInNativeAnonymousContent =
1004         mMessage != eLoad && mMessage != eLoadStart && mMessage != eLoadEnd &&
1005         mMessage != eLoadError;
1006   }
1007
1008   bool IsUserAction() const;
1009 };
1010
1011 /******************************************************************************
1012  * mozilla::WidgetGUIEvent
1013  ******************************************************************************/
1014
1015 class WidgetGUIEvent : public WidgetEvent {
1016  protected:
1017   WidgetGUIEvent(bool aIsTrusted, EventMessage aMessage, nsIWidget* aWidget,
1018                  EventClassID aEventClassID)
1019       : WidgetEvent(aIsTrusted, aMessage, aEventClassID), mWidget(aWidget) {}
1020
1021   WidgetGUIEvent() = default;
1022
1023  public:
1024   virtual WidgetGUIEvent* AsGUIEvent() override { return this; }
1025
1026   WidgetGUIEvent(bool aIsTrusted, EventMessage aMessage, nsIWidget* aWidget)
1027       : WidgetEvent(aIsTrusted, aMessage, eGUIEventClass), mWidget(aWidget) {}
1028
1029   virtual WidgetEvent* Duplicate() const override {
1030     MOZ_ASSERT(mClass == eGUIEventClass,
1031                "Duplicate() must be overridden by sub class");
1032     // Not copying widget, it is a weak reference.
1033     WidgetGUIEvent* result = new WidgetGUIEvent(false, mMessage, nullptr);
1034     result->AssignGUIEventData(*this, true);
1035     result->mFlags = mFlags;
1036     return result;
1037   }
1038
1039   // Originator of the event
1040   nsCOMPtr<nsIWidget> mWidget;
1041
1042   void AssignGUIEventData(const WidgetGUIEvent& aEvent, bool aCopyTargets) {
1043     AssignEventData(aEvent, aCopyTargets);
1044     // widget should be initialized with the constructor.
1045   }
1046 };
1047
1048 /******************************************************************************
1049  * mozilla::Modifier
1050  *
1051  * All modifier keys should be defined here.  This is used for managing
1052  * modifier states for DOM Level 3 or later.
1053  ******************************************************************************/
1054
1055 enum Modifier {
1056   MODIFIER_NONE = 0x0000,
1057   MODIFIER_ALT = 0x0001,
1058   MODIFIER_ALTGRAPH = 0x0002,
1059   MODIFIER_CAPSLOCK = 0x0004,
1060   MODIFIER_CONTROL = 0x0008,
1061   MODIFIER_FN = 0x0010,
1062   MODIFIER_FNLOCK = 0x0020,
1063   MODIFIER_META = 0x0040,
1064   MODIFIER_NUMLOCK = 0x0080,
1065   MODIFIER_SCROLLLOCK = 0x0100,
1066   MODIFIER_SHIFT = 0x0200,
1067   MODIFIER_SYMBOL = 0x0400,
1068   MODIFIER_SYMBOLLOCK = 0x0800,
1069   MODIFIER_OS = 0x1000
1070 };
1071
1072 /******************************************************************************
1073  * Modifier key names.
1074  ******************************************************************************/
1075
1076 #define NS_DOM_KEYNAME_ALT "Alt"
1077 #define NS_DOM_KEYNAME_ALTGRAPH "AltGraph"
1078 #define NS_DOM_KEYNAME_CAPSLOCK "CapsLock"
1079 #define NS_DOM_KEYNAME_CONTROL "Control"
1080 #define NS_DOM_KEYNAME_FN "Fn"
1081 #define NS_DOM_KEYNAME_FNLOCK "FnLock"
1082 #define NS_DOM_KEYNAME_META "Meta"
1083 #define NS_DOM_KEYNAME_NUMLOCK "NumLock"
1084 #define NS_DOM_KEYNAME_SCROLLLOCK "ScrollLock"
1085 #define NS_DOM_KEYNAME_SHIFT "Shift"
1086 #define NS_DOM_KEYNAME_SYMBOL "Symbol"
1087 #define NS_DOM_KEYNAME_SYMBOLLOCK "SymbolLock"
1088 #define NS_DOM_KEYNAME_OS "OS"
1089
1090 /******************************************************************************
1091  * mozilla::Modifiers
1092  ******************************************************************************/
1093
1094 typedef uint16_t Modifiers;
1095
1096 class MOZ_STACK_CLASS GetModifiersName final : public nsAutoCString {
1097  public:
1098   explicit GetModifiersName(Modifiers aModifiers) {
1099     if (aModifiers & MODIFIER_ALT) {
1100       AssignLiteral(NS_DOM_KEYNAME_ALT);
1101     }
1102     if (aModifiers & MODIFIER_ALTGRAPH) {
1103       MaybeAppendSeparator();
1104       AppendLiteral(NS_DOM_KEYNAME_ALTGRAPH);
1105     }
1106     if (aModifiers & MODIFIER_CAPSLOCK) {
1107       MaybeAppendSeparator();
1108       AppendLiteral(NS_DOM_KEYNAME_CAPSLOCK);
1109     }
1110     if (aModifiers & MODIFIER_CONTROL) {
1111       MaybeAppendSeparator();
1112       AppendLiteral(NS_DOM_KEYNAME_CONTROL);
1113     }
1114     if (aModifiers & MODIFIER_FN) {
1115       MaybeAppendSeparator();
1116       AppendLiteral(NS_DOM_KEYNAME_FN);
1117     }
1118     if (aModifiers & MODIFIER_FNLOCK) {
1119       MaybeAppendSeparator();
1120       AppendLiteral(NS_DOM_KEYNAME_FNLOCK);
1121     }
1122     if (aModifiers & MODIFIER_META) {
1123       MaybeAppendSeparator();
1124       AppendLiteral(NS_DOM_KEYNAME_META);
1125     }
1126     if (aModifiers & MODIFIER_NUMLOCK) {
1127       MaybeAppendSeparator();
1128       AppendLiteral(NS_DOM_KEYNAME_NUMLOCK);
1129     }
1130     if (aModifiers & MODIFIER_SCROLLLOCK) {
1131       MaybeAppendSeparator();
1132       AppendLiteral(NS_DOM_KEYNAME_SCROLLLOCK);
1133     }
1134     if (aModifiers & MODIFIER_SHIFT) {
1135       MaybeAppendSeparator();
1136       AppendLiteral(NS_DOM_KEYNAME_SHIFT);
1137     }
1138     if (aModifiers & MODIFIER_SYMBOL) {
1139       MaybeAppendSeparator();
1140       AppendLiteral(NS_DOM_KEYNAME_SYMBOL);
1141     }
1142     if (aModifiers & MODIFIER_SYMBOLLOCK) {
1143       MaybeAppendSeparator();
1144       AppendLiteral(NS_DOM_KEYNAME_SYMBOLLOCK);
1145     }
1146     if (aModifiers & MODIFIER_OS) {
1147       MaybeAppendSeparator();
1148       AppendLiteral(NS_DOM_KEYNAME_OS);
1149     }
1150     if (IsEmpty()) {
1151       AssignLiteral("none");
1152     }
1153   }
1154
1155  private:
1156   void MaybeAppendSeparator() {
1157     if (!IsEmpty()) {
1158       AppendLiteral(" | ");
1159     }
1160   }
1161 };
1162
1163 /******************************************************************************
1164  * mozilla::WidgetInputEvent
1165  ******************************************************************************/
1166
1167 class WidgetInputEvent : public WidgetGUIEvent {
1168  protected:
1169   WidgetInputEvent(bool aIsTrusted, EventMessage aMessage, nsIWidget* aWidget,
1170                    EventClassID aEventClassID)
1171       : WidgetGUIEvent(aIsTrusted, aMessage, aWidget, aEventClassID),
1172         mModifiers(0) {}
1173
1174   WidgetInputEvent() : mModifiers(0) {}
1175
1176  public:
1177   virtual WidgetInputEvent* AsInputEvent() override { return this; }
1178
1179   WidgetInputEvent(bool aIsTrusted, EventMessage aMessage, nsIWidget* aWidget)
1180       : WidgetGUIEvent(aIsTrusted, aMessage, aWidget, eInputEventClass),
1181         mModifiers(0) {}
1182
1183   virtual WidgetEvent* Duplicate() const override {
1184     MOZ_ASSERT(mClass == eInputEventClass,
1185                "Duplicate() must be overridden by sub class");
1186     // Not copying widget, it is a weak reference.
1187     WidgetInputEvent* result = new WidgetInputEvent(false, mMessage, nullptr);
1188     result->AssignInputEventData(*this, true);
1189     result->mFlags = mFlags;
1190     return result;
1191   }
1192
1193   /**
1194    * Returns a modifier of "Accel" virtual modifier which is used for shortcut
1195    * key.
1196    */
1197   static Modifier AccelModifier();
1198
1199   /**
1200    * GetModifier() returns a modifier flag which is activated by aDOMKeyName.
1201    */
1202   static Modifier GetModifier(const nsAString& aDOMKeyName);
1203
1204   // true indicates the accel key on the environment is down
1205   bool IsAccel() const { return ((mModifiers & AccelModifier()) != 0); }
1206
1207   // true indicates the shift key is down
1208   bool IsShift() const { return ((mModifiers & MODIFIER_SHIFT) != 0); }
1209   // true indicates the control key is down
1210   bool IsControl() const { return ((mModifiers & MODIFIER_CONTROL) != 0); }
1211   // true indicates the alt key is down
1212   bool IsAlt() const { return ((mModifiers & MODIFIER_ALT) != 0); }
1213   // true indicates the meta key is down (or, on Mac, the Command key)
1214   bool IsMeta() const { return ((mModifiers & MODIFIER_META) != 0); }
1215   // true indicates the win key is down on Windows. Or the Super or Hyper key
1216   // is down on Linux.
1217   bool IsOS() const { return ((mModifiers & MODIFIER_OS) != 0); }
1218   // true indicates the alt graph key is down
1219   // NOTE: on Mac, the option key press causes both IsAlt() and IsAltGrpah()
1220   //       return true.
1221   bool IsAltGraph() const { return ((mModifiers & MODIFIER_ALTGRAPH) != 0); }
1222   // true indicates the CapLock LED is turn on.
1223   bool IsCapsLocked() const { return ((mModifiers & MODIFIER_CAPSLOCK) != 0); }
1224   // true indicates the NumLock LED is turn on.
1225   bool IsNumLocked() const { return ((mModifiers & MODIFIER_NUMLOCK) != 0); }
1226   // true indicates the ScrollLock LED is turn on.
1227   bool IsScrollLocked() const {
1228     return ((mModifiers & MODIFIER_SCROLLLOCK) != 0);
1229   }
1230
1231   // true indicates the Fn key is down, but this is not supported by native
1232   // key event on any platform.
1233   bool IsFn() const { return ((mModifiers & MODIFIER_FN) != 0); }
1234   // true indicates the FnLock LED is turn on, but we don't know such
1235   // keyboards nor platforms.
1236   bool IsFnLocked() const { return ((mModifiers & MODIFIER_FNLOCK) != 0); }
1237   // true indicates the Symbol is down, but this is not supported by native
1238   // key event on any platforms.
1239   bool IsSymbol() const { return ((mModifiers & MODIFIER_SYMBOL) != 0); }
1240   // true indicates the SymbolLock LED is turn on, but we don't know such
1241   // keyboards nor platforms.
1242   bool IsSymbolLocked() const {
1243     return ((mModifiers & MODIFIER_SYMBOLLOCK) != 0);
1244   }
1245
1246   void InitBasicModifiers(bool aCtrlKey, bool aAltKey, bool aShiftKey,
1247                           bool aMetaKey) {
1248     mModifiers = 0;
1249     if (aCtrlKey) {
1250       mModifiers |= MODIFIER_CONTROL;
1251     }
1252     if (aAltKey) {
1253       mModifiers |= MODIFIER_ALT;
1254     }
1255     if (aShiftKey) {
1256       mModifiers |= MODIFIER_SHIFT;
1257     }
1258     if (aMetaKey) {
1259       mModifiers |= MODIFIER_META;
1260     }
1261   }
1262
1263   Modifiers mModifiers;
1264
1265   void AssignInputEventData(const WidgetInputEvent& aEvent, bool aCopyTargets) {
1266     AssignGUIEventData(aEvent, aCopyTargets);
1267
1268     mModifiers = aEvent.mModifiers;
1269   }
1270 };
1271
1272 /******************************************************************************
1273  * mozilla::InternalUIEvent
1274  *
1275  * XXX Why this inherits WidgetGUIEvent rather than WidgetEvent?
1276  ******************************************************************************/
1277
1278 class InternalUIEvent : public WidgetGUIEvent {
1279  protected:
1280   InternalUIEvent() : mDetail(0), mCausedByUntrustedEvent(false) {}
1281
1282   InternalUIEvent(bool aIsTrusted, EventMessage aMessage, nsIWidget* aWidget,
1283                   EventClassID aEventClassID)
1284       : WidgetGUIEvent(aIsTrusted, aMessage, aWidget, aEventClassID),
1285         mDetail(0),
1286         mCausedByUntrustedEvent(false) {}
1287
1288   InternalUIEvent(bool aIsTrusted, EventMessage aMessage,
1289                   EventClassID aEventClassID)
1290       : WidgetGUIEvent(aIsTrusted, aMessage, nullptr, aEventClassID),
1291         mDetail(0),
1292         mCausedByUntrustedEvent(false) {}
1293
1294  public:
1295   virtual InternalUIEvent* AsUIEvent() override { return this; }
1296
1297   /**
1298    * If the UIEvent is caused by another event (e.g., click event),
1299    * aEventCausesThisEvent should be the event.  If there is no such event,
1300    * this should be nullptr.
1301    */
1302   InternalUIEvent(bool aIsTrusted, EventMessage aMessage,
1303                   const WidgetEvent* aEventCausesThisEvent)
1304       : WidgetGUIEvent(aIsTrusted, aMessage, nullptr, eUIEventClass),
1305         mDetail(0),
1306         mCausedByUntrustedEvent(aEventCausesThisEvent &&
1307                                 !aEventCausesThisEvent->IsTrusted()) {}
1308
1309   virtual WidgetEvent* Duplicate() const override {
1310     MOZ_ASSERT(mClass == eUIEventClass,
1311                "Duplicate() must be overridden by sub class");
1312     InternalUIEvent* result = new InternalUIEvent(false, mMessage, nullptr);
1313     result->AssignUIEventData(*this, true);
1314     result->mFlags = mFlags;
1315     return result;
1316   }
1317
1318   int32_t mDetail;
1319   // mCausedByUntrustedEvent is true if the event is caused by untrusted event.
1320   bool mCausedByUntrustedEvent;
1321
1322   // If you check the event is a trusted event and NOT caused by an untrusted
1323   // event, IsTrustable() returns what you expected.
1324   bool IsTrustable() const { return IsTrusted() && !mCausedByUntrustedEvent; }
1325
1326   void AssignUIEventData(const InternalUIEvent& aEvent, bool aCopyTargets) {
1327     AssignGUIEventData(aEvent, aCopyTargets);
1328
1329     mDetail = aEvent.mDetail;
1330     mCausedByUntrustedEvent = aEvent.mCausedByUntrustedEvent;
1331   }
1332 };
1333
1334 }  // namespace mozilla
1335
1336 #endif  // mozilla_BasicEvents_h__