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