DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (d38398e5144e)

VCS Links

AlternativeCharCode

Input

InputMethodAppState

InternalEditorInputEvent

Options

Reply

ShortcutKeyCandidate

WidgetCompositionEvent

WidgetKeyboardEvent

WidgetQueryContentEvent

WidgetSelectionEvent

Macros

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_TextEvents_h__
#define mozilla_TextEvents_h__

#include <stdint.h>

#include "mozilla/Assertions.h"
#include "mozilla/BasicEvents.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/EventForwards.h" // for KeyNameIndex, temporarily
#include "mozilla/TextRange.h"
#include "mozilla/FontRange.h"
#include "nsCOMPtr.h"
#include "nsIDOMKeyEvent.h"
#include "nsISelectionController.h"
#include "nsISelectionListener.h"
#include "nsITransferable.h"
#include "nsRect.h"
#include "nsStringGlue.h"
#include "nsTArray.h"
#include "WritingModes.h"

class nsStringHashKey;
template<class, class> class nsDataHashtable;

/******************************************************************************
 * virtual keycode values
 ******************************************************************************/

enum
{
#define NS_DEFINE_VK(aDOMKeyName, aDOMKeyCode) NS_##aDOMKeyName = aDOMKeyCode,
#include "mozilla/VirtualKeyCodeList.h"
#undef NS_DEFINE_VK
  NS_VK_UNKNOWN = 0xFF
};

namespace mozilla {

enum : uint32_t
{
  eKeyLocationStandard = nsIDOMKeyEvent::DOM_KEY_LOCATION_STANDARD,
  eKeyLocationLeft     = nsIDOMKeyEvent::DOM_KEY_LOCATION_LEFT,
  eKeyLocationRight    = nsIDOMKeyEvent::DOM_KEY_LOCATION_RIGHT,
  eKeyLocationNumpad   = nsIDOMKeyEvent::DOM_KEY_LOCATION_NUMPAD
};

const nsCString GetDOMKeyCodeName(uint32_t aKeyCode);

namespace dom {
  class PBrowserParent;
  class PBrowserChild;
} // namespace dom
namespace plugins {
  class PPluginInstanceChild;
} // namespace plugins

/******************************************************************************
 * mozilla::AlternativeCharCode
 *
 * This stores alternative charCode values of a key event with some modifiers.
 * The stored values proper for testing shortcut key or access key.
 ******************************************************************************/

struct AlternativeCharCode
{
  AlternativeCharCode() :
    mUnshiftedCharCode(0), mShiftedCharCode(0)
  {
  }
  AlternativeCharCode(uint32_t aUnshiftedCharCode, uint32_t aShiftedCharCode) :
    mUnshiftedCharCode(aUnshiftedCharCode), mShiftedCharCode(aShiftedCharCode)
  {
  }
  uint32_t mUnshiftedCharCode;
  uint32_t mShiftedCharCode;
};

/******************************************************************************
 * mozilla::ShortcutKeyCandidate
 *
 * This stores a candidate of shortcut key combination.
 ******************************************************************************/

struct ShortcutKeyCandidate
{
  ShortcutKeyCandidate(uint32_t aCharCode, bool aIgnoreShift)
    : mCharCode(aCharCode)
    , mIgnoreShift(aIgnoreShift)
  {
  }
  // The mCharCode value which must match keyboard shortcut definition.
  uint32_t mCharCode;
  // true if Shift state can be ignored.  Otherwise, Shift key state must
  // match keyboard shortcut definition.
  bool mIgnoreShift;
};

/******************************************************************************
 * mozilla::WidgetKeyboardEvent
 ******************************************************************************/

class WidgetKeyboardEvent : public WidgetInputEvent
{
private:
  friend class dom::PBrowserParent;
  friend class dom::PBrowserChild;

protected:
  WidgetKeyboardEvent()
    : mNativeKeyEvent(nullptr)
    , mKeyCode(0)
    , mCharCode(0)
    , mPseudoCharCode(0)
    , mLocation(eKeyLocationStandard)
    , mAccessKeyForwardedToChild(false)
    , mUniqueId(0)
#ifdef XP_MACOSX
    , mNativeModifierFlags(0)
    , mNativeKeyCode(0)
#endif // #ifdef XP_MACOSX
    , mKeyNameIndex(KEY_NAME_INDEX_Unidentified)
    , mCodeNameIndex(CODE_NAME_INDEX_UNKNOWN)
    , mInputMethodAppState(eNotHandled)
    , mIsChar(false)
    , mIsRepeat(false)
    , mIsComposing(false)
    , mIsReserved(false)
    , mIsSynthesizedByTIP(false)
  {
  }

public:
  virtual WidgetKeyboardEvent* AsKeyboardEvent() override { return this; }

  WidgetKeyboardEvent(bool aIsTrusted, EventMessage aMessage,
                      nsIWidget* aWidget,
                      EventClassID aEventClassID = eKeyboardEventClass)
    : WidgetInputEvent(aIsTrusted, aMessage, aWidget, aEventClassID)
    , mNativeKeyEvent(nullptr)
    , mKeyCode(0)
    , mCharCode(0)
    , mPseudoCharCode(0)
    , mLocation(eKeyLocationStandard)
    , mAccessKeyForwardedToChild(false)
    , mUniqueId(0)
#ifdef XP_MACOSX
    , mNativeModifierFlags(0)
    , mNativeKeyCode(0)
#endif // #ifdef XP_MACOSX
    , mKeyNameIndex(KEY_NAME_INDEX_Unidentified)
    , mCodeNameIndex(CODE_NAME_INDEX_UNKNOWN)
    , mInputMethodAppState(eNotHandled)
    , mIsChar(false)
    , mIsRepeat(false)
    , mIsComposing(false)
    , mIsReserved(false)
    , mIsSynthesizedByTIP(false)
  {
    // If this is a keyboard event on a plugin, it shouldn't fired on content.
    mFlags.mOnlySystemGroupDispatchInContent =
      mFlags.mNoCrossProcessBoundaryForwarding = IsKeyEventOnPlugin();
  }

  static bool IsKeyDownOrKeyDownOnPlugin(EventMessage aMessage)
  {
    return aMessage == eKeyDown || aMessage == eKeyDownOnPlugin;
  }
  bool IsKeyDownOrKeyDownOnPlugin() const
  {
    return IsKeyDownOrKeyDownOnPlugin(mMessage);
  }
  static bool IsKeyUpOrKeyUpOnPlugin(EventMessage aMessage)
  {
    return aMessage == eKeyUp || aMessage == eKeyUpOnPlugin;
  }
  bool IsKeyUpOrKeyUpOnPlugin() const
  {
    return IsKeyUpOrKeyUpOnPlugin(mMessage);
  }
  static bool IsKeyEventOnPlugin(EventMessage aMessage)
  {
    return aMessage == eKeyDownOnPlugin || aMessage == eKeyUpOnPlugin;
  }
  bool IsKeyEventOnPlugin() const
  {
    return IsKeyEventOnPlugin(mMessage);
  }

  virtual WidgetEvent* Duplicate() const override
  {
    MOZ_ASSERT(mClass == eKeyboardEventClass,
               "Duplicate() must be overridden by sub class");
    // Not copying widget, it is a weak reference.
    WidgetKeyboardEvent* result =
      new WidgetKeyboardEvent(false, mMessage, nullptr);
    result->AssignKeyEventData(*this, true);
    result->mFlags = mFlags;
    return result;
  }

  // OS translated Unicode chars which are used for accesskey and accelkey
  // handling. The handlers will try from first character to last character.
  nsTArray<AlternativeCharCode> mAlternativeCharCodes;
  // DOM KeyboardEvent.key only when mKeyNameIndex is KEY_NAME_INDEX_USE_STRING.
  nsString mKeyValue;
  // DOM KeyboardEvent.code only when mCodeNameIndex is
  // CODE_NAME_INDEX_USE_STRING.
  nsString mCodeValue;

#ifdef XP_MACOSX
  // Values given by a native NSEvent, for use with Cocoa NPAPI plugins.
  nsString mNativeCharacters;
  nsString mNativeCharactersIgnoringModifiers;
  // If this is non-empty, create a text event for plugins instead of a
  // keyboard event.
  nsString mPluginTextEventString;
#endif // #ifdef XP_MACOSX

  // OS-specific native event can optionally be preserved
  void* mNativeKeyEvent;
  // A DOM keyCode value or 0.  If a keypress event whose mCharCode is 0, this
  // should be 0.
  uint32_t mKeyCode;
  // If the instance is a keypress event of a printable key, this is a UTF-16
  // value of the key.  Otherwise, 0.  This value must not be a control
  // character when some modifiers are active.  Then, this value should be an
  // unmodified value except Shift and AltGr.
  uint32_t mCharCode;
  // mPseudoCharCode is valid only when mMessage is an eKeyDown event.
  // This stores mCharCode value of keypress event which is fired with same
  // key value and same modifier state.
  uint32_t mPseudoCharCode;
  // One of eKeyLocation*
  uint32_t mLocation;
  // True if accesskey handling was forwarded to the child via
  // TabParent::HandleAccessKey. In this case, parent process menu access key
  // handling should be delayed until it is determined that there exists no
  // overriding access key in the content process.
  bool mAccessKeyForwardedToChild;
  // Unique id associated with a keydown / keypress event. Used in identifing
  // keypress events for removal from async event dispatch queue in metrofx
  // after preventDefault is called on keydown events. It's ok if this wraps
  // over long periods.
  uint32_t mUniqueId;

#ifdef XP_MACOSX
  // Values given by a native NSEvent, for use with Cocoa NPAPI plugins.
  uint32_t mNativeModifierFlags;
  uint16_t mNativeKeyCode;
#endif // #ifdef XP_MACOSX

  // DOM KeyboardEvent.key
  KeyNameIndex mKeyNameIndex;
  // DOM KeyboardEvent.code
  CodeNameIndex mCodeNameIndex;
  // Indicates that the event is being handled by input method app
  typedef uint8_t InputMethodAppStateType;
  enum InputMethodAppState : InputMethodAppStateType
  {
    eNotHandled, // not yet handled by intput method app
    eHandling,   // being handled by intput method app
    eHandled     // handled by input method app
  };
  InputMethodAppState mInputMethodAppState;

  // Indicates whether the event signifies a printable character
  bool mIsChar;
  // Indicates whether the event is generated by auto repeat or not.
  // if this is keyup event, always false.
  bool mIsRepeat;
  // Indicates whether the event is generated during IME (or deadkey)
  // composition.  This is initialized by EventStateManager.  So, key event
  // dispatchers don't need to initialize this.
  bool mIsComposing;
  // Indicates if the key combination is reserved by chrome.  This is set by
  // nsXBLWindowKeyHandler at capturing phase of the default event group.
  bool mIsReserved;
  // Indicates whether the event is synthesized from Text Input Processor
  // or an actual event from nsAppShell.
  bool mIsSynthesizedByTIP;

  // If the key should cause keypress events, this returns true.
  // Otherwise, false.
  bool ShouldCauseKeypressEvents() const;

  // mCharCode value of non-eKeyPress events is always 0.  However, if
  // non-eKeyPress event has one or more alternative char code values,
  // its first item should be the mCharCode value of following eKeyPress event.
  // PseudoCharCode() returns mCharCode value for eKeyPress event,
  // the first alternative char code value of non-eKeyPress event or 0.
  uint32_t PseudoCharCode() const
  {
    return mMessage == eKeyPress ? mCharCode : mPseudoCharCode;
  }
  void SetCharCode(uint32_t aCharCode)
  {
    if (mMessage == eKeyPress) {
      mCharCode = aCharCode;
    } else {
      mPseudoCharCode = aCharCode;
    }
  }

  void GetDOMKeyName(nsAString& aKeyName)
  {
    if (mKeyNameIndex == KEY_NAME_INDEX_USE_STRING) {
      aKeyName = mKeyValue;
      return;
    }
    GetDOMKeyName(mKeyNameIndex, aKeyName);
  }
  void GetDOMCodeName(nsAString& aCodeName)
  {
    if (mCodeNameIndex == CODE_NAME_INDEX_USE_STRING) {
      aCodeName = mCodeValue;
      return;
    }
    GetDOMCodeName(mCodeNameIndex, aCodeName);
  }

  bool IsModifierKeyEvent() const
  {
    return GetModifierForKeyName(mKeyNameIndex) != MODIFIER_NONE;
  }

  /**
   * Get the candidates for shortcut key.
   *
   * @param aCandidates [out] the candidate shortcut key combination list.
   *                          the first item is most preferred.
   */
  void GetShortcutKeyCandidates(ShortcutKeyCandidateArray& aCandidates);

  /**
   * Get the candidates for access key.
   *
   * @param aCandidates [out] the candidate access key list.
   *                          the first item is most preferred.
   */
  void GetAccessKeyCandidates(nsTArray<uint32_t>& aCandidates);

  static void Shutdown();

  /**
   * ComputeLocationFromCodeValue() returns one of .mLocation value
   * (eKeyLocation*) which is the most preferred value for the specified code
   * value.
   */
  static uint32_t ComputeLocationFromCodeValue(CodeNameIndex aCodeNameIndex);

  /**
   * ComputeKeyCodeFromKeyNameIndex() return a .mKeyCode value which can be
   * mapped from the specified key value.  Note that this returns 0 if the
   * key name index is KEY_NAME_INDEX_Unidentified or KEY_NAME_INDEX_USE_STRING.
   * This means that this method is useful only for non-printable keys.
   */
  static uint32_t ComputeKeyCodeFromKeyNameIndex(KeyNameIndex aKeyNameIndex);

  /**
   * GetModifierForKeyName() returns a value of Modifier which is activated
   * by the aKeyNameIndex.
   */
  static Modifier GetModifierForKeyName(KeyNameIndex aKeyNameIndex);

  /**
   * IsLockableModifier() returns true if aKeyNameIndex is a lockable modifier
   * key such as CapsLock and NumLock.
   */
  static bool IsLockableModifier(KeyNameIndex aKeyNameIndex);

  static void GetDOMKeyName(KeyNameIndex aKeyNameIndex,
                            nsAString& aKeyName);
  static void GetDOMCodeName(CodeNameIndex aCodeNameIndex,
                             nsAString& aCodeName);

  static KeyNameIndex GetKeyNameIndex(const nsAString& aKeyValue);
  static CodeNameIndex GetCodeNameIndex(const nsAString& aCodeValue);

  static const char* GetCommandStr(Command aCommand);

  void AssignKeyEventData(const WidgetKeyboardEvent& aEvent, bool aCopyTargets)
  {
    AssignInputEventData(aEvent, aCopyTargets);

    mKeyCode = aEvent.mKeyCode;
    mCharCode = aEvent.mCharCode;
    mPseudoCharCode = aEvent.mPseudoCharCode;
    mLocation = aEvent.mLocation;
    mAlternativeCharCodes = aEvent.mAlternativeCharCodes;
    mIsChar = aEvent.mIsChar;
    mIsRepeat = aEvent.mIsRepeat;
    mIsComposing = aEvent.mIsComposing;
    mIsReserved = aEvent.mIsReserved;
    mAccessKeyForwardedToChild = aEvent.mAccessKeyForwardedToChild;
    mKeyNameIndex = aEvent.mKeyNameIndex;
    mCodeNameIndex = aEvent.mCodeNameIndex;
    mKeyValue = aEvent.mKeyValue;
    mCodeValue = aEvent.mCodeValue;
    // Don't copy mNativeKeyEvent because it may be referred after its instance
    // is destroyed.
    mNativeKeyEvent = nullptr;
    mUniqueId = aEvent.mUniqueId;
#ifdef XP_MACOSX
    mNativeKeyCode = aEvent.mNativeKeyCode;
    mNativeModifierFlags = aEvent.mNativeModifierFlags;
    mNativeCharacters.Assign(aEvent.mNativeCharacters);
    mNativeCharactersIgnoringModifiers.
      Assign(aEvent.mNativeCharactersIgnoringModifiers);
    mPluginTextEventString.Assign(aEvent.mPluginTextEventString);
#endif
    mInputMethodAppState = aEvent.mInputMethodAppState;
    mIsSynthesizedByTIP = aEvent.mIsSynthesizedByTIP;
  }

private:
  static const char16_t* const kKeyNames[];
  static const char16_t* const kCodeNames[];
  typedef nsDataHashtable<nsStringHashKey,
                          KeyNameIndex> KeyNameIndexHashtable;
  typedef nsDataHashtable<nsStringHashKey,
                          CodeNameIndex> CodeNameIndexHashtable;
  static KeyNameIndexHashtable* sKeyNameIndexHashtable;
  static CodeNameIndexHashtable* sCodeNameIndexHashtable;
};

/******************************************************************************
 * mozilla::WidgetCompositionEvent
 ******************************************************************************/

class WidgetCompositionEvent : public WidgetGUIEvent
{
private:
  friend class mozilla::dom::PBrowserParent;
  friend class mozilla::dom::PBrowserChild;

  WidgetCompositionEvent()
  {
  }

public:
  virtual WidgetCompositionEvent* AsCompositionEvent() override
  {
    return this;
  }

  WidgetCompositionEvent(bool aIsTrusted, EventMessage aMessage,
                         nsIWidget* aWidget)
    : WidgetGUIEvent(aIsTrusted, aMessage, aWidget, eCompositionEventClass)
    , mNativeIMEContext(aWidget)
    , mOriginalMessage(eVoidEvent)
  {
  }

  virtual WidgetEvent* Duplicate() const override
  {
    MOZ_ASSERT(mClass == eCompositionEventClass,
               "Duplicate() must be overridden by sub class");
    // Not copying widget, it is a weak reference.
    WidgetCompositionEvent* result =
      new WidgetCompositionEvent(false, mMessage, nullptr);
    result->AssignCompositionEventData(*this, true);
    result->mFlags = mFlags;
    return result;
  }

  // The composition string or the commit string.  If the instance is a
  // compositionstart event, this is initialized with selected text by
  // TextComposition automatically.
  nsString mData;

  RefPtr<TextRangeArray> mRanges;

  // mNativeIMEContext stores the native IME context which causes the
  // composition event.
  widget::NativeIMEContext mNativeIMEContext;

  // If the instance is a clone of another event, mOriginalMessage stores
  // the another event's mMessage.
  EventMessage mOriginalMessage;

  void AssignCompositionEventData(const WidgetCompositionEvent& aEvent,
                                  bool aCopyTargets)
  {
    AssignGUIEventData(aEvent, aCopyTargets);

    mData = aEvent.mData;
    mOriginalMessage = aEvent.mOriginalMessage;
    mRanges = aEvent.mRanges;

    // Currently, we don't need to copy the other members because they are
    // for internal use only (not available from JS).
  }

  bool IsComposing() const
  {
    return mRanges && mRanges->IsComposing();
  }

  uint32_t TargetClauseOffset() const
  {
    return mRanges ? mRanges->TargetClauseOffset() : 0;
  }

  uint32_t TargetClauseLength() const
  {
    uint32_t length = UINT32_MAX;
    if (mRanges) {
      length = mRanges->TargetClauseLength();
    }
    return length == UINT32_MAX ? mData.Length() : length;
  }

  uint32_t RangeCount() const
  {
    return mRanges ? mRanges->Length() : 0;
  }

  bool CausesDOMTextEvent() const
  {
    return mMessage == eCompositionChange ||
           mMessage == eCompositionCommit ||
           mMessage == eCompositionCommitAsIs;
  }

  bool CausesDOMCompositionEndEvent() const
  {
    return mMessage == eCompositionEnd ||
           mMessage == eCompositionCommit ||
           mMessage == eCompositionCommitAsIs;
  }

  bool IsFollowedByCompositionEnd() const
  {
    return IsFollowedByCompositionEnd(mOriginalMessage);
  }

  static bool IsFollowedByCompositionEnd(EventMessage aEventMessage)
  {
    return aEventMessage == eCompositionCommit ||
           aEventMessage == eCompositionCommitAsIs;
  }
};

/******************************************************************************
 * mozilla::WidgetQueryContentEvent
 ******************************************************************************/

class WidgetQueryContentEvent : public WidgetGUIEvent
{
private:
  friend class dom::PBrowserParent;
  friend class dom::PBrowserChild;

  WidgetQueryContentEvent()
    : mSucceeded(false)
    , mUseNativeLineBreak(true)
    , mWithFontRanges(false)
  {
    MOZ_CRASH("WidgetQueryContentEvent is created without proper arguments");
  }

public:
  virtual WidgetQueryContentEvent* AsQueryContentEvent() override
  {
    return this;
  }

  WidgetQueryContentEvent(bool aIsTrusted, EventMessage aMessage,
                          nsIWidget* aWidget)
    : WidgetGUIEvent(aIsTrusted, aMessage, aWidget, eQueryContentEventClass)
    , mSucceeded(false)
    , mUseNativeLineBreak(true)
    , mWithFontRanges(false)
  {
  }

  WidgetQueryContentEvent(EventMessage aMessage,
                          const WidgetQueryContentEvent& aOtherEvent)
    : WidgetGUIEvent(aOtherEvent.IsTrusted(), aMessage,
                     const_cast<nsIWidget*>(aOtherEvent.mWidget.get()),
                     eQueryContentEventClass)
    , mSucceeded(false)
    , mUseNativeLineBreak(aOtherEvent.mUseNativeLineBreak)
    , mWithFontRanges(false)
  {
  }

  virtual WidgetEvent* Duplicate() const override
  {
    // This event isn't an internal event of any DOM event.
    NS_ASSERTION(!IsAllowedToDispatchDOMEvent(),
      "WidgetQueryContentEvent needs to support Duplicate()");
    MOZ_CRASH("WidgetQueryContentEvent doesn't support Duplicate()");
  }

  struct Options final
  {
    bool mUseNativeLineBreak;
    bool mRelativeToInsertionPoint;

    explicit Options()
      : mUseNativeLineBreak(true)
      , mRelativeToInsertionPoint(false)
    {
    }

    explicit Options(const WidgetQueryContentEvent& aEvent)
      : mUseNativeLineBreak(aEvent.mUseNativeLineBreak)
      , mRelativeToInsertionPoint(aEvent.mInput.mRelativeToInsertionPoint)
    {
    }
  };

  void Init(const Options& aOptions)
  {
    mUseNativeLineBreak = aOptions.mUseNativeLineBreak;
    mInput.mRelativeToInsertionPoint = aOptions.mRelativeToInsertionPoint;
    MOZ_ASSERT(mInput.IsValidEventMessage(mMessage));
  }

  void InitForQueryTextContent(int64_t aOffset, uint32_t aLength,
                               const Options& aOptions = Options())
  {
    NS_ASSERTION(mMessage == eQueryTextContent,
                 "wrong initializer is called");
    mInput.mOffset = aOffset;
    mInput.mLength = aLength;
    Init(aOptions);
    MOZ_ASSERT(mInput.IsValidOffset());
  }

  void InitForQueryCaretRect(int64_t aOffset,
                             const Options& aOptions = Options())
  {
    NS_ASSERTION(mMessage == eQueryCaretRect,
                 "wrong initializer is called");
    mInput.mOffset = aOffset;
    Init(aOptions);
    MOZ_ASSERT(mInput.IsValidOffset());
  }

  void InitForQueryTextRect(int64_t aOffset, uint32_t aLength,
                            const Options& aOptions = Options())
  {
    NS_ASSERTION(mMessage == eQueryTextRect,
                 "wrong initializer is called");
    mInput.mOffset = aOffset;
    mInput.mLength = aLength;
    Init(aOptions);
    MOZ_ASSERT(mInput.IsValidOffset());
  }

  void InitForQuerySelectedText(SelectionType aSelectionType,
                                const Options& aOptions = Options())
  {
    MOZ_ASSERT(mMessage == eQuerySelectedText);
    MOZ_ASSERT(aSelectionType != SelectionType::eNone);
    mInput.mSelectionType = aSelectionType;
    Init(aOptions);
  }

  void InitForQueryDOMWidgetHittest(const mozilla::LayoutDeviceIntPoint& aPoint)
  {
    NS_ASSERTION(mMessage == eQueryDOMWidgetHittest,
                 "wrong initializer is called");
    mRefPoint = aPoint;
  }

  void InitForQueryTextRectArray(uint32_t aOffset, uint32_t aLength,
                                 const Options& aOptions = Options())
  {
    NS_ASSERTION(mMessage == eQueryTextRectArray,
                 "wrong initializer is called");
    mInput.mOffset = aOffset;
    mInput.mLength = aLength;
    Init(aOptions);
  }

  void RequestFontRanges()
  {
    NS_ASSERTION(mMessage == eQueryTextContent,
                 "not querying text content");
    mWithFontRanges = true;
  }

  uint32_t GetSelectionStart(void) const
  {
    NS_ASSERTION(mMessage == eQuerySelectedText,
                 "not querying selection");
    return mReply.mOffset + (mReply.mReversed ? mReply.mString.Length() : 0);
  }

  uint32_t GetSelectionEnd(void) const
  {
    NS_ASSERTION(mMessage == eQuerySelectedText,
                 "not querying selection");
    return mReply.mOffset + (mReply.mReversed ? 0 : mReply.mString.Length());
  }

  mozilla::WritingMode GetWritingMode(void) const
  {
    NS_ASSERTION(mMessage == eQuerySelectedText ||
                 mMessage == eQueryCaretRect ||
                 mMessage == eQueryTextRect,
                 "not querying selection or text rect");
    return mReply.mWritingMode;
  }

  bool mSucceeded;
  bool mUseNativeLineBreak;
  bool mWithFontRanges;
  struct Input final
  {
    uint32_t EndOffset() const
    {
      CheckedInt<uint32_t> endOffset =
        CheckedInt<uint32_t>(mOffset) + mLength;
      return NS_WARN_IF(!endOffset.isValid()) ? UINT32_MAX : endOffset.value();
    }

    int64_t mOffset;
    uint32_t mLength;
    SelectionType mSelectionType;
    // If mOffset is true, mOffset is relative to the start offset of
    // composition if there is, otherwise, the start of the first selection
    // range.
    bool mRelativeToInsertionPoint;

    Input()
      : mOffset(0)
      , mLength(0)
      , mSelectionType(SelectionType::eNormal)
      , mRelativeToInsertionPoint(false)
    {
    }

    bool IsValidOffset() const
    {
      return mRelativeToInsertionPoint || mOffset >= 0;
    }
    bool IsValidEventMessage(EventMessage aEventMessage) const
    {
      if (!mRelativeToInsertionPoint) {
        return true;
      }
      switch (aEventMessage) {
        case eQueryTextContent:
        case eQueryCaretRect:
        case eQueryTextRect:
          return true;
        default:
          return false;
      }
    }
    bool MakeOffsetAbsolute(uint32_t aInsertionPointOffset)
    {
      if (NS_WARN_IF(!mRelativeToInsertionPoint)) {
        return true;
      }
      mRelativeToInsertionPoint = false;
      // If mOffset + aInsertionPointOffset becomes negative value,
      // we should assume the absolute offset is 0.
      if (mOffset < 0 && -mOffset > aInsertionPointOffset) {
        mOffset = 0;
        return true;
      }
      // Otherwise, we don't allow too large offset.
      CheckedInt<uint32_t> absOffset = mOffset + aInsertionPointOffset;
      if (NS_WARN_IF(!absOffset.isValid())) {
        mOffset = UINT32_MAX;
        return false;
      }
      mOffset = absOffset.value();
      return true;
    }
  } mInput;

  struct Reply final
  {
    void* mContentsRoot;
    uint32_t mOffset;
    // mTentativeCaretOffset is used by only eQueryCharacterAtPoint.
    // This is the offset where caret would be if user clicked at the mRefPoint.
    uint32_t mTentativeCaretOffset;
    nsString mString;
    // mRect is used by eQueryTextRect, eQueryCaretRect, eQueryCharacterAtPoint
    // and eQueryEditorRect. The coordinates is system coordinates relative to
    // the top level widget of mFocusedWidget.  E.g., if a <xul:panel> which
    // is owned by a window has focused editor, the offset of mRect is relative
    // to the owner window, not the <xul:panel>.
    mozilla::LayoutDeviceIntRect mRect;
    // The return widget has the caret. This is set at all query events.
    nsIWidget* mFocusedWidget;
    // mozilla::WritingMode value at the end (focus) of the selection
    mozilla::WritingMode mWritingMode;
    // Used by eQuerySelectionAsTransferable
    nsCOMPtr<nsITransferable> mTransferable;
    // Used by eQueryTextContent with font ranges requested
    AutoTArray<mozilla::FontRange, 1> mFontRanges;
    // Used by eQueryTextRectArray
    nsTArray<mozilla::LayoutDeviceIntRect> mRectArray;
    // true if selection is reversed (end < start)
    bool mReversed;
    // true if the selection exists
    bool mHasSelection;
    // true if DOM element under mouse belongs to widget
    bool mWidgetIsHit;

    Reply()
      : mContentsRoot(nullptr)
      , mOffset(NOT_FOUND)
      , mTentativeCaretOffset(NOT_FOUND)
      , mFocusedWidget(nullptr)
      , mReversed(false)
      , mHasSelection(false)
      , mWidgetIsHit(false)
    {
    }
  } mReply;

  enum
  {
    NOT_FOUND = UINT32_MAX
  };

  // values of mComputedScrollAction
  enum
  {
    SCROLL_ACTION_NONE,
    SCROLL_ACTION_LINE,
    SCROLL_ACTION_PAGE
  };
};

/******************************************************************************
 * mozilla::WidgetSelectionEvent
 ******************************************************************************/

class WidgetSelectionEvent : public WidgetGUIEvent
{
private:
  friend class mozilla::dom::PBrowserParent;
  friend class mozilla::dom::PBrowserChild;