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.

Implementation

Mercurial (27a812186ff4)

VCS Links

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
/* -*- 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/. */

/*
 * a node in the lexicographic tree of rules that match an element,
 * responsible for converting the rules' information into computed style
 */

#ifndef nsRuleNode_h___
#define nsRuleNode_h___

#include "nsPresContext.h"
#include "nsStyleStruct.h"

#include <stdint.h>

class nsStyleContext;
struct nsRuleData;
class nsIStyleRule;
struct nsCSSValueList;

class nsCSSValue;
struct nsCSSRect;

class nsStyleCoord;
struct nsCSSValuePairList;

template <nsStyleStructID MinIndex, nsStyleStructID Count>
class FixedStyleStructArray
{
private:
  void* mArray[Count];
public:
  void*& operator[](nsStyleStructID aIndex) {
    NS_ABORT_IF_FALSE(MinIndex <= aIndex && aIndex < (MinIndex + Count),
                      "out of range");
    return mArray[aIndex - MinIndex];
  }

  const void* operator[](nsStyleStructID aIndex) const {
    NS_ABORT_IF_FALSE(MinIndex <= aIndex && aIndex < (MinIndex + Count),
                      "out of range");
    return mArray[aIndex - MinIndex];
  }
};

struct nsInheritedStyleData
{
  FixedStyleStructArray<nsStyleStructID_Inherited_Start,
                        nsStyleStructID_Inherited_Count> mStyleStructs;

  void* operator new(size_t sz, nsPresContext* aContext) CPP_THROW_NEW {
    return aContext->AllocateFromShell(sz);
  }

  void DestroyStructs(uint64_t aBits, nsPresContext* aContext) {
#define STYLE_STRUCT_INHERITED(name, checkdata_cb) \
    void *name##Data = mStyleStructs[eStyleStruct_##name]; \
    if (name##Data && !(aBits & NS_STYLE_INHERIT_BIT(name))) \
      static_cast<nsStyle##name*>(name##Data)->Destroy(aContext);
#define STYLE_STRUCT_RESET(name, checkdata_cb)

#include "nsStyleStructList.h"

#undef STYLE_STRUCT_INHERITED
#undef STYLE_STRUCT_RESET
  }

  void Destroy(uint64_t aBits, nsPresContext* aContext) {
    DestroyStructs(aBits, aContext);
    aContext->FreeToShell(sizeof(nsInheritedStyleData), this);
  }

  nsInheritedStyleData() {
    for (nsStyleStructID i = nsStyleStructID_Inherited_Start;
         i < nsStyleStructID_Inherited_Start + nsStyleStructID_Inherited_Count;
         i = nsStyleStructID(i + 1)) {
      mStyleStructs[i] = nullptr;
    }
  }
};

struct nsResetStyleData
{
  FixedStyleStructArray<nsStyleStructID_Reset_Start,
                        nsStyleStructID_Reset_Count> mStyleStructs;

  nsResetStyleData()
  {
    for (nsStyleStructID i = nsStyleStructID_Reset_Start;
         i < nsStyleStructID_Reset_Start + nsStyleStructID_Reset_Count;
         i = nsStyleStructID(i + 1)) {
      mStyleStructs[i] = nullptr;
    }
  }

  void* operator new(size_t sz, nsPresContext* aContext) CPP_THROW_NEW {
    return aContext->AllocateFromShell(sz);
  }

  void Destroy(uint64_t aBits, nsPresContext* aContext) {
#define STYLE_STRUCT_RESET(name, checkdata_cb) \
    void *name##Data = mStyleStructs[eStyleStruct_##name]; \
    if (name##Data && !(aBits & NS_STYLE_INHERIT_BIT(name))) \
      static_cast<nsStyle##name*>(name##Data)->Destroy(aContext);
#define STYLE_STRUCT_INHERITED(name, checkdata_cb)

#include "nsStyleStructList.h"

#undef STYLE_STRUCT_RESET
#undef STYLE_STRUCT_INHERITED

    aContext->FreeToShell(sizeof(nsResetStyleData), this);
  }
};

struct nsCachedStyleData
{
  nsInheritedStyleData* mInheritedData;
  nsResetStyleData* mResetData;

  static bool IsReset(const nsStyleStructID aSID) {
    NS_ABORT_IF_FALSE(0 <= aSID && aSID < nsStyleStructID_Length,
                      "must be an inherited or reset SID");
    return nsStyleStructID_Reset_Start <= aSID;
  }

  static bool IsInherited(const nsStyleStructID aSID) {
    return !IsReset(aSID);
  }

  static uint32_t GetBitForSID(const nsStyleStructID aSID) {
    return 1 << aSID;
  }

  void* NS_FASTCALL GetStyleData(const nsStyleStructID aSID) {
    if (IsReset(aSID)) {
      if (mResetData) {
        return mResetData->mStyleStructs[aSID];
      }
    } else {
      if (mInheritedData) {
        return mInheritedData->mStyleStructs[aSID];
      }
    }
    return nullptr;
  }

  void NS_FASTCALL SetStyleData(const nsStyleStructID aSID,
                                nsPresContext *aPresContext, void *aData) {
    if (IsReset(aSID)) {
      if (!mResetData) {
        mResetData = new (aPresContext) nsResetStyleData;
      }
      mResetData->mStyleStructs[aSID] = aData;
    } else {
      if (!mInheritedData) {
        mInheritedData = new (aPresContext) nsInheritedStyleData;
      }
      mInheritedData->mStyleStructs[aSID] = aData;
    }
  }

  // Typesafe and faster versions of the above
  #define STYLE_STRUCT_INHERITED(name_, checkdata_cb_)                   \
    nsStyle##name_ * NS_FASTCALL GetStyle##name_ () {                    \
      return mInheritedData ? static_cast<nsStyle##name_*>(              \
        mInheritedData->mStyleStructs[eStyleStruct_##name_]) : nullptr;  \
    }
  #define STYLE_STRUCT_RESET(name_, checkdata_cb_)                       \
    nsStyle##name_ * NS_FASTCALL GetStyle##name_ () {                    \
      return mResetData ? static_cast<nsStyle##name_*>(                  \
        mResetData->mStyleStructs[eStyleStruct_##name_]) : nullptr;      \
    }
  #include "nsStyleStructList.h"
  #undef STYLE_STRUCT_RESET
  #undef STYLE_STRUCT_INHERITED

  void Destroy(uint64_t aBits, nsPresContext* aContext) {
    if (mResetData)
      mResetData->Destroy(aBits, aContext);
    if (mInheritedData)
      mInheritedData->Destroy(aBits, aContext);
    mResetData = nullptr;
    mInheritedData = nullptr;
  }

  nsCachedStyleData() :mInheritedData(nullptr), mResetData(nullptr) {}
  ~nsCachedStyleData() {}
};

/**
 * nsRuleNode is a node in a lexicographic tree (the "rule tree")
 * indexed by style rules (implementations of nsIStyleRule).
 *
 * The rule tree is owned by the nsStyleSet and is destroyed when the
 * presentation of the document goes away.  It is garbage-collected
 * (using mark-and-sweep garbage collection) during the lifetime of the
 * document (when dynamic changes cause the destruction of enough style
 * contexts).  Rule nodes are marked if they are pointed to by a style
 * context or one of their descendants is.
 *
 * An nsStyleContext, which represents the computed style data for an
 * element, points to an nsRuleNode.  The path from the root of the rule
 * tree to the nsStyleContext's mRuleNode gives the list of the rules
 * matched, from least important in the cascading order to most
 * important in the cascading order.
 *
 * The reason for using a lexicographic tree is that it allows for
 * sharing of style data, which saves both memory (for storing the
 * computed style data) and time (for computing them).  This sharing
 * depends on the computed style data being stored in structs (nsStyle*)
 * that contain only properties that are inherited by default
 * ("inherited structs") or structs that contain only properties that
 * are not inherited by default ("reset structs").  The optimization
 * depends on the normal case being that style rules specify relatively
 * few properties and even that elements generally have relatively few
 * properties specified.  This allows sharing in the following ways:
 *   1. [mainly reset structs] When a style data struct will contain the
 *      same computed value for any elements that match the same set of
 *      rules (common for reset structs), it can be stored on the
 *      nsRuleNode instead of on the nsStyleContext.
 *   2. [only? reset structs] When (1) occurs, and an nsRuleNode doesn't
 *      have any rules that change the values in the struct, the
 *      nsRuleNode can share that struct with its parent nsRuleNode.
 *   3. [mainly inherited structs] When an element doesn't match any
 *      rules that change the value of a property (or, in the edge case,
 *      when all the values specified are 'inherit'), the nsStyleContext
 *      can use the same nsStyle* struct as its parent nsStyleContext.
 *
 * Since the data represented by an nsIStyleRule are immutable, the data
 * represented by an nsRuleNode are also immutable.
 */

enum nsFontSizeType {
  eFontSize_HTML = 1,
  eFontSize_CSS = 2
};

class nsRuleNode {
public:
  enum RuleDetail {
    eRuleNone, // No props have been specified at all.
    eRulePartialReset, // At least one prop with a non-"inherit" value
                       // has been specified.  No props have been
                       // specified with an "inherit" value.  At least
                       // one prop remains unspecified.
    eRulePartialMixed, // At least one prop with a non-"inherit" value
                       // has been specified.  Some props may also have
                       // been specified with an "inherit" value.  At
                       // least one prop remains unspecified.
    eRulePartialInherited, // Only props with "inherit" values have
                           // have been specified.  At least one prop
                           // remains unspecified.
    eRuleFullReset, // All props have been specified.  None has an
                    // "inherit" value.
    eRuleFullMixed, // All props have been specified.  At least one has
                    // a non-"inherit" value.
    eRuleFullInherited  // All props have been specified with "inherit"
                        // values.
  };

private:
  nsPresContext* const mPresContext; // Our pres context.

  nsRuleNode* const mParent; // A pointer to the parent node in the tree.
                             // This enables us to walk backwards from the
                             // most specific rule matched to the least
                             // specific rule (which is the optimal order to
                             // use for lookups of style properties.
  nsIStyleRule* const mRule; // [STRONG] A pointer to our specific rule.

  nsRuleNode* mNextSibling; // This value should be used only by the
                            // parent, since the parent may store
                            // children in a hash, which means this
                            // pointer is not meaningful.  Order of
                            // siblings is also not meaningful.

  struct Key {
    nsIStyleRule* mRule;
    uint8_t mLevel;
    bool mIsImportantRule;

    Key(nsIStyleRule* aRule, uint8_t aLevel, bool aIsImportantRule)
      : mRule(aRule), mLevel(aLevel), mIsImportantRule(aIsImportantRule)
    {}

    bool operator==(const Key& aOther) const
    {
      return mRule == aOther.mRule &&
             mLevel == aOther.mLevel &&
             mIsImportantRule == aOther.mIsImportantRule;
    }

    bool operator!=(const Key& aOther) const
    {
      return !(*this == aOther);
    }
  };

  static PLDHashNumber
  ChildrenHashHashKey(PLDHashTable *aTable, const void *aKey);

  static bool
  ChildrenHashMatchEntry(PLDHashTable *aTable,
                         const PLDHashEntryHdr *aHdr,
                         const void *aKey);

  static const PLDHashTableOps ChildrenHashOps;

  static PLDHashOperator
  EnqueueRuleNodeChildren(PLDHashTable *table, PLDHashEntryHdr *hdr,
                          uint32_t number, void *arg);

  Key GetKey() const {
    return Key(mRule, GetLevel(), IsImportantRule());
  }

  // The children of this node are stored in either a hashtable or list
  // that maps from rules to our nsRuleNode children.  When matching
  // rules, we use this mapping to transition from node to node
  // (constructing new nodes as needed to flesh out the tree).

  union {
    void* asVoid;
    nsRuleNode* asList;
    PLDHashTable* asHash;
  } mChildren; // Accessed only through the methods below.

  enum {
    kTypeMask = 0x1,
    kListType = 0x0,
    kHashType = 0x1
  };
  enum {
    // Maximum to have in a list before converting to a hashtable.
    // XXX Need to optimize this.
    kMaxChildrenInList = 32
  };

  bool HaveChildren() const {
    return mChildren.asVoid != nullptr;
  }
  bool ChildrenAreHashed() {
    return (intptr_t(mChildren.asVoid) & kTypeMask) == kHashType;
  }
  nsRuleNode* ChildrenList() {
    return mChildren.asList;
  }
  nsRuleNode** ChildrenListPtr() {
    return &mChildren.asList;
  }
  PLDHashTable* ChildrenHash() {
    return (PLDHashTable*) (intptr_t(mChildren.asHash) & ~intptr_t(kTypeMask));
  }
  void SetChildrenList(nsRuleNode *aList) {
    NS_ASSERTION(!(intptr_t(aList) & kTypeMask),
                 "pointer not 2-byte aligned");
    mChildren.asList = aList;
  }
  void SetChildrenHash(PLDHashTable *aHashtable) {
    NS_ASSERTION(!(intptr_t(aHashtable) & kTypeMask),
                 "pointer not 2-byte aligned");
    mChildren.asHash = (PLDHashTable*)(intptr_t(aHashtable) | kHashType);
  }
  void ConvertChildrenToHash();

  nsCachedStyleData mStyleData;   // Any data we cached on the rule node.

  uint32_t mDependentBits; // Used to cache the fact that we can look up
                           // cached data under a parent rule.

  uint32_t mNoneBits; // Used to cache the fact that the branch to this
                      // node specifies no non-inherited data for a
                      // given struct type.  (This usually implies that
                      // the entire branch specifies no non-inherited
                      // data, although not necessarily, if a
                      // non-inherited value is overridden by an
                      // explicit 'inherit' value.)  For example, if an
                      // entire rule branch specifies no color
                      // information, then a bit will be set along every
                      // rule node on that branch, so that you can break
                      // out of the rule tree early and just inherit
                      // from the parent style context.  The presence of
                      // this bit means we should just get inherited
                      // data from the parent style context, and it is
                      // never used for reset structs since their
                      // Compute*Data functions don't initialize from
                      // inherited data.

  // Reference count.  This just counts the style contexts that reference this
  // rulenode.  And children the rulenode has had.  When this goes to 0 or
  // stops being 0, we notify the style set.
  // Note, in particular, that when a child is removed mRefCnt is NOT
  // decremented.  This is on purpose; the notifications to the style set are
  // only used to determine when it's worth running GC on the ruletree, and
  // this setup makes it so we only count unused ruletree leaves for purposes
  // of deciding when to GC.  We could more accurately count unused rulenodes
  // by releasing/addrefing our parent when our refcount transitions to or from
  // 0, but it doesn't seem worth it to do that.
  uint32_t mRefCnt;

public:
  // Overloaded new operator. Initializes the memory to 0 and relies on an arena
  // (which comes from the presShell) to perform the allocation.
  void* operator new(size_t sz, nsPresContext* aContext) CPP_THROW_NEW;
  void Destroy() { DestroyInternal(nullptr); }

  // Implemented in nsStyleSet.h, since it needs to know about nsStyleSet.
  inline void AddRef();

  // Implemented in nsStyleSet.h, since it needs to know about nsStyleSet.
  inline void Release();

protected:
  void DestroyInternal(nsRuleNode ***aDestroyQueueTail);
  void PropagateDependentBit(nsStyleStructID aSID, nsRuleNode* aHighestNode,
                             void* aStruct);
  void PropagateNoneBit(uint32_t aBit, nsRuleNode* aHighestNode);

  const void* SetDefaultOnRoot(const nsStyleStructID aSID,
                               nsStyleContext* aContext);

  /**
   * Resolves any property values in aRuleData for a given style struct that
   * have eCSSUnit_TokenStream values, by resolving them against the computed
   * variable values on the style context and re-parsing the property.
   *
   * @return Whether any properties with eCSSUnit_TokenStream values were
   *   encountered.
   */
  static bool ResolveVariableReferences(const nsStyleStructID aSID,
                                        nsRuleData* aRuleData,
                                        nsStyleContext* aContext);

  const void*
    WalkRuleTree(const nsStyleStructID aSID, nsStyleContext* aContext);

  const void*
    ComputeDisplayData(void* aStartStruct,
                       const nsRuleData* aRuleData,
                       nsStyleContext* aContext, nsRuleNode* aHighestNode,
                       RuleDetail aRuleDetail,
                       const bool aCanStoreInRuleTree);

  const void*
    ComputeVisibilityData(void* aStartStruct,
                          const nsRuleData* aRuleData,
                          nsStyleContext* aContext, nsRuleNode* aHighestNode,
                          RuleDetail aRuleDetail,
                          const bool aCanStoreInRuleTree);

  const void*
    ComputeFontData(void* aStartStruct,
                    const nsRuleData* aRuleData,
                    nsStyleContext* aContext, nsRuleNode* aHighestNode,
                    RuleDetail aRuleDetail,
                    const bool aCanStoreInRuleTree);

  const void*
    ComputeColorData(void* aStartStruct,
                     const nsRuleData* aRuleData,
                     nsStyleContext* aContext, nsRuleNode* aHighestNode,
                     RuleDetail aRuleDetail,
                     const bool aCanStoreInRuleTree);

  const void*
    ComputeBackgroundData(void* aStartStruct,
                          const nsRuleData* aRuleData,
                          nsStyleContext* aContext, nsRuleNode* aHighestNode,
                          RuleDetail aRuleDetail,
                          const bool aCanStoreInRuleTree);

  const void*
    ComputeMarginData(void* aStartStruct,
                      const nsRuleData* aRuleData,
                      nsStyleContext* aContext, nsRuleNode* aHighestNode,
                      RuleDetail aRuleDetail,
                      const bool aCanStoreInRuleTree);

  const void*
    ComputeBorderData(void* aStartStruct,
                      const nsRuleData* aRuleData,
                      nsStyleContext* aContext, nsRuleNode* aHighestNode,
                      RuleDetail aRuleDetail,
                      const bool aCanStoreInRuleTree);

  const void*
    ComputePaddingData(void* aStartStruct,
                       const nsRuleData* aRuleData,
                       nsStyleContext* aContext, nsRuleNode* aHighestNode,
                       RuleDetail aRuleDetail,
                       const bool aCanStoreInRuleTree);

  const void*
    ComputeOutlineData(void* aStartStruct,
                       const nsRuleData* aRuleData,
                       nsStyleContext* aContext, nsRuleNode* aHighestNode,
                       RuleDetail aRuleDetail,
                       const bool aCanStoreInRuleTree);

  const void*
    ComputeListData(void* aStartStruct,
                    const nsRuleData* aRuleData,
                    nsStyleContext* aContext, nsRuleNode* aHighestNode,
                    RuleDetail aRuleDetail,
                    const bool aCanStoreInRuleTree);

  const void*
    ComputePositionData(void* aStartStruct,
                        const nsRuleData* aRuleData,
                        nsStyleContext* aContext, nsRuleNode* aHighestNode,
                        RuleDetail aRuleDetail,
                        const bool aCanStoreInRuleTree);

  const void*
    ComputeTableData(void* aStartStruct,
                     const nsRuleData* aRuleData,
                     nsStyleContext* aContext, nsRuleNode* aHighestNode,
                     RuleDetail aRuleDetail,
                     const bool aCanStoreInRuleTree);

  const void*
    ComputeTableBorderData(void* aStartStruct,
                           const nsRuleData* aRuleData,
                           nsStyleContext* aContext, nsRuleNode* aHighestNode,
                           RuleDetail aRuleDetail,
                           const bool aCanStoreInRuleTree);

  const void*
    ComputeContentData(void* aStartStruct,
                       const nsRuleData* aRuleData,
                       nsStyleContext* aContext, nsRuleNode* aHighestNode,
                       RuleDetail aRuleDetail,
                       const bool aCanStoreInRuleTree);

  const void*
    ComputeQuotesData(void* aStartStruct,
                      const nsRuleData* aRuleData,
                      nsStyleContext* aContext, nsRuleNode* aHighestNode,
                      RuleDetail aRuleDetail,
                      const bool aCanStoreInRuleTree);

  const void*
    ComputeTextData(void* aStartStruct,
                    const nsRuleData* aRuleData,
                    nsStyleContext* aContext, nsRuleNode* aHighestNode,
                    RuleDetail aRuleDetail,
                    const bool aCanStoreInRuleTree);

  const void*
    ComputeTextResetData(void* aStartStruct,
                         const nsRuleData* aRuleData,
                         nsStyleContext* aContext, nsRuleNode* aHighestNode,
                         RuleDetail aRuleDetail,
                         const bool aCanStoreInRuleTree);

  const void*
    ComputeUserInterfaceData(void* aStartStruct,
                             const nsRuleData* aRuleData,
                             nsStyleContext* aContext,
                             nsRuleNode* aHighestNode,
                             RuleDetail aRuleDetail,
                             const bool aCanStoreInRuleTree);

  const void*
    ComputeUIResetData(void* aStartStruct,
                       const nsRuleData* aRuleData,
                       nsStyleContext* aContext, nsRuleNode* aHighestNode,
                       RuleDetail aRuleDetail,
                       const bool aCanStoreInRuleTree);

  const void*
    ComputeXULData(void* aStartStruct,
                   const nsRuleData* aRuleData,
                   nsStyleContext* aContext, nsRuleNode* aHighestNode,
                   RuleDetail aRuleDetail,
                   const bool aCanStoreInRuleTree);

  const void*
    ComputeColumnData(void* aStartStruct,
                      const nsRuleData* aRuleData,
                      nsStyleContext* aContext, nsRuleNode* aHighestNode,
                      RuleDetail aRuleDetail,
                      const bool aCanStoreInRuleTree);

  const void*
    ComputeSVGData(void* aStartStruct,
                   const nsRuleData* aRuleData,
                   nsStyleContext* aContext, nsRuleNode* aHighestNode,
                   RuleDetail aRuleDetail,
                   const bool aCanStoreInRuleTree);

  const void*
    ComputeSVGResetData(void* aStartStruct,
                        const nsRuleData* aRuleData,
                        nsStyleContext* aContext, nsRuleNode* aHighestNode,
                        RuleDetail aRuleDetail,
                        const bool aCanStoreInRuleTree);

  const void*
    ComputeVariablesData(void* aStartStruct,
                         const nsRuleData* aRuleData,
                         nsStyleContext* aContext, nsRuleNode* aHighestNode,
                         RuleDetail aRuleDetail,
                         const bool aCanStoreInRuleTree);

  // helpers for |ComputeFontData| that need access to |mNoneBits|:
  static void SetFontSize(nsPresContext* aPresContext,
                          const nsRuleData* aRuleData,
                          const nsStyleFont* aFont,
                          const nsStyleFont* aParentFont,
                          nscoord* aSize,
                          const nsFont& aSystemFont,
                          nscoord aParentSize,
                          nscoord aScriptLevelAdjustedParentSize,
                          bool aUsedStartStruct,
                          bool aAtRoot,
                          bool& aCanStoreInRuleTree);

  static void SetFont(nsPresContext* aPresContext,
                      nsStyleContext* aContext,
                      uint8_t aGenericFontID,
                      const nsRuleData* aRuleData,
                      const nsStyleFont* aParentFont,
                      nsStyleFont* aFont,
                      bool aStartStruct,
                      bool& aCanStoreInRuleTree);

  static void SetGenericFont(nsPresContext* aPresContext,
                             nsStyleContext* aContext,
                             uint8_t aGenericFontID,
                             nsStyleFont* aFont);

  void AdjustLogicalBoxProp(nsStyleContext* aContext,
                            const nsCSSValue& aLTRSource,
                            const nsCSSValue& aRTLSource,
                            const nsCSSValue& aLTRLogicalValue,
                            const nsCSSValue& aRTLLogicalValue,
                            mozilla::css::Side aSide,
                            nsCSSRect& aValueRect,
                            bool& aCanStoreInRuleTree);

  inline RuleDetail CheckSpecifiedProperties(const nsStyleStructID aSID,
                                             const nsRuleData* aRuleData);

  already_AddRefed<nsCSSShadowArray>
              GetShadowData(const nsCSSValueList* aList,
                            nsStyleContext* aContext,
                            bool aIsBoxShadow,
                            bool& aCanStoreInRuleTree);
  bool SetStyleFilterToCSSValue(nsStyleFilter* aStyleFilter,
                                const nsCSSValue& aValue,
                                nsStyleContext* aStyleContext,
                                nsPresContext* aPresContext,
                                bool& aCanStoreInRuleTree);

private:
  nsRuleNode(nsPresContext* aPresContext, nsRuleNode* aParent,
             nsIStyleRule* aRule, uint8_t aLevel, bool aIsImportant);
  ~nsRuleNode();

public:
  static nsRuleNode* CreateRootNode(nsPresContext* aPresContext);

  static void EnsureBlockDisplay(uint8_t& display,
                                 bool aConvertListItem = false);

  // Transition never returns null; on out of memory it'll just return |this|.
  nsRuleNode* Transition(nsIStyleRule* aRule, uint8_t aLevel,
                         bool aIsImportantRule);
  nsRuleNode* GetParent() const { return mParent; }
  bool IsRoot() const { return mParent == nullptr; }

  // These uint8_ts are really nsStyleSet::sheetType values.
  uint8_t GetLevel() const {
    NS_ASSERTION(!IsRoot(), "can't call on root");
    return (mDependentBits & NS_RULE_NODE_LEVEL_MASK) >>
             NS_RULE_NODE_LEVEL_SHIFT;
  }
  bool IsImportantRule() const {
    NS_ASSERTION(!IsRoot(), "can't call on root");
    return (mDependentBits & NS_RULE_NODE_IS_IMPORTANT) != 0;
  }

  /**
   * Has this rule node at some time in its lifetime been the mRuleNode
   * of some style context (as opposed to only being the ancestor of
   * some style context's mRuleNode)?
   */
  void SetUsedDirectly();
  bool IsUsedDirectly() const {
    return (mDependentBits & NS_RULE_NODE_USED_DIRECTLY) != 0;
  }

  // NOTE:  Does not |AddRef|.  Null only for the root.
  nsIStyleRule* GetRule() const { return mRule; }
  // NOTE: Does not |AddRef|.  Never null.
  nsPresContext* PresContext() const { return mPresContext; }

  const void* GetStyleData(nsStyleStructID aSID,
                           nsStyleContext* aContext,
                           bool aComputeData);

  #define STYLE_STRUCT(name_, checkdata_cb_)                                  \
    const nsStyle##name_* GetStyle##name_(nsStyleContext* aContext,           \
                                          bool aComputeData);
  #include "nsStyleStructList.h"
  #undef STYLE_STRUCT

  /*
   * Garbage collection.  Mark walks up the tree, marking any unmarked
   * ancestors until it reaches a marked one.  Sweep recursively sweeps
   * the children, destroys any that are unmarked, and clears marks,
   * returning true if the node on which it was called was destroyed.
   */
  void Mark();
  bool Sweep();

  static bool
    HasAuthorSpecifiedRules(nsStyleContext* aStyleContext,
                            uint32_t ruleTypeMask,
                            bool aAuthorColorsAllowed);

  // Expose this so media queries can use it
  static nscoord CalcLengthWithInitialFont(nsPresContext* aPresContext,
                                           const nsCSSValue& aValue);
  // Expose this so nsTransformFunctions can use it.
  static nscoord CalcLength(const nsCSSValue& aValue,
                            nsStyleContext* aStyleContext,
                            nsPresContext* aPresContext,
                            bool& aCanStoreInRuleTree);

  struct ComputedCalc {
    nscoord mLength;
    float mPercent;

    ComputedCalc(nscoord aLength, float aPercent)
      : mLength(aLength), mPercent(aPercent) {}
  };
  static ComputedCalc
  SpecifiedCalcToComputedCalc(const nsCSSValue& aValue,
                              nsStyleContext* aStyleContext,
                              nsPresContext* aPresContext,
                              bool& aCanStoreInRuleTree);

  // Compute the value of an nsStyleCoord that IsCalcUnit().
  // (Values that don't require aPercentageBasis should be handled
  // inside nsRuleNode rather than through this API.)
  static nscoord ComputeComputedCalc(const nsStyleCoord& aCoord,
                                     nscoord aPercentageBasis);

  // Compute the value of an nsStyleCoord that is either a coord, a
  // percent, or a calc expression.
  static nscoord ComputeCoordPercentCalc(const nsStyleCoord& aCoord,
                                         nscoord aPercentageBasis);

  // Return whether the rule tree for which this node is the root has
  // cached data such that we need to do dynamic change handling for
  // changes that change the results of media queries or require
  // rebuilding all style data.
  bool TreeHasCachedData() const {
    NS_ASSERTION(IsRoot(), "should only be called on root of rule tree");
    return HaveChildren() || mStyleData.mInheritedData || mStyleData.mResetData;
  }

  bool NodeHasCachedData(const nsStyleStructID aSID) {
    return !!mStyleData.GetStyleData(aSID);
  }

  static void ComputeFontFeatures(const nsCSSValuePairList *aFeaturesList,
                                  nsTArray<gfxFontFeature>& aFeatureSettings);

  static nscoord CalcFontPointSize(int32_t aHTMLSize, int32_t aBasePointSize, 
                                   nsPresContext* aPresContext,
                                   nsFontSizeType aFontSizeType = eFontSize_HTML);

  static nscoord FindNextSmallerFontSize(nscoord aFontSize, int32_t aBasePointSize, 
                                         nsPresContext* aPresContext,
                                         nsFontSizeType aFontSizeType = eFontSize_HTML);

  static nscoord FindNextLargerFontSize(nscoord aFontSize, int32_t aBasePointSize, 
                                        nsPresContext* aPresContext,
                                        nsFontSizeType aFontSizeType = eFontSize_HTML);

  /**
   * @param aValue The color value, returned from nsCSSParser::ParseColorString
   * @param aPresContext Presentation context whose preferences are used
   *                     for certain enumerated colors
   * @param aStyleContext Style context whose color is used for 'currentColor'
   *
   * @note aPresContext and aStyleContext may be null, but in that case, fully
   *       opaque black will be returned for the values that rely on these
   *       objects to compute the color. (For example, -moz-hyperlinktext.)
   *
   * @return false if we fail to extract a color; this will not happen if both
   *         aPresContext and aStyleContext are non-null
   */
  static bool ComputeColor(const nsCSSValue& aValue,
                           nsPresContext* aPresContext,
                           nsStyleContext* aStyleContext,
                           nscolor& aResult);
};

#endif