gecko-dev/layout/style/nsRuleNode.h

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/* -*- 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 "mozilla/ArenaObjectID.h"
#include "mozilla/LinkedList.h"
#include "mozilla/PodOperations.h"
#include "mozilla/RangedArray.h"
#include "mozilla/RuleNodeCacheConditions.h"
#include "mozilla/LookAndFeel.h"
#include "mozilla/SheetType.h"
#include "nsPresContext.h"
#include "nsStyleStruct.h"
class nsCSSPropertyIDSet;
class nsCSSValue;
class nsFontMetrics;
class nsIStyleRule;
class nsStyleContext;
class nsStyleCoord;
struct nsCSSRect;
struct nsCSSValueList;
struct nsCSSValuePairList;
struct nsRuleData;
struct nsInheritedStyleData
{
mozilla::RangedArray<void*,
nsStyleStructID_Inherited_Start,
nsStyleStructID_Inherited_Count> mStyleStructs;
void* operator new(size_t sz, nsPresContext* aContext) {
return aContext->PresShell()->
AllocateByObjectID(mozilla::eArenaObjectID_nsInheritedStyleData, 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->PresShell()->
FreeByObjectID(mozilla::eArenaObjectID_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
{
mozilla::RangedArray<void*,
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) {
return aContext->PresShell()->
AllocateByObjectID(mozilla::eArenaObjectID_nsResetStyleData, 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->PresShell()->
FreeByObjectID(mozilla::eArenaObjectID_nsResetStyleData, this);
}
};
struct nsConditionalResetStyleData
{
static uint32_t GetBitForSID(const nsStyleStructID aSID) {
return 1 << aSID;
}
struct Entry
{
Entry(const mozilla::RuleNodeCacheConditions& aConditions,
void* aStyleStruct,
Entry* aNext)
: mConditions(aConditions), mStyleStruct(aStyleStruct), mNext(aNext) {}
void* operator new(size_t sz, nsPresContext* aContext) {
return aContext->PresShell()->AllocateByObjectID(
mozilla::eArenaObjectID_nsConditionalResetStyleDataEntry, sz);
}
const mozilla::RuleNodeCacheConditions mConditions;
void* const mStyleStruct;
Entry* const mNext;
};
// Each entry is either a pointer to a style struct or a
// pointer to an Entry object. A bit in mConditionalBits
// means that it is an Entry.
mozilla::RangedArray<void*,
nsStyleStructID_Reset_Start,
nsStyleStructID_Reset_Count> mEntries;
uint32_t mConditionalBits;
nsConditionalResetStyleData()
{
for (nsStyleStructID i = nsStyleStructID_Reset_Start;
i < nsStyleStructID_Reset_Start + nsStyleStructID_Reset_Count;
i = nsStyleStructID(i + 1)) {
mEntries[i] = nullptr;
}
mConditionalBits = 0;
}
void* operator new(size_t sz, nsPresContext* aContext) {
return aContext->PresShell()->AllocateByObjectID(
mozilla::eArenaObjectID_nsConditionalResetStyleData, sz);
}
void* GetStyleData(nsStyleStructID aSID) const {
if (mConditionalBits & GetBitForSID(aSID)) {
return nullptr;
}
return mEntries[aSID];
}
void* GetStyleData(nsStyleStructID aSID,
nsStyleContext* aStyleContext,
bool aCanComputeData) const {
if (!(mConditionalBits & GetBitForSID(aSID))) {
return mEntries[aSID];
}
if (!aCanComputeData) {
// If aCanComputeData is false, then any previously-computed data
// would have been cached on the style context. Therefore it's
// unnecessary to check the conditional data. It's also
// incorrect, because calling e->mConditions.Matches() below could
// cause additional structs to be computed, which is incorrect
// during CalcStyleDifference.
return nullptr;
}
return GetConditionalStyleData(aSID, aStyleContext);
}
private:
// non-inline helper for GetStyleData
void* GetConditionalStyleData(nsStyleStructID aSID,
nsStyleContext* aStyleContext) const;
public:
void SetStyleData(nsStyleStructID aSID, void* aStyleStruct) {
MOZ_ASSERT(!(mConditionalBits & GetBitForSID(aSID)),
"rule node should not have unconditional and conditional style "
"data for a given struct");
mEntries[aSID] = aStyleStruct;
}
void SetStyleData(nsStyleStructID aSID,
nsPresContext* aPresContext,
void* aStyleStruct,
const mozilla::RuleNodeCacheConditions& aConditions) {
MOZ_ASSERT((mConditionalBits & GetBitForSID(aSID)) ||
!mEntries[aSID],
"rule node should not have unconditional and conditional style "
"data for a given struct");
MOZ_ASSERT(aConditions.CacheableWithDependencies(),
"don't call SetStyleData with a cache key that has no "
"conditions or is uncacheable");
#ifdef DEBUG
for (Entry* e = static_cast<Entry*>(mEntries[aSID]); e; e = e->mNext) {
NS_WARNING_ASSERTION(e->mConditions != aConditions,
"wasteful to have duplicate conditional style data");
}
#endif
mConditionalBits |= GetBitForSID(aSID);
mEntries[aSID] =
new (aPresContext) Entry(aConditions, aStyleStruct,
static_cast<Entry*>(mEntries[aSID]));
}
void Destroy(uint64_t aBits, nsPresContext* aContext) {
#define STYLE_STRUCT_RESET(name, checkdata_cb) \
void* name##Ptr = mEntries[eStyleStruct_##name]; \
if (name##Ptr) { \
if (!(mConditionalBits & NS_STYLE_INHERIT_BIT(name))) { \
if (!(aBits & NS_STYLE_INHERIT_BIT(name))) { \
static_cast<nsStyle##name*>(name##Ptr)->Destroy(aContext); \
} \
} else { \
Entry* e = static_cast<Entry*>(name##Ptr); \
MOZ_ASSERT(e, "if mConditionalBits bit is set, we must have at least " \
"one conditional style struct"); \
do { \
static_cast<nsStyle##name*>(e->mStyleStruct)->Destroy(aContext); \
Entry* next = e->mNext; \
aContext->PresShell()->FreeByObjectID( \
mozilla::eArenaObjectID_nsConditionalResetStyleDataEntry, e); \
e = next; \
} while (e); \
} \
}
#define STYLE_STRUCT_INHERITED(name, checkdata_cb)
#include "nsStyleStructList.h"
#undef STYLE_STRUCT_RESET
#undef STYLE_STRUCT_INHERITED
aContext->PresShell()->FreeByObjectID(
mozilla::eArenaObjectID_nsConditionalResetStyleData, this);
}
};
struct nsCachedStyleData
{
nsInheritedStyleData* mInheritedData;
nsConditionalResetStyleData* mResetData;
static bool IsReset(const nsStyleStructID aSID) {
MOZ_ASSERT(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 nsConditionalResetStyleData::GetBitForSID(aSID);
}
void* NS_FASTCALL GetStyleData(const nsStyleStructID aSID) {
if (IsReset(aSID)) {
if (mResetData) {
return mResetData->GetStyleData(aSID);
}
} else {
if (mInheritedData) {
return mInheritedData->mStyleStructs[aSID];
}
}
return nullptr;
}
void* NS_FASTCALL GetStyleData(const nsStyleStructID aSID,
nsStyleContext* aStyleContext,
bool aCanComputeData) {
if (IsReset(aSID)) {
if (mResetData) {
return mResetData->GetStyleData(aSID, aStyleContext, aCanComputeData);
}
} 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) nsConditionalResetStyleData;
}
mResetData->SetStyleData(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_ (nsStyleContext* aContext, \
bool aCanComputeData) { \
return mResetData ? static_cast<nsStyle##name_*>( \
mResetData->GetStyleData(eStyleStruct_##name_, aContext, \
aCanComputeData)) \
: 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. Its entries are reference-
* counted, with strong references held by child nodes, style structs
* and (for the root), the style set. Rule nodes are not immediately
* destroyed when their reference-count drops to zero, but are instead
* destroyed during a GC sweep.
*
* 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
};
// Note: This LinkedListElement is used for storing unused nodes in the
// linked list on nsStyleSet. We use mNextSibling for the singly-linked
// sibling list.
class nsRuleNode : public mozilla::LinkedListElement<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.
const RefPtr<nsRuleNode> 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.
const nsCOMPtr<nsIStyleRule> mRule; // 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;
mozilla::SheetType mLevel;
bool mIsImportantRule;
Key(nsIStyleRule* aRule, mozilla::SheetType 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(const void *aKey);
static bool
ChildrenHashMatchEntry(const PLDHashEntryHdr *aHdr, const void *aKey);
static const PLDHashTableOps ChildrenHashOps;
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(int32_t aNumKids);
void RemoveChild(nsRuleNode* aNode);
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. Style contexts hold strong references to their rule node,
// and rule nodes hold strong references to their parent.
//
// When the refcount drops to zero, we don't necessarily free the node.
// Instead, we notify the style set, which performs periodic sweeps.
uint32_t mRefCnt;
public:
// Infallible overloaded new operator that allocates from a presShell arena.
void* operator new(size_t sz, nsPresContext* aContext);
void Destroy();
// 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 PropagateDependentBit(nsStyleStructID aSID, nsRuleNode* aHighestNode,
void* aStruct);
void PropagateNoneBit(uint32_t aBit, nsRuleNode* aHighestNode);
static void PropagateGrandancestorBit(nsStyleContext* aContext,
nsStyleContext* aContextInheritedFrom);
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 mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeVisibilityData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeFontData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeColorData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeBackgroundData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeMarginData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeBorderData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputePaddingData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeOutlineData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeListData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputePositionData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeTableData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeTableBorderData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeContentData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeTextData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeTextResetData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeUserInterfaceData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext,
nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeUIResetData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeXULData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeColumnData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeSVGData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeSVGResetData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeVariablesData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
const void*
ComputeEffectsData(void* aStartStruct,
const nsRuleData* aRuleData,
nsStyleContext* aContext, nsRuleNode* aHighestNode,
RuleDetail aRuleDetail,
const mozilla::RuleNodeCacheConditions aConditions);
// helpers for |ComputeFontData| that need access to |mNoneBits|:
static void SetFontSize(nsPresContext* aPresContext,
nsStyleContext* aContext,
const nsRuleData* aRuleData,
const nsStyleFont* aFont,
const nsStyleFont* aParentFont,
nscoord* aSize,
const nsFont& aSystemFont,
nscoord aParentSize,
nscoord aScriptLevelAdjustedParentSize,
bool aUsedStartStruct,
bool aAtRoot,
mozilla::RuleNodeCacheConditions& aConditions);
static void SetFont(nsPresContext* aPresContext,
nsStyleContext* aContext,
uint8_t aGenericFontID,
const nsRuleData* aRuleData,
const nsStyleFont* aParentFont,
nsStyleFont* aFont,
bool aStartStruct,
mozilla::RuleNodeCacheConditions& aConditions);
static void SetGenericFont(nsPresContext* aPresContext,
nsStyleContext* aContext,
uint8_t aGenericFontID,
nsStyleFont* aFont);
inline RuleDetail CheckSpecifiedProperties(const nsStyleStructID aSID,
const nsRuleData* aRuleData);
private:
nsRuleNode(nsPresContext* aPresContext, nsRuleNode* aParent,
nsIStyleRule* aRule, mozilla::SheetType aLevel, bool aIsImportant);
~nsRuleNode();
public:
// This is infallible; it will never return nullptr.
static already_AddRefed<nsRuleNode> CreateRootNode(nsPresContext* aPresContext);
static void EnsureBlockDisplay(mozilla::StyleDisplay& display,
bool aConvertListItem = false);
static void EnsureInlineDisplay(mozilla::StyleDisplay& display);
static already_AddRefed<nsFontMetrics> GetMetricsFor(nsPresContext* aPresContext,
bool aIsVertical,
const nsStyleFont* aStyleFont,
nscoord aFontSize,
bool aUseUserFontSet);
static already_AddRefed<nsFontMetrics> GetMetricsFor(nsPresContext* aPresContext,
nsStyleContext* aStyleContext,
const nsStyleFont* aStyleFont,
nscoord aFontSize,
bool aUseUserFontSet);
// Transition never returns null; on out of memory it'll just return |this|.
nsRuleNode* Transition(nsIStyleRule* aRule, mozilla::SheetType aLevel,
bool aIsImportantRule);
nsRuleNode* GetParent() const { return mParent; }
bool IsRoot() const { return mParent == nullptr; }
// Return the root of the rule tree that this rule node is in.
nsRuleNode* RuleTree();
const nsRuleNode* RuleTree() const {
return const_cast<nsRuleNode*>(this)->RuleTree();
}
mozilla::SheetType GetLevel() const {
NS_ASSERTION(!IsRoot(), "can't call on root");
return mozilla::SheetType(
(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;
}
/**
* Is the mRule of this rule node an AnimValuesStyleRule?
*/
void SetIsAnimationRule() {
MOZ_ASSERT(!HaveChildren() ||
(mDependentBits & NS_RULE_NODE_IS_ANIMATION_RULE),
"SetIsAnimationRule must only set the IS_ANIMATION_RULE bit "
"before the rule node has children");
mDependentBits |= NS_RULE_NODE_IS_ANIMATION_RULE;
mNoneBits |= NS_RULE_NODE_HAS_ANIMATION_DATA;
}
bool IsAnimationRule() const {
return (mDependentBits & NS_RULE_NODE_IS_ANIMATION_RULE) != 0;
}
/**
* Is the mRule of this rule node or any of its ancestors an
* AnimValuesStyleRule?
*/
bool HasAnimationData() const {
return (mNoneBits & NS_RULE_NODE_HAS_ANIMATION_DATA) != 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);
void GetDiscretelyAnimatedCSSValue(nsCSSPropertyID aProperty,
nsCSSValue* aValue);
// See comments in GetStyleData for an explanation of what the
// code below does.
#define STYLE_STRUCT_INHERITED(name_, checkdata_cb_) \
template<bool aComputeData> \
const nsStyle##name_* \
GetStyle##name_(nsStyleContext* aContext, uint64_t& aContextStyleBits) \
{ \
NS_ASSERTION(IsUsedDirectly(), \
"if we ever call this on rule nodes that aren't used " \
"directly, we should adjust handling of mDependentBits " \
"in some way."); \
MOZ_ASSERT(!ContextHasCachedData(aContext, eStyleStruct_##name_), \
"style context should not have cached data for struct"); \
\
const nsStyle##name_ *data; \
\
/* Never use cached data for animated style inside a pseudo-element; */ \
/* see comment on cacheability in AnimValuesStyleRule::MapRuleInfoInto */ \
if (!(HasAnimationData() && ParentHasPseudoElementData(aContext))) { \
data = mStyleData.GetStyle##name_(); \
if (data != nullptr) { \
/* For inherited structs, mark the struct (which will be set on */ \
/* the context by our caller) as not being owned by the context. */ \
/* Normally this would be aContext->AddStyleBit(), but aContext is */ \
/* an incomplete type here, so we work around that with a param. */ \
aContextStyleBits |= NS_STYLE_INHERIT_BIT(name_); \
/* Our caller will cache the data on the style context. */ \
return data; \
} \
} \
\
if (!aComputeData) \
return nullptr; \
\
data = static_cast<const nsStyle##name_ *> \
(WalkRuleTree(eStyleStruct_##name_, aContext)); \
\
MOZ_ASSERT(data, "should have aborted on out-of-memory"); \
return data; \
}
#define STYLE_STRUCT_RESET(name_, checkdata_cb_) \
template<bool aComputeData> \
const nsStyle##name_* \
GetStyle##name_(nsStyleContext* aContext) \
{ \
NS_ASSERTION(IsUsedDirectly(), \
"if we ever call this on rule nodes that aren't used " \
"directly, we should adjust handling of mDependentBits " \
"in some way."); \
MOZ_ASSERT(!ContextHasCachedData(aContext, eStyleStruct_##name_), \
"style context should not have cached data for struct"); \
\
const nsStyle##name_ *data; \
\
/* Never use cached data for animated style inside a pseudo-element; */ \
/* see comment on cacheability in AnimValuesStyleRule::MapRuleInfoInto */ \
if (!(HasAnimationData() && ParentHasPseudoElementData(aContext))) { \
data = mStyleData.GetStyle##name_(aContext, aComputeData); \
if (MOZ_LIKELY(data != nullptr)) { \
if (HasAnimationData()) { \
/* If we have animation data, the struct should be cached on the */ \
/* style context so that we can peek the struct. */ \
/* See comment in AnimValuesStyleRule::MapRuleInfoInto. */ \
StoreStyleOnContext(aContext, \
eStyleStruct_##name_, \
const_cast<nsStyle##name_*>(data)); \
} \
return data; \
} \
} \
\
if (!aComputeData) \
return nullptr; \
\
data = static_cast<const nsStyle##name_ *> \
(WalkRuleTree(eStyleStruct_##name_, aContext)); \
\
MOZ_ASSERT(data, "should have aborted on out-of-memory"); \
return data; \
}
#include "nsStyleStructList.h"
#undef STYLE_STRUCT_RESET
#undef STYLE_STRUCT_INHERITED
static bool
HasAuthorSpecifiedRules(nsStyleContext* aStyleContext,
uint32_t ruleTypeMask,
bool aAuthorColorsAllowed);
/**
* Fill in to aPropertiesOverridden all of the properties in aProperties
* that, for this rule node, have a declaration that is higher than the
* animation level in the CSS Cascade.
*/
static void
ComputePropertiesOverridingAnimation(
const nsTArray<nsCSSPropertyID>& aProperties,
nsStyleContext* aStyleContext,
nsCSSPropertyIDSet& aPropertiesOverridden);
// 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,
mozilla::RuleNodeCacheConditions& aConditions);
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,
mozilla::RuleNodeCacheConditions& aConditions);
// Compute the value of an nsStyleCoord that IsCalcUnit().
// (Values that don't require aPercentageBasis should be handled
// inside nsRuleNode rather than through this API.)
// @note the caller is expected to handle percentage of an indefinite size
// and NOT call this method with aPercentageBasis == NS_UNCONSTRAINEDSIZE.
// @note the return value may be negative, e.g. for "calc(a - b%)"
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.
// @note the caller is expected to handle percentage of an indefinite size
// and NOT call this method with aPercentageBasis == NS_UNCONSTRAINEDSIZE.
// @note the return value may be negative, e.g. for "calc(a - b%)"
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;
}
// Note that this will return false if we have cached conditional
// style structs.
bool NodeHasCachedUnconditionalData(const nsStyleStructID aSID) {
return !!mStyleData.GetStyleData(aSID);
}
static void ComputeFontFeatures(const nsCSSValuePairList* aFeaturesList,
nsTArray<gfxFontFeature>& aFeatureSettings);
static void ComputeFontVariations(const nsCSSValuePairList* aVariationsList,
nsTArray<gfxFontVariation>& aVariationSettings);
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);
static uint32_t ParseFontLanguageOverride(const nsAString& aLangTag);
/**
* @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);
static bool ParentHasPseudoElementData(nsStyleContext* aContext);
static void ComputeTimingFunction(const nsCSSValue& aValue,
nsTimingFunction& aResult);
// Fill unspecified layers by cycling through their values
// till they all are of length aMaxItemCount
static void FillAllBackgroundLists(nsStyleImageLayers& aLayers,
uint32_t aMaxItemCount);
static void FillAllMaskLists(nsStyleImageLayers& aLayers,
uint32_t aMaxItemCount);
static void ComputeSystemFont(nsFont* aSystemFont,
mozilla::LookAndFeel::FontID aFontID,
const nsPresContext* aPresContext,
const nsFont* aDefaultVariableFont);
private:
#ifdef DEBUG
// non-inline helper function to allow assertions without incomplete
// type errors
bool ContextHasCachedData(nsStyleContext* aContext, nsStyleStructID aSID);
#endif
// Store style struct on the style context and tell the style context
// that it doesn't own the data
static void StoreStyleOnContext(nsStyleContext* aContext,
nsStyleStructID aSID,
void* aStruct);
};
/**
* We allocate arrays of CSS values with alloca. (These arrays are a
* fixed size per style struct, but we don't want to waste the
* allocation and construction/destruction costs of the big structs when
* we're handling much smaller ones.) Since the lifetime of an alloca
* allocation is the life of the calling function, the caller must call
* alloca. However, to ensure that constructors and destructors are
* balanced, we do the constructor and destructor calling from this RAII
* class, AutoCSSValueArray.
*/
struct AutoCSSValueArray
{
/**
* aStorage must be the result of alloca(aCount * sizeof(nsCSSValue))
*/
AutoCSSValueArray(void* aStorage, size_t aCount);
~AutoCSSValueArray();
nsCSSValue* get() { return mArray; }
private:
nsCSSValue *mArray;
size_t mCount;
};
#endif