gecko-dev/layout/style/nsRuleData.h

127 строки
5.0 KiB
C++

/* -*- 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/. */
/*
* temporary (expanded) representation of property-value pairs used to
* hold data from matched rules during style data computation.
*/
#ifndef nsRuleData_h_
#define nsRuleData_h_
#include "nsCSSProps.h"
#include "nsStyleStructFwd.h"
class nsPresContext;
class nsStyleContext;
struct nsRuleData;
typedef void (*nsPostResolveFunc)(void* aStyleStruct, nsRuleData* aData);
struct nsRuleData
{
const uint32_t mSIDs;
bool mCanStoreInRuleTree;
bool mIsImportantRule;
uint8_t mLevel; // an nsStyleSet::sheetType
nsPresContext* const mPresContext;
nsStyleContext* const mStyleContext;
const nsPostResolveFunc mPostResolveCallback;
// We store nsCSSValues needed to compute the data for one or more
// style structs (specified by the bitfield mSIDs). These are stored
// in a single array allocation (which our caller allocates; see
// AutoCSSValueArray) The offset of each property |prop| in
// mValueStorage is the sum of
// mValueOffsets[nsCSSProps::kSIDTable[prop]] and
// nsCSSProps::PropertyIndexInStruct(prop). The only place we gather
// more than one style struct's data at a time is
// nsRuleNode::HasAuthorSpecifiedRules; therefore some code that we
// know is not called from HasAuthorSpecifiedRules assumes that the
// mValueOffsets for the one struct in mSIDs is zero.
nsCSSValue* const mValueStorage; // our user owns this array
size_t mValueOffsets[nsStyleStructID_Length];
nsRuleData(uint32_t aSIDs, nsCSSValue* aValueStorage,
nsPresContext* aContext, nsStyleContext* aStyleContext);
#ifdef DEBUG
~nsRuleData();
#else
~nsRuleData() {}
#endif
/**
* Return a pointer to the value object within |this| corresponding
* to property |aProperty|.
*
* This function must only be called if the given property is in
* mSIDs.
*/
nsCSSValue* ValueFor(nsCSSProperty aProperty)
{
NS_ABORT_IF_FALSE(aProperty < eCSSProperty_COUNT_no_shorthands,
"invalid or shorthand property");
nsStyleStructID sid = nsCSSProps::kSIDTable[aProperty];
size_t indexInStruct = nsCSSProps::PropertyIndexInStruct(aProperty);
// This should really be nsCachedStyleData::GetBitForSID, but we can't
// include that here since it includes us.
NS_ABORT_IF_FALSE(mSIDs & (1 << sid),
"calling nsRuleData::ValueFor on property not in mSIDs");
NS_ABORT_IF_FALSE(sid != eStyleStruct_BackendOnly &&
indexInStruct != size_t(-1),
"backend-only property");
return mValueStorage + mValueOffsets[sid] + indexInStruct;
}
const nsCSSValue* ValueFor(nsCSSProperty aProperty) const {
return const_cast<nsRuleData*>(this)->ValueFor(aProperty);
}
/**
* Getters like ValueFor(aProperty), but for each property by name
* (ValueForBackgroundColor, etc.), and more efficient than ValueFor.
* These use the names used for the property on DOM interfaces (the
* 'method' field in nsCSSPropList.h).
*
* Like ValueFor(), the caller must check that the property is within
* mSIDs.
*/
#define CSS_PROP_DOMPROP_PREFIXED(prop_) prop_
#define CSS_PROP(name_, id_, method_, flags_, pref_, parsevariant_, \
kwtable_, stylestruct_, stylestructoffset_, animtype_) \
nsCSSValue* ValueFor##method_() { \
NS_ABORT_IF_FALSE(mSIDs & NS_STYLE_INHERIT_BIT(stylestruct_), \
"Calling nsRuleData::ValueFor" #method_ " without " \
"NS_STYLE_INHERIT_BIT(" #stylestruct_ " in mSIDs."); \
nsStyleStructID sid = eStyleStruct_##stylestruct_; \
size_t indexInStruct = \
nsCSSProps::PropertyIndexInStruct(eCSSProperty_##id_); \
NS_ABORT_IF_FALSE(sid != eStyleStruct_BackendOnly && \
indexInStruct != size_t(-1), \
"backend-only property"); \
return mValueStorage + mValueOffsets[sid] + indexInStruct; \
} \
const nsCSSValue* ValueFor##method_() const { \
return const_cast<nsRuleData*>(this)->ValueFor##method_(); \
}
#define CSS_PROP_BACKENDONLY(name_, id_, method_, flags_, pref_, \
parsevariant_, kwtable_) \
/* empty; backend-only structs are not in nsRuleData */
#include "nsCSSPropList.h"
#undef CSS_PROP
#undef CSS_PROP_DOMPROP_PREFIXED
#undef CSS_PROP_BACKENDONLY
private:
inline size_t GetPoisonOffset();
};
#endif