gecko/layout/style/Rule.h
2015-11-09 15:57:16 +08:00

147 lines
4.3 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/. */
/* base class for all rule types in a CSS style sheet */
#ifndef mozilla_css_Rule_h___
#define mozilla_css_Rule_h___
#include "mozilla/CSSStyleSheet.h"
#include "mozilla/MemoryReporting.h"
#include "nsISupports.h"
#include "nsIDOMCSSRule.h"
class nsIDocument;
struct nsRuleData;
template<class T> struct already_AddRefed;
class nsHTMLCSSStyleSheet;
namespace mozilla {
namespace css {
class GroupRule;
#define DECL_STYLE_RULE_INHERIT_NO_DOMRULE \
/* nothing */
#define DECL_STYLE_RULE_INHERIT \
DECL_STYLE_RULE_INHERIT_NO_DOMRULE \
virtual nsIDOMCSSRule* GetDOMRule() override; \
virtual nsIDOMCSSRule* GetExistingDOMRule() override;
class Rule : public nsISupports {
protected:
Rule(uint32_t aLineNumber, uint32_t aColumnNumber)
: mSheet(nullptr),
mParentRule(nullptr),
mLineNumber(aLineNumber),
mColumnNumber(aColumnNumber)
{
}
Rule(const Rule& aCopy)
: mSheet(aCopy.mSheet),
mParentRule(aCopy.mParentRule),
mLineNumber(aCopy.mLineNumber),
mColumnNumber(aCopy.mColumnNumber)
{
}
virtual ~Rule() {}
public:
#ifdef DEBUG
virtual void List(FILE* out = stdout, int32_t aIndent = 0) const = 0;
#endif
// The constants in this list must maintain the following invariants:
// If a rule of type N must appear before a rule of type M in stylesheets
// then N < M
// Note that CSSStyleSheet::RebuildChildList assumes that no other kinds of
// rules can come between two rules of type IMPORT_RULE.
enum {
UNKNOWN_RULE = 0,
CHARSET_RULE,
IMPORT_RULE,
NAMESPACE_RULE,
STYLE_RULE,
MEDIA_RULE,
FONT_FACE_RULE,
PAGE_RULE,
KEYFRAME_RULE,
KEYFRAMES_RULE,
DOCUMENT_RULE,
SUPPORTS_RULE,
FONT_FEATURE_VALUES_RULE,
COUNTER_STYLE_RULE
};
virtual int32_t GetType() const = 0;
CSSStyleSheet* GetStyleSheet() const { return mSheet; }
// Return the document the rule lives in, if any
nsIDocument* GetDocument() const
{
CSSStyleSheet* sheet = GetStyleSheet();
return sheet ? sheet->GetDocument() : nullptr;
}
virtual void SetStyleSheet(CSSStyleSheet* aSheet);
void SetParentRule(GroupRule* aRule) {
// We don't reference count this up reference. The group rule
// will tell us when it's going away or when we're detached from
// it.
mParentRule = aRule;
}
uint32_t GetLineNumber() const { return mLineNumber; }
uint32_t GetColumnNumber() const { return mColumnNumber; }
/**
* Clones |this|. Never returns nullptr.
*/
virtual already_AddRefed<Rule> Clone() const = 0;
// Note that this returns null for inline style rules since they aren't
// supposed to have a DOM rule representation (and our code wouldn't work).
virtual nsIDOMCSSRule* GetDOMRule() = 0;
// Like GetDOMRule(), but won't create one if we don't have one yet
virtual nsIDOMCSSRule* GetExistingDOMRule() = 0;
// to implement methods on nsIDOMCSSRule
nsresult GetParentRule(nsIDOMCSSRule** aParentRule);
nsresult GetParentStyleSheet(nsIDOMCSSStyleSheet** aSheet);
Rule* GetCSSRule();
// This is pure virtual because all of Rule's data members are non-owning and
// thus measured elsewhere.
virtual size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf)
const MOZ_MUST_OVERRIDE = 0;
// This is used to measure nsCOMArray<Rule>s.
static size_t SizeOfCOMArrayElementIncludingThis(css::Rule* aElement,
mozilla::MallocSizeOf aMallocSizeOf,
void* aData);
protected:
// This is sometimes null (e.g., for style attributes).
CSSStyleSheet* mSheet;
// When the parent GroupRule is destroyed, it will call SetParentRule(nullptr)
// on this object. (Through SetParentRuleReference);
GroupRule* MOZ_NON_OWNING_REF mParentRule;
// Keep the same type so that MSVC packs them.
uint32_t mLineNumber;
uint32_t mColumnNumber;
};
} // namespace css
} // namespace mozilla
#endif /* mozilla_css_Rule_h___ */