layout/style/Rule.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 /* base class for all rule types in a CSS style sheet */
   7
   8 #ifndef mozilla_css_Rule_h___
   9 #define mozilla_css_Rule_h___
  10
  11 #include "nsIStyleRule.h"
  12 #include "nsIDOMCSSRule.h"
  13 #include "nsCSSStyleSheet.h"
  14
  15 class nsIStyleSheet;
  16 class nsIDocument;
  17 struct nsRuleData;
  18 template<class T> struct already_AddRefed;
  19 class nsHTMLCSSStyleSheet;
  20
  21 namespace mozilla {
  22 namespace css {
  23 class GroupRule;
  24
  25 #define DECL_STYLE_RULE_INHERIT_NO_DOMRULE  \
  26 virtual void MapRuleInfoInto(nsRuleData* aRuleData);
  27
  28 #define DECL_STYLE_RULE_INHERIT                   \
  29   DECL_STYLE_RULE_INHERIT_NO_DOMRULE              \
  30   virtual nsIDOMCSSRule* GetDOMRule();            \
  31   virtual nsIDOMCSSRule* GetExistingDOMRule();
  32
  33 class Rule : public nsIStyleRule {
  34 protected:
  35   Rule()
  36     : mSheet(0),
  37       mParentRule(nullptr)
  38   {
  39   }
  40
  41   Rule(const Rule& aCopy)
  42     : mSheet(aCopy.mSheet),
  43       mParentRule(aCopy.mParentRule)
  44   {
  45   }
  46
  47   virtual ~Rule() {}
  48
  49 public:
  50
  51   // The constants in this list must maintain the following invariants:
  52   //   If a rule of type N must appear before a rule of type M in stylesheets
  53   //   then N < M
  54   // Note that nsCSSStyleSheet::RebuildChildList assumes that no other kinds of
  55   // rules can come between two rules of type IMPORT_RULE.
  56   enum {
  57     UNKNOWN_RULE = 0,
  58     CHARSET_RULE,
  59     IMPORT_RULE,
  60     NAMESPACE_RULE,
  61     STYLE_RULE,
  62     MEDIA_RULE,
  63     FONT_FACE_RULE,
  64     PAGE_RULE,
  65     KEYFRAME_RULE,
  66     KEYFRAMES_RULE,
  67     DOCUMENT_RULE,
  68     SUPPORTS_RULE
  69   };
  70
  71   virtual int32_t GetType() const = 0;
  72
  73   nsCSSStyleSheet* GetStyleSheet() const;
  74   nsHTMLCSSStyleSheet* GetHTMLCSSStyleSheet() const;
  75
  76   // Return the document the rule lives in, if any
  77   nsIDocument* GetDocument() const
  78   {
  79     nsCSSStyleSheet* sheet = GetStyleSheet();
  80     return sheet ? sheet->GetDocument() : nullptr;
  81   }
  82
  83   virtual void SetStyleSheet(nsCSSStyleSheet* aSheet);
  84   // This does not need to be virtual, because GroupRule and MediaRule are not
  85   // used for inline style.
  86   void SetHTMLCSSStyleSheet(nsHTMLCSSStyleSheet* aSheet);
  87
  88   void SetParentRule(GroupRule* aRule) {
  89     // We don't reference count this up reference. The group rule
  90     // will tell us when it's going away or when we're detached from
  91     // it.
  92     mParentRule = aRule;
  93   }
  94
  95   /**
  96    * Clones |this|. Never returns NULL.
  97    */
  98   virtual already_AddRefed<Rule> Clone() const = 0;
  99
 100   // Note that this returns null for inline style rules since they aren't
 101   // supposed to have a DOM rule representation (and our code wouldn't work).
 102   virtual nsIDOMCSSRule* GetDOMRule() = 0;
 103
 104   // Like GetDOMRule(), but won't create one if we don't have one yet
 105   virtual nsIDOMCSSRule* GetExistingDOMRule() = 0;
 106
 107   // to implement methods on nsIDOMCSSRule
 108   nsresult GetParentRule(nsIDOMCSSRule** aParentRule);
 109   nsresult GetParentStyleSheet(nsIDOMCSSStyleSheet** aSheet);
 110
 111   // This is pure virtual because all of Rule's data members are non-owning and
 112   // thus measured elsewhere.
 113   virtual size_t SizeOfIncludingThis(nsMallocSizeOfFun aMallocSizeOf)
 114     const MOZ_MUST_OVERRIDE = 0;
 115
 116   // This is used to measure nsCOMArray<Rule>s.
 117   static size_t SizeOfCOMArrayElementIncludingThis(css::Rule* aElement,
 118                                                    nsMallocSizeOfFun aMallocSizeOf,
 119                                                    void* aData);
 120
 121 protected:
 122   // This is either an nsCSSStyleSheet* or a nsHTMLStyleSheet*.  The former
 123   // if the low bit is 0, the latter if the low bit is 1.
 124   uintptr_t         mSheet;
 125   GroupRule*        mParentRule;
 126 };
 127
 128 } // namespace css
 129 } // namespace mozilla
 130
 131 #endif /* mozilla_css_Rule_h___ */