layout/style/CSSVariableDeclarations.h

   1 /* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
   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 /* CSS Custom Property assignments for a Declaration at a given priority */
   7
   8 #ifndef mozilla_CSSVariableDeclarations_h
   9 #define mozilla_CSSVariableDeclarations_h
  10
  11 #include "nsDataHashtable.h"
  12
  13 namespace mozilla {
  14 class CSSVariableResolver;
  15 }
  16 struct nsRuleData;
  17
  18 namespace mozilla {
  19
  20 class CSSVariableDeclarations
  21 {
  22 public:
  23   CSSVariableDeclarations();
  24   CSSVariableDeclarations(const CSSVariableDeclarations& aOther);
  25 #ifdef DEBUG
  26   ~CSSVariableDeclarations();
  27 #endif
  28   CSSVariableDeclarations& operator=(const CSSVariableDeclarations& aOther);
  29
  30   /**
  31    * Returns whether this set of variable declarations includes a variable
  32    * with a given name.
  33    *
  34    * @param aName The variable name (not including any "--" prefix that would
  35    *   be part of the custom property name).
  36    */
  37   bool Has(const nsAString& aName) const;
  38
  39   /**
  40    * Represents the type of a variable value.
  41    */
  42   enum Type {
  43     eTokenStream,  // a stream of CSS tokens (the usual type for variables)
  44     eInitial,      // 'initial'
  45     eInherit,      // 'inherit'
  46     eUnset         // 'unset'
  47   };
  48
  49   /**
  50    * Gets the value of a variable in this set of variable declarations.
  51    *
  52    * @param aName The variable name (not including any "--" prefix that would
  53    *   be part of the custom property name).
  54    * @param aType Out parameter into which the type of the variable value will
  55    *   be stored.
  56    * @param aValue Out parameter into which the value of the variable will
  57    *   be stored.  If the variable is 'initial', 'inherit' or 'unset', this will
  58    *   be the empty string.
  59    * @return Whether a variable with the given name was found.  When false
  60    *   is returned, aType and aValue will not be modified.
  61    */
  62   bool Get(const nsAString& aName, Type& aType, nsString& aValue) const;
  63
  64   /**
  65    * Adds or modifies an existing entry in this set of variable declarations
  66    * to have the value 'initial'.
  67    *
  68    * @param aName The variable name (not including any "--" prefix that would
  69    *   be part of the custom property name) whose value is to be set.
  70    */
  71   void PutInitial(const nsAString& aName);
  72
  73   /**
  74    * Adds or modifies an existing entry in this set of variable declarations
  75    * to have the value 'inherit'.
  76    *
  77    * @param aName The variable name (not including any "--" prefix that would
  78    *   be part of the custom property name) whose value is to be set.
  79    */
  80   void PutInherit(const nsAString& aName);
  81
  82   /**
  83    * Adds or modifies an existing entry in this set of variable declarations
  84    * to have the value 'unset'.
  85    *
  86    * @param aName The variable name (not including any "--" prefix that would
  87    *   be part of the custom property name) whose value is to be set.
  88    */
  89   void PutUnset(const nsAString& aName);
  90
  91   /**
  92    * Adds or modifies an existing entry in this set of variable declarations
  93    * to have a token stream value.
  94    *
  95    * @param aName The variable name (not including any "--" prefix that would
  96    *   be part of the custom property name) whose value is to be set.
  97    * @param aTokenStream The CSS token stream.
  98    */
  99   void PutTokenStream(const nsAString& aName, const nsString& aTokenStream);
 100
 101   /**
 102    * Removes an entry in this set of variable declarations.
 103    *
 104    * @param aName The variable name (not including any "--" prefix that would
 105    *   be part of the custom property name) whose entry is to be removed.
 106    */
 107   void Remove(const nsAString& aName);
 108
 109   /**
 110    * Returns the number of entries in this set of variable declarations.
 111    */
 112   uint32_t Count() const { return mVariables.Count(); }
 113
 114   /**
 115    * Copies each variable value from this object into aRuleData, unless that
 116    * variable already exists on aRuleData.
 117    */
 118   void MapRuleInfoInto(nsRuleData* aRuleData);
 119
 120   /**
 121    * Copies the variables from this object into aResolver, marking them as
 122    * specified values.
 123    */
 124   void AddVariablesToResolver(CSSVariableResolver* aResolver) const;
 125
 126   size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
 127
 128 private:
 129   /**
 130    * Adds all the variable declarations from aOther into this object.
 131    */
 132   void CopyVariablesFrom(const CSSVariableDeclarations& aOther);
 133   static PLDHashOperator EnumerateVariableForCopy(const nsAString& aName,
 134                                                   nsString aValue,
 135                                                   void* aData);
 136   static PLDHashOperator
 137     EnumerateVariableForMapRuleInfoInto(const nsAString& aName,
 138                                         nsString aValue,
 139                                         void* aData);
 140   static PLDHashOperator
 141     EnumerateVariableForAddVariablesToResolver(const nsAString& aName,
 142                                                nsString aValue,
 143                                                void* aData);
 144
 145   nsDataHashtable<nsStringHashKey, nsString> mVariables;
 146 };
 147
 148 } // namespace mozilla
 149
 150 #endif