layout/style/CSSVariableValues.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 /* computed CSS Variable values */
   7
   8 #ifndef mozilla_CSSVariableValues_h
   9 #define mozilla_CSSVariableValues_h
  10
  11 #include "nsCSSScanner.h"
  12 #include "nsDataHashtable.h"
  13 #include "nsTArray.h"
  14
  15 namespace mozilla {
  16
  17 class CSSVariableResolver;
  18
  19 class CSSVariableValues
  20 {
  21 public:
  22   CSSVariableValues();
  23   CSSVariableValues(const CSSVariableValues& aOther);
  24 #ifdef DEBUG
  25   ~CSSVariableValues();
  26 #endif
  27   CSSVariableValues& operator=(const CSSVariableValues& aOther);
  28
  29   bool operator==(const CSSVariableValues& aOther) const;
  30   bool operator!=(const CSSVariableValues& aOther) const
  31     { return !(*this == aOther); }
  32
  33   /**
  34    * Gets the value of a variable in this set of computed variables.
  35    *
  36    * @param aName The variable name (not including any "--" prefix that would
  37    *   be part of the custom property name).
  38    * @param aValue Out parameter into which the value of the variable will
  39    *   be stored.
  40    * @return Whether a variable with the given name was found.  When false
  41    *   is returned, aValue will not be modified.
  42    */
  43   bool Get(const nsAString& aName, nsString& aValue) const;
  44
  45   /**
  46    * Gets the value of a variable in this set of computed variables, along
  47    * with information on the types of tokens that appear at the start and
  48    * end of the token stream.
  49    *
  50    * @param aName The variable name (not including any "--" prefix that would
  51    *   be part of the custom property name).
  52    * @param aValue Out parameter into which the value of the variable will
  53    *   be stored.
  54    * @param aFirstToken The type of token at the start of the variable value.
  55    * @param aLastToken The type of token at the en of the variable value.
  56    * @return Whether a variable with the given name was found.  When false
  57    *   is returned, aValue, aFirstToken and aLastToken will not be modified.
  58    */
  59   bool Get(const nsAString& aName,
  60            nsString& aValue,
  61            nsCSSTokenSerializationType& aFirstToken,
  62            nsCSSTokenSerializationType& aLastToken) const;
  63
  64   /**
  65    * Gets the name of the variable at the given index.
  66    *
  67    * Variables on this object are ordered, and that order is just determined
  68    * based on the order that they are added to the object.  A consistent
  69    * ordering is required for CSSDeclaration objects in the DOM.
  70    * CSSDeclarations expose property names as indexed properties, which need to
  71    * be stable.
  72    *
  73    * @param aIndex The index of the variable to get.
  74    * @param aName Out parameter into which the name of the variable will be
  75    *   stored.
  76    */
  77   void GetVariableAt(size_t aIndex, nsAString& aName) const;
  78
  79   /**
  80    * Gets the number of variables stored on this object.
  81    */
  82   size_t Count() const;
  83
  84   /**
  85    * Adds or modifies an existing entry in this set of variable values.
  86    *
  87    * @param aName The variable name (not including any "--" prefix that would
  88    *   be part of the custom property name) whose value is to be set.
  89    * @param aValue The variable value.
  90    * @param aFirstToken The type of token at the start of the variable value.
  91    * @param aLastToken The type of token at the en of the variable value.
  92    */
  93   void Put(const nsAString& aName,
  94            nsString aValue,
  95            nsCSSTokenSerializationType aFirstToken,
  96            nsCSSTokenSerializationType aLastToken);
  97
  98   /**
  99    * Copies the variables from this object into aResolver, marking them as
 100    * computed, inherited values.
 101    */
 102   void AddVariablesToResolver(CSSVariableResolver* aResolver) const;
 103
 104 private:
 105   struct Variable
 106   {
 107     Variable()
 108       : mFirstToken(eCSSTokenSerialization_Nothing)
 109       , mLastToken(eCSSTokenSerialization_Nothing)
 110     {}
 111
 112     Variable(const nsAString& aVariableName,
 113              nsString aValue,
 114              nsCSSTokenSerializationType aFirstToken,
 115              nsCSSTokenSerializationType aLastToken)
 116       : mVariableName(aVariableName)
 117       , mValue(aValue)
 118       , mFirstToken(aFirstToken)
 119       , mLastToken(aLastToken)
 120     {}
 121
 122     nsString mVariableName;
 123     nsString mValue;
 124     nsCSSTokenSerializationType mFirstToken;
 125     nsCSSTokenSerializationType mLastToken;
 126   };
 127
 128   /**
 129    * Adds all the variables from aOther into this object.
 130    */
 131   void CopyVariablesFrom(const CSSVariableValues& aOther);
 132
 133   /**
 134    * Map of variable names to IDs.  Variable IDs are indexes into
 135    * mVariables.
 136    */
 137   nsDataHashtable<nsStringHashKey, size_t> mVariableIDs;
 138
 139   /**
 140    * Array of variables, indexed by variable ID.
 141    */
 142   nsTArray<Variable> mVariables;
 143 };
 144
 145 } // namespace mozilla
 146
 147 #endif