dom/smil/SMILCSSValueType.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /* representation of a value for a SMIL-animated CSS property */
   8
   9 #ifndef DOM_SMIL_SMILCSSVALUETYPE_H_
  10 #define DOM_SMIL_SMILCSSVALUETYPE_H_
  11
  12 #include "mozilla/Attributes.h"
  13 #include "mozilla/SMILType.h"
  14 #include "nsCSSPropertyID.h"
  15 #include "nsStringFwd.h"
  16
  17 namespace mozilla {
  18 struct AnimationValue;
  19 class DeclarationBlock;
  20 namespace dom {
  21 class Element;
  22 }  // namespace dom
  23
  24 /*
  25  * SMILCSSValueType: Represents a SMIL-animated CSS value.
  26  */
  27 class SMILCSSValueType : public SMILType {
  28  public:
  29   // Singleton for SMILValue objects to hold onto.
  30   static SMILCSSValueType sSingleton;
  31
  32  protected:
  33   // SMILType Methods
  34   // -------------------
  35   void Init(SMILValue& aValue) const override;
  36   void Destroy(SMILValue&) const override;
  37   nsresult Assign(SMILValue& aDest, const SMILValue& aSrc) const override;
  38   bool IsEqual(const SMILValue& aLeft, const SMILValue& aRight) const override;
  39   nsresult Add(SMILValue& aDest, const SMILValue& aValueToAdd,
  40                uint32_t aCount) const override;
  41   nsresult SandwichAdd(SMILValue& aDest,
  42                        const SMILValue& aValueToAdd) const override;
  43   nsresult ComputeDistance(const SMILValue& aFrom, const SMILValue& aTo,
  44                            double& aDistance) const override;
  45   nsresult Interpolate(const SMILValue& aStartVal, const SMILValue& aEndVal,
  46                        double aUnitDistance, SMILValue& aResult) const override;
  47
  48  public:
  49   // Helper Methods
  50   // --------------
  51   /**
  52    * Sets up the given SMILValue to represent the given string value.  The
  53    * string is interpreted as a value for the given property on the given
  54    * element.
  55    *
  56    * On failure, this method leaves aValue.mType == SMILNullType::sSingleton.
  57    * Otherwise, this method leaves aValue.mType == this class's singleton.
  58    *
  59    * @param       aPropID         The property for which we're parsing a value.
  60    * @param       aTargetElement  The target element to whom the property/value
  61    *                              setting applies.
  62    * @param       aString         The string to be parsed as a CSS value.
  63    * @param [out] aValue          The SMILValue to be populated. Should
  64    *                              initially be null-typed.
  65    * @param [out] aIsContextSensitive Set to true if |aString| may produce
  66    *                                  a different |aValue| depending on other
  67    *                                  CSS properties on |aTargetElement|
  68    *                                  or its ancestors (e.g. 'inherit).
  69    *                                  false otherwise. May be nullptr.
  70    *                                  Not set if the method fails.
  71    * @pre  aValue.IsNull()
  72    * @post aValue.IsNull() || aValue.mType == SMILCSSValueType::sSingleton
  73    */
  74   static void ValueFromString(nsCSSPropertyID aPropID,
  75                               dom::Element* aTargetElement,
  76                               const nsAString& aString, SMILValue& aValue,
  77                               bool* aIsContextSensitive);
  78
  79   /**
  80    * Creates a SMILValue to wrap the given animation value.
  81    *
  82    * @param aPropID         The property that |aValue| corresponds to.
  83    * @param aTargetElement  The target element to which the animation value
  84    *                        applies.
  85    * @param aValue          The animation value to use.
  86    * @return                A new SMILValue. On failure, returns a
  87    *                        SMILValue with the null type (i.e. rv.IsNull()
  88    *                        returns true).
  89    */
  90   static SMILValue ValueFromAnimationValue(nsCSSPropertyID aPropID,
  91                                            dom::Element* aTargetElement,
  92                                            const AnimationValue& aValue);
  93
  94   /**
  95    * Sets the relevant property values in the declaration block.
  96    *
  97    * Returns whether the declaration changed.
  98    */
  99   static bool SetPropertyValues(const SMILValue&, mozilla::DeclarationBlock&);
 100
 101   /**
 102    * Return the CSS property animated by the specified value.
 103    *
 104    * @param   aValue   The SMILValue to examine.
 105    * @return           The nsCSSPropertyID enum value of the property animated
 106    *                   by |aValue|, or eCSSProperty_UNKNOWN if the type of
 107    *                   |aValue| is not SMILCSSValueType.
 108    */
 109   static nsCSSPropertyID PropertyFromValue(const SMILValue& aValue);
 110
 111   /**
 112    * If |aValue| is an empty value, converts it to a suitable zero value by
 113    * matching the type of value stored in |aValueToMatch|.
 114    *
 115    * There is no indication if this method fails. If a suitable zero value could
 116    * not be created, |aValue| is simply unmodified.
 117    *
 118    * @param aValue        The SMILValue (of type SMILCSSValueType) to
 119    *                      possibly update.
 120    * @param aValueToMatch A SMILValue (of type SMILCSSValueType) for which
 121    *                      a corresponding zero value will be created if |aValue|
 122    *                      is empty.
 123    */
 124   static void FinalizeValue(SMILValue& aValue, const SMILValue& aValueToMatch);
 125
 126  private:
 127   // Private constructor: prevent instances beyond my singleton.
 128   constexpr SMILCSSValueType() = default;
 129 };
 130
 131 }  // namespace mozilla
 132
 133 #endif  // DOM_SMIL_SMILCSSVALUETYPE_H_