dom/smil/nsSMILCSSValueType.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 /* representation of a value for a SMIL-animated CSS property */
   7
   8 #ifndef NS_SMILCSSVALUETYPE_H_
   9 #define NS_SMILCSSVALUETYPE_H_
  10
  11 #include "nsISMILType.h"
  12 #include "nsCSSProperty.h"
  13 #include "mozilla/Attributes.h"
  14
  15 class nsAString;
  16
  17 namespace mozilla {
  18 namespace dom {
  19 class Element;
  20 } // namespace dom
  21 } // namespace mozilla
  22
  23 /*
  24  * nsSMILCSSValueType: Represents a SMIL-animated CSS value.
  25  */
  26 class nsSMILCSSValueType : public nsISMILType
  27 {
  28 public:
  29   typedef mozilla::dom::Element Element;
  30
  31   // Singleton for nsSMILValue objects to hold onto.
  32   static nsSMILCSSValueType sSingleton;
  33
  34 protected:
  35   // nsISMILType Methods
  36   // -------------------
  37   virtual void     Init(nsSMILValue& aValue) const MOZ_OVERRIDE;
  38   virtual void     Destroy(nsSMILValue&) const MOZ_OVERRIDE;
  39   virtual nsresult Assign(nsSMILValue& aDest,
  40                           const nsSMILValue& aSrc) const MOZ_OVERRIDE;
  41   virtual bool     IsEqual(const nsSMILValue& aLeft,
  42                            const nsSMILValue& aRight) const MOZ_OVERRIDE;
  43   virtual nsresult Add(nsSMILValue& aDest,
  44                        const nsSMILValue& aValueToAdd,
  45                        uint32_t aCount) const MOZ_OVERRIDE;
  46   virtual nsresult ComputeDistance(const nsSMILValue& aFrom,
  47                                    const nsSMILValue& aTo,
  48                                    double& aDistance) const MOZ_OVERRIDE;
  49   virtual nsresult Interpolate(const nsSMILValue& aStartVal,
  50                                const nsSMILValue& aEndVal,
  51                                double aUnitDistance,
  52                                nsSMILValue& aResult) const MOZ_OVERRIDE;
  53
  54 public:
  55   // Helper Methods
  56   // --------------
  57   /**
  58    * Sets up the given nsSMILValue to represent the given string value.  The
  59    * string is interpreted as a value for the given property on the given
  60    * element.
  61    *
  62    * On failure, this method leaves aValue.mType == nsSMILNullType::sSingleton.
  63    * Otherwise, this method leaves aValue.mType == this class's singleton.
  64    *
  65    * @param       aPropID         The property for which we're parsing a value.
  66    * @param       aTargetElement  The target element to whom the property/value
  67    *                              setting applies.
  68    * @param       aString         The string to be parsed as a CSS value.
  69    * @param [out] aValue          The nsSMILValue to be populated. Should
  70    *                              initially be null-typed.
  71    * @param [out] aIsContextSensitive Set to true if |aString| may produce
  72    *                                  a different |aValue| depending on other
  73    *                                  CSS properties on |aTargetElement|
  74    *                                  or its ancestors (e.g. 'inherit).
  75    *                                  false otherwise. May be nullptr.
  76    *                                  Not set if the method fails.
  77    * @pre  aValue.IsNull()
  78    * @post aValue.IsNull() || aValue.mType == nsSMILCSSValueType::sSingleton
  79    */
  80   static void ValueFromString(nsCSSProperty aPropID,
  81                               Element* aTargetElement,
  82                               const nsAString& aString,
  83                               nsSMILValue& aValue,
  84                               bool* aIsContextSensitive);
  85
  86   /**
  87    * Creates a string representation of the given nsSMILValue.
  88    *
  89    * Note: aValue is expected to be of this type (that is, it's expected to
  90    * have been initialized by nsSMILCSSValueType::sSingleton).  If aValue is a
  91    * freshly-initialized value, this method will succeed, though the resulting
  92    * string will be empty.
  93    *
  94    * @param       aValue   The nsSMILValue to be converted into a string.
  95    * @param [out] aString  The string to be populated with the given value.
  96    * @return               true on success, false on failure.
  97    */
  98   static bool ValueToString(const nsSMILValue& aValue, nsAString& aString);
  99
 100 private:
 101   // Private constructor: prevent instances beyond my singleton.
 102   MOZ_CONSTEXPR nsSMILCSSValueType() {}
 103 };
 104
 105 #endif // NS_SMILCSSVALUETYPE_H_