gecko-dev/content/smil/nsSMILCSSValueType.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* representation of a value for a SMIL-animated CSS property */
#ifndef NS_SMILCSSVALUETYPE_H_
#define NS_SMILCSSVALUETYPE_H_
#include "nsISMILType.h"
#include "nsCSSProperty.h"
#include "mozilla/Attributes.h"
class nsAString;
namespace mozilla {
namespace dom {
class Element;
} // namespace dom
} // namespace mozilla
/*
* nsSMILCSSValueType: Represents a SMIL-animated CSS value.
*/
class nsSMILCSSValueType : public nsISMILType
{
public:
typedef mozilla::dom::Element Element;
// Singleton for nsSMILValue objects to hold onto.
static nsSMILCSSValueType sSingleton;
protected:
// nsISMILType Methods
// -------------------
virtual void Init(nsSMILValue& aValue) const MOZ_OVERRIDE;
virtual void Destroy(nsSMILValue&) const MOZ_OVERRIDE;
virtual nsresult Assign(nsSMILValue& aDest,
const nsSMILValue& aSrc) const MOZ_OVERRIDE;
virtual bool IsEqual(const nsSMILValue& aLeft,
const nsSMILValue& aRight) const MOZ_OVERRIDE;
virtual nsresult Add(nsSMILValue& aDest,
const nsSMILValue& aValueToAdd,
PRUint32 aCount) const MOZ_OVERRIDE;
virtual nsresult ComputeDistance(const nsSMILValue& aFrom,
const nsSMILValue& aTo,
double& aDistance) const MOZ_OVERRIDE;
virtual nsresult Interpolate(const nsSMILValue& aStartVal,
const nsSMILValue& aEndVal,
double aUnitDistance,
nsSMILValue& aResult) const MOZ_OVERRIDE;
public:
// Helper Methods
// --------------
/**
* Sets up the given nsSMILValue to represent the given string value. The
* string is interpreted as a value for the given property on the given
* element.
*
* On failure, this method leaves aValue.mType == nsSMILNullType::sSingleton.
* Otherwise, this method leaves aValue.mType == this class's singleton.
*
* @param aPropID The property for which we're parsing a value.
* @param aTargetElement The target element to whom the property/value
* setting applies.
* @param aString The string to be parsed as a CSS value.
* @param [out] aValue The nsSMILValue to be populated. Should
* initially be null-typed.
* @param [out] aIsContextSensitive Set to true if |aString| may produce
* a different |aValue| depending on other
* CSS properties on |aTargetElement|
* or its ancestors (e.g. 'inherit).
* false otherwise. May be nsnull.
* Not set if the method fails.
* @pre aValue.IsNull()
* @post aValue.IsNull() || aValue.mType == nsSMILCSSValueType::sSingleton
*/
static void ValueFromString(nsCSSProperty aPropID,
Element* aTargetElement,
const nsAString& aString,
nsSMILValue& aValue,
bool* aIsContextSensitive);
/**
* Creates a string representation of the given nsSMILValue.
*
* Note: aValue is expected to be of this type (that is, it's expected to
* have been initialized by nsSMILCSSValueType::sSingleton). If aValue is a
* freshly-initialized value, this method will succeed, though the resulting
* string will be empty.
*
* @param aValue The nsSMILValue to be converted into a string.
* @param [out] aString The string to be populated with the given value.
* @return true on success, false on failure.
*/
static bool ValueToString(const nsSMILValue& aValue, nsAString& aString);
private:
// Private constructor & destructor: prevent instances beyond my singleton,
// and prevent others from deleting my singleton.
nsSMILCSSValueType() {}
~nsSMILCSSValueType() {}
};
#endif // NS_SMILCSSVALUETYPE_H_