gecko-dev/dom/smil/nsSMILCSSValueType.h

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "nsCSSPropertyID.h"
#include "nsStringFwd.h"
#include "mozilla/Attributes.h"
namespace mozilla {
struct AnimationValue;
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;
typedef mozilla::AnimationValue AnimationValue;
// Singleton for nsSMILValue objects to hold onto.
static nsSMILCSSValueType sSingleton;
protected:
// nsISMILType Methods
// -------------------
void Init(nsSMILValue& aValue) const override;
void Destroy(nsSMILValue&) const override;
nsresult Assign(nsSMILValue& aDest,
const nsSMILValue& aSrc) const override;
bool IsEqual(const nsSMILValue& aLeft,
const nsSMILValue& aRight) const override;
nsresult Add(nsSMILValue& aDest,
const nsSMILValue& aValueToAdd,
uint32_t aCount) const override;
nsresult SandwichAdd(nsSMILValue& aDest,
const nsSMILValue& aValueToAdd) const override;
nsresult ComputeDistance(const nsSMILValue& aFrom,
const nsSMILValue& aTo,
double& aDistance) const override;
nsresult Interpolate(const nsSMILValue& aStartVal,
const nsSMILValue& aEndVal,
double aUnitDistance,
nsSMILValue& aResult) const 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 nullptr.
* Not set if the method fails.
* @pre aValue.IsNull()
* @post aValue.IsNull() || aValue.mType == nsSMILCSSValueType::sSingleton
*/
static void ValueFromString(nsCSSPropertyID aPropID,
Element* aTargetElement,
const nsAString& aString,
nsSMILValue& aValue,
bool* aIsContextSensitive);
/**
* Creates an nsSMILValue to wrap the given animation value.
*
* @param aPropID The property that |aValue| corresponds to.
* @param aTargetElement The target element to which the animation value
* applies.
* @param aValue The animation value to use.
* @return A new nsSMILValue. On failure, returns an
* nsSMILValue with the null type (i.e. rv.IsNull()
* returns true).
*/
static nsSMILValue ValueFromAnimationValue(nsCSSPropertyID aPropID,
Element* aTargetElement,
const AnimationValue& aValue);
/**
* 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 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.
*/
static void ValueToString(const nsSMILValue& aValue, nsAString& aString);
/**
* Return the CSS property animated by the specified value.
*
* @param aValue The nsSMILValue to examine.
* @return The nsCSSPropertyID enum value of the property animated
* by |aValue|, or eCSSProperty_UNKNOWN if the type of
* |aValue| is not nsSMILCSSValueType.
*/
static nsCSSPropertyID PropertyFromValue(const nsSMILValue& aValue);
/**
* If |aValue| is an empty value, converts it to a suitable zero value by
* matching the type of value stored in |aValueToMatch|.
*
* There is no indication if this method fails. If a suitable zero value could
* not be created, |aValue| is simply unmodified.
*
* @param aValue The nsSMILValue (of type nsSMILCSSValueType) to
* possibly update.
* @param aValueToMatch A nsSMILValue (of type nsSMILCSSValueType) for which
* a corresponding zero value will be created if |aValue|
* is empty.
*/
static void FinalizeValue(nsSMILValue& aValue,
const nsSMILValue& aValueToMatch);
private:
// Private constructor: prevent instances beyond my singleton.
constexpr nsSMILCSSValueType() {}
};
#endif // NS_SMILCSSVALUETYPE_H_