gecko-dev/dom/svg/SVGAnimatedPointList.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/. */
#ifndef MOZILLA_SVGANIMATEDPOINTLIST_H__
#define MOZILLA_SVGANIMATEDPOINTLIST_H__
#include "mozilla/Attributes.h"
#include "nsAutoPtr.h"
#include "nsISMILAttr.h"
#include "SVGPointList.h"
class nsSMILValue;
class nsSVGElement;
namespace mozilla {
namespace dom {
class SVGAnimationElement;
}
/**
* Class SVGAnimatedPointList
*
* Despite the fact that no SVGAnimatedPointList interface or objects exist
* in the SVG specification (unlike e.g. SVGAnimated*Length*List), we
* nevertheless have this internal class. (Note that there is an
* SVGAnimatedPoints interface, but that's quite different to
* SVGAnimatedLengthList since it is inherited by elements, as opposed to
* elements having members of that type.) The reason that we have this class is
* to provide a single locked down point of entry to the SVGPointList objects,
* which helps ensure that the DOM wrappers for SVGPointList objects' are
* always kept in sync. This is vitally important (see the comment in
* DOMSVGPointList::InternalListWillChangeTo) and frees consumers from having
* to know or worry about wrappers (or forget about them!) for the most part.
*/
class SVGAnimatedPointList
{
// friends so that they can get write access to mBaseVal and mAnimVal
friend class DOMSVGPoint;
friend class DOMSVGPointList;
public:
SVGAnimatedPointList() {}
/**
* Because it's so important that mBaseVal and its DOMSVGPointList wrapper
* (if any) be kept in sync (see the comment in
* DOMSVGPointList::InternalListWillChangeTo), this method returns a const
* reference. Only our friend classes may get mutable references to mBaseVal.
*/
const SVGPointList& GetBaseValue() const {
return mBaseVal;
}
nsresult SetBaseValueString(const nsAString& aValue);
void ClearBaseValue();
/**
* const! See comment for GetBaseValue!
*/
const SVGPointList& GetAnimValue() const {
return mAnimVal ? *mAnimVal : mBaseVal;
}
nsresult SetAnimValue(const SVGPointList& aValue,
nsSVGElement *aElement);
void ClearAnimValue(nsSVGElement *aElement);
/**
* Needed for correct DOM wrapper construction since GetAnimValue may
* actually return the baseVal!
*/
void *GetBaseValKey() const {
return (void*)&mBaseVal;
}
void *GetAnimValKey() const {
return (void*)&mAnimVal;
}
bool IsAnimating() const {
return !!mAnimVal;
}
/// Callers own the returned nsISMILAttr
nsISMILAttr* ToSMILAttr(nsSVGElement* aElement);
private:
// mAnimVal is a pointer to allow us to determine if we're being animated or
// not. Making it a non-pointer member and using mAnimVal.IsEmpty() to check
// if we're animating is not an option, since that would break animation *to*
// the empty string (<set to="">).
SVGPointList mBaseVal;
nsAutoPtr<SVGPointList> mAnimVal;
struct SMILAnimatedPointList : public nsISMILAttr
{
public:
SMILAnimatedPointList(SVGAnimatedPointList* aVal,
nsSVGElement* aElement)
: mVal(aVal)
, mElement(aElement)
{}
// These will stay alive because a nsISMILAttr only lives as long
// as the Compositing step, and DOM elements don't get a chance to
// die during that.
SVGAnimatedPointList *mVal;
nsSVGElement *mElement;
// nsISMILAttr methods
virtual nsresult ValueFromString(const nsAString& aStr,
const dom::SVGAnimationElement* aSrcElement,
nsSMILValue& aValue,
bool& aPreventCachingOfSandwich) const override;
virtual nsSMILValue GetBaseValue() const override;
virtual void ClearAnimValue() override;
virtual nsresult SetAnimValue(const nsSMILValue& aValue) override;
};
};
} // namespace mozilla
#endif // MOZILLA_SVGANIMATEDPOINTLIST_H__