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 DOM_SVG_SVGANIMATEDPOINTLIST_H_
#define DOM_SVG_SVGANIMATEDPOINTLIST_H_
#include "mozilla/Attributes.h"
#include "mozilla/SMILAttr.h"
#include "mozilla/UniquePtr.h"
#include "SVGPointList.h"
namespace mozilla {
class SMILValue;
namespace dom {
class DOMSVGPoint;
class DOMSVGPointList;
class SVGAnimationElement;
class SVGElement;
} // namespace dom
/**
* 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 dom::DOMSVGPoint;
friend class dom::DOMSVGPointList;
public:
SVGAnimatedPointList() = default;
/**
* 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& aNewAnimValue,
dom::SVGElement* aElement);
void ClearAnimValue(dom::SVGElement* 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; }
UniquePtr<SMILAttr> ToSMILAttr(dom::SVGElement* 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;
UniquePtr<SVGPointList> mAnimVal;
struct SMILAnimatedPointList : public SMILAttr {
public:
SMILAnimatedPointList(SVGAnimatedPointList* aVal, dom::SVGElement* aElement)
: mVal(aVal), mElement(aElement) {}
// These will stay alive because a SMILAttr only lives as long
// as the Compositing step, and DOM elements don't get a chance to
// die during that.
SVGAnimatedPointList* mVal;
dom::SVGElement* mElement;
// SMILAttr methods
virtual nsresult ValueFromString(
const nsAString& aStr, const dom::SVGAnimationElement* aSrcElement,
SMILValue& aValue, bool& aPreventCachingOfSandwich) const override;
virtual SMILValue GetBaseValue() const override;
virtual void ClearAnimValue() override;
virtual nsresult SetAnimValue(const SMILValue& aValue) override;
};
};
} // namespace mozilla
#endif // DOM_SVG_SVGANIMATEDPOINTLIST_H_