/* -*- 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 "mozilla/UniquePtr.h"

#include "nsAutoPtr.h"

#include "nsISMILAttr.h"

#include "SVGPointList.h"

class nsSMILValue;

class nsSVGElement;

namespace mozilla {

namespace dom {

class SVGAnimationElement;

} // 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 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;

  }

  UniquePtr<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__