/* -*- 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_SVGANIMATEDTRANSFORMLIST_H__

#define MOZILLA_SVGANIMATEDTRANSFORMLIST_H__

#include "mozilla/Attributes.h"

#include "mozilla/UniquePtr.h"

#include "nsAutoPtr.h"

#include "nsISMILAttr.h"

#include "SVGTransformList.h"

class nsAtom;

class nsSMILValue;

class nsSVGElement;

namespace mozilla {

namespace dom {

class SVGAnimationElement;

class SVGTransform;

} // namespace dom

/**

 * Class nsSVGAnimatedTransformList

 *

 * This class is very different to the SVG DOM interface of the same name found

 * in the SVG specification. This is a lightweight internal class - see

 * SVGAnimatedTransformList for the heavier DOM class that wraps instances of

 * this class and implements the SVG specification's SVGAnimatedTransformList

 * DOM interface.

 *

 * Except where noted otherwise, this class' methods take care of keeping the

 * appropriate DOM wrappers in sync (see the comment in

 * SVGAnimatedTransformList::InternalBaseValListWillChangeTo) so that their

 * consumers don't need to concern themselves with that.

 */

class nsSVGAnimatedTransformList

{

  // friends so that they can get write access to mBaseVal

  friend class dom::SVGTransform;

  friend class DOMSVGTransformList;

public:

  nsSVGAnimatedTransformList()

    : mIsAttrSet(false),

      mRequiresFrameReconstruction(true) { }

  /**

   * Because it's so important that mBaseVal and its DOMSVGTransformList wrapper

   * (if any) be kept in sync (see the comment in

   * SVGAnimatedTransformList::InternalBaseValListWillChangeTo), this method

   * returns a const reference. Only our friend classes may get mutable

   * references to mBaseVal.

   */

  const SVGTransformList& GetBaseValue() const {

    return mBaseVal;

  }

  nsresult SetBaseValue(const SVGTransformList& aValue,

                        nsSVGElement* aSVGElement);

  nsresult SetBaseValueString(const nsAString& aValue,

                              nsSVGElement* aSVGElement);

  void ClearBaseValue();

  const SVGTransformList& GetAnimValue() const {

    return mAnimVal ? *mAnimVal : mBaseVal;

  }

  nsresult SetAnimValue(const SVGTransformList& aNewAnimValue,

                        nsSVGElement *aElement);

  void ClearAnimValue(nsSVGElement *aElement);

  /**

   * Returns true if the corresponding transform attribute is set (or animated)

   * to a valid value. Unlike HasTransform it will return true for an empty

   * transform.

   */

  bool IsExplicitlySet() const;

  /**

   * Returns true if the corresponding transform attribute is set (or animated)

   * to a valid value, such that we have at least one transform in our list.

   * Returns false otherwise (e.g. if the transform attribute is missing or empty

   * or invalid).

   */

  bool HasTransform() const

    { return (mAnimVal && !mAnimVal->IsEmpty()) || !mBaseVal.IsEmpty(); }

  bool IsAnimating() const {

    return !!mAnimVal;

  }

  /**

   * Returns true if we need to reconstruct the frame of the element associated

   * with this transform list because the stacking context has changed.

   *

   * (This is used as part of an optimization in

   * SVGTransformableElement::GetAttributeChangeHint. That function reports an

   * inexpensive nsChangeHint when a transform has just modified -- but this

   * accessor lets it detect cases where the "modification" is actually adding

   * a transform where we previously had none. These cases require a more

   * thorough nsChangeHint.)

   */

  bool RequiresFrameReconstruction() const {

    return mRequiresFrameReconstruction;

  }

  mozilla::UniquePtr<nsISMILAttr> ToSMILAttr(nsSVGElement* aSVGElement);

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="">).

  SVGTransformList mBaseVal;

  nsAutoPtr<SVGTransformList> mAnimVal;

  bool mIsAttrSet;

   // (See documentation for accessor, RequiresFrameReconstruction.)

  bool mRequiresFrameReconstruction;

  struct SMILAnimatedTransformList : public nsISMILAttr

  {

  public:

    SMILAnimatedTransformList(nsSVGAnimatedTransformList* aVal,

                              nsSVGElement* aSVGElement)

      : mVal(aVal)

      , mElement(aSVGElement)

    {}

    // 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;

  protected:

    static void ParseValue(const nsAString& aSpec,

                           const nsAtom* aTransformType,

                           nsSMILValue& aResult);

    static int32_t ParseParameterList(const nsAString& aSpec, float* aVars,

                                      int32_t aNVars);

    // 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.

    nsSVGAnimatedTransformList* mVal;

    nsSVGElement* mElement;

  };

};

} // namespace mozilla

#endif // MOZILLA_SVGANIMATEDTRANSFORMLIST_H__