tor-browser

SVGAnimatedTransformList.h (5872B)

---

/* -*- 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_SVGANIMATEDTRANSFORMLIST_H_
#define DOM_SVG_SVGANIMATEDTRANSFORMLIST_H_

#include "mozilla/SMILAttr.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/dom/SVGTransformList.h"

class nsAtom;

namespace mozilla {

class SMILValue;

namespace dom {
class SVGAnimationElement;
class SVGElement;
class DOMSVGTransform;
}  // namespace dom

/**
* Class SVGAnimatedTransformList
*
* 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
* DOMSVGAnimatedTransformList 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
* DOMSVGAnimatedTransformList::InternalBaseValListWillChangeTo) so that their
* consumers don't need to concern themselves with that.
*/
class SVGAnimatedTransformList {
 // friends so that they can get write access to mBaseVal
 friend class dom::DOMSVGTransform;
 friend class dom::DOMSVGTransformList;

public:
 SVGAnimatedTransformList()
     : mIsBaseSet(false), mCreatedOrRemovedOnLastChange(true) {}

 SVGAnimatedTransformList& operator=(const SVGAnimatedTransformList& aOther) {
   mBaseVal = aOther.mBaseVal;
   if (aOther.mAnimVal) {
     mAnimVal = MakeUnique<SVGTransformList>(*aOther.mAnimVal);
   }
   mIsBaseSet = aOther.mIsBaseSet;
   mCreatedOrRemovedOnLastChange = aOther.mCreatedOrRemovedOnLastChange;
   return *this;
 }

 /**
  * Because it's so important that mBaseVal and its DOMSVGTransformList wrapper
  * (if any) be kept in sync (see the comment in
  * DOMSVGAnimatedTransformList::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,
                       dom::SVGElement* aSVGElement);

 nsresult SetBaseValueString(const nsAString& aValue,
                             dom::SVGElement* aSVGElement);

 void ClearBaseValue();

 const SVGTransformList& GetAnimValue() const {
   return mAnimVal ? *mAnimVal : mBaseVal;
 }

 nsresult SetAnimValue(const SVGTransformList& aValue,
                       dom::SVGElement* aElement);

 void ClearAnimValue(dom::SVGElement* 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 the last change of this transform went from having to not
  * having a transform or vice versa.
  *
  * (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 creating
  * a transform where we previously had none. These cases require a more
  * thorough nsChangeHint.)
  */
 bool CreatedOrRemovedOnLastChange() const {
   return mCreatedOrRemovedOnLastChange;
 }

 UniquePtr<SMILAttr> ToSMILAttr(dom::SVGElement* 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;
 UniquePtr<SVGTransformList> mAnimVal;
 bool mIsBaseSet;
 // See documentation for accessor.
 bool mCreatedOrRemovedOnLastChange;

 struct SMILAnimatedTransformList : public SMILAttr {
  public:
   SMILAnimatedTransformList(SVGAnimatedTransformList* aVal,
                             dom::SVGElement* aSVGElement)
       : mVal(aVal), mElement(aSVGElement) {}

   // SMILAttr methods
   nsresult ValueFromString(const nsAString& aStr,
                            const dom::SVGAnimationElement* aSrcElement,
                            SMILValue& aValue,
                            bool& aPreventCachingOfSandwich) const override;
   SMILValue GetBaseValue() const override;
   void ClearAnimValue() override;
   nsresult SetAnimValue(const SMILValue& aNewAnimValue) override;

  protected:
   static void ParseValue(const nsAString& aSpec, const nsAtom* aTransformType,
                          SMILValue& aResult);
   static int32_t ParseParameterList(const nsAString& aSpec, float* aVars,
                                     int32_t aNVars);

   // 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.
   SVGAnimatedTransformList* mVal;
   dom::SVGElement* mElement;
 };
};

}  // namespace mozilla

#endif  // DOM_SVG_SVGANIMATEDTRANSFORMLIST_H_