gecko-dev/dom/svg/nsSVGAnimatedTransformList.h

164 lines
5.5 KiB
C++

/* -*- 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 "nsAutoPtr.h"
#include "nsISMILAttr.h"
#include "SVGTransformList.h"
class nsIAtom;
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),
mHadTransformBeforeLastBaseValChange(false) { }
/**
* 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);
nsresult SetBaseValueString(const nsAString& aValue);
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 iff "HasTransform" returned true just before our most recent
* SetBaseValue/SetBaseValueString/ClearBaseValue change.
*
* (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 HadTransformBeforeLastBaseValChange() const {
return mHadTransformBeforeLastBaseValChange;
}
/// Callers own the returned nsISMILAttr
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, HadTransformBeforeLastBaseValChange.)
bool mHadTransformBeforeLastBaseValChange;
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 nsIAtom* 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__