gecko-dev/dom/svg/SVGAnimatedLengthList.cpp

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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: */
2012-05-21 15:12:37 +04:00
/* 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/. */
#include "SVGAnimatedLengthList.h"
#include "DOMSVGAnimatedLengthList.h"
#include "mozilla/Move.h"
#include "nsSVGElement.h"
#include "nsSVGAttrTearoffTable.h"
#include "nsSMILValue.h"
#include "SVGLengthListSMILType.h"
namespace mozilla {
nsresult
SVGAnimatedLengthList::SetBaseValueString(const nsAString& aValue)
{
SVGLengthList newBaseValue;
nsresult rv = newBaseValue.SetValueFromString(aValue);
if (NS_FAILED(rv)) {
return rv;
}
DOMSVGAnimatedLengthList *domWrapper =
DOMSVGAnimatedLengthList::GetDOMWrapperIfExists(this);
if (domWrapper) {
// We must send this notification *before* changing mBaseVal! If the length
// of our baseVal is being reduced, our baseVal's DOM wrapper list may have
// to remove DOM items from itself, and any removed DOM items need to copy
// their internal counterpart values *before* we change them.
//
domWrapper->InternalBaseValListWillChangeTo(newBaseValue);
}
// We don't need to call DidChange* here - we're only called by
// nsSVGElement::ParseAttribute under Element::SetAttr,
// which takes care of notifying.
rv = mBaseVal.CopyFrom(newBaseValue);
if (NS_FAILED(rv) && domWrapper) {
// Attempting to increase mBaseVal's length failed - reduce domWrapper
// back to the same length:
domWrapper->InternalBaseValListWillChangeTo(mBaseVal);
}
return rv;
}
void
SVGAnimatedLengthList::ClearBaseValue(uint32_t aAttrEnum)
{
DOMSVGAnimatedLengthList *domWrapper =
DOMSVGAnimatedLengthList::GetDOMWrapperIfExists(this);
if (domWrapper) {
// We must send this notification *before* changing mBaseVal! (See above.)
domWrapper->InternalBaseValListWillChangeTo(SVGLengthList());
}
mBaseVal.Clear();
// Caller notifies
}
nsresult
SVGAnimatedLengthList::SetAnimValue(const SVGLengthList& aNewAnimValue,
nsSVGElement *aElement,
uint32_t aAttrEnum)
{
DOMSVGAnimatedLengthList *domWrapper =
DOMSVGAnimatedLengthList::GetDOMWrapperIfExists(this);
if (domWrapper) {
// A new animation may totally change the number of items in the animVal
// list, replacing what was essentially a mirror of the baseVal list, or
// else replacing and overriding an existing animation. When this happens
// we must try and keep our animVal's DOM wrapper in sync (see the comment
// in DOMSVGAnimatedLengthList::InternalBaseValListWillChangeTo).
//
// It's not possible for us to reliably distinguish between calls to this
// method that are setting a new sample for an existing animation, and
// calls that are setting the first sample of an animation that will
// override an existing animation. Happily it's cheap to just blindly
// notify our animVal's DOM wrapper of its internal counterpart's new value
// each time this method is called, so that's what we do.
//
// Note that we must send this notification *before* setting or changing
// mAnimVal! (See the comment in SetBaseValueString above.)
//
domWrapper->InternalAnimValListWillChangeTo(aNewAnimValue);
}
if (!mAnimVal) {
mAnimVal = new SVGLengthList();
}
nsresult rv = mAnimVal->CopyFrom(aNewAnimValue);
if (NS_FAILED(rv)) {
// OOM. We clear the animation, and, importantly, ClearAnimValue() ensures
// that mAnimVal and its DOM wrapper (if any) will have the same length!
ClearAnimValue(aElement, aAttrEnum);
return rv;
}
aElement->DidAnimateLengthList(aAttrEnum);
return NS_OK;
}
void
SVGAnimatedLengthList::ClearAnimValue(nsSVGElement *aElement,
uint32_t aAttrEnum)
{
DOMSVGAnimatedLengthList *domWrapper =
DOMSVGAnimatedLengthList::GetDOMWrapperIfExists(this);
if (domWrapper) {
// When all animation ends, animVal simply mirrors baseVal, which may have
// a different number of items to the last active animated value. We must
// keep the length of our animVal's DOM wrapper list in sync, and again we
// must do that before touching mAnimVal. See comments above.
//
domWrapper->InternalAnimValListWillChangeTo(mBaseVal);
}
mAnimVal = nullptr;
aElement->DidAnimateLengthList(aAttrEnum);
}
UniquePtr<nsISMILAttr>
SVGAnimatedLengthList::ToSMILAttr(nsSVGElement *aSVGElement,
uint8_t aAttrEnum,
uint8_t aAxis,
bool aCanZeroPadList)
{
return MakeUnique<SMILAnimatedLengthList>(this, aSVGElement, aAttrEnum,
aAxis, aCanZeroPadList);
}
nsresult
SVGAnimatedLengthList::
SMILAnimatedLengthList::ValueFromString(const nsAString& aStr,
const dom::SVGAnimationElement* /*aSrcElement*/,
nsSMILValue& aValue,
bool& aPreventCachingOfSandwich) const
{
nsSMILValue val(&SVGLengthListSMILType::sSingleton);
SVGLengthListAndInfo *llai = static_cast<SVGLengthListAndInfo*>(val.mU.mPtr);
nsresult rv = llai->SetValueFromString(aStr);
if (NS_SUCCEEDED(rv)) {
llai->SetInfo(mElement, mAxis, mCanZeroPadList);
aValue = Move(val);
// If any of the lengths in the list depend on their context, then we must
// prevent caching of the entire animation sandwich. This is because the
// units of a length at a given index can change from sandwich layer to
// layer, and indeed even be different within a single sandwich layer. If
// any length in the result of an animation sandwich is the result of the
// addition of lengths where one or more of those lengths is context
// dependent, then naturally the resultant length is also context
// dependent, regardless of whether its actual unit is context dependent or
// not. Unfortunately normal invalidation mechanisms won't cause us to
// recalculate the result of the sandwich if the context changes, so we
// take the (substantial) performance hit of preventing caching of the
// sandwich layer, causing the animation sandwich to be recalculated every
// single sample.
aPreventCachingOfSandwich = false;
for (uint32_t i = 0; i < llai->Length(); ++i) {
uint8_t unit = (*llai)[i].GetUnit();
if (unit == nsIDOMSVGLength::SVG_LENGTHTYPE_PERCENTAGE ||
unit == nsIDOMSVGLength::SVG_LENGTHTYPE_EMS ||
unit == nsIDOMSVGLength::SVG_LENGTHTYPE_EXS) {
aPreventCachingOfSandwich = true;
break;
}
}
}
return rv;
}
nsSMILValue
SVGAnimatedLengthList::SMILAnimatedLengthList::GetBaseValue() const
{
// To benefit from Return Value Optimization and avoid copy constructor calls
// due to our use of return-by-value, we must return the exact same object
// from ALL return points. This function must only return THIS variable:
nsSMILValue val;
nsSMILValue tmp(&SVGLengthListSMILType::sSingleton);
SVGLengthListAndInfo *llai = static_cast<SVGLengthListAndInfo*>(tmp.mU.mPtr);
nsresult rv = llai->CopyFrom(mVal->mBaseVal);
if (NS_SUCCEEDED(rv)) {
llai->SetInfo(mElement, mAxis, mCanZeroPadList);
val = Move(tmp);
}
return val;
}
nsresult
SVGAnimatedLengthList::SMILAnimatedLengthList::SetAnimValue(const nsSMILValue& aValue)
{
NS_ASSERTION(aValue.mType == &SVGLengthListSMILType::sSingleton,
"Unexpected type to assign animated value");
if (aValue.mType == &SVGLengthListSMILType::sSingleton) {
mVal->SetAnimValue(*static_cast<SVGLengthListAndInfo*>(aValue.mU.mPtr),
mElement,
mAttrEnum);
}
return NS_OK;
}
void
SVGAnimatedLengthList::SMILAnimatedLengthList::ClearAnimValue()
{
if (mVal->mAnimVal) {
mVal->ClearAnimValue(mElement, mAttrEnum);
}
}
} // namespace mozilla