dom/svg/SVGAnimatedPointList.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "SVGAnimatedPointList.h"
   8
   9 #include <utility>
  10
  11 #include "DOMSVGPointList.h"
  12 #include "SVGPointListSMILType.h"
  13 #include "mozilla/SMILValue.h"
  14 #include "mozilla/dom/SVGElement.h"
  15
  16 using namespace mozilla::dom;
  17
  18 // See the comments in this file's header!
  19
  20 namespace mozilla {
  21
  22 nsresult SVGAnimatedPointList::SetBaseValueString(const nsAString& aValue) {
  23   SVGPointList newBaseValue;
  24
  25   // The spec says that the point data is parsed and accepted up to the first
  26   // error encountered, so we don't return early if an error occurs. However,
  27   // we do want to throw any error code from setAttribute if there's a problem.
  28
  29   nsresult rv = newBaseValue.SetValueFromString(aValue);
  30
  31   // We must send these notifications *before* changing mBaseVal! Our baseVal's
  32   // DOM wrapper list may have to remove DOM items from itself, and any removed
  33   // DOM items need to copy their internal counterpart's values *before* we
  34   // change them. See the comments in
  35   // DOMSVGPointList::InternalListWillChangeTo().
  36
  37   DOMSVGPointList* baseValWrapper =
  38       DOMSVGPointList::GetDOMWrapperIfExists(GetBaseValKey());
  39   if (baseValWrapper) {
  40     baseValWrapper->InternalListWillChangeTo(newBaseValue);
  41   }
  42
  43   DOMSVGPointList* animValWrapper = nullptr;
  44   if (!IsAnimating()) {  // DOM anim val wraps our base val too!
  45     animValWrapper = DOMSVGPointList::GetDOMWrapperIfExists(GetAnimValKey());
  46     if (animValWrapper) {
  47       animValWrapper->InternalListWillChangeTo(newBaseValue);
  48     }
  49   }
  50
  51   // Only now may we modify mBaseVal!
  52
  53   // We don't need to call DidChange* here - we're only called by
  54   // SVGElement::ParseAttribute under Element::SetAttr,
  55   // which takes care of notifying.
  56
  57   mBaseVal.SwapWith(newBaseValue);
  58   return rv;
  59 }
  60
  61 void SVGAnimatedPointList::ClearBaseValue() {
  62   // We must send these notifications *before* changing mBaseVal! (See above.)
  63
  64   DOMSVGPointList* baseValWrapper =
  65       DOMSVGPointList::GetDOMWrapperIfExists(GetBaseValKey());
  66   if (baseValWrapper) {
  67     baseValWrapper->InternalListWillChangeTo(SVGPointList());
  68   }
  69
  70   if (!IsAnimating()) {  // DOM anim val wraps our base val too!
  71     DOMSVGPointList* animValWrapper =
  72         DOMSVGPointList::GetDOMWrapperIfExists(GetAnimValKey());
  73     if (animValWrapper) {
  74       animValWrapper->InternalListWillChangeTo(SVGPointList());
  75     }
  76   }
  77
  78   mBaseVal.Clear();
  79   // Caller notifies
  80 }
  81
  82 nsresult SVGAnimatedPointList::SetAnimValue(const SVGPointList& aNewAnimValue,
  83                                             SVGElement* aElement) {
  84   // Note that a new animation may totally change the number of items in the
  85   // animVal list, either replacing what was essentially a mirror of the
  86   // baseVal list, or else replacing and overriding an existing animation.
  87   // It is not possible for us to reliably distinguish between calls to this
  88   // method that are setting a new sample for an existing animation (in which
  89   // case our list length isn't changing and we wouldn't need to notify our DOM
  90   // wrapper to keep its length in sync), and calls to this method that are
  91   // setting the first sample of a new animation that will override the base
  92   // value/an existing animation (in which case our length may be changing and
  93   // our DOM wrapper may need to be notified). Happily though, it's cheap to
  94   // just blindly notify our animVal's DOM wrapper of our new value each time
  95   // this method is called, so that's what we do.
  96
  97   // We must send this notification *before* changing mAnimVal! (See above.)
  98
  99   DOMSVGPointList* domWrapper =
 100       DOMSVGPointList::GetDOMWrapperIfExists(GetAnimValKey());
 101   if (domWrapper) {
 102     domWrapper->InternalListWillChangeTo(aNewAnimValue);
 103   }
 104   if (!mAnimVal) {
 105     mAnimVal = MakeUnique<SVGPointList>();
 106   }
 107   nsresult rv = mAnimVal->CopyFrom(aNewAnimValue);
 108   if (NS_FAILED(rv)) {
 109     // OOM. We clear the animation and, importantly, ClearAnimValue() ensures
 110     // that mAnimVal's DOM wrapper (if any) is kept in sync!
 111     ClearAnimValue(aElement);
 112     return rv;
 113   }
 114   aElement->DidAnimatePointList();
 115   return NS_OK;
 116 }
 117
 118 void SVGAnimatedPointList::ClearAnimValue(SVGElement* aElement) {
 119   // We must send these notifications *before* changing mAnimVal! (See above.)
 120
 121   DOMSVGPointList* domWrapper =
 122       DOMSVGPointList::GetDOMWrapperIfExists(GetAnimValKey());
 123   if (domWrapper) {
 124     // When all animation ends, animVal simply mirrors baseVal, which may have
 125     // a different number of items to the last active animated value.
 126     //
 127     domWrapper->InternalListWillChangeTo(mBaseVal);
 128   }
 129   mAnimVal = nullptr;
 130   aElement->DidAnimatePointList();
 131 }
 132
 133 UniquePtr<SMILAttr> SVGAnimatedPointList::ToSMILAttr(SVGElement* aElement) {
 134   return MakeUnique<SMILAnimatedPointList>(this, aElement);
 135 }
 136
 137 nsresult SVGAnimatedPointList::SMILAnimatedPointList::ValueFromString(
 138     const nsAString& aStr, const dom::SVGAnimationElement* /*aSrcElement*/,
 139     SMILValue& aValue, bool& aPreventCachingOfSandwich) const {
 140   SMILValue val(&SVGPointListSMILType::sSingleton);
 141   SVGPointListAndInfo* list = static_cast<SVGPointListAndInfo*>(val.mU.mPtr);
 142   nsresult rv = list->SetValueFromString(aStr);
 143   if (NS_SUCCEEDED(rv)) {
 144     list->SetInfo(mElement);
 145     aValue = std::move(val);
 146   }
 147   return rv;
 148 }
 149
 150 SMILValue SVGAnimatedPointList::SMILAnimatedPointList::GetBaseValue() const {
 151   // To benefit from Return Value Optimization and avoid copy constructor calls
 152   // due to our use of return-by-value, we must return the exact same object
 153   // from ALL return points. This function must only return THIS variable:
 154   SMILValue val;
 155
 156   SMILValue tmp(&SVGPointListSMILType::sSingleton);
 157   auto* list = static_cast<SVGPointListAndInfo*>(tmp.mU.mPtr);
 158   nsresult rv = list->CopyFrom(mVal->mBaseVal);
 159   if (NS_SUCCEEDED(rv)) {
 160     list->SetInfo(mElement);
 161     std::swap(val, tmp);
 162   }
 163   return val;
 164 }
 165
 166 nsresult SVGAnimatedPointList::SMILAnimatedPointList::SetAnimValue(
 167     const SMILValue& aValue) {
 168   NS_ASSERTION(aValue.mType == &SVGPointListSMILType::sSingleton,
 169                "Unexpected type to assign animated value");
 170   if (aValue.mType == &SVGPointListSMILType::sSingleton) {
 171     mVal->SetAnimValue(*static_cast<SVGPointListAndInfo*>(aValue.mU.mPtr),
 172                        mElement);
 173   }
 174   return NS_OK;
 175 }
 176
 177 void SVGAnimatedPointList::SMILAnimatedPointList::ClearAnimValue() {
 178   if (mVal->mAnimVal) {
 179     mVal->ClearAnimValue(mElement);
 180   }
 181 }
 182
 183 }  // namespace mozilla