1 files changed, 185 insertions, 0 deletions
diff --git a/dom/svg/SVGAnimatedLengthList.cpp b/dom/svg/SVGAnimatedLengthList.cpp
new file mode 100644
index 0000000000..7f2aab8465
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+++ b/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: */
+/* 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 <utility>
+
+#include "DOMSVGAnimatedLengthList.h"
+#include "SVGLengthListSMILType.h"
+#include "mozilla/SMILValue.h"
+#include "mozilla/Try.h"
+#include "mozilla/dom/SVGElement.h"
+#include "mozilla/dom/SVGLengthBinding.h"
+
+namespace mozilla {
+
+using namespace dom;
+
+nsresult SVGAnimatedLengthList::SetBaseValueString(const nsAString& aValue) {
+  SVGLengthList newBaseValue;
+  MOZ_TRY(newBaseValue.SetValueFromString(aValue));
+
+  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
+  // SVGElement::ParseAttribute under Element::SetAttr,
+  // which takes care of notifying.
+  mBaseVal.SwapWith(newBaseValue);
+  return NS_OK;
+}
+
+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,
+                                             SVGElement* 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 = MakeUnique<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(SVGElement* 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<SMILAttr> SVGAnimatedLengthList::ToSMILAttr(SVGElement* 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*/,
+    SMILValue& aValue, bool& aPreventCachingOfSandwich) const {
+  SMILValue 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 = std::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.
+
+    for (uint32_t i = 0; i < llai->Length(); ++i) {
+      uint8_t unit = (*llai)[i].GetUnit();
+      if (!SVGLength::IsAbsoluteUnit(unit)) {
+        aPreventCachingOfSandwich = true;
+        break;
+      }
+    }
+  }
+  return rv;
+}
+
+SMILValue 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:
+  SMILValue val;
+
+  SMILValue 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 = std::move(tmp);
+  }
+  return val;
+}
+
+nsresult SVGAnimatedLengthList::SMILAnimatedLengthList::SetAnimValue(
+    const SMILValue& 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