dom/svg/DOMSVGNumber.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 "DOMSVGNumber.h"
   8 #include "DOMSVGNumberList.h"
   9 #include "DOMSVGAnimatedNumberList.h"
  10 #include "SVGAnimatedNumberList.h"
  11 #include "nsSVGElement.h"
  12 #include "nsError.h"
  13 #include "nsContentUtils.h" // for NS_ENSURE_FINITE
  14 #include "mozilla/dom/SVGNumberBinding.h"
  15
  16 // See the architecture comment in DOMSVGAnimatedNumberList.h.
  17
  18 namespace mozilla {
  19
  20 // We could use NS_IMPL_CYCLE_COLLECTION(, except that in Unlink() we need to
  21 // clear our list's weak ref to us to be safe. (The other option would be to
  22 // not unlink and rely on the breaking of the other edges in the cycle, as
  23 // NS_SVG_VAL_IMPL_CYCLE_COLLECTION does.)
  24 NS_IMPL_CYCLE_COLLECTION_CLASS(DOMSVGNumber)
  25
  26 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(DOMSVGNumber)
  27   // We may not belong to a list, so we must null check tmp->mList.
  28   if (tmp->mList) {
  29     tmp->mList->mItems[tmp->mListIndex] = nullptr;
  30   }
  31   NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
  32   NS_IMPL_CYCLE_COLLECTION_UNLINK(mList)
  33   NS_IMPL_CYCLE_COLLECTION_UNLINK(mParent)
  34 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
  35 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(DOMSVGNumber)
  36   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mList)
  37   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mParent)
  38 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
  39 NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(DOMSVGNumber)
  40   NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER
  41 NS_IMPL_CYCLE_COLLECTION_TRACE_END
  42
  43 NS_IMPL_CYCLE_COLLECTING_ADDREF(DOMSVGNumber)
  44 NS_IMPL_CYCLE_COLLECTING_RELEASE(DOMSVGNumber)
  45
  46 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DOMSVGNumber)
  47   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  48   NS_INTERFACE_MAP_ENTRY(nsISupports)
  49 NS_INTERFACE_MAP_END
  50
  51 //----------------------------------------------------------------------
  52 // Helper class: AutoChangeNumberNotifier
  53 // Stack-based helper class to pair calls to WillChangeNumberList and
  54 // DidChangeNumberList.
  55 class MOZ_RAII AutoChangeNumberNotifier
  56 {
  57 public:
  58   explicit AutoChangeNumberNotifier(DOMSVGNumber* aNumber MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
  59     : mNumber(aNumber)
  60   {
  61     MOZ_GUARD_OBJECT_NOTIFIER_INIT;
  62     MOZ_ASSERT(mNumber, "Expecting non-null number");
  63     MOZ_ASSERT(mNumber->HasOwner(),
  64                "Expecting list to have an owner for notification");
  65     mEmptyOrOldValue =
  66       mNumber->Element()->WillChangeNumberList(mNumber->mAttrEnum);
  67   }
  68
  69   ~AutoChangeNumberNotifier()
  70   {
  71     mNumber->Element()->DidChangeNumberList(mNumber->mAttrEnum,
  72                                             mEmptyOrOldValue);
  73     if (mNumber->mList->IsAnimating()) {
  74       mNumber->Element()->AnimationNeedsResample();
  75     }
  76   }
  77
  78 private:
  79   DOMSVGNumber* const mNumber;
  80   nsAttrValue   mEmptyOrOldValue;
  81   MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
  82 };
  83
  84 DOMSVGNumber::DOMSVGNumber(DOMSVGNumberList *aList,
  85                            uint8_t aAttrEnum,
  86                            uint32_t aListIndex,
  87                            bool aIsAnimValItem)
  88   : mList(aList)
  89   , mParent(aList)
  90   , mListIndex(aListIndex)
  91   , mAttrEnum(aAttrEnum)
  92   , mIsAnimValItem(aIsAnimValItem)
  93   , mValue(0.0f)
  94 {
  95   // These shifts are in sync with the members in the header.
  96   MOZ_ASSERT(aList &&
  97              aAttrEnum < (1 << 4) &&
  98              aListIndex <= MaxListIndex(),
  99              "bad arg");
 100
 101   MOZ_ASSERT(IndexIsValid(), "Bad index for DOMSVGNumber!");
 102 }
 103
 104 DOMSVGNumber::DOMSVGNumber(nsISupports* aParent)
 105   : mList(nullptr)
 106   , mParent(aParent)
 107   , mListIndex(0)
 108   , mAttrEnum(0)
 109   , mIsAnimValItem(false)
 110   , mValue(0.0f)
 111 {
 112 }
 113
 114 float
 115 DOMSVGNumber::Value()
 116 {
 117   if (mIsAnimValItem && HasOwner()) {
 118     Element()->FlushAnimations(); // May make HasOwner() == false
 119   }
 120   return HasOwner() ? InternalItem() : mValue;
 121 }
 122
 123 void
 124 DOMSVGNumber::SetValue(float aValue, ErrorResult& aRv)
 125 {
 126   if (mIsAnimValItem) {
 127     aRv.Throw(NS_ERROR_DOM_NO_MODIFICATION_ALLOWED_ERR);
 128     return;
 129   }
 130
 131   if (HasOwner()) {
 132     if (InternalItem() == aValue) {
 133       return;
 134     }
 135     AutoChangeNumberNotifier notifier(this);
 136     InternalItem() = aValue;
 137     return;
 138   }
 139
 140   mValue = aValue;
 141 }
 142
 143 void
 144 DOMSVGNumber::InsertingIntoList(DOMSVGNumberList *aList,
 145                                 uint8_t aAttrEnum,
 146                                 uint32_t aListIndex,
 147                                 bool aIsAnimValItem)
 148 {
 149   NS_ASSERTION(!HasOwner(), "Inserting item that is already in a list");
 150
 151   mList = aList;
 152   mAttrEnum = aAttrEnum;
 153   mListIndex = aListIndex;
 154   mIsAnimValItem = aIsAnimValItem;
 155
 156   MOZ_ASSERT(IndexIsValid(), "Bad index for DOMSVGNumber!");
 157 }
 158
 159 void
 160 DOMSVGNumber::RemovingFromList()
 161 {
 162   mValue = InternalItem();
 163   mList = nullptr;
 164   mIsAnimValItem = false;
 165 }
 166
 167 float
 168 DOMSVGNumber::ToSVGNumber()
 169 {
 170   return HasOwner() ? InternalItem() : mValue;
 171 }
 172
 173 float&
 174 DOMSVGNumber::InternalItem()
 175 {
 176   SVGAnimatedNumberList *alist = Element()->GetAnimatedNumberList(mAttrEnum);
 177   return mIsAnimValItem && alist->mAnimVal ?
 178     (*alist->mAnimVal)[mListIndex] :
 179     alist->mBaseVal[mListIndex];
 180 }
 181
 182 #ifdef DEBUG
 183 bool
 184 DOMSVGNumber::IndexIsValid()
 185 {
 186   SVGAnimatedNumberList *alist = Element()->GetAnimatedNumberList(mAttrEnum);
 187   return (mIsAnimValItem &&
 188           mListIndex < alist->GetAnimValue().Length()) ||
 189          (!mIsAnimValItem &&
 190           mListIndex < alist->GetBaseValue().Length());
 191 }
 192 #endif
 193
 194 JSObject*
 195 DOMSVGNumber::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
 196 {
 197   return dom::SVGNumber_Binding::Wrap(aCx, this, aGivenProto);
 198 }
 199
 200 } // namespace mozilla