dom/svg/SVGUseElement.h

   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 #ifndef DOM_SVG_SVGUSEELEMENT_H_
   8 #define DOM_SVG_SVGUSEELEMENT_H_
   9
  10 #include "mozilla/dom/FromParser.h"
  11 #include "mozilla/dom/IDTracker.h"
  12 #include "mozilla/dom/SVGGraphicsElement.h"
  13 #include "mozilla/RefPtr.h"
  14 #include "nsCOMPtr.h"
  15 #include "nsStubMutationObserver.h"
  16 #include "SVGAnimatedLength.h"
  17 #include "SVGAnimatedString.h"
  18 #include "nsTArray.h"
  19
  20 class nsIContent;
  21
  22 nsresult NS_NewSVGSVGElement(
  23     nsIContent** aResult, already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo,
  24     mozilla::dom::FromParser aFromParser);
  25 nsresult NS_NewSVGUseElement(
  26     nsIContent** aResult, already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo);
  27
  28 namespace mozilla {
  29 class Encoding;
  30 class SVGUseFrame;
  31 struct URLExtraData;
  32
  33 namespace dom {
  34
  35 using SVGUseElementBase = SVGGraphicsElement;
  36
  37 class SVGUseElement final : public SVGUseElementBase,
  38                             public nsStubMutationObserver {
  39   friend class mozilla::SVGUseFrame;
  40
  41  protected:
  42   friend nsresult(::NS_NewSVGUseElement(
  43       nsIContent** aResult,
  44       already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo));
  45   explicit SVGUseElement(already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo);
  46   virtual ~SVGUseElement();
  47   JSObject* WrapNode(JSContext* cx, JS::Handle<JSObject*> aGivenProto) override;
  48
  49  public:
  50   NS_IMPL_FROMNODE_WITH_TAG(SVGUseElement, kNameSpaceID_SVG, use)
  51
  52   nsresult BindToTree(BindContext&, nsINode& aParent) override;
  53   void UnbindFromTree(UnbindContext&) override;
  54
  55   // interfaces:
  56   NS_DECL_ISUPPORTS_INHERITED
  57   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(SVGUseElement, SVGUseElementBase)
  58
  59   NS_DECL_NSIMUTATIONOBSERVER_CHARACTERDATACHANGED
  60   NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED
  61   NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED
  62   NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED
  63   NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED
  64   NS_DECL_NSIMUTATIONOBSERVER_NODEWILLBEDESTROYED
  65
  66   // SVGElement specializations:
  67   gfxMatrix PrependLocalTransformsTo(
  68       const gfxMatrix& aMatrix,
  69       SVGTransformTypes aWhich = eAllTransforms) const override;
  70   bool HasValidDimensions() const override;
  71
  72   // nsIContent interface
  73   nsresult Clone(dom::NodeInfo*, nsINode** aResult) const override;
  74   NS_IMETHOD_(bool) IsAttributeMapped(const nsAtom* aAttribute) const override;
  75
  76   static nsCSSPropertyID GetCSSPropertyIdForAttrEnum(uint8_t aAttrEnum);
  77
  78   // WebIDL
  79   already_AddRefed<DOMSVGAnimatedString> Href();
  80   already_AddRefed<DOMSVGAnimatedLength> X();
  81   already_AddRefed<DOMSVGAnimatedLength> Y();
  82   already_AddRefed<DOMSVGAnimatedLength> Width();
  83   already_AddRefed<DOMSVGAnimatedLength> Height();
  84
  85   nsIURI* GetSourceDocURI();
  86   const Encoding* GetSourceDocCharacterSet();
  87   URLExtraData* GetContentURLData() const { return mContentURLData; }
  88
  89   // Updates the internal shadow tree to be an up-to-date clone of the
  90   // referenced element.
  91   void UpdateShadowTree();
  92
  93   // Shared code between AfterSetAttr and SVGUseFrame::AttributeChanged.
  94   //
  95   // This is needed because SMIL doesn't go through AfterSetAttr unfortunately.
  96   void ProcessAttributeChange(int32_t aNamespaceID, nsAtom* aAttribute);
  97
  98   void AfterSetAttr(int32_t aNamespaceID, nsAtom* aAttribute,
  99                     const nsAttrValue* aValue, const nsAttrValue* aOldValue,
 100                     nsIPrincipal* aSubjectPrincipal, bool aNotify) final;
 101
 102  protected:
 103   // Information from walking our ancestors and a given target.
 104   enum class ScanResult {
 105     // Nothing that should stop us from rendering the shadow tree.
 106     Ok,
 107     // We're never going to be displayed, so no point in updating the shadow
 108     // tree.
 109     //
 110     // However if we're referenced from another tree that tree may need to be
 111     // rendered.
 112     Invisible,
 113     // We're a cyclic reference to either an ancestor or another shadow tree. We
 114     // shouldn't render this <use> element.
 115     CyclicReference,
 116     // We're too deep in our clone chain, we shouldn't be rendered.
 117     TooDeep,
 118   };
 119   ScanResult ScanAncestors(const Element& aTarget) const;
 120   ScanResult ScanAncestorsInternal(const Element& aTarget,
 121                                    uint32_t& aCount) const;
 122
 123   /**
 124    * Helper that provides a reference to the element with the ID that is
 125    * referenced by the 'use' element's 'href' attribute, and that will update
 126    * the 'use' element if the element that that ID identifies changes to a
 127    * different element (or none).
 128    */
 129   class ElementTracker final : public IDTracker {
 130    public:
 131     explicit ElementTracker(SVGUseElement* aOwningUseElement)
 132         : mOwningUseElement(aOwningUseElement) {}
 133
 134    private:
 135     void ElementChanged(Element* aFrom, Element* aTo) override {
 136       IDTracker::ElementChanged(aFrom, aTo);
 137       if (aFrom) {
 138         aFrom->RemoveMutationObserver(mOwningUseElement);
 139       }
 140       mOwningUseElement->TriggerReclone();
 141     }
 142
 143     SVGUseElement* mOwningUseElement;
 144   };
 145
 146   SVGUseFrame* GetFrame() const;
 147
 148   LengthAttributesInfo GetLengthInfo() override;
 149   StringAttributesInfo GetStringInfo() override;
 150
 151   /**
 152    * Returns true if our width and height should be used, or false if they
 153    * should be ignored. As per the spec, this depends on the type of the
 154    * element that we're referencing.
 155    */
 156   bool OurWidthAndHeightAreUsed() const;
 157   void SyncWidthOrHeight(nsAtom* aName);
 158   void LookupHref();
 159   void TriggerReclone();
 160   void UnlinkSource();
 161
 162   enum { ATTR_X, ATTR_Y, ATTR_WIDTH, ATTR_HEIGHT };
 163   SVGAnimatedLength mLengthAttributes[4];
 164   static LengthInfo sLengthInfo[4];
 165
 166   enum { HREF, XLINK_HREF };
 167   SVGAnimatedString mStringAttributes[2];
 168   static StringInfo sStringInfo[2];
 169
 170   RefPtr<SVGUseElement> mOriginal;  // if we've been cloned, our "real" copy
 171   ElementTracker mReferencedElementTracker;
 172   RefPtr<URLExtraData> mContentURLData;  // URL data for its anonymous content
 173 };
 174
 175 }  // namespace dom
 176 }  // namespace mozilla
 177
 178 #endif  // DOM_SVG_SVGUSEELEMENT_H_