1 files changed, 175 insertions, 0 deletions
diff --git a/dom/svg/SVGUseElement.h b/dom/svg/SVGUseElement.h
new file mode 100644
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+++ b/dom/svg/SVGUseElement.h
@@ -0,0 +1,175 @@
+/* -*- 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/. */
+
+#ifndef DOM_SVG_SVGUSEELEMENT_H_
+#define DOM_SVG_SVGUSEELEMENT_H_
+
+#include "mozilla/dom/FromParser.h"
+#include "mozilla/dom/IDTracker.h"
+#include "mozilla/dom/SVGGraphicsElement.h"
+#include "mozilla/RefPtr.h"
+#include "nsCOMPtr.h"
+#include "nsStubMutationObserver.h"
+#include "SVGAnimatedLength.h"
+#include "SVGAnimatedString.h"
+#include "nsTArray.h"
+
+class nsIContent;
+
+nsresult NS_NewSVGSVGElement(
+    nsIContent** aResult, already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo,
+    mozilla::dom::FromParser aFromParser);
+nsresult NS_NewSVGUseElement(
+    nsIContent** aResult, already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo);
+
+namespace mozilla {
+class Encoding;
+class SVGUseFrame;
+struct URLExtraData;
+
+namespace dom {
+
+using SVGUseElementBase = SVGGraphicsElement;
+
+class SVGUseElement final : public SVGUseElementBase,
+                            public nsStubMutationObserver {
+  friend class mozilla::SVGUseFrame;
+
+ protected:
+  friend nsresult(::NS_NewSVGUseElement(
+      nsIContent** aResult,
+      already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo));
+  explicit SVGUseElement(already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo);
+  virtual ~SVGUseElement();
+  JSObject* WrapNode(JSContext* cx, JS::Handle<JSObject*> aGivenProto) override;
+
+ public:
+  NS_IMPL_FROMNODE_WITH_TAG(SVGUseElement, kNameSpaceID_SVG, use)
+
+  bool IsNodeOfType(uint32_t aFlags) const override;
+  nsresult BindToTree(BindContext&, nsINode& aParent) override;
+  void UnbindFromTree(bool aNullParent = true) override;
+
+  // interfaces:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(SVGUseElement, SVGUseElementBase)
+
+  NS_DECL_NSIMUTATIONOBSERVER_CHARACTERDATACHANGED
+  NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED
+  NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED
+  NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED
+  NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED
+  NS_DECL_NSIMUTATIONOBSERVER_NODEWILLBEDESTROYED
+
+  // SVGElement specializations:
+  gfxMatrix PrependLocalTransformsTo(
+      const gfxMatrix& aMatrix,
+      SVGTransformTypes aWhich = eAllTransforms) const override;
+  bool HasValidDimensions() const override;
+
+  // nsIContent interface
+  nsresult Clone(dom::NodeInfo*, nsINode** aResult) const override;
+  NS_IMETHOD_(bool) IsAttributeMapped(const nsAtom* aAttribute) const override;
+
+  static nsCSSPropertyID GetCSSPropertyIdForAttrEnum(uint8_t aAttrEnum);
+
+  // WebIDL
+  already_AddRefed<DOMSVGAnimatedString> Href();
+  already_AddRefed<DOMSVGAnimatedLength> X();
+  already_AddRefed<DOMSVGAnimatedLength> Y();
+  already_AddRefed<DOMSVGAnimatedLength> Width();
+  already_AddRefed<DOMSVGAnimatedLength> Height();
+
+  nsIURI* GetSourceDocURI();
+  const Encoding* GetSourceDocCharacterSet();
+  URLExtraData* GetContentURLData() const { return mContentURLData; }
+
+  // Updates the internal shadow tree to be an up-to-date clone of the
+  // referenced element.
+  void UpdateShadowTree();
+
+  // Shared code between AfterSetAttr and SVGUseFrame::AttributeChanged.
+  //
+  // This is needed because SMIL doesn't go through AfterSetAttr unfortunately.
+  void ProcessAttributeChange(int32_t aNamespaceID, nsAtom* aAttribute);
+
+  nsresult AfterSetAttr(int32_t aNamespaceID, nsAtom* aAttribute,
+                        const nsAttrValue* aValue, const nsAttrValue* aOldValue,
+                        nsIPrincipal* aSubjectPrincipal, bool aNotify) final;
+
+ protected:
+  // Information from walking our ancestors and a given target.
+  enum class ScanResult {
+    // Nothing that should stop us from rendering the shadow tree.
+    Ok,
+    // We're never going to be displayed, so no point in updating the shadow
+    // tree.
+    //
+    // However if we're referenced from another tree that tree may need to be
+    // rendered.
+    Invisible,
+    // We're a cyclic reference to either an ancestor or another shadow tree. We
+    // shouldn't render this <use> element.
+    CyclicReference,
+  };
+  ScanResult ScanAncestors(const Element& aTarget) const;
+
+  /**
+   * Helper that provides a reference to the element with the ID that is
+   * referenced by the 'use' element's 'href' attribute, and that will update
+   * the 'use' element if the element that that ID identifies changes to a
+   * different element (or none).
+   */
+  class ElementTracker final : public IDTracker {
+   public:
+    explicit ElementTracker(SVGUseElement* aOwningUseElement)
+        : mOwningUseElement(aOwningUseElement) {}
+
+   private:
+    void ElementChanged(Element* aFrom, Element* aTo) override {
+      IDTracker::ElementChanged(aFrom, aTo);
+      if (aFrom) {
+        aFrom->RemoveMutationObserver(mOwningUseElement);
+      }
+      mOwningUseElement->TriggerReclone();
+    }
+
+    SVGUseElement* mOwningUseElement;
+  };
+
+  SVGUseFrame* GetFrame() const;
+
+  LengthAttributesInfo GetLengthInfo() override;
+  StringAttributesInfo GetStringInfo() override;
+
+  /**
+   * Returns true if our width and height should be used, or false if they
+   * should be ignored. As per the spec, this depends on the type of the
+   * element that we're referencing.
+   */
+  bool OurWidthAndHeightAreUsed() const;
+  void SyncWidthOrHeight(nsAtom* aName);
+  void LookupHref();
+  void TriggerReclone();
+  void UnlinkSource();
+
+  enum { ATTR_X, ATTR_Y, ATTR_WIDTH, ATTR_HEIGHT };
+  SVGAnimatedLength mLengthAttributes[4];
+  static LengthInfo sLengthInfo[4];
+
+  enum { HREF, XLINK_HREF };
+  SVGAnimatedString mStringAttributes[2];
+  static StringInfo sStringInfo[2];
+
+  RefPtr<SVGUseElement> mOriginal;  // if we've been cloned, our "real" copy
+  ElementTracker mReferencedElementTracker;
+  RefPtr<URLExtraData> mContentURLData;  // URL data for its anonymous content
+};
+
+}  // namespace dom
+}  // namespace mozilla
+
+#endif  // DOM_SVG_SVGUSEELEMENT_H_