1 files changed, 113 insertions, 0 deletions
diff --git a/dom/svg/SVGMPathElement.h b/dom/svg/SVGMPathElement.h
new file mode 100644
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+++ b/dom/svg/SVGMPathElement.h
@@ -0,0 +1,113 @@
+/* -*- 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_SVGMPATHELEMENT_H_
+#define DOM_SVG_SVGMPATHELEMENT_H_
+
+#include "mozilla/dom/IDTracker.h"
+#include "mozilla/dom/SVGElement.h"
+#include "nsStubMutationObserver.h"
+#include "SVGAnimatedString.h"
+
+nsresult NS_NewSVGMPathElement(
+    nsIContent** aResult, already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo);
+
+namespace mozilla::dom {
+class SVGGeometryElement;
+
+using SVGMPathElementBase = SVGElement;
+
+class SVGMPathElement final : public SVGMPathElementBase,
+                              public nsStubMutationObserver {
+ protected:
+  friend nsresult(::NS_NewSVGMPathElement(
+      nsIContent** aResult,
+      already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo));
+  explicit SVGMPathElement(
+      already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo);
+  ~SVGMPathElement();
+
+  JSObject* WrapNode(JSContext* aCx,
+                     JS::Handle<JSObject*> aGivenProto) override;
+
+ public:
+  // interfaces:
+  NS_DECL_ISUPPORTS_INHERITED
+
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(SVGMPathElement, SVGMPathElementBase)
+
+  NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED
+
+  // nsIContent interface
+  nsresult Clone(dom::NodeInfo*, nsINode** aResult) const override;
+  nsresult BindToTree(BindContext&, nsINode& aParent) override;
+  void UnbindFromTree(bool aNullParent) override;
+
+  // Element specializations
+  void AfterSetAttr(int32_t aNamespaceID, nsAtom* aName,
+                    const nsAttrValue* aValue, const nsAttrValue* aOldValue,
+                    nsIPrincipal* aMaybeScriptedPrincipal,
+                    bool aNotify) override;
+
+  // Public helper method: If our xlink:href attribute links to a Shape
+  // element, this method returns a pointer to that element. Otherwise,
+  // this returns nullptr.
+  SVGGeometryElement* GetReferencedPath();
+
+  // WebIDL
+  already_AddRefed<DOMSVGAnimatedString> Href();
+
+ protected:
+  /**
+   * Helper that provides a reference to the 'path' element with the ID that is
+   * referenced by the 'mpath' element's 'href' attribute, and that will
+   * invalidate the parent of the 'mpath' and update mutation observers to the
+   * new path element if the element that that ID identifies changes to a
+   * different element (or none).
+   */
+  class PathElementTracker final : public IDTracker {
+   public:
+    explicit PathElementTracker(SVGMPathElement* aMpathElement)
+        : mMpathElement(aMpathElement) {}
+
+   protected:
+    // We need to be notified when target changes, in order to request a sample
+    // (which will clear animation effects that used the old target-path
+    // and recompute the animation effects using the new target-path).
+    void ElementChanged(Element* aFrom, Element* aTo) override {
+      IDTracker::ElementChanged(aFrom, aTo);
+      if (aFrom) {
+        aFrom->RemoveMutationObserver(mMpathElement);
+      }
+      if (aTo) {
+        aTo->AddMutationObserver(mMpathElement);
+      }
+      mMpathElement->NotifyParentOfMpathChange(mMpathElement->GetParent());
+    }
+
+    // We need to override IsPersistent to get persistent tracking (beyond the
+    // first time the target changes)
+    bool IsPersistent() override { return true; }
+
+   private:
+    SVGMPathElement* const mMpathElement;
+  };
+
+  StringAttributesInfo GetStringInfo() override;
+
+  void UpdateHrefTarget(nsIContent* aParent, const nsAString& aHrefStr);
+  void UnlinkHrefTarget(bool aNotifyParent);
+  void NotifyParentOfMpathChange(nsIContent* aParent);
+
+  enum { HREF, XLINK_HREF };
+  SVGAnimatedString mStringAttributes[2];
+  static StringInfo sStringInfo[2];
+  PathElementTracker mPathTracker;
+};
+
+}  // namespace mozilla::dom
+
+#endif  // DOM_SVG_SVGMPATHELEMENT_H_