dom/svg/SVGMPathElement.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_SVGMPATHELEMENT_H_
   8 #define DOM_SVG_SVGMPATHELEMENT_H_
   9
  10 #include "mozilla/dom/IDTracker.h"
  11 #include "mozilla/dom/SVGElement.h"
  12 #include "nsStubMutationObserver.h"
  13 #include "SVGAnimatedString.h"
  14
  15 nsresult NS_NewSVGMPathElement(
  16     nsIContent** aResult, already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo);
  17
  18 namespace mozilla::dom {
  19 class SVGGeometryElement;
  20
  21 using SVGMPathElementBase = SVGElement;
  22
  23 class SVGMPathElement final : public SVGMPathElementBase,
  24                               public nsStubMutationObserver {
  25  protected:
  26   friend nsresult(::NS_NewSVGMPathElement(
  27       nsIContent** aResult,
  28       already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo));
  29   explicit SVGMPathElement(
  30       already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo);
  31   ~SVGMPathElement();
  32
  33   JSObject* WrapNode(JSContext* aCx,
  34                      JS::Handle<JSObject*> aGivenProto) override;
  35
  36  public:
  37   // interfaces:
  38   NS_DECL_ISUPPORTS_INHERITED
  39
  40   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(SVGMPathElement, SVGMPathElementBase)
  41
  42   NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED
  43
  44   // nsIContent interface
  45   nsresult Clone(dom::NodeInfo*, nsINode** aResult) const override;
  46   nsresult BindToTree(BindContext&, nsINode& aParent) override;
  47   void UnbindFromTree(bool aNullParent) override;
  48
  49   // Element specializations
  50   void AfterSetAttr(int32_t aNamespaceID, nsAtom* aName,
  51                     const nsAttrValue* aValue, const nsAttrValue* aOldValue,
  52                     nsIPrincipal* aMaybeScriptedPrincipal,
  53                     bool aNotify) override;
  54
  55   // Public helper method: If our xlink:href attribute links to a Shape
  56   // element, this method returns a pointer to that element. Otherwise,
  57   // this returns nullptr.
  58   SVGGeometryElement* GetReferencedPath();
  59
  60   // WebIDL
  61   already_AddRefed<DOMSVGAnimatedString> Href();
  62
  63  protected:
  64   /**
  65    * Helper that provides a reference to the 'path' element with the ID that is
  66    * referenced by the 'mpath' element's 'href' attribute, and that will
  67    * invalidate the parent of the 'mpath' and update mutation observers to the
  68    * new path element if the element that that ID identifies changes to a
  69    * different element (or none).
  70    */
  71   class PathElementTracker final : public IDTracker {
  72    public:
  73     explicit PathElementTracker(SVGMPathElement* aMpathElement)
  74         : mMpathElement(aMpathElement) {}
  75
  76    protected:
  77     // We need to be notified when target changes, in order to request a sample
  78     // (which will clear animation effects that used the old target-path
  79     // and recompute the animation effects using the new target-path).
  80     void ElementChanged(Element* aFrom, Element* aTo) override {
  81       IDTracker::ElementChanged(aFrom, aTo);
  82       if (aFrom) {
  83         aFrom->RemoveMutationObserver(mMpathElement);
  84       }
  85       if (aTo) {
  86         aTo->AddMutationObserver(mMpathElement);
  87       }
  88       mMpathElement->NotifyParentOfMpathChange(mMpathElement->GetParent());
  89     }
  90
  91     // We need to override IsPersistent to get persistent tracking (beyond the
  92     // first time the target changes)
  93     bool IsPersistent() override { return true; }
  94
  95    private:
  96     SVGMPathElement* const mMpathElement;
  97   };
  98
  99   StringAttributesInfo GetStringInfo() override;
 100
 101   void UpdateHrefTarget(nsIContent* aParent, const nsAString& aHrefStr);
 102   void UnlinkHrefTarget(bool aNotifyParent);
 103   void NotifyParentOfMpathChange(nsIContent* aParent);
 104
 105   enum { HREF, XLINK_HREF };
 106   SVGAnimatedString mStringAttributes[2];
 107   static StringInfo sStringInfo[2];
 108   PathElementTracker mPathTracker;
 109 };
 110
 111 }  // namespace mozilla::dom
 112
 113 #endif  // DOM_SVG_SVGMPATHELEMENT_H_