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The Tor Browser
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SMILTargetIdentifier.h (2683B)

      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_SMIL_SMILTARGETIDENTIFIER_H_
      8 #define DOM_SMIL_SMILTARGETIDENTIFIER_H_
      9 
     10 // XXX Avoid including this here by moving function bodies to the cpp file
     11 #include "mozilla/dom/Element.h"
     12 #include "nsAtom.h"
     13 #include "nsIContent.h"
     14 
     15 class nsIContent;
     16 
     17 namespace mozilla {
     18 namespace dom {
     19 class Element;
     20 }
     21 
     22 /**
     23 * Struct: SMILTargetIdentifier
     24 *
     25 * Tuple of: { Animated Element, Attribute Name }
     26 *
     27 * Used in SMILAnimationController as hash key for mapping an animation
     28 * target to the SMILCompositor for that target.
     29 *
     30 * NOTE: Need a nsRefPtr for the element & attribute name, because
     31 * SMILAnimationController retain its hash table for one sample into the
     32 * future, and we need to make sure their target isn't deleted in that time.
     33 */
     34 
     35 struct SMILTargetIdentifier {
     36  SMILTargetIdentifier()
     37      : mElement(nullptr),
     38        mAttributeName(nullptr),
     39        mAttributeNamespaceID(kNameSpaceID_Unknown) {}
     40 
     41  inline bool Equals(const SMILTargetIdentifier& aOther) const {
     42    return (aOther.mElement == mElement &&
     43            aOther.mAttributeName == mAttributeName &&
     44            aOther.mAttributeNamespaceID == mAttributeNamespaceID);
     45  }
     46 
     47  RefPtr<mozilla::dom::Element> mElement;
     48  RefPtr<nsAtom> mAttributeName;
     49  int32_t mAttributeNamespaceID;
     50 };
     51 
     52 /**
     53 * Class: SMILWeakTargetIdentifier
     54 *
     55 * Version of the above struct that uses non-owning pointers.  These are kept
     56 * private, to ensure that they aren't ever dereferenced (or used at all,
     57 * outside of Equals()).
     58 *
     59 * This is solely for comparisons to determine if a target has changed
     60 * from one sample to the next.
     61 */
     62 class SMILWeakTargetIdentifier {
     63 public:
     64  // Trivial constructor
     65  SMILWeakTargetIdentifier() : mElement(nullptr), mAttributeName(nullptr) {}
     66 
     67  // Allow us to update a weak identifier to match a given non-weak identifier
     68  SMILWeakTargetIdentifier& operator=(const SMILTargetIdentifier& aOther) {
     69    mElement = aOther.mElement;
     70    mAttributeName = aOther.mAttributeName;
     71    return *this;
     72  }
     73 
     74  // Allow for comparison vs. non-weak identifier
     75  inline bool Equals(const SMILTargetIdentifier& aOther) const {
     76    return (aOther.mElement == mElement &&
     77            aOther.mAttributeName == mAttributeName);
     78  }
     79 
     80 private:
     81  const nsIContent* mElement;
     82  const nsAtom* mAttributeName;
     83 };
     84 
     85 }  // namespace mozilla
     86 
     87 #endif  // DOM_SMIL_SMILTARGETIDENTIFIER_H_