dom/smil/nsSMILTargetIdentifier.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef NS_SMILTARGETIDENTIFIER_H_
   7 #define NS_SMILTARGETIDENTIFIER_H_
   8
   9 #include "mozilla/dom/Element.h"
  10 #include "nsAutoPtr.h"
  11
  12 /**
  13  * Struct: nsSMILTargetIdentifier
  14  *
  15  * Tuple of: { Animated Element, Attribute Name, Attribute Type (CSS vs. XML) }
  16  *
  17  * Used in nsSMILAnimationController as hash key for mapping an animation
  18  * target to the nsSMILCompositor for that target.
  19  *
  20  * NOTE: Need a nsRefPtr for the element & attribute name, because
  21  * nsSMILAnimationController retain its hash table for one sample into the
  22  * future, and we need to make sure their target isn't deleted in that time.
  23  */
  24
  25 struct nsSMILTargetIdentifier
  26 {
  27   nsSMILTargetIdentifier()
  28     : mElement(nullptr), mAttributeName(nullptr),
  29       mAttributeNamespaceID(kNameSpaceID_Unknown), mIsCSS(false) {}
  30
  31   inline bool Equals(const nsSMILTargetIdentifier& aOther) const
  32   {
  33     return (aOther.mElement              == mElement &&
  34             aOther.mAttributeName        == mAttributeName &&
  35             aOther.mAttributeNamespaceID == mAttributeNamespaceID &&
  36             aOther.mIsCSS                == mIsCSS);
  37   }
  38
  39   nsRefPtr<mozilla::dom::Element> mElement;
  40   nsRefPtr<nsIAtom>    mAttributeName;
  41   int32_t              mAttributeNamespaceID;
  42   bool                 mIsCSS;
  43 };
  44
  45 /**
  46  * Class: nsSMILWeakTargetIdentifier
  47  *
  48  * Version of the above struct that uses non-owning pointers.  These are kept
  49  * private, to ensure that they aren't ever dereferenced (or used at all,
  50  * outside of Equals()).
  51  *
  52  * This is solely for comparisons to determine if a target has changed
  53  * from one sample to the next.
  54  */
  55 class nsSMILWeakTargetIdentifier
  56 {
  57 public:
  58   // Trivial constructor
  59   nsSMILWeakTargetIdentifier()
  60     : mElement(nullptr), mAttributeName(nullptr), mIsCSS(false) {}
  61
  62   // Allow us to update a weak identifier to match a given non-weak identifier
  63   nsSMILWeakTargetIdentifier&
  64     operator=(const nsSMILTargetIdentifier& aOther)
  65   {
  66     mElement = aOther.mElement;
  67     mAttributeName = aOther.mAttributeName;
  68     mIsCSS = aOther.mIsCSS;
  69     return *this;
  70   }
  71
  72   // Allow for comparison vs. non-weak identifier
  73   inline bool Equals(const nsSMILTargetIdentifier& aOther) const
  74   {
  75     return (aOther.mElement       == mElement &&
  76             aOther.mAttributeName == mAttributeName &&
  77             aOther.mIsCSS         == mIsCSS);
  78   }
  79
  80 private:
  81   const nsIContent* mElement;
  82   const nsIAtom*    mAttributeName;
  83   bool              mIsCSS;
  84 };
  85
  86 #endif // NS_SMILTARGETIDENTIFIER_H_