dom/smil/SMILAttr.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_SMIL_SMILATTR_H_
   8 #define DOM_SMIL_SMILATTR_H_
   9
  10 #include "nscore.h"
  11 #include "nsStringFwd.h"
  12
  13 class nsIContent;
  14
  15 namespace mozilla {
  16
  17 class SMILValue;
  18
  19 namespace dom {
  20 class SVGAnimationElement;
  21 }  // namespace dom
  22
  23 ////////////////////////////////////////////////////////////////////////
  24 // SMILAttr: A variable targeted by SMIL for animation and can therefore have
  25 // an underlying (base) value and an animated value For example, an attribute of
  26 // a particular SVG element.
  27 //
  28 // These objects only exist during the compositing phase of SMIL animation
  29 // calculations. They have a single owner who is responsible for deleting the
  30 // object.
  31
  32 class SMILAttr {
  33  public:
  34   /**
  35    * Creates a new SMILValue for this attribute from a string. The string is
  36    * parsed in the context of this attribute so that context-dependent values
  37    * such as em-based units can be resolved into a canonical form suitable for
  38    * animation (including interpolation etc.).
  39    *
  40    * @param aStr        A string defining the new value to be created.
  41    * @param aSrcElement The source animation element. This may be needed to
  42    *                    provided additional context data such as for
  43    *                    animateTransform where the 'type' attribute is needed to
  44    *                    parse the value.
  45    * @param[out] aValue Outparam for storing the parsed value.
  46    * @param[out] aPreventCachingOfSandwich
  47    *                    Outparam to indicate whether the attribute contains
  48    *                    dependencies on its context that should prevent the
  49    *                    result of the animation sandwich from being cached and
  50    *                    reused in future samples.
  51    * @return NS_OK on success or an error code if creation failed.
  52    */
  53   virtual nsresult ValueFromString(
  54       const nsAString& aStr,
  55       const mozilla::dom::SVGAnimationElement* aSrcElement, SMILValue& aValue,
  56       bool& aPreventCachingOfSandwich) const = 0;
  57
  58   /**
  59    * Gets the underlying value of this attribute.
  60    *
  61    * @return a SMILValue object. returned_object.IsNull() will be true if an
  62    * error occurred.
  63    */
  64   virtual SMILValue GetBaseValue() const = 0;
  65
  66   /**
  67    * Clears the animated value of this attribute.
  68    *
  69    * NOTE: The animation target is not guaranteed to be in a document when this
  70    * method is called. (See bug 523188)
  71    */
  72   virtual void ClearAnimValue() = 0;
  73
  74   /**
  75    * Sets the presentation value of this attribute.
  76    *
  77    * @param aValue  The value to set.
  78    * @return NS_OK on success or an error code if setting failed.
  79    */
  80   virtual nsresult SetAnimValue(const SMILValue& aValue) = 0;
  81
  82   /**
  83    * Returns the targeted content node, for any SMILAttr implementations
  84    * that want to expose that to the animation logic.  Otherwise, returns
  85    * null.
  86    *
  87    * @return the targeted content node, if this SMILAttr implementation
  88    * wishes to make it avaiable.  Otherwise, nullptr.
  89    */
  90   virtual const nsIContent* GetTargetNode() const { return nullptr; }
  91
  92   /**
  93    * Virtual destructor, to make sure subclasses can clean themselves up.
  94    */
  95   virtual ~SMILAttr() = default;
  96 };
  97
  98 }  // namespace mozilla
  99
 100 #endif  // DOM_SMIL_SMILATTR_H_