michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef NS_ISMILATTR_H_
michael@0: #define NS_ISMILATTR_H_
michael@0: 
michael@0: #include "nscore.h"
michael@0: 
michael@0: class nsSMILValue;
michael@0: class nsISMILType;
michael@0: class nsIContent;
michael@0: class nsAString;
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace dom {
michael@0: class SVGAnimationElement;
michael@0: }
michael@0: }
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////
michael@0: // nsISMILAttr: A variable targeted by SMIL for animation and can therefore have
michael@0: // an underlying (base) value and an animated value For example, an attribute of
michael@0: // a particular SVG element.
michael@0: //
michael@0: // These objects only exist during the compositing phase of SMIL animation
michael@0: // calculations. They have a single owner who is responsible for deleting the
michael@0: // object.
michael@0: 
michael@0: class nsISMILAttr
michael@0: {
michael@0: public:
michael@0:   /**
michael@0:    * Creates a new nsSMILValue for this attribute from a string. The string is
michael@0:    * parsed in the context of this attribute so that context-dependent values
michael@0:    * such as em-based units can be resolved into a canonical form suitable for
michael@0:    * animation (including interpolation etc.).
michael@0:    *
michael@0:    * @param aStr        A string defining the new value to be created.
michael@0:    * @param aSrcElement The source animation element. This may be needed to
michael@0:    *                    provided additional context data such as for
michael@0:    *                    animateTransform where the 'type' attribute is needed to
michael@0:    *                    parse the value.
michael@0:    * @param[out] aValue Outparam for storing the parsed value.
michael@0:    * @param[out] aPreventCachingOfSandwich
michael@0:    *                    Outparam to indicate whether the attribute contains
michael@0:    *                    dependencies on its context that should prevent the
michael@0:    *                    result of the animation sandwich from being cached and
michael@0:    *                    reused in future samples.
michael@0:    * @return NS_OK on success or an error code if creation failed.
michael@0:    */
michael@0:   virtual nsresult ValueFromString(const nsAString& aStr,
michael@0:                                    const mozilla::dom::SVGAnimationElement* aSrcElement,
michael@0:                                    nsSMILValue& aValue,
michael@0:                                    bool& aPreventCachingOfSandwich) const = 0;
michael@0: 
michael@0:   /**
michael@0:    * Gets the underlying value of this attribute.
michael@0:    *
michael@0:    * @return an nsSMILValue object. returned_object.IsNull() will be true if an
michael@0:    * error occurred.
michael@0:    */
michael@0:   virtual nsSMILValue GetBaseValue() const = 0;
michael@0: 
michael@0:   /**
michael@0:    * Clears the animated value of this attribute.
michael@0:    *
michael@0:    * NOTE: The animation target is not guaranteed to be in a document when this
michael@0:    * method is called. (See bug 523188)
michael@0:    */
michael@0:   virtual void ClearAnimValue() = 0;
michael@0: 
michael@0:   /**
michael@0:    * Sets the presentation value of this attribute.
michael@0:    *
michael@0:    * @param aValue  The value to set.
michael@0:    * @return NS_OK on success or an error code if setting failed.
michael@0:    */
michael@0:   virtual nsresult SetAnimValue(const nsSMILValue& aValue) = 0;
michael@0: 
michael@0:   /**
michael@0:    * Returns the targeted content node, for any nsISMILAttr implementations
michael@0:    * that want to expose that to the animation logic.  Otherwise, returns
michael@0:    * null.
michael@0:    *
michael@0:    * @return the targeted content node, if this nsISMILAttr implementation
michael@0:    * wishes to make it avaiable.  Otherwise, nullptr.
michael@0:    */
michael@0:   virtual const nsIContent* GetTargetNode() const { return nullptr; }
michael@0: 
michael@0:   /**
michael@0:    * Virtual destructor, to make sure subclasses can clean themselves up.
michael@0:    */
michael@0:   virtual ~nsISMILAttr() {}
michael@0: };
michael@0: 
michael@0: #endif // NS_ISMILATTR_H_