/*
* Copyright (c) 2001 World Wide Web Consortium,
* (Massachusetts Institute of Technology, Institut National de
* Recherche en Informatique et en Automatique, Keio University). All
* Rights Reserved. This program is distributed under the W3C's Software
* Intellectual Property License. This program is distributed in the
* hope that it will be useful, but WITHOUT ANY WARRANTY; without even
* the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE.
* See W3C License http://www.w3.org/Consortium/Legal/ for more details.
*
*/
package mf.org.w3c.dom.smil;
import mf.org.w3c.dom.DOMException;
/**
* <p><a href='http://www.w3.org/TR/2000/WD-smil-animation-20000731/'>SMILAnimation</a>
* supports several methods for controlling the behavior of animation:
* <code>beginElement()</code> and <code>endElement()</code>, et al. These
* methods are used to begin and end an animation that has declared the timing
* to respond to the DOM, using the following syntax:</p>
* <pre><animate begin="indefinite" end="indefinite" .../></pre>
*
* <p>Note that only one of <code>begin</code> or <code>end</code> need be
* specified - either or both can be used. The <code>beginElement()</code>
* and <code>beginElementAt()</code> methods must do nothing if the animation
* is not explicitly set with the <code>begin="indefinite"</code> syntax
* above. The <code>endElement()</code> and <code>endElementAt()</code>
* methods must do nothing if the animation is not explicitly set with the
* <code>end</code><code>="indefinite"</code> syntax above.</p>
*
* <p>Calling <code>beginElement()</code> causes the animation to begin in much
* the same way that an animation with event-based begin timing begins. The
* effective begin time is the current presentation time at the time of the DOM
* method call. Note that <code>beginElement()</code> is subject to the
* <code>restart</code> attribute in the same manner that event-based begin
* timing is. If an animation is specified to disallow restarting at a given
* point, <code>beginElement()</code> methods calls must fail. Refer also to
* the section <a href="http://www.w3.org/TR/2000/WD-smil-animation-20000731/#Restart">Restarting
* animations</a>.</p>
*
* <p>Calling <code>beginElementAt()</code> has the same effect as
* <code>beginElement()</code>, except that the effective begin time is offset
* from the current presentation time by an amount specified as a parameter.
* Passing a negative value for the offset causes the element to begin as for
* <code>beginElement()</code>, but has the effect that the element begins at
* the specified offset into its active duration. The
* <code>beginElementAt()</code> method must also respect the
* <code>restart</code> attribute. The restart semantics for a
* <code>beginElementAt()</code> method call are evaluated at the time of the
* method call, and not at the effective begin time specified by the offset
* parameter.</p>
*
* <p>Calling <code>endElement()</code> causes an animation to end the active
* duration, just as <code>end</code> does. Depending upon the value of the
* <code>fill</code> attribute, the animation effect may no longer be applied,
* or it may be frozen at the current effect. Refer also to the section <a
* href="#Fill">Freezing animations</a>. If an animation is not currently
* active (i.e. if it has not yet begun or if it is frozen), the
* <code>endElement()</code> method will fail.</p>
*
* <p>Calling <code>endElementAt()</code> causes an animation to end the active
* duration, just as <code>endElement()</code> does, but allows the caller to
* specify a positive offset, to cause the element to end at a point in the
* future. Other than delaying when the end actually happens, the semantics are
* identical to those for <code>endElement()</code>. If
* <code>endElementAt()</code> is called more than once while an element is
* active, the end time specified by the last method call will determine the
* end behavior. </p>
*
* <p>The expectation of the following interface is that an instance of the
* ElementTimeControl interface can be obtained by using binding-specific
* casting methods on an instance of an animate element. A DOM application can
* use the <code>hasFeature</code> method of the <a
* href="http://www.w3.org/TR/2000/REC-DOM-Level-2-Core-20001113/#ID-5CED94D7">DOMImplementation</a>
* interface to determine whether the <a
* href="http://www.w3.org/TR/2000/WD-smil-animation-20000731/#ElementTimeControl"><code>ElementTimeControl</code></a> interface is
* supported or not. The feature string for this interface is
* <code>"TimeControl"</code>.</p>
*
* @see <a href="http://www.w3.org/TR/2000/WD-smil-animation-20000731/">SMIL Animation</a>.
*/
public interface ElementTimeControl {
/**
* Causes this element to begin the local timeline (subject to restart constraints).
* @return <code>true</code> if the method call was successful and the
* element was begun. <code>false</code> if the method call
* failed. Possible reasons for failure include:
* <ul>
* <li>The element does not support the <code>beginElement</code>
* method. The <code>begin</code> attribute is not set to
* <code>"indefinite"</code>.</li>
* <li>The element is already active and cannot be restarted when it is
* active. The <code>restart</code> attribute is set to
* <code>"whenNotActive"</code>.</li>
* <li>The element is active or has been active and cannot be
* restarted. The <code>restart</code> attribute is set to
* <code>"never"</code>.</li>
* </ul>
* @raise DOMException <code>SYNTAX_ERR</code>: The element was not defined
* with the appropriate syntax to allow <code>beginElement</code> calls.
*/
public boolean beginElement()
throws DOMException;
/**
* Causes this element to begin the local timeline (subject to restart
* constraints), at the passed offset from the current time when the method
* is called. If the offset is >= 0, the semantics are equivalent to an
* event-base begin with the specified offset. If the offset is < 0, the
* semantics are equivalent to beginElement(), but the element active
* duration is evaluated as though the element had begun at the passed
* (negative) offset from the current time when the method is called.
*
* @param offset The offset in seconds at which to begin the element.
* @return <code>true</code> if the method call was successful and the element was begun.
* <code>false</code> if the method call failed.
* Possible reasons for failure include:
* <ul>
* <li>The element does not support the
* <code>beginElementAt</code> method. The
* <code>begin</code> attribute is not set to
* <code>"indefinite"</code>.</li>
* <li>The element is already active and cannot be
* restarted when it is active. The
* <code>restart</code> attribute is set to
* <code>"whenNotActive"</code>.</li>
* <li>The element is active or has been active and
* cannot be restarted. The <code>restart</code>
* attribute is set to <code>"never"</code>.</li>
* </ul>
* @raise DOMException SYNTAX_ERR: The element was not defined with the appropriate
* syntax to allow <code>beginElementAt</code> calls.
*/
public boolean beginElementAt(float offset)
throws DOMException;
/**
* Causes this element to end the local timeline.
*
* @return <code>true</code> if the method call was
* successful and the element was ended.
* <code>false</code> if method call failed. Possible
* reasons for failure include:
* <ul>
* <li>The element does not support the
* <code>endElement</code> method. The
* <code>end</code> attribute is not set to
* <code>"indefinite"</code>.</li>
* <li>The element is not active.</li>
* </ul>
* @raise DOMException SYNTAX_ERR: The element was not defined with the
* appropriate syntax to allow <code>endElement</code>
* calls.
*/
public boolean endElement()
throws DOMException;
/**
* Causes this element to end the local timeline at the specified offset
* from the current time when the method is called
*
* @param offset The offset in seconds at which to end the element.
* Must be <code>>= 0</code>.
* @return <code>true</code> if the method call was
* successful and the element was ended.
* <code>false</code> if method call failed. Possible
* reasons for failure include:
* <ul>
* <li>The element does not support the
* <code>endElementAt</code> method. The
* <code>end</code> attribute is not set to
* <code>"indefinite"</code>.</li>
* <li>The element is not active.</li>
* </ul>
* @raise DOMException SYNTAX_ERR: The element was not defined with the
* appropriate syntax to allow
* <code>endElementAt</code> calls.
*/
public boolean endElementAt(float offset)
throws DOMException;
}