[web-animations-2] Mark up custom effects as tentative

Author: fantasai

web-animations-2/Overview.bs

@@ -149,9 +149,14 @@ previous level of this specification:
 *   <a>group effects</a> and <a>sequence effects</a>,
 *   an <a>animation effect</a>-specific
     [=animation effect/playback rate=],
-*   <a>custom effects</a>.
 *   Support for non-monotonic (scroll) timelines.
 
+<div class="amendment" id=amend-CE>
+This module also includes some exploratory proposals for [[#custom-effects]],
+however there are some concerns about the design of this feature
+and it may be replaced in a future revision.
+</div>
+
 <h2 id="timing-model">Timing model</h2>
 
 This section describes and defines the behavior of the Web Animations
@@ -340,10 +345,12 @@ follows:
     <var>animation</var> with the <var>did seek</var> flag set to false, and
     the <var>synchronously notify</var> flag set to false.
 
+<ins cite="#amend-CE">
 Issue: If <var>new timeline</var> is null, we should ensure that <a>custom
 effects</a> get called with an <a>unresolved</a> <a>iteration progress</a>
 (unless a subsequent change in the same script execution context makes this
 redundant).
+</ins>
 
 <h4 id="setting-the-target-effect">Setting the target effect of an
   animation</h4>
@@ -355,6 +362,7 @@ After the step to reschedule a <a>pending play task</a> add the following step:
 >     <a lt="remove an animation effect">remove</a> <var>new effect</var> from
 >     its <a>parent group</a>.
 
+<ins cite="#amend-CE">
 After the step to assign <var>new effect</var> as <var>animation</var>'s
 <a>associated effect</a> include the following step:
 
@@ -370,19 +378,19 @@ After the step to assign <var>new effect</var> as <var>animation</var>'s
 >       The definition of when <a>custom effects</a> gets called needs to be
 >       audited and probably rewritten.
 >     </div>
-
+</ins>
 
 <h4 id='waiting-for-the-associated-effect'>Waiting for the associated effect</h4>
 
 The definition of when an animation is ready needs to be extended to consider
-descendant effects and custom effects such that the first condition is:
+descendant effects <ins cite="#amend-CE">and custom effects</ins> such that the first condition is:
 
 > *   the user agent has completed any setup required to begin the playback of
 >     each <a>inclusive descendant</a> of
 >     the animation's <a>associated effect</a>
 >     including rendering the first frame of any <a>keyframe
->     effect</a> or executing any <a>custom effects</a> associated with an
->     <a>animation effect</a>.
+>     effect</a><ins cite="#amend-CE"> or executing any <a>custom effects</a> associated with an
+>     <a>animation effect</a></ins>.
 
 <h4 id='validating-a-css-numberish-time'>Validating a CSSNumberish time</h4>
 
@@ -783,12 +791,13 @@ updating [=custom effects=].
 The procedure to [=pause an animation=] needs to refer not only to the
 [=associated effect=] but also any descendants of the [=associated effect=].
 
-Likewise, the procedure to [=pause an animation=] needs to include scheduling
-a task for updating [=custom effects=].
+<ins cite="#amend-CE">Likewise, the procedure to [=pause an animation=] needs to include scheduling
+a task for updating [=custom effects=].</ins>
 
 
 <h4 id='canceling-an-animation-section'>Canceling an animation</h4>
 
+<ins cite="#amend-CE">
 Append the final step:
 
 > 1.  Queue a task to call any <a>custom effects</a> associated with
@@ -799,6 +808,7 @@ Append the final step:
 >     Issue: The procedures for calling custom effects need to be reworked.
 >            Currently they probably involve calling too often for changes that
 >            could be coalesced.
+</ins>
 
 <h4 id="speed-control">Speed control</h4>
 
@@ -2005,7 +2015,7 @@ as follows:
     href="#the-effect-value-of-a-keyframe-animation-effect"
     section></a>.
 
-
+<ins cite="#amend-CE">
 <h3 id="custom-effects">Custom effects</h3>
 
 (This section is added.)
@@ -2156,6 +2166,8 @@ order of execution is the same as that defined for <a>animation effects</a> in
 [[#the-effect-stack]].
 Items sorted earlier are executed before those sorted later.
 
+</ins>
+
 <!-- End of animation model -->
 
 <h2 id="programming-interface">Programming interface</h2>
@@ -2954,6 +2966,8 @@ enum IterationCompositeOperation { "replace", "accumulate" };
 
 <h3 id="the-effectcallback-callback-function">The <code>EffectCallback</code> callback function</h3>
 
+<ins cite="#amend-CE">
+
 <a>Custom effects</a> can be defined in script by providing an
 {{EffectCallback}} callback function.
 
@@ -2999,6 +3013,8 @@ with which it is associated is updated.
 
 </div>
 
+</ins>
+
 <h3 id="the-animatable-interface">The <code>Animatable</code> interface</h3>
 
 <div class="methods">