[css-display] Edit in Seattle F2F resolutions:

  * Remove issue about root being out-of-flow; file against CSS2.1 to make it in-flow
  * Make table-caption and table-cell use flow-root for their inner display type
  * Drop box-suppress/display-or-not property
  * Make replaced elements and form controls with 'display: contents' behave as 'display: inline'
  * Remove issue about 'display: contents' and counters; to be filed against Lists
  * Clarify that ::before and ::after still exist for a 'display: contents' element
  * Clarify that p::first-letter selects the first letter of the first run-in inside the <p> (if any)
  * Clarify that events are not affected by 'display: contents'
  * Mark two-keyword display values at-risk

Author: fantasai

css-display/Overview.bs

@@ -13,8 +13,11 @@ Previous Version: https://www.w3.org/TR/2015/WD-css-display-3-20150721/
 Previous Version: https://www.w3.org/TR/2014/WD-css-display-3-20140911/
 Editor: Tab Atkins Jr., Google, http://xanthir.com/contact/
 Editor: Elika J. Etemad / fantasai, Invited Expert, http://fantasai.inkedblade.net/contact
-Abstract: This module describes how the CSS formatting box tree is generated from the document element tree and defines the 'display' and 'display-or-not' properties that control it.
+Abstract: This module describes how the CSS formatting box tree is generated from the document element tree and defines the 'display' property that controls it.
 Ignored Terms: display-model, display-role, table row group box, absolutely positioned
+At Risk: Application of ''::first-letter'' in the presence of run-ins
+At Risk: ''display: run-in''
+At Risk: All two-keyword values of 'display' and ''display: inline-list-item''
 </pre>
 <pre class="link-defaults">
 spec:css-break-3; type:dfn; text:fragment;
@@ -40,14 +43,14 @@ Introduction</h2>
 	(See [[!CSS3-CASCADE]].)
 
 	Then, for each element, it generates zero or more boxes
-	as specified by that element's 'display' and 'display-or-not' properties.
+	as specified by that element's 'display' property.
 	Typically, an element generates a single <a>box</a>.
 	However, some 'display' values
 	(e.g. ''display: list-item'')
 	generate more than one box
 	(e.g. a <a href="https://www.w3.org/TR/CSS2/visuren.html#principal-box">principal block box</a> and a <a href="https://www.w3.org/TR/CSS2/generate.html#lists">marker box</a>).
 	And some values
-	(such as ''display:none'', ''display: contents'', and ''display-or-not: discard'')
+	(such as ''display/none'' or ''display/contents'')
 	cause the <a>element</a> and/or its descendants to not generate any <a>boxes</a> at all.
 	<a>Boxes</a> are assigned the same styles as their generating <a>element</a>, unless otherwise indicated.
 	They're often referred to by their 'display' type--
@@ -130,7 +133,7 @@ Box Layout Modes: the 'display' property</h2>
 
 	Some 'display' values have additional side-effects:
 	such as ''list-item'', which also generates a ''::marker'' pseudo-element,
-	and ''none'', which causes the element's entire subtree to be left out of the box tree.
+	and ''display/none'', which causes the element's entire subtree to be left out of the box tree.
 
 	Values are defined as follows:
 
@@ -162,11 +165,11 @@ Box Layout Modes: the 'display' property</h2>
 				<th>Generated box
 		<tbody title="Box Suppression Display Types">
 			<tr>
-				<td>''none''
+				<td>''display/none''
 				<td>&#x3003;
 				<td>subtree omitted from <a>box tree</a>
 			<tr>
-				<td>''contents''
+				<td>''display/contents''
 				<td>&#x3003;
 				<td>element replaced by contents in <a>box tree</a>
 		<tbody title="Flow Layout Display Types">
@@ -238,11 +241,11 @@ Box Layout Modes: the 'display' property</h2>
 		<tbody title="Layout-internal display types">
 			<tr>
 				<td>''table-cell''
-				<td>''table-cell flow''
+				<td>''table-cell flow-root''
 				<td>table cell <a>block container</a>
 			<tr>
 				<td>''table-caption''
-				<td>''table-caption flow''
+				<td>''table-caption flow-root''
 				<td>table cell <a>block container</a>
 			<tr>
 				<td>''ruby-base''
@@ -393,7 +396,7 @@ Layout-Internal Display Types: the ''table-*'' and ''ruby-*'' keywords</h3>
 			The element is an <dfn dfn>internal table element</dfn>,
 			and participates in a table layout context. [[!CSS2]]
 
-			''table-cell'' and ''table-caption'' have a ''flow'' <a>inner display type</a>.
+			''table-cell'' and ''table-caption'' have a ''flow-root'' <a>inner display type</a>.
 
 		<dt><dfn>ruby-base</dfn>, <dfn>ruby-text</dfn>, <dfn>ruby-base-container</dfn>, <dfn>ruby-text-container</dfn>
 		<dd>
@@ -456,7 +459,7 @@ Layout-Internal Display Types: the ''table-*'' and ''ruby-*'' keywords</h3>
 	</div>
 
 <h3 id="box-generation">
-Box Generation: the ''none'' and ''contents'' keywords</h3>
+Box Generation: the ''display/none'' and ''display/contents'' keywords</h3>
 
 	While 'display' can control the <em>types</em> of boxes an element will generate,
 	it can also control whether an element will generate any boxes at all.
@@ -470,18 +473,21 @@ Box Generation: the ''none'' and ''contents'' keywords</h3>
 			but its children and pseudo-elements still generate boxes as normal.
 			For the purposes of box generation and layout,
 			the element must be treated as if it had been replaced with its children and pseudo-elements in the document tree.
+			However, its ''::before'' and ''::after'' pseudo-elements still exist,
+			and are parented by the element's parent's principal box along with the rest of the element's box-generating contents.
 
-			Issue: ''contents'' currently only has an effect on box generation and layout.
-			Other things that care about the document tree are unaffected, like counter scopes.
-			Is this what we want?
+			Note: As only the box tree is affected,
+			any semantics based on the document tree,
+			such as selector-matching and event handling,
+			are not affected.
+
+			This value has no effect on replaced elements and form controls;
+			it computes to ''inline'' exactly as if the UA style sheet had specified
+			''display: inline !important'' on such elements.
 
 		<dt><dfn>none</dfn>
 		<dd>
 			The element and its descendants generates no boxes.
-
-			Advisement: It is recommended that 'display-or-not' be used instead of ''display: none'',
-			so that the element's display type is automatically preserved
-			for when it's no longer suppressed.
 	</dl>
 
 	Elements with either of these values do not have <a>inner</a> or <a>outer display types</a>,
@@ -528,7 +534,8 @@ Automatic Box Type Transformations</h3>
 
 	Some layout effects require <dfn export lt="blockify|blockification">blockification</dfn>
 	or <dfn export lt="inlinify|inlinification">inlinification</dfn> of the box type,
-	which sets the box’s <a>outer display type</a>, if it is not ''none'' or ''contents'',
+	which sets the box’s <a>outer display type</a>,
+	if it is not ''display/none'' or ''display/contents'',
 	to ''block'' or ''inline'' (respectively).
 
 	<div class='example'>
@@ -549,8 +556,9 @@ Automatic Box Type Transformations</h3>
 	break up the inline formatting context in which it participates.
 
 	The root element’s display type is always <a>blockified</a>.
-	Additionally, a 'display' of ''contents'' computes to ''block'' on the root element.
+	Additionally, a 'display' of ''display/contents'' computes to ''block'' on the root element.
 
+<!--
 
 <h2 id='box-suppress'>
 Toggling Box Generation: the 'display-or-not' property</h2>
@@ -569,15 +577,15 @@ Toggling Box Generation: the 'display-or-not' property</h2>
 	The ''display: none'' value was historically used as a "toggle"
 	to switch between showing and hiding an element.
 	Making this reversible requires either setting up the CSS <a>cascade</a> carefully,
-	or remembering what the 'display' value was before it was set to ''none''.
+	or remembering what the 'display' value was before it was set to ''display/none''.
 	To make this common use-case easier,
 	this module introduces the separate 'display-or-not' property to do the same thing,
 	so that toggling whether or not an element appears in the formatting tree
 	can now be done without affecting its display type when it <em>is</em> displayed.
 
 	Issue: This property (which needs a better name)
 	along with a <css>display-type</css> (or possibly <css>display-as</css>) longhand
-	which takes all values of 'display' other than ''none'',
+	which takes all values of 'display' other than ''display/none'',
 	are intended to be longhands of 'display'.
 	This has not yet been edited in, as this split feature is likely to be deferred to the next level
 	in order to have time to thoroughly work through and accommodate the
@@ -619,6 +627,8 @@ Toggling Box Generation: the 'display-or-not' property</h2>
 	Issue: Please send use cases (examples of where this property or something close to it is useful and necessary)
 	<a href="mailto:www-style@w3.org?subject=%5Bcss-display%5D%20box-suppres%20use%20cases">to the CSSWG</a> so that we can be sure we're designing the details of its behavior correctly.
 
+-->
+
 <h2 id='run-in-layout'>
 Run-In Layout</h2>
 
@@ -693,12 +703,18 @@ Run-In Layout</h2>
 	A <dfn>run-in sequence</dfn> is a maximal sequence of consecutive sibling <a>run-in boxes</a>
 	and intervening white space and/or out-of-flow boxes.
 
-	Issue: Should out-of-flow elements get reparented, left behind, or break apart the sequence?
-	<a href="http://lists.w3.org/Archives/Public/www-style/2012Aug/0257.html">See thread.</a>
+	Note: This statement implies that out-of-flow boxes are reparented
+	if they are between two run-in boxes.
+	Another alternative would be to leave behind the intervening out-of-flow boxes,
+	or to have out-of-flow boxes impede the running-in of earlier boxes.
+	Implementers and authors are encouraged to contact the CSSWG if they have a preferred behavior, as this one was picked somewhat at random.
 
-	Note: This run-in model is slightly different from the one proposed in earlier revisions of [[!CSS2]].
+	Note: As the earliest run-in represents the first text on the <a>first formatted line</a> of its containing block,
+	a ''::first-letter'' pseudo-element applied to that block element
+	selects the first letter of the run-in,
+	rather than the first letter of its own contents.
 
-	Issue: <a href="http://www.w3.org/mid/B81F7808-D972-458D-970F-3900E82A0F27@rivoal.net">Interaction of run-in and ::first-letter</a>
+	Note: This run-in model is slightly different from the one proposed in earlier revisions of [[!CSS2]].
 
 <h2 id='glossary'>
 Appendix A: Glossary</h2>
@@ -833,11 +849,6 @@ Appendix A: Glossary</h2>
 
 			Note: some formatting contexts inhibit floating,
 			so that an element with ''float: left'' is not necessarily <a>out-of-flow</a>.
-
-			Issue: CSS2.1 defines the root element as out-of-flow.
-			This <a href="https://lists.w3.org/Archives/Public/www-style/2015Aug/0332.html">seems to me</a>
-			to be more likely to cause problems in our specs than not.
-			Should we change that definition or copy it over?
 	</dl>
 
 	See [[!CSS2]] <a href="https://www.w3.org/TR/CSS2/visuren.html">Chapter 9</a> for a fuller definition of these terms.
@@ -852,13 +863,27 @@ Acknowledgments</h2>
 	and Anton Prowse,
 	whose relentless assault on CSS2.1 Chapter 9 forced some order out of the chaos.
 
+<!--
 	We would also like to thank the many JavaScript libraries such as jQuery
 	which have hacked around the "what 'display' should I give it when you call .show()?" problem,
 	making it extremely clear that something needed to be done on our part.
+-->
 
 <h2 class=no-num id="changes">
 Changes</h2>
 
+	Changes since the ??? Working Draft include:
+	<ul>
+		<li>Deferred the <css>box-suppress/display-or-not</css> property to the next level of Display,
+		in order to provide time for futher discussion of use cases.
+		<li>Specified that ''display: contents'' computes to ''display: inline'' on replaced elements and form controls.
+		<li>Clarified that an element’s ''::before'' and ''::after'' pseudo-elements still exist if its own box is not generated due to ''display: contents''.
+		<li>Clarified that event bubbling is not affected by ''display: contents''.
+		<li>Clarified interaction of run-ins with out-of-flow elements and ''::first-letter''.
+		<li>Switched ''table-caption'' and ''table-cell'' to use ''flow'' as their <a>inner display type</a>, since they always form a formatting context root.
+		<li>Closed off remaining issues and added at-risk list.
+	</ul>
+
 	Changes since the <a href="https://www.w3.org/TR/2015/WD-css-display-3-20150721/">21 July 2015 Working Draft</a> include:
 
 	<ul>