[css-align] Revert the swallowing of stretch by <item-position>, since combining it with <overflow-position> makes no sense.

--HG--
extra : rebase_source : 1bbc8427562798cf65e5f6e92baade7253335bbe

Author: fantasai

css-align/Overview.bs

@@ -7,8 +7,8 @@ Group: csswg
 Status: WD
 Date: 2014-12-18
 ED: http://dev.w3.org/csswg/css-align/
-TR: http://www.w3.org/TR/css3-align/
-Editor: fantasai, Invited Expert, http://fantasai.inkedblade.net/contact
+TR: http://www.w3.org/TR/css-align-3/
+Editor: Elika J. Etemad, Invited Expert, http://fantasai.inkedblade.net/contact
 Editor: Tab Atkins Jr., Google, http://xanthir.com/contact/
 Previous Version: http://www.w3.org/TR/2013/WD-css3-align-20130514/
 Previous Version: http://www.w3.org/TR/2012/WD-css3-align-20120612/
@@ -154,7 +154,7 @@ Overview of Alignment Properties</h2>
 
 	Note: The '*-items' values don't affect the element itself.
 	When set on a flex container or grid container,
-	they specify the interpretation of any ''align/justify-self: auto'' used on the items in the container element.
+	they specify the interpretation of any ''*-self: auto'' used on the items in the container element.
 
 <h2 id='alignment-values'>
 Alignment Values</h2>
@@ -179,7 +179,7 @@ Alignment Values</h2>
 	</dl>
 
 <h3 id='positional-values'>
-Positional Alignment: the ''center'', ''start'', ''end'', ''self-start'', ''self-end'', ''flex-start'', ''flex-end'', ''left'', ''right'', and ''<item-position>/stretch'' keywords</h3>
+Positional Alignment: the ''center'', ''start'', ''end'', ''self-start'', ''self-end'', ''flex-start'', ''flex-end'', ''left'', and ''right'' keywords</h3>
 
 	The positional alignment keywords specify a position for an <a>alignment subject</a>
 	with respect to its <a>alignment container</a>.
@@ -193,7 +193,7 @@ Positional Alignment: the ''center'', ''start'', ''end'', ''self-start'', ''self
 
 	<pre class='prod'>
 		<dfn>&lt;item-position></dfn> = center | start | end | self-start | self-end |
-		                   flex-start | flex-end | left | right | stretch;
+		                   flex-start | flex-end | left | right;
 		<dfn>&lt;content-position></dfn> = center | start | end | flex-start | flex-end | left | right;
 	</pre>
 
@@ -204,18 +204,6 @@ Positional Alignment: the ''center'', ''start'', ''end'', ''self-start'', ''self
 		<dt><dfn for="<item-position>, <content-position>">center</dfn>
 		<dd>Centers the <a>alignment subject</a> within its <a>alignment container</a>.
 
-		<dt><dfn for="<item-position>">stretch</dfn>
-		<dd>If the 'width' or 'height' (as appropriate) of the <a>alignment subject</a> is ''width/auto'',
-			and its outer size is smaller than the <a>alignment container</a>,
-			its used value is increased to the length necessary to make the <a>alignment subject</a>’s outer size
-			as close to the size of the <a>alignment container</a> as possible,
-			while still respecting the constraints imposed by 'max-height'/'max-width'.
-
-			The <a>alignment subject</a> is then aligned as per ''flex-start''.
-			<span class='note'>(For layout modes other than flex layout, ''flex-start'' is identical to ''start''.)</span>
-
-			Issue: Should this value allow a fallback alignment, like the <<content-distribution>> values do?
-
 		<dt><dfn for="<item-position>, <content-position>">start</dfn>
 		<dd>Aligns the <a>alignment subject</a> to be flush with the <a>alignment container</a>’s start edge.
 
@@ -371,13 +359,16 @@ Distributed Alignment: the ''<content-distribution>/stretch'', ''space-between''
 		<dt><dfn>stretch</dfn>
 		<dd>
 			If the combined size of the <a>alignment subjects</a> is less than the size of the <a>alignment container</a>,
-			any ''width/auto''-sized <a>alignment subjects</a> have their size increased equally (not proportionally)
-			so that the combined size exactly fills the <a>alignment container</a>,
-			and then clamped by their 'max-width'/'max-height' constraints.
+			any ''width/auto''-sized <a>alignment subjects</a> have their size increased equally (not proportionally),
+			while still respecting the constraints imposed by 'max-height'/'max-width',
+			so that the combined size exactly fills the <a>alignment container</a>.
 
 			Unless otherwise specified,
 			this value falls back to ''flex-start''.
 			<span class='note'>(For layout modes other than flex layout, ''flex-start'' is identical to ''start''.)</span>
+			
+			Issue: Should this value allow a fallback alignment on 'align-self' and 'justify-self',
+			like it does on 'align-content' and 'justify-content'?
 	</dl>
 
 	<p class='issue'>
@@ -421,12 +412,6 @@ Overflow Alignment: the ''safe'' and ''true'' keywords</h3>
 	<p class='issue'>
 		Transplant example 10 from flexbox.
 
-	<p class='issue'>
-		The current grammar constructions allow combining ''safe'' and ''true''
-		with ''<item-position>/stretch'' for 'justify-self'/'align-self'
-		but not with ''<content-position>/stretch'' for 'justify-content'/'align-content'.
-		This is inconsistent.
-
 <h2 id='content-distribution'>
 Content Distribution: the 'justify-content' and 'align-content' properties</h2>
 
@@ -541,14 +526,14 @@ Baseline Content-Alignment</h3>
 			A <a>flex item</a> participates in first (last) <a>baseline content-alignment</a>
 			in its flex line if
 			its computed 'align-content' is ''baseline'' (''last-baseline'')
-			and its computed 'align-self' is ''<item-position>/stretch'' or ''start'' (''end'').
+			and its computed 'align-self' is ''<content-distribution>/stretch'' or ''start'' (''end'').
 
 		<dt>Grid Items:
 		<dd>
 			A <a>grid item</a> participates in first (last) <a>baseline content-alignment</a>
 			in either its row or column (whichever matches its <a>inline axis</a>)
 			if its computed 'align-content' is ''baseline'' (''last-baseline''),
-			and its computed 'align-self' or 'justify-self' (whichever affects its <a>block axis</a>) is ''<item-position>/stretch'' or ''start'' (''end'').
+			and its computed 'align-self' or 'justify-self' (whichever affects its <a>block axis</a>) is ''<content-distribution>/stretch'' or ''start'' (''end'').
 	</dl>
 
 	If a box spans multiple <a>shared alignment contexts</a>,
@@ -597,7 +582,7 @@ Inline/Main-Axis Alignment: the 'justify-self' property</h3>
 
 	<pre class="propdef">
 	Name: justify-self
-	Value: auto | <<baseline-position>> | [ <<overflow-position>>? && <<item-position>> ]
+	Value: auto | stretch | <<baseline-position>> | [ <<overflow-position>>? && <<item-position>> ]
 	Initial: auto
 	Applies to: block-level boxes, absolutely-positioned boxes, and grid items
 	Inherited: no
@@ -646,7 +631,7 @@ Inline/Main-Axis Alignment: the 'justify-self' property</h3>
 
 			When neither margin in this dimension is ''margin/auto''
 			and neither offset property in this dimension is ''top/auto'',
-			values other than ''<item-position>/stretch'' cause <a href="http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-width">non-replaced absolutely-positioned boxes</a>
+			values other than ''<content-distribution>/stretch'' cause <a href="http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-width">non-replaced absolutely-positioned boxes</a>
 			to use shrink-to-fit sizing for calculating ''width/auto'' measures,
 			and 'justify-self' dictates alignment as follows:
 
@@ -661,7 +646,7 @@ Inline/Main-Axis Alignment: the 'justify-self' property</h3>
 			and the used value of the offset properties are not adjusted to correct for the over-constraint.
 
 			The ''justify-self/auto'' keyword is equivalent to ''start'' on replaced absolutely-positioned boxes,
-			and equivalent to ''<item-position>/stretch'' on all other absolutely-positioned boxes.
+			and equivalent to ''<content-distribution>/stretch'' on all other absolutely-positioned boxes.
 			(This is because CSS 2.1 does not stretch replaced elements to fit into fixed offsets.)
 
 		<dt>Table Cells:
@@ -698,7 +683,7 @@ Block/Cross-Axis Alignment: the 'align-self' property</h3>
 
 	<pre class="propdef">
 	Name: align-self
-	Value: auto | <<baseline-position>> | [ <<overflow-position>>? && <<item-position>> ]
+	Value: auto | stretch | <<baseline-position>> | [ <<overflow-position>>? && <<item-position>> ]
 	Initial: auto
 	Applies to: flex items, grid items, and absolutely-positioned boxes
 	Inherited: no
@@ -733,7 +718,7 @@ Block/Cross-Axis Alignment: the 'align-self' property</h3>
 
 			When neither margin in this dimension is ''margin/auto''
 			and neither offset property in this dimension is ''top/auto'',
-			values other than ''<item-position>/stretch'' cause <a href="http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-height">non-replaced absolutely-positioned boxes</a>
+			values other than ''<content-distribution>/stretch'' cause <a href="http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-height">non-replaced absolutely-positioned boxes</a>
 			to use shrink-to-fit sizing for calculating ''width/auto'' measures,
 			and 'align-self' dictates alignment as follows:
 
@@ -748,7 +733,7 @@ Block/Cross-Axis Alignment: the 'align-self' property</h3>
 			and the used value of the offset properties are not adjusted to correct for the over-constraint.
 
 			The ''align-self/auto'' keyword is equivalent to ''start'' on replaced absolutely-positioned boxes,
-			and equivalent to ''<item-position>/stretch'' on all other absolutely-positioned boxes.
+			and equivalent to ''<content-distribution>/stretch'' on all other absolutely-positioned boxes.
 			(This is because CSS 2.1 does not stretch replaced elements to fit into fixed offsets.)
 
 		<dt>Table Cells:
@@ -826,7 +811,7 @@ Inline/Main-Axis Alignment: the 'justify-items' property</h3>
 
 	<pre class="propdef">
 	Name: justify-items
-	Value: auto | <<baseline-position>> | [ <<item-position>> && <<overflow-position>>? ] | [ legacy && [ ''<content-position>/left'' | ''<content-position>/right'' | ''<content-position>/center'' ] ]
+	Value: auto | stretch | <<baseline-position>> | [ <<item-position>> && <<overflow-position>>? ] | [ legacy && [ ''<content-position>/left'' | ''<content-position>/right'' | ''<content-position>/center'' ] ]
 	Initial: auto
 	Applies to: block containers, flex containers, and grid containers
 	Inherited: no
@@ -850,7 +835,7 @@ Inline/Main-Axis Alignment: the 'justify-items' property</h3>
 			Otherwise, ''justify-items/auto'' computes to:
 
 			<ul>
-				<li>''<item-position>/stretch'' for flex containers and grid containers
+				<li>''<content-distribution>/stretch'' for flex containers and grid containers
 				<li>''start'' for everything else
 			</ul>
 
@@ -870,7 +855,7 @@ Block/Cross-Axis Alignment: the 'align-items' property</h3>
 
 	<pre class="propdef">
 	Name: align-items
-	Value: auto | <<baseline-position>> | [ <<item-position>> && <<overflow-position>>? ]
+	Value: auto | stretch | <<baseline-position>> | [ <<item-position>> && <<overflow-position>>? ]
 	Initial: auto
 	Applies to: block-level elements
 	Inherited: no
@@ -891,7 +876,7 @@ Block/Cross-Axis Alignment: the 'align-items' property</h3>
 			Computes to:
 
 			<ul>
-				<li>''<item-position>/stretch'' for flex containers and grid containers
+				<li>''<content-distribution>/stretch'' for flex containers and grid containers
 				<li>''start'' for everything else
 			</ul>
 	</dl>
@@ -1053,7 +1038,7 @@ Changes</h2>
 
 	* Added ''last-baseline'' keyword.
 	* Improved details of baseline alignment.
-	* Changed handling of ''justify-self/auto''/''<item-position>/stretch'' for block-level and abspos elements in 'justify-self'/'align-self' to be more powerful and less confusing.
+	* Changed handling of ''justify-self/auto''/''<content-distribution>/stretch'' for block-level and abspos elements in 'justify-self'/'align-self' to be more powerful and less confusing.
 	* Tightened up grammar combinations with <<overflow-position>> to be restricted to values that actually make sense.
 	* Various clarifications.