[css-align] Markup fixes, better linking, specify how to resolve a conflict between self and content baseline alignment on the same box.

--HG--
extra : rebase_source : de45114ffa146314fa1f97f7a4c8eba53dfbeed4

Author: tabatkins

css-align/Overview.bs

@@ -14,7 +14,7 @@ Previous Version: http://www.w3.org/TR/2012/WD-css3-align-20120612/
 Abstract: This module contains the features of <a href="http://www.w3.org/TR/CSS/">CSS</a> relating to the alignment of boxes within their containers in the various CSS box layout models: block layout, table layout, flex layout, and grid layout. (The alignment of text and inline-level content is defined in [[CSS3TEXT]] and [[CSS3LINE]].)
 !Issue Tracking: <a href="http://www.w3.org/Style/CSS/Tracker/products/39">http://www.w3.org/Style/CSS/Tracker/products/39</a>
 Link Defaults: selectors-3 (dfn) first formatted line, css-flexbox-1 (dfn) flex line, css-multicol-1 (dfn) multi-column element, css-fonts-3 (dfn) first available font, css21 (property) max-width/max-height/min-width/min-height
-Ignored Terms: table cell
+Ignored Terms: table cell, stretch
 At Risk: ''last-baseline''
 </pre>
 
@@ -280,7 +280,7 @@ Baseline Alignment: the ''baseline'' and ''last-baseline'' keywords</h3>
 	<dl dfn-type=value dfn-for="justify-content, justify-self, justify-items, align-content, align-self, align-items">
 		<dt><dfn>baseline</dfn>
 		<dd>
-			Indicates <dfn>first-baseline alignment</dfn>:
+			Indicates <dfn dfn>first-baseline alignment</dfn>:
 			aligns one of the box's <a>first baselines</a>
 			with the corresponding <a>first baselines</a>
 			of all the boxes in its <a>baseline-sharing group</a>.
@@ -291,7 +291,7 @@ Baseline Alignment: the ''baseline'' and ''last-baseline'' keywords</h3>
 
 		<dt><dfn>last-baseline</dfn>
 		<dd>
-			Indicates <dfn>last-baseline alignment</dfn>:
+			Indicates <dfn dfn>last-baseline alignment</dfn>:
 			aligns one of the box's <a>last baselines</a>
 			with the corresponding <a>last baselines</a>
 			of all the boxes in its <a>baseline-sharing group</a>.
@@ -301,17 +301,27 @@ Baseline Alignment: the ''baseline'' and ''last-baseline'' keywords</h3>
 			(Content that has no <a>last baselines</a> is thus end-aligned.)
 	</dl>
 
+	These values give a box a <dfn>baseline alignment preference</dfn>:
+	either "first" or "last", respectively.
+
 	When specified for 'align-content'/'justify-content',
 	these values trigger <a>baseline content-alignment</a>,
 	shifting the content of the box within the box,
 	and may also affect the sizing of the box itself.
-	See <a section href="#baseline-align-content"></a>.
+	See [#baseline-align-content].
 
 	When specified for 'align-self'/'justify-self',
 	these values trigger <a>baseline self-alignment</a>,
 	shifting the entire box within its container,
 	which may affect the sizing of its container.
-	See <a section href="#baseline-align-self"></a>.
+	See [#baseline-align-self].
+
+	If both <a>baseline content-alignment</a> <em>and</em> <a>baseline self-alignment</a> are specified in the same axis,
+	only <a>baseline self-alignment</a> is honored in that axis;
+	the content-alignment in that axis must be treated as ''self-start''.
+
+	Issue: The previous paragraph is fairly arbitrary.
+	Need some experience to make sure it's the correct choice out of the two possibilities.
 
 	<p class='issue'>Add example images.
 
@@ -325,9 +335,10 @@ Baseline Alignment: the ''baseline'' and ''last-baseline'' keywords</h3>
 	This is possible only if they
 
 	<ul>
-		<li>share an <a>alignment context</a> whose axis is parallel to their <i>inline axis</i>
-		<li>have the same <a>block flow direction</a> and <a>line orientation</a>,
-		<li>participate in the same type of baseline alignment (first- vs. last-line, content- vs. self-alignment)
+		<li>share an <a>alignment context</a> whose axis is parallel to their <a>inline axis</a>
+		<li>either have the same <a>block flow direction</a> and <a>baseline alignment preference</a>,
+			or have opposite <a>block flow direction</a> and opposite <a>baseline alignment preference</a>
+			(in other words, the baselines that want to align are on the same side of the alignment context).
 	</ul>
 
 	Boxes <dfn title="shared alignment context|alignment context">share an alignment context</dfn> along a particular axis when they are:
@@ -919,7 +930,7 @@ Block/Cross-Axis Alignment: the 'align-items' property</h3>
 <h2 id='baseline-rules'>
 Determining the Baseline of a Box</h2>
 
-	The <dfn title="baselines of a box"></dfn><dfn>first baselines</dfn> (and <dfn>last baselines</dfn>) of a box
+	The <dfn export title="first baselines|baselines of a box">first baselines</dfn> (and <dfn export>last baselines</dfn>) of a box
 	for a given axis
 	are a set of baselines (alphabetic, central, etc.)
 	nominally associated with the first (last) line of text within the box.
@@ -928,15 +939,15 @@ Determining the Baseline of a Box</h2>
 	(See 'alignment-baseline'.)
 	Note that boxes might not have baselines in a particular axis.
 
-	The first and last <i>baselines of a box</i>
+	The first and last <a>baselines of a box</a>
 	are determined differently based on the layout model, as follows:
 
 	<dl>
 		<dt>block containers
 		<dd>
 			The first (last) inline-axis baselines of a block container
-			are generated from the dominant baseline of the first (last) in-flow line box in the block container,
-			or are taken from the first (last) in-flow block-level child in the block container that contributes a set of baselines,
+			are <a>generated</a> from the dominant first (last) baseline of the first (last) in-flow line box in the block container,
+			or are taken from the first (last) in-flow block-level child in the block container that contributes a set of first (last) baselines,
 			whichever comes first (last).
 			If there is no such line box or child,
 			then the block container has no baselines.
@@ -949,23 +960,23 @@ Determining the Baseline of a Box</h2>
 		<dt>tables
 		<dd>
 			The first (last) inline-axis baselines of a table box are
-			the baselines of its first (last) row.
+			the first (last) baselines of its first (last) row.
 
 			When finding the baselines of an inline-block,
 			any baselines contributed by table boxes must be skipped.
 			(This quirk is a legacy behavior from [[CSS21]].)
 
-			The block-axis baselines of a table box are the baselines of its first (last) column.
+			The first (last) block-axis baselines of a table box are the first (last) baselines of its first (last) column.
 
 		<dt>table rows
 		<dd>
 			If any cells in the row participate in ''baseline'' (''last-baseline'') alignment along the row axis,
 			the first (last) inline-axis baselines of the row
-			are generated from their shared <a>alignment baseline</a>
+			are <a>generated</a> from their shared <a>alignment baseline</a>
 			and the row's <a>first available font</a>,
 			after alignment has been performed.
 			Otherwise, the first (last) inline-axis baselines of the row
-			are synthesized from the lowest and highest content edges of the cells in the row.
+			are <a>synthesized</a> from the lowest and highest content edges of the cells in the row.
 			[[!CSS21]]
 
 			A table row has no block-axis baselines.
@@ -975,11 +986,11 @@ Determining the Baseline of a Box</h2>
 			If any cells in the column participate in ''baseline'' (''last-baseline'') alignment
 			along the column axis (by having a writing mode perpendicular to that of the table),
 			the first (last) block-axis baselines of the column
-			are generated from their shared <a>alignment baseline</a>
+			are <a>generated</a> from their shared <a>alignment baseline</a>
 			and the column's <a>first available font</a>,
 			after alignment has been performed.
 			Otherwise, the the first (last) inline-axis baselines of the row
-			are synthesized from the extreme content edges of the cells in the row.
+			are <a>synthesized</a> from the extreme content edges of the cells in the row.
 			[[!CSS21]]
 
 			A table column has no inline-axis baselines.
@@ -993,10 +1004,10 @@ Determining the Baseline of a Box</h2>
 			See <a href="http://www.w3.org/TR/css3-grid-layout/#grid-baselines">Grid Baselines</a> in [[!CSS3-GRID-LAYOUT]].
 	</dl>
 
-	To <dfn>generate baselines</dfn> for a box from a single baseline,
+	To <dfn local-title=generate|generated>generate baselines</dfn> for a box from a single baseline,
 	use the baseline table from the font settings and <a>first available font</a> of that box.
 
-	To <dfn>synthesize baselines</dfn> from a rectangle (or two parallel lines),
+	To <dfn local-title=synthesize|synthesized>synthesize baselines</dfn> from a rectangle (or two parallel lines),
 	synthesize the alphabetic baseline from the lower line
 	and the central baseline by averaging the positions of the upper and lower lines.