Using A and C edges instead of head and tail.

Author: bert-github

css3-layout/Overview.src.html

@@ -45,7 +45,7 @@ <h2 class="no-num no-toc">[LONGSTATUS] [DATE: 3 August 2004]</h2>
 
   <dt>Latest version:
 
-  <dd> <a href="[LATEST]">http://www.w3.org/TR/css3-layout/</a>
+  <dd><a href="[LATEST]">http://www.w3.org/TR/css3-layout/</a>
 
   <dt>Previous version:
 
@@ -92,8 +92,8 @@ <h2 class="no-num no-toc" id=abstract>Abstract</h2>
 slots so that the visual order becomes independent of the document
 order.
 
-<p>The '::slot()' pseudo-element allows to style the slots
-(backgrounds, borders, etc.)
+<p>The <span>'::slot()' pseudo-element</span> allows to style the
+slots (backgrounds, borders, etc.)
 
 <p>The 'grid-position' property can be used instead of the 'top',
 'left', 'right' and 'bottom' properties from level 2 to position
@@ -739,7 +739,7 @@ <h2>Declaring templates</h2>
 <!--=================================================================-->
 
 
-<h3 id=grid-template> Declaring a template: 'grid-template'</h3>
+<h3 id=grid-template >Declaring a template: 'grid-template'</h3>
 
 <p>The 'grid-template' property implicitly assigns a grid to an
 element and defines named slots in the grid. It can also designate a
@@ -869,7 +869,7 @@ <h3 id=grid-template> Declaring a template: 'grid-template'</h3>
 
 
 
-<h3 id=grid-column-sizes> Specifying the widths of columns:
+<h3 id=grid-column-sizes >Specifying the widths of columns:
 'grid-columns'</h3>
 
 <table class=propdef>
@@ -984,7 +984,7 @@ <h3 id=grid-column-sizes> Specifying the widths of columns:
 
 <!--=================================================================-->
 
-<h3 id=grid-row-sizes> Specifying the height of rows: 'grid-rows'</h3>
+<h3 id=grid-row-sizes >Specifying the height of rows: 'grid-rows'</h3>
 
 <table class=propdef>
 <tbody>
@@ -1097,7 +1097,7 @@ <h3 id=grid-row-sizes> Specifying the height of rows: 'grid-rows'</h3>
 
 <!--=================================================================-->
 
-<h3 id=grid-shorthand> The 'grid' shorthand property</h3>
+<h3 id=grid-shorthand >The 'grid' shorthand property</h3>
 
 <table class=propdef>
 <tbody>
@@ -1281,8 +1281,9 @@ <h3 id=slot-sizes>Calculating the size of the grid</h3>
 <li>Otherwise, if the slot is <em>vertical,</em> then <var>MINW</var>
 is the <em>block dimension</em> of the slot, plus its horizontal
 padding, border and margin (i.e., any 'margin-left', 'margin-right',
-etc., that is set on it by means of the '::slot()' pseudo-element).
-Any ''auto'' margins are counted as 0 in this case.
+etc., that is set on it by means of the <span>'::slot()'
+pseudo-element</span>). Any ''auto'' margins are counted as 0 in this
+case.
 
 <li>Otherwise, if the slot spans at least one column whose width is
 specified as ''max-content'' (or 'minmax()' with a first argument of
@@ -2302,7 +2303,7 @@ <h3>Absolute positioning using a grid: 'grid-position-x' and
 
 <!--=================================================================-->
 
-<h3 id=grid-position> The 'grid-position' shorthand property</h3>
+<h3 id=grid-position >The 'grid-position' shorthand property</h3>
 
 <table class=propdef>
 <tbody>
@@ -2476,15 +2477,8 @@ <h2>Rendering of grid elements</h2>
 
 <h3 id=vertical-alignment>Vertical alignment of the contents of slots</h3>
 
-<p>The 'vertical-align' property of a '::slot()' pseudo-element can be
-used to align elements vertically in a slot (or horizontally, if the
-slot is <span>vertical</span>). The effect is as if the
-<em title="anonymous block of a slot">hypothetical anonymous block</em>
-that contains the slot's contents is positioned as defined below.
-
-<p>For the purpose of this section we define the <dfn>tail edge</dfn>
-and <dfn>head edge</dfn> of a box as a writing-mode-dependent edge as
-follows:
+<p class=issue>Add the effect of 'margin-{top,bottom}: auto',
+generalized from flexbox. (By reference to css3-box?)
 
 <div class=issue>
 <p>Especially in paged material, it is very common for a column of
@@ -2510,34 +2504,43 @@ <h3 id=vertical-alignment>Vertical alignment of the contents of slots</h3>
 <pre>padding-top: 0.5em + 1fill</pre>
 </div>
 
+<p>For the purpose of this section we define the <dfn>A edge</dfn>
+and <dfn>C edge</dfn> of a box as a writing-mode-dependent edge as
+follows:
+
 <table class=equiv-table>
 <thead>
-<tr><th>Value of 'writing-mode' <th>Meaning of “head” <th>Meaning of “tail”
+<tr><th>Value of 'writing-mode' <th>Meaning of “A” <th>Meaning of “C”
 <tbody>
 <tr><th>''horizontal-tb'' <td>top <td>bottom
 <tr><th>''vertical-rl'' <td>right <td>left
 <tr><th>''vertical-lr'' <td>left <td>right
 </table>
 
-<p>E.g., if a box is <span>horizontal,</span> “head edge” means the
-top edge.
+<p>E.g., if a box is <span>horizontal,</span> the “A edge” is the top
+edge.
+
+<p>The 'vertical-align' property of a '::slot()' pseudo-element can be
+used to align elements vertically in a slot (or horizontally, if the
+slot is <span>vertical</span>). The effect is as if the
+<em title="anonymous block of a slot">hypothetical anonymous block</em>
+that contains the slot's contents is positioned as defined below.
 
 <dl>
 <dt>bottom
 <dd>
-The content of the slot is aligned to the <span>tail edge</span> of
-the slot: the tail margin edge of the anonymous block coincides with
-the tail margin edge of the slot.
+The content of the slot is aligned to the <span>C edge</span> of the
+slot: the C margin edge of the anonymous block coincides with the C
+margin edge of the slot.
 
 <dt>middle
 <dd>
 The content of the slot is centered in the slot: the distance between
-the <span title="head edge">head</span> margin edge of the anonymous
-block and the <span title="head edge">head</span> margin edge of the
-slot is equal to the distance between the <span title="tail
-edge">tail</span> margin edge of the anonymous block and
-the <span title="tail edge">tail</span> margin edge of the
-slot.
+the <span title="A edge">A</span> margin edge of the anonymous block
+and the <span title="A edge">A</span> margin edge of the slot is equal
+to the distance between the <span title="C edge">C</span> margin edge
+of the anonymous block and the <span title="C edge">C</span> margin
+edge of the slot.
 
 <p class=note>(Note that if the content overflows the slot, it will
 overflow at both edges.)
@@ -2549,9 +2552,9 @@ <h3 id=vertical-alignment>Vertical alignment of the contents of slots</h3>
 under two constraints:
 
 <ol>
-<li>The <span title="head edge">head</span> margin edge of the
-anonymous block may not be beyond the <span title="head edge">head</span>
-margin edge of the slot.
+<li>The <span title="A edge">A</span> margin edge of the anonymous
+block may not be beyond the <span title="A edge">A</span> margin edge
+of the slot.
 
 <li>If the content has a relevant first line (see below), then the
 baseline of that line must align with the baselines of the relevant
@@ -2582,6 +2585,10 @@ <h3 id=vertical-alignment>Vertical alignment of the contents of slots</h3>
 
 <p>For all other values, the content is aligned as for ''baseline''.
 
+<p class=note>Note that baseline alignment may cause a slot to
+overflow (if the slot is the last in a 'chain') or to remain empty
+(because the first line box is put in the next chained slot instead).
+
 <!--=================================================================-->
 
 <h3 id=paged>Breaking grid elements across pages or columns</h3>
@@ -4168,10 +4175,10 @@ <h2 class="no-num" id="acknowledgments">Acknowledgments</h2>
 prototype.</a> Andrew Fedoniouk
 built <a
 href="http://lists.w3.org/Archives/Public/www-style/2009Mar/0278.html"
-> the second.</a>
+>the second.</a>
 A <a
 href="http://lists.w3.org/Archives/Public/www-style/2009Apr/0383.html"
-> third prototype</a> was made by Alexis Deveria.
+>third prototype</a> was made by Alexis Deveria.
 
 <!--=================================================================-->