- From: Elika Etemad via cvs-syncmail <cvsmail@w3.org>
- Date: Fri, 20 May 2011 02:09:58 +0000
- To: public-css-commits@w3.org
Update of /sources/public/csswg/css3-writing-modes
In directory hutz:/tmp/cvs-serv31949
Modified Files:
Overview.html Overview.src.html
Log Message:
Clarifications to orthogonal flows mappings
Index: Overview.html
===================================================================
RCS file: /sources/public/csswg/css3-writing-modes/Overview.html,v
retrieving revision 1.122
retrieving revision 1.123
diff -u -d -r1.122 -r1.123
--- Overview.html 19 May 2011 23:13:40 -0000 1.122
+++ Overview.html 20 May 2011 02:09:56 -0000 1.123
@@ -30,7 +30,7 @@
<h1>CSS Writing Modes Module Level 3</h1>
- <h2 class="no-num no-toc" id=longstatus-date>Editor's Draft 19 May 2011</h2>
+ <h2 class="no-num no-toc" id=longstatus-date>Editor's Draft 20 May 2011</h2>
<dl>
<dt>This version:
@@ -38,7 +38,7 @@
<dd><a
href="http://dev.w3.org/csswg/css3-writing-modes/">http://dev.w3.org/csswg/css3-writing-modes/</a>
<!--
- <dd><a href="http://www.w3.org/TR/2011/WD-css3-writing-modes-20110519">http://www.w3.org/TR/2011/ED-css3-writing-modes-20110519/</a>
+ <dd><a href="http://www.w3.org/TR/2011/WD-css3-writing-modes-20110520">http://www.w3.org/TR/2011/ED-css3-writing-modes-20110520/</a>
-->
@@ -2331,11 +2331,15 @@
href="#vertical-rl"><code class=css>vertical-rl</code></a>’).
</ul>
- <p>To handle the second case, for the purposes of calculating the layout of
- the box, the physical dimensions corresponding to the extent and measure
- of the containing block are determined using the writing mode of the box
- under consideration, not the writing mode of the element associated with
- the containing block.
+ <p>To handle the second case, CSS layout calculations are divided into two
+ phases: sizing a box, and positioning the box within its flow. In the
+ sizing phase—calculating the width and height of the box—the
+ dimensions of the box and the containing block are mapped to the measure
+ and extent and calculations performed accordingly using the writing mode
+ of the element. In the positioning phase—calculating the positioning
+ offsets, margins, borders, and padding—the dimensions of the box and
+ its containing block are mapped to the measure and extent and calculations
+ performed according to the writing mode of the containing block.
<p>For example, if a vertical block is placed inside a horizontal block,
then when calculating the physical height (which is the measure) of the
@@ -2343,37 +2347,39 @@
the measure of the child's containing block, even though the physical
height is the extent, not the measure, of the parent block.
+ <p>Since auto auto margins are resolved consistent with the containing
+ block's writing mode, a box establishing an orthogonal flow, can, once
+ sized, be aligned or centered within its containing block just like other
+ block-level elements by using auto margins.
+
<p>It is common in CSS for a containing block to have a defined measure,
but not a defined extent. This typically happens in CSS2.1 when a
containing block has an ‘<a href="#auto"><code
class=css>auto</code></a>’ height, for example: its width is given
by the calculations in <a
href="http://www.w3.org/TR/CSS21/visudet.html#blockwidth">10.3.3</a>, but
- its extent depends on its contents. In such cases the <i>available
- measure</i> is defined, but the <i>available extent</i> is infinite.
+ its extent depends on its contents. In such cases the <dfn
+ id=available-measure>available measure</dfn> is defined as the measure of
+ the containing block; but the <dfn id=available-extent>available
+ extent</dfn>, which would otherwise be the extent of the containing block,
+ is infinite.
- <p>Orthogonal flows allow the opposite to happen: for the <i>available
- extent</i> to be defined, but the <i>available measure</i> to be infinite.
- In such cases a percentage of the containing block measure cannot be
- defined, and thus the initial containing block's measure is used to
- calculate such percentages instead. <span class=issue>Is this definition
- of percentages a good idea?</span>
+ <p>Orthogonal flows allow the opposite to happen: for the <a
+ href="#available-extent"><i>available extent</i></a> to be defined, but
+ the <a href="#available-measure"><i>available measure</i></a> to be
+ infinite. In such cases a percentage of the containing block measure
+ cannot be defined, and thus the initial containing block's measure is used
+ instead as a <a href="#fallback-measure"><i>fallback measure</i></a> to
+ calculate such percentages.
<h4 id=orthogonal-auto><span class=secno>7.3.1. </span> Auto-sizing in
Orthogonal Flows</h4>
<p>If the computed measure of an element establishing an orthogonal flow is
‘<a href="#auto"><code class=css>auto</code></a>’, then the
- used measure is calculated as the shrink-to-fit (<a
- href="#fit-content"><i>fit-content</i></a>) value using the initial
- containing block's measure as the available size in the shrink-to-fit
- algorithm.
-
- <p class=note>As with other shrink-to-fit boxes, the width and height
- calculations occur before auto margin calculations in the inline
- dimension, and therefore a block box establishing an orthogonal flow, once
- sized, can be aligned or centered within its containing block just like
- other block-level elements by using auto margins.
+ used measure is calculated as the <a
+ href="#fit-content"><i>fit-content</i></a> (shrink-to-fit) size using the
+ initial containing block's measure as the available measure.
<h4 id=orthogonal-multicol><span class=secno>7.3.2. </span> Multi-column
Layout in Orthogonal Flows</h4>
@@ -3064,9 +3070,10 @@
href="http://www.w3.org/TR/CSS21/visudet.html#blockwidth">CSS2.1§10.3.3</a>,
the <dfn id=fill-available-measure>fill-available measure</dfn> is
calculated by subtracting out the element's margins, borders, and padding
- from the <i>available measure</i> and flooring the result at zero. If the
- available measure is infinite, then a <dfn id=fallback-measure>fallback
- measure</dfn> is used in place of the <i>available measure</i> in this
+ from the <a href="#available-measure"><i>available measure</i></a> and
+ flooring the result at zero. If the available measure is infinite, then a
+ <dfn id=fallback-measure>fallback measure</dfn> is used in place of the
+ <a href="#available-measure"><i>available measure</i></a> in this
calculation. (In the case of orthogonal flows, this is the measure of the
initial containing block.) The <dfn
id=fill-available-extent>fill-available extent</dfn> is similarly
Index: Overview.src.html
===================================================================
RCS file: /sources/public/csswg/css3-writing-modes/Overview.src.html,v
retrieving revision 1.127
retrieving revision 1.128
diff -u -d -r1.127 -r1.128
--- Overview.src.html 19 May 2011 23:13:40 -0000 1.127
+++ Overview.src.html 20 May 2011 02:09:56 -0000 1.128
@@ -1698,12 +1698,18 @@
example, ''horizontal-tb'' and ''vertical-rl'').</li>
</ul>
- <p>To handle the second case, for the purposes of calculating the
- layout of the box, the physical dimensions corresponding to the
- extent and measure of the containing block are determined
- using the writing mode of the box under consideration, not the
- writing mode of the element associated with the containing block.
-
+ <p>To handle the second case, CSS layout calculations are divided into
+ two phases: sizing a box, and positioning the box within its flow.
+ In the sizing phase—calculating the width and height of the
+ box—the dimensions of the box and the containing block
+ are mapped to the measure and extent and calculations performed
+ accordingly using the writing mode of the element.
+ In the positioning phase—calculating the positioning offsets,
+ margins, borders, and padding—the dimensions of the box and
+ its containing block are mapped to the measure and extent and
+ calculations performed according to the writing mode of the
+ containing block.
+
<p>For example, if a vertical block is placed inside a horizontal
block, then when calculating the physical height (which is the
measure) of the child block the physical height of the parent
@@ -1711,37 +1717,36 @@
block, even though the physical height is the extent, not the
measure, of the parent block.</p>
+ <p>Since auto auto margins are resolved consistent with the containing
+ block's writing mode, a box establishing an orthogonal flow, can,
+ once sized, be aligned or centered within its containing block just
+ like other block-level elements by using auto margins.
+
<p>It is common in CSS for a containing block to have a defined
measure, but not a defined extent. This typically happens in
CSS2.1 when a containing block has an ''auto'' height, for
example: its width is given by the calculations in
<a href="http://www.w3.org/TR/CSS21/visudet.html#blockwidth">10.3.3</a>,
but its extent depends on its contents. In such cases the
- <i>available measure</i> is defined, but the <i>available extent</i>
- is infinite.
+ <dfn>available measure</dfn> is defined as the measure of the
+ containing block; but the <dfn>available extent</dfn>, which
+ would otherwise be the extent of the containing block, is
+ infinite.
<p>Orthogonal flows allow the opposite to happen: for the
<i>available extent</i> to be defined, but the <i>available
measure</i> to be infinite. In such cases a percentage of the
containing block measure cannot be defined, and thus the
- initial containing block's measure is used to calculate such
- percentages instead. <span class="issue">Is this definition
- of percentages a good idea?</span>
+ initial containing block's measure is used instead as a
+ <i>fallback measure</i> to calculate such percentages.
<h4 id="orthogonal-auto">
Auto-sizing in Orthogonal Flows</h4>
<p>If the computed measure of an element establishing an orthogonal
flow is ''auto'', then the used measure is calculated as the
- shrink-to-fit (<i>fit-content</i>) value using the initial containing
- block's measure as the available size in the shrink-to-fit algorithm.
-
- <p class="note">As with other shrink-to-fit boxes, the width and
- height calculations occur before auto margin calculations in the
- inline dimension, and therefore a block box establishing an
- orthogonal flow, once sized, can be aligned or centered within
- its containing block just like other block-level elements by
- using auto margins.
+ <i>fit-content</i> (shrink-to-fit) size using the initial containing
+ block's measure as the available measure.
<h4 id="orthogonal-multicol">
Multi-column Layout in Orthogonal Flows</h4>
Received on Friday, 20 May 2011 02:10:00 UTC