(1) specify closest support font size when specified size isn't (8.2.9);
authorGlenn Adams <glenn@skynav.com>
Thu, 20 Jun 2013 12:35:40 +0800
changeset 409 70165fde28e1
parent 408 c364f0b4f06e
child 410 7c7dd3e5b383
(1) specify closest support font size when specified size isn't (8.2.9);
(2) add to second note that single length using 'c' unit is in relation to cell height (8.2.9);
(3) add to note that intent is that per-inline-height-rectangle apply for line allocation rectangle (8.2.12);
(4) rephrase mapping of origin/extent in step (5) to use top, left, right, bottom (9.3.3);
(5) add explicit line-stacking-strategy mapping in step (5) (9.3.3;
(6) revert prior change to exclusivity of metadata attributes vs child elements, improve language to reflect both can be used (12.1.1);
--- a/ttml10/spec/ttaf1-dfxp.xml	Wed Jun 19 17:21:18 2013 +0800
+++ b/ttml10/spec/ttaf1-dfxp.xml	Thu Jun 20 12:35:40 2013 +0800
@@ -4265,11 +4265,13 @@
 each character child of a <el>p</el> element is considered to be enclosed in an anonymous
 <p>If a specified value of this attribute is not supported,
-then a presentation processor must interpret the attribute as if the
-value <code>1c</code> were specified.</p>
+then a presentation processor must interpret the attribute as if the closest supported value were
 <note role="elaboration">
 <p>The expression <code>1c</code> means one cell, where <code>'c'</code> expresses
-the <emph>cell</emph> length unit as defined by <specref ref="style-value-length"/>.</p>
+the <emph>cell</emph> length unit as defined by <specref ref="style-value-length"/>.
+When a single &lt;length&gt; is expressed using cell units, then it refers to the height of
+the <emph>Computed Cell Size</emph>.</p>
 <note role="example">
 <p>As specified above, the use of percentage units to express font size are interpreted as
@@ -4620,7 +4622,10 @@
 <note role="derivation">
 <p>The semantics of the style property
 represented by this attribute are based upon that defined by <bibref ref="xsl11"/>,
-&sect; 7.16.4.</p>
+&sect; 7.16.4. Furthermore, it is the intention of this specification that the
+allocation rectangle of a line be consistent with the <phrase role="strong">per-inline-height-rectangle</phrase>
+as defined by <bibref ref="xsl11"/>, &sect; 4.5, i.e., that a CSS-style line box stacking strategy be used.
 <div3 id="style-attribute-opacity">
@@ -7449,9 +7454,9 @@
 <p>map each non-empty <el>region</el> element to an <el>fo:block-container</el>
 element with an <att>absolute-position</att> attribute with value
-<code>absolute</code>, and where the region's position and extent are mapped to equivalent
-<att>top</att>, <att>left</att>, <att>width</att>, and <att>height</att>
+<code>absolute</code>, with <att>top</att>, <att>left</att>, <att>bottom</att>, and <att>right</att>
+attributes that express a rectangle equivalent to the region's origin and
+extent, and with a <att>line-stacking-strategy</att> attribute with value <code>line-height</code>;</p>
 <p>for each <el>body</el>, <el>div</el>, and <el>p</el> element that is not
@@ -8089,16 +8094,12 @@
 <p>The <el>metadata</el> element functions as a generic container for metadata
-<p>A <el>metadata</el> element must not express <emph>metadata information</emph>
-by both (1) specifying this information in the form of one or more attributes and (2)
-specifying this information in the form of one or more child elements.  Both types
-of <emph>metadata information</emph> are referred to in this document as metadata
-<note role="elaboration">
-<p>In other words, a given <el>metadata</el> element may specify metadata information
-either (1) as attributes, or (2) as child elements, but it may not specify both forms
-of metadata information together.</p>
+<p>Metadata information may be expressed with a <el>metadata</el> element by specifying
+(1) one or more metadata attributes on the <el>metadata</el> element,
+(2) one or more metadata child elements in the <el>metadata</el> element, or
+(3) a combination of metadata attributes and metadata child elements.  Both types
+of metadata information are referred to in this document as <emph>metadata
 <table id="elt-syntax-metadata" role="syntax">
 <caption>XML Representation &ndash; Element Information Item: metadata</caption>
@@ -8120,8 +8121,8 @@
 <note role="explanation">
 <p>The meaning of a specific metadata item must be evaluated in the
-context of where it appears. The core vocabulary catalog permits an
-arbitrary number of <el>metadata</el> element children of any
+context where it appears. The core vocabulary catalog permits an
+arbitrary number of <el>metadata</el> element children on any
 content element type except for the <el>tt</el> element. See specific element
 vocabulary definitions for any constraints that apply to such
--- a/ttml10/spec/ttml-changes.html	Wed Jun 19 17:21:18 2013 +0800
+++ b/ttml10/spec/ttml-changes.html	Thu Jun 20 12:35:40 2013 +0800
@@ -134,11 +134,19 @@
   intended to supplant or change the nominal interpretation of this property as defined
   by XSL-FO and CSS2.
 * In 8.2.9, replace "metrics" with "units".
+* In 8.2.9, specify that the closest supported font size should be used when the exact
+  specified font size is not supported. Previously the size '1c' was indicated for use
+  as a fallback size, however, this causes undesirable behavior when the specified value
+  is closer to a supported size than 1c, which itself need not be a supported size.
+* In 8.2.9, add to second note that a single length that uses cell units refers to the
+  height of the computed cell size.
 * In 8.2.9, clarify that meaning of percentage when expressed on root element (which has
   no parent) is interpreted relative to cell size.
 * In 8.2.9, add note with example of using percentage on font size on root element.
 * In 8.2.9, clarify that a negative value in a font size is not valid.
 * In 8.2.12, clarify that a negative value in a line height is not valid.
+* In 8.2.12, extend note (at end of section) to indicate intent that line allocation
+  rectangle be the per-inline-height-rectangle per XSL1.1 section 4.5.
 * In 8.2.13, remove redundant requirement to threshold alpha value greater than 1.0
   since this is already mandated in 8.3.1.
 * In 8.2.14, remove "if specified, or the external authoring context, if not specified"
@@ -180,6 +188,10 @@
 * In 9.3.3, add note expressing the conceptual rather than literal use of XSL-FO as
   a means for defining formatting semantics.
 * In 9.3.3, remove confusing "be equivalent to" qualifications.
+* In 9.3.3 step (5), rephrase the mapping of region's position (origin) and extent to specify
+  use of top, left, right, and bottom instead of top, left, width, and height.
+* In 9.3.3 step (5), add line-stacking-strategy attribute to indicate that line-height (i.e.,
+  CSS compatible) stacking strategy applies.
 * In 9.3.3 step (7), clarify the intended use of synthesized blocks in order before and after a
   block's nominal content in order to provide necessary space filler along the before and
   after edges to fill a region with the block's background color. See also new note at end
@@ -190,9 +202,6 @@
 * In 10.3.1, clarify that use of frames and sub-frames with clock time base is considered
   an error.
 * In 10.4, add references to new time expression semantics appendix (N).
-* In 12.1.1, improve language expressing mutual exclusion constraint on use of metadata
-  element to express either (1) attributes or (2) element children [but not both]. Add
-  note clarifying this even further.
 * In 12.2.1, clarify that a duplicate IDREF should not appear in xs:IDREFS value of
   ttm:agent attribute.
 * In 12.2.2, add note suggesting use of infix organization identifier to prevent