[css-inline-3] Define interaction of 'text-align' and 'initial-letters'. #884

Author: fantasai

css-inline-3/Overview.bs

@@ -462,7 +462,7 @@ Creating Initial Letters: the 'initial-letters' property</h3>
 		<dt><dfn><<integer>></dfn>
 		<dd>
 			This optional second argument 
-			defines the number of lines the initial letter should sink.
+			defines the number of lines the initial letter should <dfn>sink</dfn>.
 			Values less than one are invalid.
 			If omitted, it duplicates the first argument,
 			floored to the nearest positive whole number.
@@ -513,8 +513,10 @@ Creating Initial Letters: the 'initial-letters' property</h3>
 		The following code will create a 2-line dropped initial letter at the beginning of each paragraph:
 		<pre>p::first-letter { initial-letters: 2; }</pre>
 	</div>
-	
-	<p id="first-most-inline-level">
+
+<h4 id="first-most-inline-leve">
+Applicability</h4>
+
 	To give authors more control over which characters can be styled as an <a>initial letter</a>
 	and to allow the possibility of multi-character <a>initial letters</a>
 	(such as for first word or first phrase styling),
@@ -570,7 +572,8 @@ Creating Initial Letters: the 'initial-letters' property</h3>
 	its <a>used value</a> is ''initial-letters/normal'',
 	and it is not formatted as an <a>initial letter</a>.
 
-	The 'initial-letters' property is undefined on children of <a>ruby</a> base container boxes
+	The effect of the 'initial-letters' property is undefined
+	on children of <a>ruby</a> base container boxes
 	and on <a>ruby</a> container boxes.
 
 <h4 id="initial-letter-properties">
@@ -1133,7 +1136,46 @@ Initial Letter Wrapping: the 'initial-letters-wrap' property</h3>
 	</div>
 
 <h3 id="initial-letter-indentation">
-Indentation and Multi-line Effects</h3>
+Line Layout</h3>
+
+	An <a>initial letter box</a> is considered in-flow in its <a>block formatting context</a>,
+	and is part of the contents of the <a>line box</a> in which it originates.
+	Aside from vertical alignment,
+	its interaction with the rest of the contents of the line is as normal,
+	except in a few specific circumstances&hellip;
+
+<h4 id="initial-letter-inline-flow">
+Inline Flow Layout: Alignment and Justification</h4>
+
+	For a raised <a>initial letter box</a> (<a>sink</a> of ''1'')
+	no special consideration is given for alignment and justification:
+	it is treated similar to any other inline-level content.
+
+	However, if the <a>initial letter box</a> is sunk by more than ''1'',
+	then its inline-start edge is anchored to the inline-start edge
+	of the line box (after indentation)
+	and text alignment affects the remaining content of the line
+	in the remaining space,
+	without moving the <a>initial letter box</a> itself.
+
+	Note: The CSSWG was not aware of any reasonable use cases
+	for mixing non-start text alignment with dropped initial letters,
+	and this was the most sensible behavior proposed.
+	This behavior may be reconsidered if use cases require otherwise.
+
+	In addition, to ensure consistent alignment of all the impacted lines,
+	any 'letter-spacing' or <a>justification opportunity</a>
+	that would normally be introduced by
+	the juxtaposition of the contents of a sunken <a>initial letter</a>
+	and the subsequent contents of the line
+	is suppressed.
+	(Note that this does not affect 'word-spacing' or
+	the <a>justification opportunity</a> introduced by a <a>word separator</a>
+	because that space is provided by the <a>typographic character unit</a> alone
+	and not by its juxtaposition with an adjacent character.)
+
+<h4 id="initial-letter-indentation">
+Edge Effects: Indentation and Hanging Punctuation</h4>
 
 	'text-indent' and 'hanging-punctuation'
 	apply to the first line of text as normal in the presence of initial letters.
@@ -1144,7 +1186,10 @@ Indentation and Multi-line Effects</h3>
 		<img src="images/InitialLetterWithTextIndent.png" width="300"
 		     alt="initial letter with text indent">
 		<figcaption>Initial letter with text indent. </figcaption>
-	</figure>
+	</figure>b
+
+<h4 id="initial-letter-multi-line">
+Multi-line Initial Letters</h4
 
 	If an initial letter is too long to fit on one line,
 	it wraps (according to the usual text-wrapping rules),