[css-ruby-1] Tighten up ruby layout section. w3c#4986 w3c#4980 w3c#4979 w3c#4976 w3c#4974 w3c#4936 w3c#4935 p=fantasai+frivoal

Author: fantasai

css-ruby-1/Overview.bs

@@ -212,7 +212,7 @@ Ruby-specific 'display' Values</h3>
 The Ruby Formatting Context</h4>
 
 	[=Ruby containers=] are non-atomic [=inline-level=] boxes.
-	Like [=inline boxes=] (see [[css-inline-3#model]]),
+	Like regular [=inline boxes=] (see [[css-inline-3#model]]),
 	they break across lines,
 	and their [=containing block=] is the nearest [=block container=] ancestor.
 	And just as the contents of an [=inline box=]
@@ -221,22 +221,27 @@ The Ruby Formatting Context</h4>
 	participate in the same [=inline formatting context=] that contains the [=ruby container=] itself.
 
 	However [=ruby containers=] also establish a <dfn export>ruby formatting context</dfn>
-	that builds further structure around their segment of the [=inline formatting context=].
+	that builds further structure around their segment of the [=inline formatting context=]
+	in order to host their annotations.
 	<span class=note>Note: this [=formatting context=] is <em>not</em> an [=independent formatting context=].</span>
 	[=Ruby bases=], [=ruby annotations=], [=ruby base containers=], and [=ruby annotation containers=]
 	are <dfn export lt="internal ruby boxes|internal ruby display types">internal ruby boxes</dfn>:
 	like [=internal table elements=],
 	they have specific roles in ruby layout,
 	and participate in their [=ruby container=]’s [=ruby formatting context=].
+	In addition to their role in the [=ruby formatting context=],
+	[=ruby bases=] simultaneously participate
+	in the same base-level [=inline formatting context=] as the [=ruby container=],
+	while [=ruby annotations=] participate
+	in separate annotation-level [=inline formatting contexts=]
+	established by the [=ruby container=].
 
 	As with the contents of [=inline boxes=],
 	the [=containing block=] for the contents of a [=ruby container=] (and all its [=internal ruby boxes=])
 	is the [=containing block=] of the [=ruby container=].
 	So floats, for example, are trapped by the [=ruby container=]’s [=containing block=],
 	not any of the ruby box types.
 
-	Issue: Are internal ruby boxes inline-level?
-
 <h4 id="block-ruby">
 Non-Inline Ruby</h4>
 
@@ -653,36 +658,48 @@ White Space Collapsing</h3>
 Ruby Layout</h2>
 
 	When a ruby structure is laid out,
-	its [=base level=] is laid out on the line,
-	aligned according to its 'vertical-align' property
-	exactly as if its [=ruby bases=] were a regular sequence of inline boxes.
-	Each [=ruby base container=] is sized and positioned
-	to contain exactly all of its [=ruby bases=]’ margin boxes.
-	If a [=ruby base container=] has no [=in-flow=] content,
+	its [=base level=] is laid out on the line
+	exactly as if its [=ruby bases=] were a regular sequence of [=inline boxes=]
+	and the [=ruby container=] a regular [=inline box=] wrapped around it
+
+	Each [=base container=] is then sized and positioned
+	to contain exactly all of its [=ruby bases=]’ margin boxes
+	as well as the margin boxes of [=ruby bases=] and [=ruby annotations=]
+	of any descendant [=ruby containers=]
+	also participating in this [=inline formatting context=].
+	(If a [=base container=] has no [=in-flow=] content,
 	it is sized and positioned
-	as if it contained a single empty [=ruby base=].
-
-	[=Ruby annotations=] associated with the [=base level=]
-	are then positioned with respect to their [=ruby base boxes=]
-	according to the applicable 'ruby-position' values.
-	[=Ruby annotations=] within a level (within a single [=ruby container=])
-	are aligned to each other as if they were inline boxes
-	participating in the same inline formatting context.
-	Each [=ruby annotation container=] is sized and positioned
-	to contain exactly all of its [=ruby annotations=]’ margin boxes.
-	If a [=ruby annotation container=] has no [=in-flow=] content,
+	as if it contained a single empty [=ruby base=].)
+
+	[=Ruby annotations=] within a level
+	are aligned to each other in the block axis
+	as if they were [=inline boxes=]
+	participating in the same [=inline formatting context=],
+	effectively establishing a [=line box=]
+	for that [=level=] of annotation in the [=ruby container=].
+	In the inline axis, [=ruby annotations=] are aligned
+	with respect to their [=ruby base boxes=]
+	in accordance with their [=annotation container=]’s 'ruby-merge' value.
+
+	Each [=annotation container=] is then sized and positioned
+	to contain exactly all of its [=ruby annotations=]’ margin boxes
+	as well as the margin boxes of [=ruby bases=] and [=ruby annotations=]
+	of any descendant [=ruby containers=]
+	also participating in this [=annotation level=]’s [=inline formatting context=].
+	(If an [=annotation container=] has no [=in-flow=] content,
 	it is sized and positioned
-	as if it contained a single empty [=ruby annotation=].
-
-	[=Ruby annotation containers=] are stacked outward
-	over or under (depending on 'ruby-position') their corresponding [=ruby base container=],
-	without any intervening space.
+	as if it contained a single empty [=ruby annotation=].)
+	[=Annotation containers=] are then stacked outward
+	over or under (depending on 'ruby-position') their corresponding [=base container=],
+	without any intervening space,
+	thus determining the block-axis positioning of the [=ruby annotations=]
+	with respect to their [=ruby bases=].
 
 	Issue: Should block-axis margins collapse?
 	This makes layout more robust,
 	but is inconsistent with how inlines behave along the inline-axis.
 
-	A ruby container (or fragment thereof)
+	A [=ruby container=] (or fragment thereof)
 	measures as wide as the content of its widest level.
 	Similarly, [=ruby base boxes=] and [=ruby annotation boxes=]
 	within a ruby “column” have the measure of the widest content in that “column”.
@@ -698,6 +715,10 @@ Ruby Layout</h2>
 	Issue: Should the ruby bases and annotations size to the column,
 	or size to the content?
 
+	As in other CSS layout models,
+	relative positioning, transforms, and other graphical effects
+	apply after this layout of the boxes.
+
 <h3 id="inter-character-layout">
 Inter-character Ruby Layout</h3>
 
@@ -719,20 +740,31 @@ Inter-character Ruby Layout</h3>
 <h3 id="box-style">
 Styling Ruby Boxes</h3>
 
-	The 'margin', 'border', and 'padding' properties
-	do not apply to [=ruby base container boxes=]
-	nor to [=ruby annotation container boxes=].
-
-	Issue: Should they also not apply to
-	<a href="#nested-pairing">ruby-internal ruby container boxes</a>?
-	If they do, what does that mean?
-
-	Additionally,
-	the UA is not required to support
+	[=Ruby bases=] and [=ruby containers=] are treated as [=inline boxes=],
+	and all properties that apply to [=inline boxes=],
+	unless otherwise specified,
+	also apply to them in the same way.
+	However, the [=line-relative shift values=] of 'vertical-align'
+	(''vertical-align/top'', ''vertical-align/bottom'')
+	must be ignored (treated as zero).
+
+	All properties that apply to [=inline boxes=],
+	unless otherwise specified,
+	also apply to [=ruby annotations=] in the same way,
+	except 'line-height', which does not apply.
+	Also, the [=line-relative shift values=] of 'vertical-align'
+	(''vertical-align/top'', ''vertical-align/bottom'')
+	must be ignored (treated as zero).
+
+	Neither the [=margin=], [=padding=], [=border=] properties
+	nor the any properties that do not apply to [=inline boxes=]
+	apply to [=base containers=] or [=annotation containers=].
+	Additionally, 'line-height' does not apply to [=annotation containers=].
+
+	The UA is not required to support
 	any of the background properties or outline properties,
 	or any other property that illustrates the bounds of the box
-	on [=ruby base container boxes=], [=ruby annotation container boxes=],
-	or <a href="#nested-pairing">ruby-internal ruby container boxes</a>.
+	on [=ruby base container boxes=] or [=ruby annotation container boxes=].
 	The UA may implement these boxes simply as abstractions for inheritance
 	and control over the layout of their contents.