[css-inline-3] Align 'line-sizing' property to latest WG discussions. #3199

Author: fantasai

css-inline-3/Overview.bs

@@ -329,95 +329,62 @@ Line Sizing Containment: the 'line-sizing' property
 
 	
 	Name: line-sizing
-	Value: quirks-behavior | current-behavior | better-behavior | box-model-behavior | absolute-behavior
-	Initial: current-behavior
-	Applies to: block containers? inline boxes?
+	Value: legacy | normal
+	Initial: legacy
+	Applies to: inline boxes
 	Inherited: yes
 	Percentages: N/A
 	Computed value: the specified keyword
 	
 
 	ISSUE: This is a rought draft of a proposal, and has not yet been approved by the CSSWG.
-	Many variants have been included to promote discussion of possible behaviors;
-	not all of them are expected to be kept.
 	See discussion in Issue 3199, Hyatt's message, and dbaron's proposal.
-	Also all the keywords are expected to be renamed.
 
 	This property controls the method by which line boxes are sized,
 	and thus the spacing between lines of text.
 
 	Values have the following meanings:
 
 	
-		quirks-behavior
+		legacy
 		
-			Line boxes are sized, and content positioned within them,
-			as defined in [[!CSS2]] except that
+			The inline box contributes to the sizing of its line box
+			based on its 'line-height',
+			rather than based on its box edges,
+			as defined in [[!CSS2]].
+			In Quirks Mode [[!QUIRKS]],
 			any inline box fragment
 			that has zero borders and padding and
 			that does not directly contain text or preserved white space [[!CSS-TEXT-3]]
-			is ignored for this purpose.
-
-		current-behavior
-		
-			Line boxes are sized, and content positioned within them,
-			as defined in [[!CSS2]].
+			is ignored when sizing the line box.
 
 			Note: In this model, vertical rhythm is broken
 			any time there is a change in font metrics within a paragraph.
 
-		better-behavior
+		normal
 		
-			Line boxes are sized, and content positioned within them,
-			as defined in [[!CSS2]],
-			except that positive half-leading is not applied
-			to any box other than the root inline box.
+			The inline box contributes to the sizing of its line box
+			based on its margin box,
+			rather than its 'line-height'.
+			Half-leading is inserted inside the content box edges,
+			rather than overlapping the padding/border/margin areas.
+			However, positive half-leading is only applied to the root inline box.
+			Negative half-leading is applied to all inline boxes,-
+			reducing the size of the content box as needed.
 
 			Note: This will give consistent line spacing
 			as long as there is some amount of leading added,
 			such that the half-leading on the root inline
-			is large enough to accommodate the unleaded ascent of its descendants.
-			The line box will grow to accommodate
+			is large enough to accommodate the unleaded ascent/descent of its descendants.
+			The line box will grow, however, to accommodate
 			content that would otherwise overflow,
-			avoiding overlap between lines.
-
-		box-model-behavior
-		
-			Line boxes are sized to fit the root inline box
-			and its half-leading,
-			as well as the outer edges of any inline-level descendants
-			in the same inline formatting context.
-			Positive half-leading is not applied to any other inline box;
-			negative half-leading is applied as negative margins
-			to inline boxes whose block-axis margins, borders, and padding
-			are zero.
-
-			Note: This mode is similar to ''better-behavior'',
-			but re-uses the familiar margin/border/padding box model
-			of controlling spacing.
-			However to ensure that 'line-height' < 1 behaves as expected,
-			the default case (no margin/border/padding)
-			needs to apply negative leading to such inlines.
-
-		absolute-behavior
-		
-			Line boxes are sized to fit the root inline box
-			and its half-leading;
-			no other boxes are considered.
-			Inline-level content may overflow the line box
-			and overlap adjacent lines
-			if it extends higher or lower
-			than the edges of the root inline box’s leading.
+			to avoid overlap between lines.
 	
 
 	ISSUE: Should this property apply to block containers or to inline boxes?
 	In the latter case, an individual inline could say "pay attention to me"
 	or "don't pay attention to me".
 
-	ISSUE: Need better names. Maybe `loose | normal | strict | absolute`?
-	Maybe `quirks | legacy | normal | absolute`?
-	Something else?
-
 
 Drawing Inline Boxes
 
@@ -451,10 +418,11 @@ Inline Box Heights: the 'inline-sizing' property
 
 		stretch
 		
-			The logical height of the content area
+			Once the line box has been sized,
+			the final logical height of the inline box’s content area
 			is calculated as the stretch fit
-			into the line box.
-			The box is then positioned such that its margin edges
+			into the line box,
+			and it is positioned such that its margin edges
 			coincide with the line box’s edges.
 	
 
@@ -1841,13 +1809,23 @@ A.2: Synthesizing Baselines for Replaced Content
 
 Changes
 
+	Changes since the
+	8 August 2018 Working Draft
+	include:
+
+	
+		
+			Added 'line-sizing' property to control how inter-line spacing is calculated.
+			(Issue 3199)
+	
+
 	Changes since the
 	24 May 2016 Working Draft
 	include:
 
 	
 		
-			Added outline of property to control the logical height of inline boxes.
+			Sketched out property to control the logical height of inline boxes.
 			(Issue 1974)
 		
 			Better defined handling of initial letters