[css-text-5] Move text-fit to L5 where it belongs #12885

Author: fantasai

css-text-4/Overview.bs

@@ -3,7 +3,7 @@ Title: CSS Text Module Level 4
 Shortname: css-text
 Level: 4
 Status: ED
-Work Status: Exploring
+Work Status: Refining
 Group: csswg
 ED: https://drafts.csswg.org/css-text-4/
 TR: https://www.w3.org/TR/css-text-4/
@@ -9737,175 +9737,6 @@ Aligning a block of text within its container: the 'text-group-align' property</
 			</wpt>
 	</dl>
 
-<h3 id="text-fit-property">
-Text fitting: the 'text-fit' property</h3>
-
-	<wpt title="
-		This section has no coverage yet.
-	"></wpt>
-
-	<pre class="propdef">
-	Name: text-fit
-	Value: [ none | grow | shrink ] [consistent | per-line | per-line-all]? <<percentage>>?
-	Initial: none
-	Applies to: <a>block containers</a>
-	Inherited: yes
-	Percentages: N/A
-	Computed value: specified keywords or computed <<percentage>> value
-	Canonical order: per grammar
-	Animation type: discrete
-	</pre>
-
-	<p>The 'text-fit' property describes how [=inline-level=] contents are
-	scaled if they do not fit to the [=line box=].
-
-	<p>Values have the following meanings:
-
-	<dl dfn-for=text-fit dfn-type=value>
-		<dt><dfn>none</dfn>
-		<dd>
-		    The user agent doesn't scale [=inline-level=] contents to fit to
-			the [=line box=].
-		</dd>
-
-		<dt><dfn>grow</dfn>
-		<dd>
-		    The user agent scales up [=inline-level=] contents to fit to the
-			[=line box=].
-		</dd>
-
-		<dt><dfn>shrink</dfn>
-		<dd>
-		    The user agent scales down [=inline-level=] contents to fit to the
-			[=line box=].
-		</dd>
-
-		<dt><dfn>consistent</dfn>
-		<dd>
-		    Specifies that all lines in the container are scaled with a single
-			scaling factor.
-			This keyword has no effect if ''text-fit/none'' is specified.
-			If none of ''text-fit/consistent'', ''text-fit/per-line'', or
-			''text-fit/per-line-all'' are specified, ''text-fit/consistent'' is
-			assumed.
-		</dd>
-
-		<dt><dfn>per-line</dfn>
-		<dd>
-		    Specifies that each line is scaled with its own scaling factor.
-			However, the last line of the block and lines that end in a forced
-			break are not scaled.
-			This keyword has no effect if ''text-fit/none'' is specified.
-		</dd>
-
-		<dt><dfn>per-line-all</dfn>
-		<dd>
-		    Specifies that each line is scaled with its own scaling factor,
-			including the last line of the block and lines that end in a forced
-			break.
-			This keyword has no effect if ''text-fit/none'' is specified.
-		</dd>
-
-		<dt><dfn>&lt;percentage&gt;</dfn>
-		<dd>
-		    Specifies the limit of the scaling factor.
-		    If ''text-fit/grow'' is specified and the value is 100% or greater,
-			it is the maximum scaling factor.
-		    If ''text-fit/shrink'' is specified and the value is between 0% and
-			100% inclusive, it is the minimum scaling factor.
-		    Otherwise, or if this component is omitted, there is no limit on
-			the scaling factor.
-		</dd>
-	</dl>
-
-	<p>This property provides a functionality to make [=inline-level=] contents
-	exactly fill the inline size of the [=line box=].
-	Unlike ''text-align/justify'' of the 'text-align' property, which achieves
-	this by adjusting spacing between characters, this property scales the
-	font size.
-
-	<p>When ''text-fit/grow'' or ''text-fit/shrink'' is specified,
-	a [=line scaling factor=] is computed for each [=line box=].
-	If ''text-fit/consistent'' applies, all [=line boxes=] are scaled by the
-	smallest computed [=line scaling factor=].
-	Otherwise, each [=line box=] is scaled by its own [=line scaling factor=].
-
-	<p>This property does not affect the 'font-size' [=computed value=],
-	and thus does not affect font-size-relative <<length>> values of other properties.
-	For example, "line-height: 1.5em" and "letter-spacing: 0.1em" are not
-	affected by this scaling.
-
-	<p>The [=used value=] of the text 'font-size' is its [=computed value=]
-	multiplied by the [=line scaling factor=].
-
-	<p>Scaling can change the [=block size=] of a [=line box=],
-	which can in turn change its position along the [=block-axis=].
-	If any feature is active that would cause the [=inline size=] of the
-	[=line box=] to change based on its [=block-axis=] position	(such as
-	'float' or 'initial-letter'), scaling is disabled for the block.
-
-	<div class="issue">
-		If the [=inline size=] of a block container depends on the size of
-		the viewport, its apparent [=inline size=] may not change even if
-		the user changes the page zoom level.
-		In that case, if text is fitted with this feature, the text size may
-		not change at all even though the zoom level has changed.
-		There is no agreement yet on how to deal with this issue. See
-		<a href="https://github.com/w3c/csswg-drafts/issues/12886">csswg#12886</a>.
-	</div>
-
-	<h4 id="text-fit-scaling-factor">Computing line scaling factor</h4>
-
-	<p>The parts of the [=line box=]'s contents that can be scaled by this
-	property are called <dfn>scalable parts</dfn>.
-	These include:
-
-	<ul>
-		<li>
-			Text, including text in [=inline boxes=], but excluding trailing
-			white space.
-
-		<li>
-			Spacing whose [=inline size=] is proportional to the 'font-size'
-			used value.
-			E.g. percentage-based 'letter-spacing' or 'word-spacing', and 'text-autospace'.
-	</ul>
-
-	<p class="note">
-	'text-indent', 'line-padding', non-percentage-based 'letter-spacing' and
-	'word-spacing',	and [=atomic inlines=] are not [=scalable parts=].
-	The [=inline-axis=] 'padding', 'border', and 'margin' of inline boxes are
-	also not [=scalable parts=].
-
-	<p>A <dfn>line scaling factor</dfn> is the ratio by which the
-	[=scalable parts=] of a line must be scaled in order to make its
-	[=inline-level=] content exactly fit the [=line box=]’s [=inline size=].
-
-	<p>A [=line scaling factor=] is computed from:
-
-	<ul>
-		<li>The total [=inline size=] of the [=scalable parts=] in the line.
-		<li>
-			The remaining space in the [=line box=], including any trailing whitespace
-			(which may be negative if the content overflows the [=line box=]).
-	</ul>
-
-	<p>If a <<percentage>> is specified, it clamps the [=line scaling factor=].
-
-	<p class="note">
-	A simple calculation for the [=line scaling factor=] would be
-	<code>(A + B) / A</code>, where A is the total [=inline size=] of
-	[=scalable parts=] and B is the remaining space.
-	However, due to [[css-fonts-4#font-optical-sizing-def|optical sizing]], the
-	[=inline size=] of text might not be perfectly proportional to its
-	'font-size'.
-	The exact method for determining a reasonable [=line scaling factor=]
-	is up to the implementation.
-
-	<p>The [=line scaling factor=] for a [=line box=] with no
-	[=scalable parts=] is 1.
-
-
 <h2 id="spacing">
 Spacing</h2>
 
@@ -12301,13 +12132,6 @@ Text Processing Order of Operations</h2>
 			* 'letter-spacing', 'word-spacing', 'text-spacing', and 'line-padding'
 			* [[#hanging-punctuation-property|hanging punctuation]]
 
-		<li>
-			[[#text-fit-property|text fitting]]
-
-			* <a href="https://www.w3.org/TR/css-fonts-3/">font/glyph selection
-				and positioning</a> [[!CSS-FONTS-3]] may be done again
-			* 'letter-spacing', 'word-spacing', and 'text-spacing' may be updated.
-
 		<li>
 			[[#justification|justification]]
 			(which may affect glyph selection and/or text wrapping, looping back into that step)
@@ -13477,9 +13301,6 @@ Changes</h2>
 	<strong>This draft is kept in sync with [[CSS-TEXT-3]], see [[css-text-3#changes]].</strong><br>
 	Changes specific to Level 4 are listed below.
 
-	Significant changes since the <a href="https://www.w3.org/TR/2024/WD-css-text-4-2024052">29 May 2024 Working Draft</a> include:
-	* Add 'text-fit' property.
-
 	Significant changes since the <a href="https://www.w3.org/TR/2024/WD-css-text-4-20240219/">19 February 2024 Working Draft</a> include:
 	* Renamed the 'text-spacing-trim' value <css>trim-auto</css> to ''trim-both''.
 		(<a href="https://github.com/w3c/csswg-drafts/issues/10161">Issue 10161</a>)