(merge)

Author: bert-github

css-font-loading/Overview.bs

@@ -336,6 +336,16 @@ The <code>load()</code> method</h3>
 	When this happens,
 	they must act as if they had called the corresponding {{FontFace}}’s {{FontFace/load()}} method described here.
 
+	Note: Some UAs utilize a "font cache"
+	which avoids having to download the same font multiple times
+	on a page or on multiple pages within the same origin.
+	Multiple {{FontFace}} objects can be mapped to the same entry in the font cache,
+	which means that a {{FontFace}} object might start loading unexpectedly,
+	even if it's not in a {{FontFaceSet}},
+	because some other {{FontFace}} object pointing to the same font data
+	(perhaps on a different page entirely!)
+	has been loaded.
+
 <h3 id='font-face-css-connection'>
 Interaction with CSS’s ''@font-face'' Rule</h3>
 
@@ -429,7 +439,7 @@ The <code>FontFaceSet</code> Interface</h2>
 		<dd>
 			This attribute reflects the {{FontFaceSet}}'s {{[[ReadyPromise]]}} slot.
 
-			See <a section href="#font-face-set-ready"></a> for more details on this {{Promise}} and its use.
+			See [[#font-face-set-ready]] for more details on this {{Promise}} and its use.
 
 		<dt><dfn>size</dfn> <span attribute-info for=FontFaceSet/size></span>
 		<dd>
@@ -486,15 +496,21 @@ The <code>FontFaceSet</code> Interface</h2>
 	which is initialized to a fresh pending {{Promise}},
 	and a <dfn attribute for=FontFaceSet>\[[ContainedFonts]]</dfn> slot,
 	which is initialized by the <a constructor title="FontFaceSet()">FontFaceSet constructor</a> to a {{Set}} object
-	(though see <a section href="#document-font-face-set"></a> for information on how the Set may be pre-filled
+	(though see [[#document-font-face-set]] for information on how the Set may be pre-filled
 	for {{FontFaceSet}} objects created by the user agent).
 
 	Because font families are loaded only when they are used,
 	content sometimes needs to understand when the loading of fonts occurs.
 	Authors can use the events and methods defined here to allow greater control over actions
 	that are dependent upon the availability of specific fonts.
 
-	There are <dfn>no pending font loads</dfn> whenever all of the following are true:
+	There are <dfn>no pending font loads</dfn> for a given {{FontFaceSet}} whenever
+	none of its contained {{FontFace}} objects have a {{FontFace/status}} of <code>"loading"</code>.
+
+	For {{FontFaceSet}}s that are <a>font sources</a>,
+	in addition to the above constriant,
+	the following must all be true
+	for them to be considered as having <a>no pending font loads</a>:
 
 	<ul>
 		<li>
@@ -503,20 +519,12 @@ The <code>FontFaceSet</code> Interface</h2>
 		<li>
 			There are no pending stylesheet requests.
 
-		<li>
-			There are no <a>available font faces</a>
-			with a {{FontFace/status}} of "loading".
-
 		<li>
 			There are no pending layout operations which might cause the user agent to request a font.
 	</ul>
 
-	If any of the above conditions are false,
-	there are <dfn>possibly pending font loads</dfn>.
-
-	Issue: The above is wrong; it assumes that you're only asking about the <a>font source</a>.
-	The {{FontFaceSet/status}} promise needs to pay attention to what {{FontFaceSet}} it's attached to.
-	I guess only the <a>font source's</a> {{FontFaceSet/status}} promise should care about pending layout operations.
+	If a {{FontFaceSet}} can't be considered to have <a>no pending font loads</a>,
+	it instead has <dfn>possibly pending font loads</dfn>.
 
 <!--
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@@ -574,7 +582,7 @@ Events</h3>
 			The {{FontFaceSetLoadEvent/fontfaces}} attribute is initialized to the given list of {{FontFace}} objects.
 	</ol>
 
-	Whenever one or more <a>available font faces</a> for a given {{FontFaceSet}}
+	Whenever one or more {{FontFace}} objects within a given {{FontFaceSet}}
 	change their {{FontFace/status}} attribute to "loading",
 	the user agent must run the following steps:
 
@@ -624,6 +632,12 @@ Events</h3>
 	user agents must run these steps:
 
 	<ol>
+		<li>
+			If this is not the first time the {{FontFaceSet}} has had <a>no pending font loads</a>,
+			and none of its contained {{FontFace}} objects began loading
+			since the last time it had <a>no pending font loads</a>,
+			abort this algorithm.
+
 		<li>
 			Set <var>font face set's</var> {{FontFaceSet/status}} attribute to "loaded".
 
@@ -951,6 +965,11 @@ Interaction with CSS’s ''@font-face'' Rule</h3>
 	must be added or removed from the document's <a>font source</a>,
 	and maintain this ordering.
 
+	Note: Authors can still maintain references to a removed {{FontFace}},
+	even if it's been automatically removed from a <a>font source</a>.
+	As specified in [[#font-face-css-connection]], though,
+	the {{FontFace}} is no longer <a>CSS-connected</a> at that point.
+
 	All non-<a>CSS-connected</a> {{FontFace}} objects must be sorted after the <a>CSS-connected</a> ones,
 	in insertion order.