Differences

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--- spec:css3-regions:regions-styling [2012/03/16 09:54] – astearns
+++ spec:css3-regions:regions-styling [2012/03/16 10:21] – vhardy
@@ Line 51: / Line 51: @@
 The issues with the current @region rule are:
-  - requires additional DOM interfaces to access the @rule
+  - requires [[https://www.w3.org/Bugs/Public/show_bug.cgi?id=15116|additional DOM interfaces]] DOM interfaces to access the @rule
   - is not consistent with ::first-line and other existing pseudo-elements which select a fragment of an element
   - inconsistency between the CSS syntax (@region) and the getComputedStyle calls (use '::in-region' or equivalent)
@@ Line 76: / Line 76: @@
 === Open questions ===
-  * Can we chain pseudo-elements? For example, can we do the following:
+  * Limitation: nested regions.
+Consider the following use case:
 <code>
-window.getComputedStyle(elem, "::before::in-region(regionA)");
+<div id="postit-A"></div>
+<div id="postit-B"></div>
+<div id="regionA"></div>
+<div id="regionB"></div>
+<div id="regionC"></div>
+<div id="regionD"></div>
+#postit-A, #postit-B {
+	flow-from: block-flow;
+}
+#regionA, #regionB, #regionC, #regionD {
+	flow-into: block-flow;
+	flow-from: article;
+}
 </code>
-According to the [[http://dev.w3.org/csswg/selectors3/#w3cselgrammar|Selectors Level 3]] specification:
+What if we want to have special styling for a '.title' that falls into regionB if regionB is in postit-A but not in postit-B?
-<file>
+.title::in-region(regionB) selects the fragment of .title that falls into regionB. There is no way to say "… that falls
-Note that pseudo-elements are restricted to one per selector and occur only in the last simple_selector_sequence.
+into the fragment of regionB that falls into postit-A.
-</file>
-which seems to prevent the combination of a '::before' pseudo-element selector with another '::in-region()' pseudo selector.
+Proposed resolution: accept this limitation.