Aggregate CSS manipulation functions in html lib.

sdk/lib/html/dart2js/html_dart2js.dart

Index: sdk/lib/html/dart2js/html_dart2js.dart
diff --git a/sdk/lib/html/dart2js/html_dart2js.dart b/sdk/lib/html/dart2js/html_dart2js.dart
index d67a2c9ff3950b3d9a770804f89d73a70f63118f..f8b09a918f502812ceceedfb89adfac00a5d12bf 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -6541,8 +6541,8 @@ class Document extends Node  native "Document"
    * For details about CSS selector syntax, see the
    * [CSS selector specification](http://www.w3.org/TR/css3-selectors/).
    */
-  List<Element> queryAll(String selectors) {
-    return new _FrozenElementList._wrap($dom_querySelectorAll(selectors));
+  HtmlList<Element> queryAll(String selectors) {
+    return new HtmlList._wrap($dom_querySelectorAll(selectors));
   }
 }
 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
@@ -7939,10 +7939,14 @@ class _ChildrenElementList extends ListBase<Element> {
 // a better option given that we cannot quite force NodeList to be an
 // ElementList as there are valid cases where a NodeList JavaScript object
 // contains Node objects that are not Elements.
-class _FrozenElementList<T extends Element> extends ListBase<T> {
+/** 
+ * An immutable list containing HTML elements. This list contains some
+ * additional methods for ease of CSS manipulation on a group of elements.
+ */
+class HtmlList<T extends Element> extends ListBase<T> {
   final List<Node> _nodeList;
 
-  _FrozenElementList._wrap(this._nodeList);
+  HtmlList._wrap(this._nodeList);
 
   int get length => _nodeList.length;
 
@@ -7965,6 +7969,86 @@ class _FrozenElementList<T extends Element> extends ListBase<T> {
   Element get last => _nodeList.last;
 
   Element get single => _nodeList.single;
+
+  /**
+   * The union of all CSS classes applied to the elements in this list.
+   *
+   * This set makes it easy to add, remove or toggle (add if not present, remove
+   * if present) the classes applied to a collection of elements.
+   *
+   *     htmlList.classes.add('selected');
+   *     htmlList.classes.toggle('isOnline');
+   *     htmlList.classes.remove('selected');
+   */
+  CssClassSet get classes => new _MultiElementCssClassSet(
+      _nodeList.where((e) => e is Element));
+
+  /** Replace the classes with `value` for every element in this list. */
+  void set classes(Iterable<String> value) {
+    _nodeList.where((e) => e is Element).forEach((e) { 
+        e.classes.clear();
+        e.classes.addAll(value); 
+      });
+  }
+}
+
+/**
+ * A set (union) of the CSS classes that are present in a set of elements.
+ * Implemented separately from _ElementCssClassSet for performance.
+ */
+class _MultiElementCssClassSet extends CssClassSet {
+  final Iterable<Element> _elementIterable;
+  Iterable<_ElementCssClassSet> _elementCssClassSetIterable;
+
+  _MultiElementCssClassSet(this._elementIterable) {
+    _elementCssClassSetIterable = new List.from(_elementIterable).map(
+        (e) => new _ElementCssClassSet(e));
+  }
+
+  Set<String> readClasses() {
+    var s = new LinkedHashSet<String>();
+    _elementCssClassSetIterable.forEach((e) => s.addAll(e.readClasses()));
+    return s;
+  }
+
+  void writeClasses(Set<String> s) {
+    var classes = new List.from(s).join(' ');
+    for (Element e in _elementIterable) {
+      e.$dom_className = classes;
+    }
+  }
+
+  /**
+   * Helper method used to modify the set of css classes on this element.
+   *
+   *   f - callback with:
+   *   s - a Set of all the css class name currently on this element.
+   *
+   *   After f returns, the modified set is written to the
+   *       className property of this element.
+   */
+  void modify( f(Set<String> s)) {
+    _elementCssClassSetIterable.forEach((e) => e.modify(f));
+  }
+
+  /**
+   * Adds the class [value] to the element if it is not on it, removes it if it
+   * is.
+   */
+  bool toggle(String value) => 
+      _modifyWithReturnValue((e) => e.toggle(value));
+  
+  /**
+   * Remove the class [value] from element, and return true on successful
+   * removal.
+   *
+   * This is the Dart equivalent of jQuery's
+   * [removeClass](http://api.jquery.com/removeClass/).
+   */
+  bool remove(Object value) => _modifyWithReturnValue((e) => e.remove(value));
+
+  bool _modifyWithReturnValue(f) => _elementCssClassSetIterable.fold(
+      false, (prevValue, element) => f(element) || prevValue);
 }
 
 class _ElementCssClassSet extends CssClassSet {
@@ -8088,8 +8172,8 @@ abstract class Element extends Node implements ElementTraversal native "Element"
    *
    *     var items = element.query('.itemClassName');
    */
-  List<Element> queryAll(String selectors) =>
-    new _FrozenElementList._wrap($dom_querySelectorAll(selectors));
+  HtmlList<Element> queryAll(String selectors) =>
+    new HtmlList._wrap($dom_querySelectorAll(selectors));
 
   /**
    * The set of CSS classes applied to this element.
@@ -26572,7 +26656,7 @@ abstract class CssClassSet implements Set<String> {
   void add(String value) {
     // TODO - figure out if we need to do any validation here
     // or if the browser natively does enough.
-    _modify((s) => s.add(value));
+    modify((s) => s.add(value));
   }
 
   /**
@@ -26598,7 +26682,7 @@ abstract class CssClassSet implements Set<String> {
    */
   void addAll(Iterable<String> iterable) {
     // TODO - see comment above about validation.
-    _modify((s) => s.addAll(iterable));
+    modify((s) => s.addAll(iterable));
   }
 
   /**
@@ -26608,7 +26692,7 @@ abstract class CssClassSet implements Set<String> {
    * [removeClass](http://api.jquery.com/removeClass/).
    */
   void removeAll(Iterable<String> iterable) {
-    _modify((s) => s.removeAll(iterable));
+    modify((s) => s.removeAll(iterable));
   }
 
   /**
@@ -26623,15 +26707,15 @@ abstract class CssClassSet implements Set<String> {
   }
 
   void retainAll(Iterable<String> iterable) {
-    _modify((s) => s.retainAll(iterable));
+    modify((s) => s.retainAll(iterable));
   }
 
   void removeWhere(bool test(String name)) {
-    _modify((s) => s.removeWhere(test));
+    modify((s) => s.removeWhere(test));
   }
 
   void retainWhere(bool test(String name)) {
-    _modify((s) => s.retainWhere(test));
+    modify((s) => s.retainWhere(test));
   }
 
   bool containsAll(Iterable<String> collection) =>
@@ -26667,7 +26751,7 @@ abstract class CssClassSet implements Set<String> {
   String elementAt(int index) => readClasses().elementAt(index);
 
   void clear() {
-    _modify((s) => s.clear());
+    modify((s) => s.clear());
   }
   // interface Set - END
 
@@ -26680,7 +26764,7 @@ abstract class CssClassSet implements Set<String> {
    *   After f returns, the modified set is written to the
    *       className property of this element.
    */
-  void _modify( f(Set<String> s)) {
+  void modify( f(Set<String> s)) {
     Set<String> s = readClasses();
     f(s);
     writeClasses(s);