Splitting SVG types out of dart:html.

sdk/lib/html/src/CssClassSet.dart

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+abstract class CssClassSet implements Set<String> {
+
+  String toString() {
+    return Strings.join(new List.from(readClasses()), ' ');
+  }
+
+  /**
+   * Adds the class [token] to the element if it is not on it, removes it if it
+   * is.
+   */
+  bool toggle(String value) {
+    Set<String> s = readClasses();
+    bool result = false;
+    if (s.contains(value)) {
+      s.remove(value);
+    } else {
+      s.add(value);
+      result = true;
+    }
+    writeClasses(s);
+    return result;
+  }
+
+  /**
+   * Returns [:true:] if classes cannot be added or removed from this
+   * [:CssClassSet:].
+   */
+  bool get frozen => false;
+
+  // interface Iterable - BEGIN
+  Iterator<String> iterator() => readClasses().iterator();
+  // interface Iterable - END
+
+  // interface Collection - BEGIN
+  void forEach(void f(String element)) {
+    readClasses().forEach(f);
+  }
+
+  Collection map(f(String element)) => readClasses().map(f);
+
+  Collection<String> filter(bool f(String element)) => readClasses().filter(f);
+
+  bool every(bool f(String element)) => readClasses().every(f);
+
+  bool some(bool f(String element)) => readClasses().some(f);
+
+  bool get isEmpty => readClasses().isEmpty;
+
+  int get length =>readClasses().length;
+  // interface Collection - END
+
+  // interface Set - BEGIN
+  bool contains(String value) => readClasses().contains(value);
+
+  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));
+  }
+
+  bool remove(String value) {
+    Set<String> s = readClasses();
+    bool result = s.remove(value);
+    writeClasses(s);
+    return result;
+  }
+
+  void addAll(Collection<String> collection) {
+    // TODO - see comment above about validation
+    _modify((s) => s.addAll(collection));
+  }
+
+  void removeAll(Collection<String> collection) {
+    _modify((s) => s.removeAll(collection));
+  }
+
+  bool isSubsetOf(Collection<String> collection) =>
+    readClasses().isSubsetOf(collection);
+
+  bool containsAll(Collection<String> collection) =>
+    readClasses().containsAll(collection);
+
+  Set<String> intersection(Collection<String> other) =>
+    readClasses().intersection(other);
+
+  void clear() {
+    _modify((s) => s.clear());
+  }
+  // interface Set - END
+
+  /**
+   * 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)) {
+    Set<String> s = readClasses();
+    f(s);
+    writeClasses(s);
+  }
+
+  /**
+   * Read the class names from the Element class property,
+   * and put them into a set (duplicates are discarded).
+   * This is intended to be overridden by specific implementations.
+   */
+  Set<String> readClasses();
+
+  /**
+   * Join all the elements of a set into one string and write
+   * back to the element.
+   * This is intended to be overridden by specific implementations.
+   */
+  void writeClasses(Set<String> s);
+}