Add magnitude getter to Point.

tools/dom/src/Point.dart

 // Copyright (c) 2013, 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.
 
 part of html;
 
 /**
  * A utility class for representing two-dimensional positions.
  */
 class Point {
@@ skipping 17 matching lines @@
 
   Point operator -(Point other) {
     return new Point(x - other.x, y - other.y);
   }
 
   Point operator *(num factor) {
     return new Point(x * factor, y * factor);
   }
 
   /**
+   * Get the straight line (Euclidean) distance between the origin (0, 0) and
+   * this point.
+   */
+  num get magnitude => sqrt(x * x + y * y);
+
+  /**
    * Returns the distance between two points.
    */
   double distanceTo(Point other) {
     var dx = x - other.x;
     var dy = y - other.y;
     return sqrt(dx * dx + dy * dy);
   }
 
   /**
    * Returns the squared distance between two points.
    *
    * Squared distances can be used for comparisons when the actual value is not
    * required.
    */
   num squaredDistanceTo(Point other) {
     var dx = x - other.x;
     var dy = y - other.y;
     return dx * dx + dy * dy;
   }
 
   Point ceil() => new Point(x.ceil(), y.ceil());
   Point floor() => new Point(x.floor(), y.floor());
   Point round() => new Point(x.round(), y.round());
 
   /**
    * Truncates x and y to integers and returns the result as a new point.
    */
   Point toInt() => new Point(x.toInt(), y.toInt());
 }