Make isEmpty a getter.

samples/ui_lib/touch/Momentum.dart

 // Copyright (c) 2011, 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.
 
 /**
  * Implementations can be used to simulate the deceleration of an element within
  * a certain region. To use this behavior you need to provide an initial
  * velocity that is meant to represent the gesture that is initiating this
  * deceleration. You also provide the bounds of the region that the element
  * exists in, and the current offset of the element within that region. The
@@ skipping 437 matching lines @@
     assert (_stepTimeout === null);
     assert(minCoord.x <= maxCoord.x);
     assert(minCoord.y <= maxCoord.y);
     _previousOffset = initialOffset.clone();
     physicsX.configure(minCoord.x, maxCoord.x, initialOffset.x,
                        _customDecelerationFactor, velocity.x);
     physicsY.configure(minCoord.y, maxCoord.y, initialOffset.y,
                        _customDecelerationFactor, velocity.y);
     if (!physicsX.isDone() || !physicsY.isDone()) {
       _calculateMoves();
-      if (!_moves.isEmpty()) {
+      if (!_moves.isEmpty) {
         num firstTime = _moves.first().time;
         _stepTimeout = Env.requestAnimationFrame(
             _step, null, firstTime);
         _decelerating = true;
         return true;
       }
     }
     _decelerating = false;
     return false;
   }
@@ skipping 14 matching lines @@
 
   /**
    * Calculate the next offset of the element and animate it to that position.
    */
   void _step(num timestamp) {
     _stepTimeout = null;
 
     // Prune moves that are more than 1 frame behind when we have more
     // available moves.
     num lastEpoch = timestamp - SingleDimensionPhysics._MS_PER_FRAME;
-    while (!_moves.isEmpty() && _moves.first() !== _moves.last()
+    while (!_moves.isEmpty && _moves.first() !== _moves.last()
         && _moves.first().time < lastEpoch) {
       _moves.removeFirst();
     }
 
-    if (!_moves.isEmpty()) {
+    if (!_moves.isEmpty) {
       final move = _moves.removeFirst();
       _delegate.onDecelerate(move.x, move.y);
-      if (!_moves.isEmpty()) {
+      if (!_moves.isEmpty) {
         num nextTime = _moves.first().time;
         assert(_stepTimeout === null);
         _stepTimeout = Env.requestAnimationFrame(_step, null, nextTime);
       } else {
         stop();
       }
     }
   }
 
   void abort() {
     _decelerating = false;
     _moves.clear();
     if (_stepTimeout !== null) {
       Env.cancelRequestAnimationFrame(_stepTimeout);
       _stepTimeout = null;
     }
   }
 
   Coordinate stop() {
     final wasDecelerating = _decelerating;
     _decelerating = false;
     Coordinate velocity;
-    if (!_moves.isEmpty()) {
+    if (!_moves.isEmpty) {
       final move = _moves.first();
       // This is a workaround for the ugly hacks that get applied when a user
       // passed a velocity in to this Momentum implementation.
       num velocityScale = SingleDimensionPhysics._MS_PER_FRAME *
           SingleDimensionPhysics._INITIAL_VELOCITY_BOOST_FACTOR;
       velocity = new Coordinate(
           move.vx / velocityScale, move.vy / velocityScale);
     } else {
       velocity = new Coordinate(0, 0);
     }
     _moves.clear();
     if (_stepTimeout !== null) {
       Env.cancelRequestAnimationFrame(_stepTimeout);
       _stepTimeout = null;
     }
     if (wasDecelerating) {
       _delegate.onDecelerationEnd();
     }
     return velocity;
   }
 
   Coordinate get destination {
-    if (!_moves.isEmpty()) {
+    if (!_moves.isEmpty) {
       final lastMove = _moves.last();
       return new Coordinate(lastMove.x, lastMove.y);
     } else {
       return null;
     }
   }
 }