Add operator==, hashCode, and toString for Rect and Point dart classes.

sky/engine/core/painting/Rect.dart

Index: sky/engine/core/painting/Rect.dart
diff --git a/sky/engine/core/painting/Rect.dart b/sky/engine/core/painting/Rect.dart
index a54f7aeaf9cbeffd2f17600846bb8cf9268ba14e..39cefedb4f213f79b2071b7e6163318f0c5beee8 100644
--- a/sky/engine/core/painting/Rect.dart
+++ b/sky/engine/core/painting/Rect.dart
@@ -4,6 +4,7 @@
 
 part of dart.sky;
 
+/// Holds 4 floating-point coordinates for a rectangle.
 class Rect {
   Float32List _value;

[sethladd, 2015/05/28 17:09:03]

you could initialize this value here.

Float32List _value = new Float32List(4);

(consider making it final)

Then, you don't need to initialize it in all of your constructors.

[Matt Perry, 2015/05/28 17:25:06]

Done.

   double get left => _value[0];
@@ -11,22 +12,22 @@ class Rect {
   double get right => _value[2];
   double get bottom => _value[3];
 
-  Rect() : new Float32List(4);
+  Rect() : _value = new Float32List(4);
 
   Rect.fromPointAndSize(Point point, Size size) {
     _value = new Float32List(4)
-        ..[0] = point.x
-        ..[1] = point.y
-        ..[2] = point.x + size.width
-        ..[3] = point.y + size.height;
+      ..[0] = point.x
+      ..[1] = point.y
+      ..[2] = point.x + size.width
+      ..[3] = point.y + size.height;
   }
 
   Rect.fromLTRB(double left, double top, double right, double bottom) {
     _value = new Float32List(4)
-        ..[0] = left
-        ..[1] = top
-        ..[2] = right
-        ..[3] = bottom;
+      ..[0] = left
+      ..[1] = top
+      ..[2] = right
+      ..[3] = bottom;
   }
 
   Point get upperLeft => new Point(left, top);
@@ -36,13 +37,25 @@ class Rect {
 
   // Rects are inclusive of the top and left edges but exclusive of the bottom
   // right edges.
-  bool contains(Point point) => point.x >= left && point.x < right
-                             && point.y >= top && point.y < bottom;
+  bool contains(Point point) =>
+      point.x >= left && point.x < right && point.y >= top && point.y < bottom;
 
   void setLTRB(double left, double top, double right, double bottom) {
     _value[0] = left
-        ..[1] = top
-        ..[2] = right
-        ..[3] = bottom;
+      ..[1] = top
+      ..[2] = right
+      ..[3] = bottom;
   }
+
+  bool operator ==(other) {
+    if (!(other is Rect)) return false;
+    for (var i = 0; i < 4; ++i) {
+      if (_value[i] != other._value[i]) return false;
+    }
+    return true;
+  }
+  int get hashCode {
+    return _value.fold(373, (value, item) => (37 * value + item.hashCode));
+  }
+  String toString() => "Rect.LTRB($left, $top, $right, $bottom)";
 }