Sky: Add a Point class.

Also, fix the style in Rect.cpp/.h.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1158843002

engine/core/core.gni

@@ -1125,7 +1125,11 @@ core_idl_files = get_path_info([
                                ],
                                "abspath")
 
-core_dart_files = get_path_info([ "painting/Rect.dart" ], "abspath")
+core_dart_files = get_path_info([
+                                  "painting/Rect.dart",
+                                  "painting/Point.dart",
+                                ],
+                                "abspath")
 
 # Files for which bindings (.cpp and .h files) will be generated
 # 'partial interface', target (right side of) 'implements', and

engine/core/painting/Point.cpp

@@ -0,0 +1,38 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "sky/engine/config.h"
+#include "sky/engine/core/painting/Point.h"
+
+#include "sky/engine/tonic/dart_error.h"
+#include "sky/engine/tonic/dart_state.h"
+#include "base/logging.h"
+
+namespace blink {
+
+// Convert dartPoint.x,y ==> SkPoint.
+Point DartConverter<Point, void>::FromArgumentsWithNullCheck(
+    Dart_NativeArguments args,
+    int index,
+    Dart_Handle& exception) {
+  Point result;
+  result.is_null = true;
+
+  Dart_Handle dartPoint = Dart_GetNativeArgument(args, index);
+  DCHECK(!LogIfError(dartPoint));
+
+  Dart_Handle xValue = Dart_GetField(dartPoint, Dart_NewStringFromCString("x"));
+  Dart_Handle yValue = Dart_GetField(dartPoint, Dart_NewStringFromCString("y"));
+
+  double x = 0.0, y = 0.0;
+  Dart_Handle err = Dart_DoubleValue(xValue, &x);
+  DCHECK(!LogIfError(err));
+  err = Dart_DoubleValue(xValue, &y);
+  DCHECK(!LogIfError(err));
+  result.sk_point.set(x, y);
+  result.is_null = false;
+  return result;
+}
+
+} // namespace blink

engine/core/painting/Point.dart

@@ -0,0 +1,13 @@
+// Copyright 2015 The Chromium Authors. 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 dart.sky;
+
+class Point {
+  double x;
+  double y;
+
+  Point(this.x, this.y);
+}
+

engine/core/painting/Point.h

@@ -0,0 +1,29 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef SKY_ENGINE_CORE_PAINTING_POINT_H_
+#define SKY_ENGINE_CORE_PAINTING_POINT_H_
+
+#include "dart/runtime/include/dart_api.h"
+#include "sky/engine/tonic/dart_converter.h"
+#include "third_party/skia/include/core/SkPoint.h"
+
+namespace blink {
+// Very simple wrapper for SkPoint to add a null state.
+class Point {
+ public:
+  SkPoint sk_point;
+  bool is_null;
+};
+
+template<>
+struct DartConverter<Point, void> {
+  static Point FromArgumentsWithNullCheck(Dart_NativeArguments args,
+                                          int index,
+                                          Dart_Handle& exception);
+};
+
+} // namespace blink
+
+#endif  // SKY_ENGINE_CORE_PAINTING_POINT_H_

examples/raw/painting.sky

@@ -14,13 +14,14 @@ void main() {
   var element = document.getElementById('canvas');
   element.requestPaint((PaintingContext context) {
     Paint paint = new Paint();
-    double radius = math.min(context.width, context.height) / 2.0;
+    Point mid = new Point(context.width / 2.0, context.height / 2.0);
+    double radius = math.min(mid.x, mid.y);
 
     context.save();
 
     context.clipRect(new Rect()..setLTRB(0.0, 0.0, context.width, radius));
 
-    context.translate(context.width / 2.0, context.height / 2.0);
+    context.translate(mid.x, mid.y);
     paint.setARGB(128, 255, 0, 255);
     context.rotateDegrees(45.0);