Port touch-demo.sky to Dart and make it work in SkyShell

sky/shell/ui/input_event_converter.cc

+// Copyright 2014 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/shell/ui/input_event_converter.h"
+
+#include "base/logging.h"
+#include "base/time/time.h"
+#include "sky/engine/public/platform/WebInputEvent.h"
+
+namespace sky {
+namespace {
+
+scoped_ptr<blink::WebInputEvent> BuildWebPointerEvent(
+    const InputEventPtr& event, float device_pixel_ratio) {
+  scoped_ptr<blink::WebPointerEvent> web_event(new blink::WebPointerEvent);
+
+  web_event->timeStampMS =
+      base::TimeDelta::FromInternalValue(event->time_stamp).InMillisecondsF();
+
+  switch (event->type) {
+    case EVENT_TYPE_POINTER_DOWN:
+      web_event->type = blink::WebInputEvent::PointerDown;
+      break;
+    case EVENT_TYPE_POINTER_UP:
+      web_event->type = blink::WebInputEvent::PointerUp;
+      break;
+    case EVENT_TYPE_POINTER_MOVE:
+      web_event->type = blink::WebInputEvent::PointerMove;
+      break;
+    case EVENT_TYPE_POINTER_CANCEL:
+      web_event->type = blink::WebInputEvent::PointerCancel;
+      break;
+    default:
+      NOTIMPLEMENTED() << "Received unexpected event: " << event->type;
+      break;
+  }
+
+  if (event->pointer_data) {
+    if (event->pointer_data->kind == POINTER_KIND_TOUCH)
+        web_event->kind = blink::WebPointerEvent::Touch;
+    web_event->pointer = event->pointer_data->pointer;
+    web_event->x = event->pointer_data->x / device_pixel_ratio;
+    web_event->y = event->pointer_data->y / device_pixel_ratio;
+  }
+
+  return web_event.Pass();
+}
+
+}  // namespace
+
+scoped_ptr<blink::WebInputEvent> ConvertEvent(const InputEventPtr& event,
+                                              float device_pixel_ratio) {
+  if (event->type == EVENT_TYPE_POINTER_DOWN ||
+      event->type == EVENT_TYPE_POINTER_UP ||
+      event->type == EVENT_TYPE_POINTER_MOVE ||
+      event->type == EVENT_TYPE_POINTER_CANCEL) {
+    return BuildWebPointerEvent(event, device_pixel_ratio);
+  }
+
+  return scoped_ptr<blink::WebInputEvent>();
+}
+
+}  // namespace mojo