Split the event library into a cross-platform and native part. Part 1.

ui/events/platform/platform_event_builder.h

+// 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 UI_EVENTS_PLATFORM_EVENT_PLATFORM_EVENT_BUILDER_H_
+#define UI_EVENTS_PLATFORM_EVENT_PLATFORM_EVENT_BUILDER_H_
+
+#include "base/event_types.h"
+#include "base/gtest_prod_util.h"
+#include "base/macros.h"
+
+namespace ui {
+
+class Event;
+class KeyEvent;
+class LocatedEvent;
+class MouseEvent;
+class MouseWheelEvent;
+class ScrollEvent;
+class TouchEvent;
+
+// Builds ui::Events from native events.
+//
+// In chromium, this functionality was put inline on the individual Event
+// subclasses. This was fine there since all chromium binaries included the
+// system windowing system libraries. In mojo, we have small binaries which
+// have want to have generic events while only the native viewport needs the
+// capability to generate events from platform events.
+class PlatformEventBuilder {
+ public:
+  static MouseEvent BuildMouseEvent(const base::NativeEvent& native_event);
+  static MouseWheelEvent BuildMouseWheelEvent(
+      const base::NativeEvent& native_event);
+  static TouchEvent BuildTouchEvent(const base::NativeEvent& native_event);
+  static KeyEvent BuildKeyEvent(const base::NativeEvent& native_event);
+  static ScrollEvent BuildScrollEvent(const base::NativeEvent& native_event);
+
+  // Returns the repeat count based on the previous mouse click, if it is
+  // recent enough and within a small enough distance. Exposed for testing.
+  static int GetRepeatCount(const base::NativeEvent& native_event,
+                            const MouseEvent& event);
+
+ private:
+  FRIEND_TEST_ALL_PREFIXES(PlatformEventBuilderXTest,
+                           DoubleClickRequiresRelease);
+  FRIEND_TEST_ALL_PREFIXES(PlatformEventBuilderXTest, SingleClickRightLeft);
+
+  // Resets the last_click_event_ for unit tests.
+  static void ResetLastClickForTest();
+
+  // Takes data from |native_event| and fills the per class details on |event|.
+  static void FillEventFrom(const base::NativeEvent& native_event,
+                            Event* event);
+  static void FillLocatedEventFrom(const base::NativeEvent& native_event,
+                                   LocatedEvent* located_event);
+  static void FillMouseEventFrom(const base::NativeEvent& native_event,
+                                 MouseEvent* mouse_event);
+  static void FillMouseWheelEventFrom(const base::NativeEvent& native_event,
+                                      MouseWheelEvent* mouse_wheel_event);
+  static void FillTouchEventFrom(const base::NativeEvent& native_event,
+                                 TouchEvent* touch_event);
+  static void FillKeyEventFrom(const base::NativeEvent& native_event,
+                               KeyEvent* key_event);
+  static void FillScrollEventFrom(const base::NativeEvent& native_event,
+                                  ScrollEvent* scroll_event);
+
+  DISALLOW_COPY_AND_ASSIGN(PlatformEventBuilder);
+};
+
+}  // namespace ui
+
+#endif  // UI_EVENTS_PLATFORM_EVENT_PLATFORM_EVENT_BUILDER_H_