IPC::ParamTraits for ui::Event (towards ui::Events over mojo IPC)

ui/events/event.h

Index: ui/events/event.h
diff --git a/ui/events/event.h b/ui/events/event.h
index 35999bf463bd902c9a421963c83112e990fbda67..ca383d70a33054b0b2e0758c4392ea84ebda61ee 100644
--- a/ui/events/event.h
+++ b/ui/events/event.h
@@ -6,7 +6,6 @@
 #define UI_EVENTS_EVENT_H_
 
 #include <stdint.h>
-
 #include "base/compiler_specific.h"
 #include "base/event_types.h"
 #include "base/gtest_prod_util.h"
@@ -27,6 +26,10 @@ namespace gfx {
 class Transform;
 }
 
+namespace IPC {
+template <class P> struct ParamTraits;
+}
+
 namespace ui {
 class EventTarget;
 class KeyEvent;
@@ -36,6 +39,10 @@ class PointerEvent;
 class ScrollEvent;
 class TouchEvent;
 enum class DomCode;
+class Event;
+class MouseWheelEvent;
+
+using ScopedEvent = scoped_ptr<Event>;
 
 class EVENTS_EXPORT Event {
  public:
@@ -282,6 +289,9 @@ class EVENTS_EXPORT Event {
  private:
   friend class EventTestApi;
 
+  // For (de)serialization.
+  friend struct IPC::ParamTraits<ui::ScopedEvent>;
+
   EventType type_;
   std::string name_;
   base::TimeDelta time_stamp_;
@@ -303,6 +313,13 @@ class EVENTS_EXPORT CancelModeEvent : public Event {
  public:
   CancelModeEvent();
   ~CancelModeEvent() override;
+
+ private:
+  // For (de)serialization.
+  CancelModeEvent(EventType type, base::TimeDelta time_stamp, int flags)
+      : Event(type, time_stamp, flags) {}
+  friend struct IPC::ParamTraits<ui::ScopedEvent>;
+  friend struct IPC::ParamTraits<ui::CancelModeEvent>;
 };
 
 class EVENTS_EXPORT LocatedEvent : public Event {
@@ -346,6 +363,13 @@ class EVENTS_EXPORT LocatedEvent : public Event {
 
  protected:
   friend class LocatedEventTestApi;
+
+  // For (de)serialization.
+  LocatedEvent(EventType type, base::TimeDelta time_stamp, int flags)
+      : Event(type, time_stamp, flags) {}
+  friend struct IPC::ParamTraits<ui::ScopedEvent>;
+  friend struct IPC::ParamTraits<ui::LocatedEvent>;
+
   explicit LocatedEvent(const base::NativeEvent& native_event);
 
   // Create a new LocatedEvent which is identical to the provided model.
@@ -406,6 +430,9 @@ struct EVENTS_EXPORT PointerDetails {
            tilt_y == other.tilt_y;
   }
 
+  // For serialization.
+  friend struct IPC::ParamTraits<ui::PointerDetails>;
+
   // The type of pointer device.
   EventPointerType pointer_type = EventPointerType::POINTER_TYPE_UNKNOWN;
 
@@ -525,6 +552,13 @@ class EVENTS_EXPORT MouseEvent : public LocatedEvent {
     pointer_details_ = details;
   }
 
+ protected:
+  // For (de)serialization.
+  MouseEvent(EventType type, base::TimeDelta time_stamp, int flags)
+      : LocatedEvent(type, time_stamp, flags) {}
+  friend struct IPC::ParamTraits<ui::ScopedEvent>;
+  friend struct IPC::ParamTraits<ui::MouseEvent>;
+
  private:
   FRIEND_TEST_ALL_PREFIXES(EventTest, DoubleClickRequiresRelease);
   FRIEND_TEST_ALL_PREFIXES(EventTest, SingleClickRightLeft);
@@ -585,6 +619,12 @@ class EVENTS_EXPORT MouseWheelEvent : public MouseEvent {
   const gfx::Vector2d& offset() const { return offset_; }
 
  private:
+  // For (de)serialization.
+  MouseWheelEvent(EventType type, base::TimeDelta time_stamp, int flags)
+      : MouseEvent(type, time_stamp, flags) {}
+  friend struct IPC::ParamTraits<ui::ScopedEvent>;
+  friend struct IPC::ParamTraits<ui::MouseWheelEvent>;
+
   gfx::Vector2d offset_;
 };
 
@@ -657,15 +697,22 @@ class EVENTS_EXPORT TouchEvent : public LocatedEvent {
   }
 
  private:
+  // For (de)serialization.
+  TouchEvent(EventType type, base::TimeDelta time_stamp, int flags)
+      : LocatedEvent(type, time_stamp, flags),
+        should_remove_native_touch_id_mapping_(false) {}
+  friend struct IPC::ParamTraits<ui::ScopedEvent>;
+  friend struct IPC::ParamTraits<ui::TouchEvent>;
+
   // Adjusts rotation_angle_ to within the acceptable range.
   void FixRotationAngle();
 
   // The identity (typically finger) of the touch starting at 0 and incrementing
   // for each separable additional touch that the hardware can detect.
-  const int touch_id_;
+  int touch_id_;
 
   // A unique identifier for the touch event.
-  const uint32_t unique_event_id_;
+  uint32_t unique_event_id_;
 
   // Clockwise angle (in degrees) of the major axis from the X axis. Must be
   // less than 180 and non-negative.
@@ -875,6 +922,11 @@ class EVENTS_EXPORT KeyEvent : public Event {
   void set_is_char(bool is_char) { is_char_ = is_char; }
 
  private:
+  // For (de)serialization.
+  KeyEvent(EventType type, base::TimeDelta time_stamp, int flags);
+  friend struct IPC::ParamTraits<ui::ScopedEvent>;
+  friend struct IPC::ParamTraits<ui::KeyEvent>;
+
   // Determine key_ on a keystroke event from code_ and flags().
   void ApplyLayout() const;
 
@@ -953,6 +1005,12 @@ class EVENTS_EXPORT ScrollEvent : public MouseEvent {
   int finger_count() const { return finger_count_; }
 
  private:
+  // For (de)serialization.
+  ScrollEvent(EventType type, base::TimeDelta time_stamp, int flags)
+      : MouseEvent(type, time_stamp, flags) {}
+  friend struct IPC::ParamTraits<ui::ScopedEvent>;
+  friend struct IPC::ParamTraits<ui::ScrollEvent>;
+
   // Potential accelerated offsets.
   float x_offset_;
   float y_offset_;
@@ -985,6 +1043,12 @@ class EVENTS_EXPORT GestureEvent : public LocatedEvent {
   const GestureEventDetails& details() const { return details_; }
 
  private:
+  // For (de)serialization.
+  GestureEvent(EventType type, base::TimeDelta time_stamp, int flags)
+      : LocatedEvent(type, time_stamp, flags) {}
+  friend struct IPC::ParamTraits<ui::ScopedEvent>;
+  friend struct IPC::ParamTraits<ui::GestureEvent>;
+
   GestureEventDetails details_;
 };