Handle alternate types in HandleMouseEvent.

ui/base/events/event.h

Index: ui/base/events/event.h
diff --git a/ui/base/events/event.h b/ui/base/events/event.h
index a17da790ba21d77e2e8b922dfbb9508fe5e770b3..23c3298fdefad499e2d83c0d4aa17afd1c0c9854 100644
--- a/ui/base/events/event.h
+++ b/ui/base/events/event.h
@@ -1,712 +1,717 @@
-// Copyright (c) 2012 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_BASE_EVENTS_EVENT_H_
-#define UI_BASE_EVENTS_EVENT_H_
-
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "base/event_types.h"
-#include "base/logging.h"
-#include "base/time.h"
-#include "ui/base/dragdrop/os_exchange_data.h"
-#include "ui/base/events/event_constants.h"
-#include "ui/base/gestures/gesture_types.h"
-#include "ui/base/keycodes/keyboard_codes.h"
-#include "ui/base/latency_info.h"
-#include "ui/base/ui_export.h"
-#include "ui/gfx/point.h"
-
-namespace gfx {
-class Transform;
-}
-
-namespace ui {
-class EventTarget;
-
-class UI_EXPORT Event {
- public:
-  virtual ~Event();
-
-  class DispatcherApi {
-   public:
-    explicit DispatcherApi(Event* event) : event_(event) {}
-
-    void set_target(EventTarget* target) {
-      event_->target_ = target;
-    }
-
-    void set_phase(EventPhase phase) { event_->phase_ = phase; }
-    void set_result(int result) {
-      event_->result_ = static_cast<EventResult>(result);
-    }
-
-   private:
-    DispatcherApi();
-    Event* event_;
-
-    DISALLOW_COPY_AND_ASSIGN(DispatcherApi);
-  };
-
-  // For testing.
-  class TestApi {
-   public:
-    explicit TestApi(Event* event) : event_(event) {}
-
-    void set_time_stamp(base::TimeDelta time_stamp) {
-      event_->time_stamp_ = time_stamp;
-    }
-
-   private:
-    TestApi();
-    Event* event_;
-  };
-
-  const base::NativeEvent& native_event() const { return native_event_; }
-  EventType type() const { return type_; }
-  const std::string& name() const { return name_; }
-  // time_stamp represents time since machine was booted.
-  const base::TimeDelta& time_stamp() const { return time_stamp_; }
-  int flags() const { return flags_; }
-
-  // This is only intended to be used externally by classes that are modifying
-  // events in EventFilter::PreHandleKeyEvent().
-  void set_flags(int flags) { flags_ = flags; }
-
-  EventTarget* target() const { return target_; }
-  EventPhase phase() const { return phase_; }
-  EventResult result() const { return result_; }
-  bool dispatch_to_hidden_targets() const {
-    return dispatch_to_hidden_targets_;
-  }
-
-  LatencyInfo* latency() { return &latency_; }
-  void set_latency(const LatencyInfo& latency) { latency_ = latency; }
-
-  // By default, events are "cancelable", this means any default processing that
-  // the containing abstraction layer may perform can be prevented by calling
-  // SetHandled(). SetHandled() or StopPropagation() must not be called for
-  // events that are not cancelable.
-  bool cancelable() const { return cancelable_; }
-
-  // The following methods return true if the respective keys were pressed at
-  // the time the event was created.
-  bool IsShiftDown() const { return (flags_ & EF_SHIFT_DOWN) != 0; }
-  bool IsControlDown() const { return (flags_ & EF_CONTROL_DOWN) != 0; }
-  bool IsCapsLockDown() const { return (flags_ & EF_CAPS_LOCK_DOWN) != 0; }
-  bool IsAltDown() const { return (flags_ & EF_ALT_DOWN) != 0; }
-
-  bool IsKeyEvent() const {
-    return type_ == ET_KEY_PRESSED ||
-           type_ == ET_KEY_RELEASED ||
-           type_ == ET_TRANSLATED_KEY_PRESS ||
-           type_ == ET_TRANSLATED_KEY_RELEASE;
-  }
-
-  bool IsMouseEvent() const {
-    return type_ == ET_MOUSE_PRESSED ||
-           type_ == ET_MOUSE_DRAGGED ||
-           type_ == ET_MOUSE_RELEASED ||
-           type_ == ET_MOUSE_MOVED ||
-           type_ == ET_MOUSE_ENTERED ||
-           type_ == ET_MOUSE_EXITED ||
-           type_ == ET_MOUSEWHEEL ||
-           type_ == ET_MOUSE_CAPTURE_CHANGED;
-  }
-
-  bool IsTouchEvent() const {
-    return type_ == ET_TOUCH_RELEASED ||
-           type_ == ET_TOUCH_PRESSED ||
-           type_ == ET_TOUCH_MOVED ||
-           type_ == ET_TOUCH_STATIONARY ||
-           type_ == ET_TOUCH_CANCELLED;
-  }
-
-  bool IsGestureEvent() const {
-    switch (type_) {
-      case ET_GESTURE_SCROLL_BEGIN:
-      case ET_GESTURE_SCROLL_END:
-      case ET_GESTURE_SCROLL_UPDATE:
-      case ET_GESTURE_TAP:
-      case ET_GESTURE_TAP_CANCEL:
-      case ET_GESTURE_TAP_DOWN:
-      case ET_GESTURE_BEGIN:
-      case ET_GESTURE_END:
-      case ET_GESTURE_TWO_FINGER_TAP:
-      case ET_GESTURE_PINCH_BEGIN:
-      case ET_GESTURE_PINCH_END:
-      case ET_GESTURE_PINCH_UPDATE:
-      case ET_GESTURE_LONG_PRESS:
-      case ET_GESTURE_LONG_TAP:
-      case ET_GESTURE_MULTIFINGER_SWIPE:
-        return true;
-
-      case ET_SCROLL_FLING_CANCEL:
-      case ET_SCROLL_FLING_START:
-        // These can be ScrollEvents too. EF_FROM_TOUCH determines if they're
-        // Gesture or Scroll events.
-        return (flags_ & EF_FROM_TOUCH) == EF_FROM_TOUCH;
-
-      default:
-        break;
-    }
-    return false;
-  }
-
-  bool IsScrollEvent() const {
-    // Flings can be GestureEvents too. EF_FROM_TOUCH determins if they're
-    // Gesture or Scroll events.
-    return type_ == ET_SCROLL ||
-           ((type_ == ET_SCROLL_FLING_START ||
-           type_ == ET_SCROLL_FLING_CANCEL) &&
-           !(flags() & EF_FROM_TOUCH));
-  }
-
-  bool IsScrollGestureEvent() const {
-    return type_ == ET_GESTURE_SCROLL_BEGIN ||
-           type_ == ET_GESTURE_SCROLL_UPDATE ||
-           type_ == ET_GESTURE_SCROLL_END;
-  }
-
-  bool IsFlingScrollEvent() const {
-    return type_ == ET_SCROLL_FLING_CANCEL ||
-           type_ == ET_SCROLL_FLING_START;
-  }
-
-  // Returns true if the event has a valid |native_event_|.
-  bool HasNativeEvent() const;
-
-  // Immediately stops the propagation of the event. This must be called only
-  // from an EventHandler during an event-dispatch. Any event handler that may
-  // be in the list will not receive the event after this is called.
-  // Note that StopPropagation() can be called only for cancelable events.
-  void StopPropagation();
-  bool stopped_propagation() const { return !!(result_ & ER_CONSUMED); }
-
-  // Marks the event as having been handled. A handled event does not reach the
-  // next event phase. For example, if an event is handled during the pre-target
-  // phase, then the event is dispatched to all pre-target handlers, but not to
-  // the target or post-target handlers.
-  // Note that SetHandled() can be called only for cancelable events.
-  void SetHandled();
-  bool handled() const { return result_ != ER_UNHANDLED; }
-
- protected:
-  Event(EventType type, base::TimeDelta time_stamp, int flags);
-  Event(const base::NativeEvent& native_event, EventType type, int flags);
-  Event(const Event& copy);
-  void SetType(EventType type);
-  void set_delete_native_event(bool delete_native_event) {
-    delete_native_event_ = delete_native_event;
-  }
-  void set_cancelable(bool cancelable) { cancelable_ = cancelable; }
-  void set_dispatch_to_hidden_targets(bool dispatch_to_hidden_targets) {
-    dispatch_to_hidden_targets_ = dispatch_to_hidden_targets;
-  }
-
-  void set_time_stamp(const base::TimeDelta& time_stamp) {
-    time_stamp_ = time_stamp;
-  }
-
-  void set_name(const std::string& name) { name_ = name; }
-
-  void InitLatencyInfo();
-
- private:
-  void operator=(const Event&);
-
-  // Safely initializes the native event members of this class.
-  void Init();
-  void InitWithNativeEvent(const base::NativeEvent& native_event);
-
-  EventType type_;
-  std::string name_;
-  base::TimeDelta time_stamp_;
-  LatencyInfo latency_;
-  int flags_;
-  bool dispatch_to_hidden_targets_;
-  base::NativeEvent native_event_;
-  bool delete_native_event_;
-  bool cancelable_;
-  EventTarget* target_;
-  EventPhase phase_;
-  EventResult result_;
-};
-
-class UI_EXPORT CancelModeEvent : public Event {
- public:
-  CancelModeEvent();
-  virtual ~CancelModeEvent();
-};
-
-class UI_EXPORT LocatedEvent : public Event {
- public:
-  // For testing.
-  class TestApi : public Event::TestApi {
-   public:
-    explicit TestApi(LocatedEvent* located_event)
-        : Event::TestApi(located_event),
-          located_event_(located_event) {}
-
-    void set_location(const gfx::Point& location) {
-      located_event_->location_ = location;
-    }
-
-   private:
-    TestApi();
-    LocatedEvent* located_event_;
-  };
-
-  virtual ~LocatedEvent();
-
-  int x() const { return location_.x(); }
-  int y() const { return location_.y(); }
-  void set_location(const gfx::Point& location) { location_ = location; }
-  gfx::Point location() const { return location_; }
-  void set_root_location(const gfx::Point& root_location) {
-    root_location_ = root_location;
-  }
-  gfx::Point root_location() const { return root_location_; }
-
-  // Transform the locations using |inverted_root_transform|.
-  // This is applied to both |location_| and |root_location_|.
-  virtual void UpdateForRootTransform(
-      const gfx::Transform& inverted_root_transform);
-
-  template <class T> void ConvertLocationToTarget(T* source, T* target) {
-    if (target && target != source)
-      T::ConvertPointToTarget(source, target, &location_);
-  }
-
- protected:
-  explicit LocatedEvent(const base::NativeEvent& native_event);
-
-  // Create a new LocatedEvent which is identical to the provided model.
-  // If source / target windows are provided, the model location will be
-  // converted from |source| coordinate system to |target| coordinate system.
-  template <class T>
-  LocatedEvent(const LocatedEvent& model, T* source, T* target)
-      : Event(model),
-        location_(model.location_),
-        root_location_(model.root_location_) {
-    ConvertLocationToTarget(source, target);
-  }
-
-  // Used for synthetic events in testing.
-  LocatedEvent(EventType type,
-               const gfx::Point& location,
-               const gfx::Point& root_location,
-               base::TimeDelta time_stamp,
-               int flags);
-
-  gfx::Point location_;
-
-  // |location_| multiplied by an optional transformation matrix for
-  // rotations, animations and skews.
-  gfx::Point root_location_;
-};
-
-class UI_EXPORT MouseEvent : public LocatedEvent {
- public:
-  explicit MouseEvent(const base::NativeEvent& native_event);
-
-  // Create a new MouseEvent based on the provided model.
-  // Uses the provided |type| and |flags| for the new event.
-  // If source / target windows are provided, the model location will be
-  // converted from |source| coordinate system to |target| coordinate system.
-  template <class T>
-  MouseEvent(const MouseEvent& model, T* source, T* target)
-      : LocatedEvent(model, source, target),
-        changed_button_flags_(model.changed_button_flags_) {
-  }
-
-  template <class T>
-  MouseEvent(const MouseEvent& model,
-             T* source,
-             T* target,
-             EventType type,
-             int flags)
-      : LocatedEvent(model, source, target),
-        changed_button_flags_(model.changed_button_flags_) {
-    SetType(type);
-    set_flags(flags);
-  }
-
-  // Used for synthetic events in testing and by the gesture recognizer.
-  MouseEvent(EventType type,
-             const gfx::Point& location,
-             const gfx::Point& root_location,
-             int flags);
-
-  // Conveniences to quickly test what button is down
-  bool IsOnlyLeftMouseButton() const {
-    return (flags() & EF_LEFT_MOUSE_BUTTON) &&
-      !(flags() & (EF_MIDDLE_MOUSE_BUTTON | EF_RIGHT_MOUSE_BUTTON));
-  }
-
-  bool IsLeftMouseButton() const {
-    return (flags() & EF_LEFT_MOUSE_BUTTON) != 0;
-  }
-
-  bool IsOnlyMiddleMouseButton() const {
-    return (flags() & EF_MIDDLE_MOUSE_BUTTON) &&
-      !(flags() & (EF_LEFT_MOUSE_BUTTON | EF_RIGHT_MOUSE_BUTTON));
-  }
-
-  bool IsMiddleMouseButton() const {
-    return (flags() & EF_MIDDLE_MOUSE_BUTTON) != 0;
-  }
-
-  bool IsOnlyRightMouseButton() const {
-    return (flags() & EF_RIGHT_MOUSE_BUTTON) &&
-      !(flags() & (EF_LEFT_MOUSE_BUTTON | EF_MIDDLE_MOUSE_BUTTON));
-  }
-
-  bool IsRightMouseButton() const {
-    return (flags() & EF_RIGHT_MOUSE_BUTTON) != 0;
-  }
-
-  bool IsAnyButton() const {
-    return (flags() & (EF_LEFT_MOUSE_BUTTON | EF_MIDDLE_MOUSE_BUTTON |
-                       EF_RIGHT_MOUSE_BUTTON)) != 0;
-  }
-
-  // Compares two mouse down events and returns true if the second one should
-  // be considered a repeat of the first.
-  static bool IsRepeatedClickEvent(
-      const MouseEvent& event1,
-      const MouseEvent& event2);
-
-  // Get the click count. Can be 1, 2 or 3 for mousedown messages, 0 otherwise.
-  int GetClickCount() const;
-
-  // Set the click count for a mousedown message. Can be 1, 2 or 3.
-  void SetClickCount(int click_count);
-
-  // Identifies the button that changed. During a press this corresponds to the
-  // button that was pressed and during a release this corresponds to the button
-  // that was released.
-  // NOTE: during a press and release flags() contains the complete set of
-  // flags. Use this to determine the button that was pressed or released.
-  int changed_button_flags() const { return changed_button_flags_; }
-
- private:
-  // Returns the repeat count based on the previous mouse click, if it is
-  // recent enough and within a small enough distance.
-  static int GetRepeatCount(const MouseEvent& click_event);
-
-  gfx::Point root_location_;
-
-  // See description above getter for details.
-  int changed_button_flags_;
-
-  static MouseEvent* last_click_event_;
-};
-
-class ScrollEvent;
-
-class UI_EXPORT MouseWheelEvent : public MouseEvent {
- public:
-  // See |offset| for details.
-  static const int kWheelDelta;
-
-  explicit MouseWheelEvent(const base::NativeEvent& native_event);
-  explicit MouseWheelEvent(const ScrollEvent& scroll_event);
-  MouseWheelEvent(const MouseEvent& mouse_event, int x_offset, int y_offset);
-
-  template <class T>
-  MouseWheelEvent(const MouseWheelEvent& model,
-                  T* source,
-                  T* target,
-                  EventType type,
-                  int flags)
-      : MouseEvent(model, source, target, type, flags),
-        offset_(model.x_offset(), model.y_offset()){
-  }
-
-  // The amount to scroll. This is in multiples of kWheelDelta.
-  // Note: x_offset() > 0/y_offset() > 0 means scroll left/up.
-  int x_offset() const { return offset_.x(); }
-  int y_offset() const { return offset_.y(); }
-  const gfx::Vector2d& offset() const { return offset_; }
-
- private:
-  gfx::Vector2d offset_;
-
-  DISALLOW_COPY_AND_ASSIGN(MouseWheelEvent);
-};
-
-class UI_EXPORT TouchEvent : public LocatedEvent {
- public:
-  explicit TouchEvent(const base::NativeEvent& native_event);
-
-  // Create a new TouchEvent which is identical to the provided model.
-  // If source / target windows are provided, the model location will be
-  // converted from |source| coordinate system to |target| coordinate system.
-  template <class T>
-  TouchEvent(const TouchEvent& model, T* source, T* target)
-      : LocatedEvent(model, source, target),
-        touch_id_(model.touch_id_),
-        radius_x_(model.radius_x_),
-        radius_y_(model.radius_y_),
-        rotation_angle_(model.rotation_angle_),
-        force_(model.force_) {
-  }
-
-  TouchEvent(EventType type,
-             const gfx::Point& root_location,
-             int touch_id,
-             base::TimeDelta time_stamp);
-
-  TouchEvent(EventType type,
-             const gfx::Point& location,
-             int flags,
-             int touch_id,
-             base::TimeDelta timestamp,
-             float radius_x,
-             float radius_y,
-             float angle,
-             float force);
-
-  virtual ~TouchEvent();
-
-  int touch_id() const { return touch_id_; }
-  float radius_x() const { return radius_x_; }
-  float radius_y() const { return radius_y_; }
-  float rotation_angle() const { return rotation_angle_; }
-  float force() const { return force_; }
-
-  // Relocate the touch-point to a new |origin|.
-  // This is useful when touch event is in X Root Window coordinates,
-  // and it needs to be mapped into Aura Root Window coordinates.
-  void Relocate(const gfx::Point& origin);
-
-  // Used for unit tests.
-  void set_radius_x(const float r) { radius_x_ = r; }
-  void set_radius_y(const float r) { radius_y_ = r; }
-
-  // Overridden from LocatedEvent.
-  virtual void UpdateForRootTransform(
-      const gfx::Transform& inverted_root_transform) OVERRIDE;
-
- protected:
-  void set_radius(float radius_x, float radius_y) {
-    radius_x_ = radius_x;
-    radius_y_ = radius_y;
-  }
-
-  void set_rotation_angle(float rotation_angle) {
-    rotation_angle_ = rotation_angle;
-  }
-
-  void set_force(float force) { force_ = force; }
-
- private:
-  // 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_;
-
-  // Radius of the X (major) axis of the touch ellipse. 0.0 if unknown.
-  float radius_x_;
-
-  // Radius of the Y (minor) axis of the touch ellipse. 0.0 if unknown.
-  float radius_y_;
-
-  // Angle of the major axis away from the X axis. Default 0.0.
-  float rotation_angle_;
-
-  // Force (pressure) of the touch. Normalized to be [0, 1]. Default to be 0.0.
-  float force_;
-};
-
-class UI_EXPORT KeyEvent : public Event {
- public:
-  KeyEvent(const base::NativeEvent& native_event, bool is_char);
-
-  // Used for synthetic events.
-  KeyEvent(EventType type, KeyboardCode key_code, int flags, bool is_char);
-
-  // These setters allow an I18N virtual keyboard to fabricate a keyboard event
-  // which does not have a corresponding KeyboardCode (example: U+00E1 Latin
-  // small letter A with acute, U+0410 Cyrillic capital letter A.)
-  // GetCharacter() and GetUnmodifiedCharacter() return the character.
-  void set_character(uint16 character) { character_ = character; }
-  void set_unmodified_character(uint16 unmodified_character) {
-    unmodified_character_ = unmodified_character;
-  }
-
-  // Gets the character generated by this key event. It only supports Unicode
-  // BMP characters.
-  uint16 GetCharacter() const;
-
-  // Gets the character generated by this key event ignoring concurrently-held
-  // modifiers (except shift).
-  uint16 GetUnmodifiedCharacter() const;
-
-  // Returns the copy of this key event. Used in NativeWebKeyboardEvent.
-  KeyEvent* Copy() const;
-
-  KeyboardCode key_code() const { return key_code_; }
-  bool is_char() const { return is_char_; }
-
-  // This is only intended to be used externally by classes that are modifying
-  // events in EventFilter::PreHandleKeyEvent().  set_character() should also be
-  // called.
-  void set_key_code(KeyboardCode key_code) { key_code_ = key_code; }
-
-  // Returns true for [Alt]+<num-pad digit> Unicode alt key codes used by Win.
-  // TODO(msw): Additional work may be needed for analogues on other platforms.
-  bool IsUnicodeKeyCode() const;
-
-  // Normalizes flags_ to make it Windows/Mac compatible. Since the way
-  // of setting modifier mask on X is very different than Windows/Mac as shown
-  // in http://crbug.com/127142#c8, the normalization is necessary.
-  void NormalizeFlags();
-
- private:
-  KeyboardCode key_code_;
-  // True if this is a translated character event (vs. a raw key down). Both
-  // share the same type: ET_KEY_PRESSED.
-  bool is_char_;
-
-  uint16 character_;
-  uint16 unmodified_character_;
-};
-
-// A key event which is translated by an input method (IME).
-// For example, if an IME receives a KeyEvent(VKEY_SPACE), and it does not
-// consume the key, the IME usually generates and dispatches a
-// TranslatedKeyEvent(VKEY_SPACE) event. If the IME receives a KeyEvent and
-// it does consume the event, it might dispatch a
-// TranslatedKeyEvent(VKEY_PROCESSKEY) event as defined in the DOM spec.
-class UI_EXPORT TranslatedKeyEvent : public KeyEvent {
- public:
-  TranslatedKeyEvent(const base::NativeEvent& native_event, bool is_char);
-
-  // Used for synthetic events such as a VKEY_PROCESSKEY key event.
-  TranslatedKeyEvent(bool is_press, KeyboardCode key_code, int flags);
-
-  // Changes the type() of the object from ET_TRANSLATED_KEY_* to ET_KEY_* so
-  // that RenderWidgetHostViewAura and NativeWidgetAura could handle the event.
-  void ConvertToKeyEvent();
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(TranslatedKeyEvent);
-};
-
-class UI_EXPORT DropTargetEvent : public LocatedEvent {
- public:
-  DropTargetEvent(const OSExchangeData& data,
-                  const gfx::Point& location,
-                  const gfx::Point& root_location,
-                  int source_operations);
-
-  const OSExchangeData& data() const { return data_; }
-  int source_operations() const { return source_operations_; }
-
- private:
-  // Data associated with the drag/drop session.
-  const OSExchangeData& data_;
-
-  // Bitmask of supported DragDropTypes::DragOperation by the source.
-  int source_operations_;
-
-  DISALLOW_COPY_AND_ASSIGN(DropTargetEvent);
-};
-
-class UI_EXPORT ScrollEvent : public MouseEvent {
- public:
-  explicit ScrollEvent(const base::NativeEvent& native_event);
-  template <class T>
-  ScrollEvent(const ScrollEvent& model,
-              T* source,
-              T* target)
-      : MouseEvent(model, source, target),
-        x_offset_(model.x_offset_),
-        y_offset_(model.y_offset_),
-        x_offset_ordinal_(model.x_offset_ordinal_),
-        y_offset_ordinal_(model.y_offset_ordinal_),
-        finger_count_(model.finger_count_){
-  }
-
-  // Used for tests.
-  ScrollEvent(EventType type,
-              const gfx::Point& location,
-              base::TimeDelta time_stamp,
-              int flags,
-              float x_offset,
-              float y_offset,
-              float x_offset_ordinal,
-              float y_offset_ordinal,
-              int finger_count);
-
-  // Scale the scroll event's offset value.
-  // This is useful in the multi-monitor setup where it needs to be scaled
-  // to provide a consistent user experience.
-  void Scale(const float factor);
-
-  float x_offset() const { return x_offset_; }
-  float y_offset() const { return y_offset_; }
-  float x_offset_ordinal() const { return x_offset_ordinal_; }
-  float y_offset_ordinal() const { return y_offset_ordinal_; }
-  int finger_count() const { return finger_count_; }
-
-  // Overridden from LocatedEvent.
-  virtual void UpdateForRootTransform(
-      const gfx::Transform& inverted_root_transform) OVERRIDE;
-
- private:
-  // Potential accelerated offsets.
-  float x_offset_;
-  float y_offset_;
-  // Unaccelerated offsets.
-  float x_offset_ordinal_;
-  float y_offset_ordinal_;
-  // Number of fingers on the pad.
-  int finger_count_;
-};
-
-class UI_EXPORT GestureEvent : public LocatedEvent {
- public:
-  GestureEvent(EventType type,
-               int x,
-               int y,
-               int flags,
-               base::TimeDelta time_stamp,
-               const GestureEventDetails& details,
-               unsigned int touch_ids_bitfield);
-
-  // Create a new GestureEvent which is identical to the provided model.
-  // If source / target windows are provided, the model location will be
-  // converted from |source| coordinate system to |target| coordinate system.
-  template <typename T>
-  GestureEvent(const GestureEvent& model, T* source, T* target)
-      : LocatedEvent(model, source, target),
-        details_(model.details_),
-        touch_ids_bitfield_(model.touch_ids_bitfield_) {
-  }
-
-  virtual ~GestureEvent();
-
-  const GestureEventDetails& details() const { return details_; }
-
-  // Returns the lowest touch-id of any of the touches which make up this
-  // gesture. If there are no touches associated with this gesture, returns -1.
-  int GetLowestTouchId() const;
-
- private:
-  GestureEventDetails details_;
-
-  // The set of indices of ones in the binary representation of
-  // touch_ids_bitfield_ is the set of touch_ids associate with this gesture.
-  // This value is stored as a bitfield because the number of touch ids varies,
-  // but we currently don't need more than 32 touches at a time.
-  const unsigned int touch_ids_bitfield_;
-
-  DISALLOW_COPY_AND_ASSIGN(GestureEvent);
-};
-
-}  // namespace ui
-
-#endif  // UI_BASE_EVENTS_EVENT_H_
+// Copyright (c) 2012 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_BASE_EVENTS_EVENT_H_
+#define UI_BASE_EVENTS_EVENT_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/event_types.h"
+#include "base/logging.h"
+#include "base/time.h"
+#include "ui/base/dragdrop/os_exchange_data.h"
+#include "ui/base/events/event_constants.h"
+#include "ui/base/gestures/gesture_types.h"
+#include "ui/base/keycodes/keyboard_codes.h"
+#include "ui/base/latency_info.h"
+#include "ui/base/ui_export.h"
+#include "ui/gfx/point.h"
+
+namespace gfx {
+class Transform;
+}
+
+namespace ui {
+class EventTarget;
+
+class UI_EXPORT Event {
+ public:
+  virtual ~Event();
+
+  class DispatcherApi {
+   public:
+    explicit DispatcherApi(Event* event) : event_(event) {}
+
+    void set_target(EventTarget* target) {
+      event_->target_ = target;
+    }
+
+    void set_phase(EventPhase phase) { event_->phase_ = phase; }
+    void set_result(int result) {
+      event_->result_ = static_cast<EventResult>(result);
+    }
+
+   private:
+    DispatcherApi();
+    Event* event_;
+
+    DISALLOW_COPY_AND_ASSIGN(DispatcherApi);
+  };
+
+  // For testing.
+  class TestApi {
+   public:
+    explicit TestApi(Event* event) : event_(event) {}
+
+    void set_time_stamp(base::TimeDelta time_stamp) {
+      event_->time_stamp_ = time_stamp;
+    }
+
+   private:
+    TestApi();
+    Event* event_;
+  };
+
+  const base::NativeEvent& native_event() const { return native_event_; }
+  EventType type() const { return type_; }
+  const std::string& name() const { return name_; }
+  // time_stamp represents time since machine was booted.
+  const base::TimeDelta& time_stamp() const { return time_stamp_; }
+  int flags() const { return flags_; }
+
+  // This is only intended to be used externally by classes that are modifying
+  // events in EventFilter::PreHandleKeyEvent().
+  void set_flags(int flags) { flags_ = flags; }
+
+  EventTarget* target() const { return target_; }
+  EventPhase phase() const { return phase_; }
+  EventResult result() const { return result_; }
+  bool dispatch_to_hidden_targets() const {
+    return dispatch_to_hidden_targets_;
+  }
+
+  LatencyInfo* latency() { return &latency_; }
+  void set_latency(const LatencyInfo& latency) { latency_ = latency; }
+
+  // By default, events are "cancelable", this means any default processing that
+  // the containing abstraction layer may perform can be prevented by calling
+  // SetHandled(). SetHandled() or StopPropagation() must not be called for
+  // events that are not cancelable.
+  bool cancelable() const { return cancelable_; }
+
+  // The following methods return true if the respective keys were pressed at
+  // the time the event was created.
+  bool IsShiftDown() const { return (flags_ & EF_SHIFT_DOWN) != 0; }
+  bool IsControlDown() const { return (flags_ & EF_CONTROL_DOWN) != 0; }
+  bool IsCapsLockDown() const { return (flags_ & EF_CAPS_LOCK_DOWN) != 0; }
+  bool IsAltDown() const { return (flags_ & EF_ALT_DOWN) != 0; }
+
+  bool IsKeyEvent() const {
+    return type_ == ET_KEY_PRESSED ||
+           type_ == ET_KEY_RELEASED ||
+           type_ == ET_TRANSLATED_KEY_PRESS ||
+           type_ == ET_TRANSLATED_KEY_RELEASE;
+  }
+
+  bool IsMouseEvent() const {
+    return type_ == ET_MOUSE_PRESSED ||
+           type_ == ET_MOUSE_DRAGGED ||
+           type_ == ET_MOUSE_RELEASED ||
+           type_ == ET_MOUSE_MOVED ||
+           type_ == ET_MOUSE_ENTERED ||
+           type_ == ET_MOUSE_EXITED ||
+           type_ == ET_MOUSEWHEEL ||
+           type_ == ET_MOUSE_CAPTURE_CHANGED;
+  }
+
+  bool IsTouchEvent() const {
+    return type_ == ET_TOUCH_RELEASED ||
+           type_ == ET_TOUCH_PRESSED ||
+           type_ == ET_TOUCH_MOVED ||
+           type_ == ET_TOUCH_STATIONARY ||
+           type_ == ET_TOUCH_CANCELLED;
+  }
+
+  bool IsGestureEvent() const {
+    switch (type_) {
+      case ET_GESTURE_SCROLL_BEGIN:
+      case ET_GESTURE_SCROLL_END:
+      case ET_GESTURE_SCROLL_UPDATE:
+      case ET_GESTURE_TAP:
+      case ET_GESTURE_TAP_CANCEL:
+      case ET_GESTURE_TAP_DOWN:
+      case ET_GESTURE_BEGIN:
+      case ET_GESTURE_END:
+      case ET_GESTURE_TWO_FINGER_TAP:
+      case ET_GESTURE_PINCH_BEGIN:
+      case ET_GESTURE_PINCH_END:
+      case ET_GESTURE_PINCH_UPDATE:
+      case ET_GESTURE_LONG_PRESS:
+      case ET_GESTURE_LONG_TAP:
+      case ET_GESTURE_MULTIFINGER_SWIPE:
+        return true;
+
+      case ET_SCROLL_FLING_CANCEL:
+      case ET_SCROLL_FLING_START:
+        // These can be ScrollEvents too. EF_FROM_TOUCH determines if they're
+        // Gesture or Scroll events.
+        return (flags_ & EF_FROM_TOUCH) == EF_FROM_TOUCH;
+
+      default:
+        break;
+    }
+    return false;
+  }
+
+  bool IsScrollEvent() const {
+    // Flings can be GestureEvents too. EF_FROM_TOUCH determins if they're
+    // Gesture or Scroll events.
+    return type_ == ET_SCROLL ||
+           ((type_ == ET_SCROLL_FLING_START ||
+           type_ == ET_SCROLL_FLING_CANCEL) &&
+           !(flags() & EF_FROM_TOUCH));
+  }
+
+  bool IsScrollGestureEvent() const {
+    return type_ == ET_GESTURE_SCROLL_BEGIN ||
+           type_ == ET_GESTURE_SCROLL_UPDATE ||
+           type_ == ET_GESTURE_SCROLL_END;
+  }
+
+  bool IsFlingScrollEvent() const {
+    return type_ == ET_SCROLL_FLING_CANCEL ||
+           type_ == ET_SCROLL_FLING_START;
+  }
+
+  bool IsMouseWheelEvent() const {
+    return type_ == ET_MOUSEWHEEL;
+  }
+
+  // Returns true if the event has a valid |native_event_|.
+  bool HasNativeEvent() const;
+
+  // Immediately stops the propagation of the event. This must be called only
+  // from an EventHandler during an event-dispatch. Any event handler that may
+  // be in the list will not receive the event after this is called.
+  // Note that StopPropagation() can be called only for cancelable events.
+  void StopPropagation();
+  bool stopped_propagation() const { return !!(result_ & ER_CONSUMED); }
+
+  // Marks the event as having been handled. A handled event does not reach the
+  // next event phase. For example, if an event is handled during the pre-target
+  // phase, then the event is dispatched to all pre-target handlers, but not to
+  // the target or post-target handlers.
+  // Note that SetHandled() can be called only for cancelable events.
+  void SetHandled();
+  bool handled() const { return result_ != ER_UNHANDLED; }
+
+ protected:
+  Event(EventType type, base::TimeDelta time_stamp, int flags);
+  Event(const base::NativeEvent& native_event, EventType type, int flags);
+  Event(const Event& copy);
+  void SetType(EventType type);
+  void set_delete_native_event(bool delete_native_event) {
+    delete_native_event_ = delete_native_event;
+  }
+  void set_cancelable(bool cancelable) { cancelable_ = cancelable; }
+  void set_dispatch_to_hidden_targets(bool dispatch_to_hidden_targets) {
+    dispatch_to_hidden_targets_ = dispatch_to_hidden_targets;
+  }
+
+  void set_time_stamp(const base::TimeDelta& time_stamp) {
+    time_stamp_ = time_stamp;
+  }
+
+  void set_name(const std::string& name) { name_ = name; }
+
+  void InitLatencyInfo();
+
+ private:
+  void operator=(const Event&);
+
+  // Safely initializes the native event members of this class.
+  void Init();
+  void InitWithNativeEvent(const base::NativeEvent& native_event);
+
+  EventType type_;
+  std::string name_;
+  base::TimeDelta time_stamp_;
+  LatencyInfo latency_;
+  int flags_;
+  bool dispatch_to_hidden_targets_;
+  base::NativeEvent native_event_;
+  bool delete_native_event_;
+  bool cancelable_;
+  EventTarget* target_;
+  EventPhase phase_;
+  EventResult result_;
+};
+
+class UI_EXPORT CancelModeEvent : public Event {
+ public:
+  CancelModeEvent();
+  virtual ~CancelModeEvent();
+};
+
+class UI_EXPORT LocatedEvent : public Event {
+ public:
+  // For testing.
+  class TestApi : public Event::TestApi {
+   public:
+    explicit TestApi(LocatedEvent* located_event)
+        : Event::TestApi(located_event),
+          located_event_(located_event) {}
+
+    void set_location(const gfx::Point& location) {
+      located_event_->location_ = location;
+    }
+
+   private:
+    TestApi();
+    LocatedEvent* located_event_;
+  };
+
+  virtual ~LocatedEvent();
+
+  int x() const { return location_.x(); }
+  int y() const { return location_.y(); }
+  void set_location(const gfx::Point& location) { location_ = location; }
+  gfx::Point location() const { return location_; }
+  void set_root_location(const gfx::Point& root_location) {
+    root_location_ = root_location;
+  }
+  gfx::Point root_location() const { return root_location_; }
+
+  // Transform the locations using |inverted_root_transform|.
+  // This is applied to both |location_| and |root_location_|.
+  virtual void UpdateForRootTransform(
+      const gfx::Transform& inverted_root_transform);
+
+  template <class T> void ConvertLocationToTarget(T* source, T* target) {
+    if (target && target != source)
+      T::ConvertPointToTarget(source, target, &location_);
+  }
+
+ protected:
+  explicit LocatedEvent(const base::NativeEvent& native_event);
+
+  // Create a new LocatedEvent which is identical to the provided model.
+  // If source / target windows are provided, the model location will be
+  // converted from |source| coordinate system to |target| coordinate system.
+  template <class T>
+  LocatedEvent(const LocatedEvent& model, T* source, T* target)
+      : Event(model),
+        location_(model.location_),
+        root_location_(model.root_location_) {
+    ConvertLocationToTarget(source, target);
+  }
+
+  // Used for synthetic events in testing.
+  LocatedEvent(EventType type,
+               const gfx::Point& location,
+               const gfx::Point& root_location,
+               base::TimeDelta time_stamp,
+               int flags);
+
+  gfx::Point location_;
+
+  // |location_| multiplied by an optional transformation matrix for
+  // rotations, animations and skews.
+  gfx::Point root_location_;
+};
+
+class UI_EXPORT MouseEvent : public LocatedEvent {
+ public:
+  explicit MouseEvent(const base::NativeEvent& native_event);
+
+  // Create a new MouseEvent based on the provided model.
+  // Uses the provided |type| and |flags| for the new event.
+  // If source / target windows are provided, the model location will be
+  // converted from |source| coordinate system to |target| coordinate system.
+  template <class T>
+  MouseEvent(const MouseEvent& model, T* source, T* target)
+      : LocatedEvent(model, source, target),
+        changed_button_flags_(model.changed_button_flags_) {
+  }
+
+  template <class T>
+  MouseEvent(const MouseEvent& model,
+             T* source,
+             T* target,
+             EventType type,
+             int flags)
+      : LocatedEvent(model, source, target),
+        changed_button_flags_(model.changed_button_flags_) {
+    SetType(type);
+    set_flags(flags);
+  }
+
+  // Used for synthetic events in testing and by the gesture recognizer.
+  MouseEvent(EventType type,
+             const gfx::Point& location,
+             const gfx::Point& root_location,
+             int flags);
+
+  // Conveniences to quickly test what button is down
+  bool IsOnlyLeftMouseButton() const {
+    return (flags() & EF_LEFT_MOUSE_BUTTON) &&
+      !(flags() & (EF_MIDDLE_MOUSE_BUTTON | EF_RIGHT_MOUSE_BUTTON));
+  }
+
+  bool IsLeftMouseButton() const {
+    return (flags() & EF_LEFT_MOUSE_BUTTON) != 0;
+  }
+
+  bool IsOnlyMiddleMouseButton() const {
+    return (flags() & EF_MIDDLE_MOUSE_BUTTON) &&
+      !(flags() & (EF_LEFT_MOUSE_BUTTON | EF_RIGHT_MOUSE_BUTTON));
+  }
+
+  bool IsMiddleMouseButton() const {
+    return (flags() & EF_MIDDLE_MOUSE_BUTTON) != 0;
+  }
+
+  bool IsOnlyRightMouseButton() const {
+    return (flags() & EF_RIGHT_MOUSE_BUTTON) &&
+      !(flags() & (EF_LEFT_MOUSE_BUTTON | EF_MIDDLE_MOUSE_BUTTON));
+  }
+
+  bool IsRightMouseButton() const {
+    return (flags() & EF_RIGHT_MOUSE_BUTTON) != 0;
+  }
+
+  bool IsAnyButton() const {
+    return (flags() & (EF_LEFT_MOUSE_BUTTON | EF_MIDDLE_MOUSE_BUTTON |
+                       EF_RIGHT_MOUSE_BUTTON)) != 0;
+  }
+
+  // Compares two mouse down events and returns true if the second one should
+  // be considered a repeat of the first.
+  static bool IsRepeatedClickEvent(
+      const MouseEvent& event1,
+      const MouseEvent& event2);
+
+  // Get the click count. Can be 1, 2 or 3 for mousedown messages, 0 otherwise.
+  int GetClickCount() const;
+
+  // Set the click count for a mousedown message. Can be 1, 2 or 3.
+  void SetClickCount(int click_count);
+
+  // Identifies the button that changed. During a press this corresponds to the
+  // button that was pressed and during a release this corresponds to the button
+  // that was released.
+  // NOTE: during a press and release flags() contains the complete set of
+  // flags. Use this to determine the button that was pressed or released.
+  int changed_button_flags() const { return changed_button_flags_; }
+
+ private:
+  // Returns the repeat count based on the previous mouse click, if it is
+  // recent enough and within a small enough distance.
+  static int GetRepeatCount(const MouseEvent& click_event);
+
+  // See description above getter for details.
+  int changed_button_flags_;
+
+  static MouseEvent* last_click_event_;
+};
+
+class ScrollEvent;
+
+class UI_EXPORT MouseWheelEvent : public MouseEvent {
+ public:
+  // See |offset| for details.
+  static const int kWheelDelta;
+
+  explicit MouseWheelEvent(const base::NativeEvent& native_event);
+  explicit MouseWheelEvent(const ScrollEvent& scroll_event);
+  MouseWheelEvent(const MouseEvent& mouse_event, int x_offset, int y_offset);
+  MouseWheelEvent(const MouseWheelEvent& mouse_wheel_event);
+
+  template <class T>
+  MouseWheelEvent(const MouseWheelEvent& model,
+                  T* source,
+                  T* target,
+                  EventType type,
+                  int flags)
+      : MouseEvent(model, source, target, type, flags),
+        offset_(model.x_offset(), model.y_offset()){
+  }
+
+  // The amount to scroll. This is in multiples of kWheelDelta.
+  // Note: x_offset() > 0/y_offset() > 0 means scroll left/up.
+  int x_offset() const { return offset_.x(); }
+  int y_offset() const { return offset_.y(); }
+  const gfx::Vector2d& offset() const { return offset_; }
+
+  // Overridden from LocatedEvent.
+  virtual void UpdateForRootTransform(
+      const gfx::Transform& inverted_root_transform) OVERRIDE;
+
+ private:
+  gfx::Vector2d offset_;
+};
+
+class UI_EXPORT TouchEvent : public LocatedEvent {
+ public:
+  explicit TouchEvent(const base::NativeEvent& native_event);
+
+  // Create a new TouchEvent which is identical to the provided model.
+  // If source / target windows are provided, the model location will be
+  // converted from |source| coordinate system to |target| coordinate system.
+  template <class T>
+  TouchEvent(const TouchEvent& model, T* source, T* target)
+      : LocatedEvent(model, source, target),
+        touch_id_(model.touch_id_),
+        radius_x_(model.radius_x_),
+        radius_y_(model.radius_y_),
+        rotation_angle_(model.rotation_angle_),
+        force_(model.force_) {
+  }
+
+  TouchEvent(EventType type,
+             const gfx::Point& root_location,
+             int touch_id,
+             base::TimeDelta time_stamp);
+
+  TouchEvent(EventType type,
+             const gfx::Point& location,
+             int flags,
+             int touch_id,
+             base::TimeDelta timestamp,
+             float radius_x,
+             float radius_y,
+             float angle,
+             float force);
+
+  virtual ~TouchEvent();
+
+  int touch_id() const { return touch_id_; }
+  float radius_x() const { return radius_x_; }
+  float radius_y() const { return radius_y_; }
+  float rotation_angle() const { return rotation_angle_; }
+  float force() const { return force_; }
+
+  // Relocate the touch-point to a new |origin|.
+  // This is useful when touch event is in X Root Window coordinates,
+  // and it needs to be mapped into Aura Root Window coordinates.
+  void Relocate(const gfx::Point& origin);
+
+  // Used for unit tests.
+  void set_radius_x(const float r) { radius_x_ = r; }
+  void set_radius_y(const float r) { radius_y_ = r; }
+
+  // Overridden from LocatedEvent.
+  virtual void UpdateForRootTransform(
+      const gfx::Transform& inverted_root_transform) OVERRIDE;
+
+ protected:
+  void set_radius(float radius_x, float radius_y) {
+    radius_x_ = radius_x;
+    radius_y_ = radius_y;
+  }
+
+  void set_rotation_angle(float rotation_angle) {
+    rotation_angle_ = rotation_angle;
+  }
+
+  void set_force(float force) { force_ = force; }
+
+ private:
+  // 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_;
+
+  // Radius of the X (major) axis of the touch ellipse. 0.0 if unknown.
+  float radius_x_;
+
+  // Radius of the Y (minor) axis of the touch ellipse. 0.0 if unknown.
+  float radius_y_;
+
+  // Angle of the major axis away from the X axis. Default 0.0.
+  float rotation_angle_;
+
+  // Force (pressure) of the touch. Normalized to be [0, 1]. Default to be 0.0.
+  float force_;
+};
+
+class UI_EXPORT KeyEvent : public Event {
+ public:
+  KeyEvent(const base::NativeEvent& native_event, bool is_char);
+
+  // Used for synthetic events.
+  KeyEvent(EventType type, KeyboardCode key_code, int flags, bool is_char);
+
+  // These setters allow an I18N virtual keyboard to fabricate a keyboard event
+  // which does not have a corresponding KeyboardCode (example: U+00E1 Latin
+  // small letter A with acute, U+0410 Cyrillic capital letter A.)
+  // GetCharacter() and GetUnmodifiedCharacter() return the character.
+  void set_character(uint16 character) { character_ = character; }
+  void set_unmodified_character(uint16 unmodified_character) {
+    unmodified_character_ = unmodified_character;
+  }
+
+  // Gets the character generated by this key event. It only supports Unicode
+  // BMP characters.
+  uint16 GetCharacter() const;
+
+  // Gets the character generated by this key event ignoring concurrently-held
+  // modifiers (except shift).
+  uint16 GetUnmodifiedCharacter() const;
+
+  // Returns the copy of this key event. Used in NativeWebKeyboardEvent.
+  KeyEvent* Copy() const;
+
+  KeyboardCode key_code() const { return key_code_; }
+  bool is_char() const { return is_char_; }
+
+  // This is only intended to be used externally by classes that are modifying
+  // events in EventFilter::PreHandleKeyEvent().  set_character() should also be
+  // called.
+  void set_key_code(KeyboardCode key_code) { key_code_ = key_code; }
+
+  // Returns true for [Alt]+<num-pad digit> Unicode alt key codes used by Win.
+  // TODO(msw): Additional work may be needed for analogues on other platforms.
+  bool IsUnicodeKeyCode() const;
+
+  // Normalizes flags_ to make it Windows/Mac compatible. Since the way
+  // of setting modifier mask on X is very different than Windows/Mac as shown
+  // in http://crbug.com/127142#c8, the normalization is necessary.
+  void NormalizeFlags();
+
+ private:
+  KeyboardCode key_code_;
+  // True if this is a translated character event (vs. a raw key down). Both
+  // share the same type: ET_KEY_PRESSED.
+  bool is_char_;
+
+  uint16 character_;
+  uint16 unmodified_character_;
+};
+
+// A key event which is translated by an input method (IME).
+// For example, if an IME receives a KeyEvent(VKEY_SPACE), and it does not
+// consume the key, the IME usually generates and dispatches a
+// TranslatedKeyEvent(VKEY_SPACE) event. If the IME receives a KeyEvent and
+// it does consume the event, it might dispatch a
+// TranslatedKeyEvent(VKEY_PROCESSKEY) event as defined in the DOM spec.
+class UI_EXPORT TranslatedKeyEvent : public KeyEvent {
+ public:
+  TranslatedKeyEvent(const base::NativeEvent& native_event, bool is_char);
+
+  // Used for synthetic events such as a VKEY_PROCESSKEY key event.
+  TranslatedKeyEvent(bool is_press, KeyboardCode key_code, int flags);
+
+  // Changes the type() of the object from ET_TRANSLATED_KEY_* to ET_KEY_* so
+  // that RenderWidgetHostViewAura and NativeWidgetAura could handle the event.
+  void ConvertToKeyEvent();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TranslatedKeyEvent);
+};
+
+class UI_EXPORT DropTargetEvent : public LocatedEvent {
+ public:
+  DropTargetEvent(const OSExchangeData& data,
+                  const gfx::Point& location,
+                  const gfx::Point& root_location,
+                  int source_operations);
+
+  const OSExchangeData& data() const { return data_; }
+  int source_operations() const { return source_operations_; }
+
+ private:
+  // Data associated with the drag/drop session.
+  const OSExchangeData& data_;
+
+  // Bitmask of supported DragDropTypes::DragOperation by the source.
+  int source_operations_;
+
+  DISALLOW_COPY_AND_ASSIGN(DropTargetEvent);
+};
+
+class UI_EXPORT ScrollEvent : public MouseEvent {
+ public:
+  explicit ScrollEvent(const base::NativeEvent& native_event);
+  template <class T>
+  ScrollEvent(const ScrollEvent& model,
+              T* source,
+              T* target)
+      : MouseEvent(model, source, target),
+        x_offset_(model.x_offset_),
+        y_offset_(model.y_offset_),
+        x_offset_ordinal_(model.x_offset_ordinal_),
+        y_offset_ordinal_(model.y_offset_ordinal_),
+        finger_count_(model.finger_count_){
+  }
+
+  // Used for tests.
+  ScrollEvent(EventType type,
+              const gfx::Point& location,
+              base::TimeDelta time_stamp,
+              int flags,
+              float x_offset,
+              float y_offset,
+              float x_offset_ordinal,
+              float y_offset_ordinal,
+              int finger_count);
+
+  // Scale the scroll event's offset value.
+  // This is useful in the multi-monitor setup where it needs to be scaled
+  // to provide a consistent user experience.
+  void Scale(const float factor);
+
+  float x_offset() const { return x_offset_; }
+  float y_offset() const { return y_offset_; }
+  float x_offset_ordinal() const { return x_offset_ordinal_; }
+  float y_offset_ordinal() const { return y_offset_ordinal_; }
+  int finger_count() const { return finger_count_; }
+
+  // Overridden from LocatedEvent.
+  virtual void UpdateForRootTransform(
+      const gfx::Transform& inverted_root_transform) OVERRIDE;
+
+ private:
+  // Potential accelerated offsets.
+  float x_offset_;
+  float y_offset_;
+  // Unaccelerated offsets.
+  float x_offset_ordinal_;
+  float y_offset_ordinal_;
+  // Number of fingers on the pad.
+  int finger_count_;
+};
+
+class UI_EXPORT GestureEvent : public LocatedEvent {
+ public:
+  GestureEvent(EventType type,
+               int x,
+               int y,
+               int flags,
+               base::TimeDelta time_stamp,
+               const GestureEventDetails& details,
+               unsigned int touch_ids_bitfield);
+
+  // Create a new GestureEvent which is identical to the provided model.
+  // If source / target windows are provided, the model location will be
+  // converted from |source| coordinate system to |target| coordinate system.
+  template <typename T>
+  GestureEvent(const GestureEvent& model, T* source, T* target)
+      : LocatedEvent(model, source, target),
+        details_(model.details_),
+        touch_ids_bitfield_(model.touch_ids_bitfield_) {
+  }
+
+  virtual ~GestureEvent();
+
+  const GestureEventDetails& details() const { return details_; }
+
+  // Returns the lowest touch-id of any of the touches which make up this
+  // gesture. If there are no touches associated with this gesture, returns -1.
+  int GetLowestTouchId() const;
+
+ private:
+  GestureEventDetails details_;
+
+  // The set of indices of ones in the binary representation of
+  // touch_ids_bitfield_ is the set of touch_ids associate with this gesture.
+  // This value is stored as a bitfield because the number of touch ids varies,
+  // but we currently don't need more than 32 touches at a time.
+  const unsigned int touch_ids_bitfield_;
+
+  DISALLOW_COPY_AND_ASSIGN(GestureEvent);
+};
+
+}  // namespace ui
+
+#endif  // UI_BASE_EVENTS_EVENT_H_