Do not mutate ui::Event properties during nested event processing

ui/events/event.cc

 // 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.
 
 #include "ui/events/event.h"
 
 #if defined(USE_X11)
 #include <X11/extensions/XInput2.h>
 #include <X11/Xlib.h>
 #endif
@@ skipping 218 matching lines @@
 // CancelModeEvent
 
 CancelModeEvent::CancelModeEvent()
     : Event(ET_CANCEL_MODE, base::TimeDelta(), 0) {
   set_cancelable(false);
 }
 
 CancelModeEvent::~CancelModeEvent() {
 }
 
+scoped_ptr<Event> CancelModeEvent::Clone() const {
+  return scoped_ptr<Event>(new CancelModeEvent(*this));
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // LocatedEvent
 
 LocatedEvent::~LocatedEvent() {
 }
 
 LocatedEvent::LocatedEvent(const base::NativeEvent& native_event)
     : Event(native_event,
             EventTypeFromNative(native_event),
             EventFlagsFromNative(native_event)),
@@ skipping 13 matching lines @@
 
 void LocatedEvent::UpdateForRootTransform(
     const gfx::Transform& reversed_root_transform) {
   // Transform has to be done at root level.
   gfx::Point3F p(location_);
   reversed_root_transform.TransformPoint(&p);
   location_ = p.AsPointF();
   root_location_ = location_;
 }
 
+scoped_ptr<Event> LocatedEvent::Clone() const {
+  return scoped_ptr<Event>(new LocatedEvent(*this));
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // MouseEvent
 
 MouseEvent::MouseEvent(const base::NativeEvent& native_event)
     : LocatedEvent(native_event),
       changed_button_flags_(
           GetChangedMouseButtonFlagsFromNative(native_event)) {
   if (type() == ET_MOUSE_PRESSED || type() == ET_MOUSE_RELEASED)
     SetClickCount(GetRepeatCount(*this));
 }
@@ skipping 116 matching lines @@
       f &= ~EF_IS_TRIPLE_CLICK;
       break;
     case 3:
       f &= ~EF_IS_DOUBLE_CLICK;
       f |= EF_IS_TRIPLE_CLICK;
       break;
   }
   set_flags(f);
 }
 
+scoped_ptr<Event> MouseEvent::Clone() const {
+  return scoped_ptr<Event>(new MouseEvent(*this));
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // MouseWheelEvent
 
 MouseWheelEvent::MouseWheelEvent(const base::NativeEvent& native_event)
     : MouseEvent(native_event),
       offset_(GetMouseWheelOffset(native_event)) {
 }
 
 MouseWheelEvent::MouseWheelEvent(const ScrollEvent& scroll_event)
     : MouseEvent(scroll_event),
@@ skipping 38 matching lines @@
   LocatedEvent::UpdateForRootTransform(inverted_root_transform);
   gfx::DecomposedTransform decomp;
   bool success = gfx::DecomposeTransform(&decomp, inverted_root_transform);
   DCHECK(success);
   if (decomp.scale[0])
     offset_.set_x(offset_.x() * decomp.scale[0]);
   if (decomp.scale[1])
     offset_.set_y(offset_.y() * decomp.scale[1]);
 }
 
+scoped_ptr<Event> MouseWheelEvent::Clone() const {
+  return scoped_ptr<Event>(new MouseWheelEvent(*this));
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // TouchEvent
 
 TouchEvent::TouchEvent(const base::NativeEvent& native_event)
     : LocatedEvent(native_event),
       touch_id_(GetTouchId(native_event)),
       radius_x_(GetTouchRadiusX(native_event)),
       radius_y_(GetTouchRadiusY(native_event)),
       rotation_angle_(GetTouchAngle(native_event)),
       force_(GetTouchForce(native_event)) {
@@ skipping 54 matching lines @@
   LocatedEvent::UpdateForRootTransform(inverted_root_transform);
   gfx::DecomposedTransform decomp;
   bool success = gfx::DecomposeTransform(&decomp, inverted_root_transform);
   DCHECK(success);
   if (decomp.scale[0])
     radius_x_ *= decomp.scale[0];
   if (decomp.scale[1])
     radius_y_ *= decomp.scale[1];
 }
 
+scoped_ptr<Event> TouchEvent::Clone() const {
+  return scoped_ptr<Event>(new TouchEvent(*this));
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // KeyEvent
 
 // static
 KeyEvent* KeyEvent::last_key_event_ = NULL;
 
 // static
 bool KeyEvent::IsRepeated(const KeyEvent& event) {
   // A safe guard in case if there were continous key pressed events that are
   // not auto repeat.
@@ skipping 206 matching lines @@
       break;
     case ET_KEY_RELEASED:
     case ET_TRANSLATED_KEY_RELEASE:
       SetType(translated ? ET_TRANSLATED_KEY_RELEASE : ET_KEY_RELEASED);
       break;
     default:
       NOTREACHED();
   }
 }
 
+scoped_ptr<Event> KeyEvent::Clone() const {
+  return scoped_ptr<Event>(new KeyEvent(*this));
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // ScrollEvent
 
 ScrollEvent::ScrollEvent(const base::NativeEvent& native_event)
     : MouseEvent(native_event) {
   if (type() == ET_SCROLL) {
     GetScrollOffsets(native_event,
                      &x_offset_, &y_offset_,
                      &x_offset_ordinal_, &y_offset_ordinal_,
                      &finger_count_);
@@ skipping 28 matching lines @@
   CHECK(IsScrollEvent());
 }
 
 void ScrollEvent::Scale(const float factor) {
   x_offset_ *= factor;
   y_offset_ *= factor;
   x_offset_ordinal_ *= factor;
   y_offset_ordinal_ *= factor;
 }
 
+scoped_ptr<Event> ScrollEvent::Clone() const {
+  return scoped_ptr<Event>(new ScrollEvent(*this));
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // GestureEvent
 
 GestureEvent::GestureEvent(float x,
                            float y,
                            int flags,
                            base::TimeDelta time_stamp,
                            const GestureEventDetails& details)
     : LocatedEvent(details.type(),
                    gfx::PointF(x, y),
                    gfx::PointF(x, y),
                    time_stamp,
                    flags | EF_FROM_TOUCH),
       details_(details) {
 }
 
 GestureEvent::~GestureEvent() {
 }
 
+scoped_ptr<Event> GestureEvent::Clone() const {
+  return scoped_ptr<Event>(new GestureEvent(*this));
+}
+
 }  // namespace ui