Desktop Aura: Allow tab drags out of window.

ui/base/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_EVENT_H_
 #define UI_BASE_EVENT_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/event_types.h"
@@ skipping 127 matching lines @@
     LocatedEvent* located_event_;
   };
 
   virtual ~LocatedEvent();
 
   int x() const { return location_.x(); }
   int y() const { return location_.y(); }
   gfx::Point location() const { return location_; }
   gfx::Point root_location() const { return root_location_; }
 
+  bool valid_system_location() const {
+    return system_location_ != gfx::Point(-1, -1);
+  }
+  void set_system_location(const gfx::Point& loc) { system_location_ = loc; }
+  gfx::Point system_location() const { return system_location_; }
+
+
   // Applies |root_transform| to the event.
   // This is applied to both |location_| and |root_location_|.
   virtual void UpdateForRootTransform(const Transform& root_transform);
 
  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_) {
+        root_location_(model.root_location_),
+        system_location_(model.system_location_) {
+    // TODO(erg): May need to create system_location_ by converting location to
+    // system coordinates here.
     if (target && target != source)
       T::ConvertPointToTarget(source, target, &location_);
   }
 
   // Used for synthetic events in testing.
   LocatedEvent(EventType type,
                const gfx::Point& location,
                const gfx::Point& root_location,
                int flags);
 
   LocatedEvent(const LocatedEvent& model);
 
   gfx::Point location_;
 
   gfx::Point root_location_;
+
+  gfx::Point system_location_;

[Daniel Erat, 2012/08/15 20:30:57]

Add a comment describing what "system" means here.  How does it differ from
|root_location_|?  It looks like you're actually using the root location from
the event in the X11 implementation.

[Elliot Glaysher, 2012/08/15 20:55:59]

Commented. "Root location" in aura and "root location" in x11 mean different
things. This tripped me up in an earlier porting patch when I fed the X11 root
location into |root_location_| and broke some chromeos stuff.

 };
 
 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.
@@ skipping 300 matching lines @@
   // 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_EVENT_H_