ash/drag_drop/drag_drop_tracker.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef ASH_DRAG_DROP_DRAG_DROP_TRACKER_H_
   6 #define ASH_DRAG_DROP_DRAG_DROP_TRACKER_H_
   7
   8 #include "ash/ash_export.h"
   9 #include "base/basictypes.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "ui/events/event.h"
  12
  13 namespace aura {
  14 class Window;
  15 class WindowDelegate;
  16 }
  17
  18 namespace ash {
  19
  20 // Provides functions for handling drag events inside and outside the root
  21 // window where drag is started. This internally sets up a capture window for
  22 // tracking drag events outside the root window where drag is initiated.
  23 // ash/wm/coordinate_conversion.h is used internally and only X11 environment
  24 // is supported for now.
  25 class ASH_EXPORT DragDropTracker {
  26  public:
  27   DragDropTracker(aura::Window* context_root,
  28                   aura::WindowDelegate* delegate);
  29   ~DragDropTracker();
  30
  31   aura::Window* capture_window() { return capture_window_.get(); }
  32
  33   // Tells our |capture_window_| to take capture. This is not done right at
  34   // creation to give the caller a chance to perform any operations needed
  35   // before the capture is transfered.
  36   void TakeCapture();
  37
  38   // Gets the target located at |event| in the coordinates of the active root
  39   // window.
  40   aura::Window* GetTarget(const ui::LocatedEvent& event);
  41
  42   // Converts the locations of |event| in the coordinates of the active root
  43   // window to the ones in |target|'s coordinates.
  44   // Caller takes ownership of the returned object.
  45   ui::LocatedEvent* ConvertEvent(aura::Window* target,
  46                                  const ui::LocatedEvent& event);
  47
  48  private:
  49   // A window for capturing drag events while dragging.
  50   scoped_ptr<aura::Window> capture_window_;
  51
  52   DISALLOW_COPY_AND_ASSIGN(DragDropTracker);
  53 };
  54
  55 }  // namespace ash
  56
  57 #endif  // ASH_DRAG_DROP_DRAG_DROP_TRACKER_H_