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 RootWindow;
  15 class Window;
  16 class WindowDelegate;
  17 }
  18
  19 namespace ash {
  20 namespace internal {
  21
  22 // Provides functions for handling drag events inside and outside the root
  23 // window where drag is started. This internally sets up a capture window for
  24 // tracking drag events outside the root window where drag is initiated.
  25 // ash/wm/coordinate_conversion.h is used internally and only X11 environment
  26 // is supported for now.
  27 class ASH_EXPORT DragDropTracker {
  28  public:
  29   DragDropTracker(aura::RootWindow* context_root,
  30                   aura::WindowDelegate* delegate);
  31   ~DragDropTracker();
  32
  33   aura::Window* capture_window() { return capture_window_.get(); }
  34
  35   // Tells our |capture_window_| to take capture. This is not done right at
  36   // creation to give the caller a chance to perform any operations needed
  37   // before the capture is transfered.
  38   void TakeCapture();
  39
  40   // Gets the target located at |event| in the coordinates of the active root
  41   // window.
  42   aura::Window* GetTarget(const ui::LocatedEvent& event);
  43
  44   // Converts the locations of |event| in the coordinates of the active root
  45   // window to the ones in |target|'s coordinates.
  46   // Caller takes ownership of the returned object.
  47   ui::LocatedEvent* ConvertEvent(aura::Window* target,
  48                                  const ui::LocatedEvent& event);
  49
  50  private:
  51   // A window for capturing drag events while dragging.
  52   scoped_ptr<aura::Window> capture_window_;
  53
  54   DISALLOW_COPY_AND_ASSIGN(DragDropTracker);
  55 };
  56
  57 }  // namespace internal
  58 }  // namespace ash
  59
  60 #endif  // ASH_DRAG_DROP_DRAG_DROP_TRACKER_H_