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      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_IMAGE_VIEW_H_
      6 #define ASH_DRAG_DROP_DRAG_IMAGE_VIEW_H_
      7 
      8 #include "ui/base/dragdrop/drag_drop_types.h"
      9 #include "ui/views/controls/image_view.h"
     10 
     11 namespace views {
     12 class Widget;
     13 }
     14 
     15 namespace ash {
     16 namespace internal {
     17 
     18 // This class allows to show a (native) view always on top of everything. It
     19 // does this by creating a widget and setting the content as the given view. The
     20 // caller can then use this object to freely move / drag it around on the
     21 // desktop in screen coordinates.
     22 class DragImageView : public views::ImageView {
     23  public:
     24   // |context is the native view context used to create the widget holding the
     25   // drag image.
     26   // |source| is the event source that started this drag drop operation (touch
     27   // or mouse). It is used to determine attributes of the drag image such as
     28   // whether to show drag operation hint on top of the image.
     29   DragImageView(gfx::NativeView context,
     30                 ui::DragDropTypes::DragEventSource source);
     31   virtual ~DragImageView();
     32 
     33   // Sets the bounds of the native widget in screen
     34   // coordinates.
     35   // TODO(oshima): Looks like this is root window's
     36   // coordinate. Change this to screen's coordinate.
     37   void SetBoundsInScreen(const gfx::Rect& bounds);
     38 
     39   // Sets the position of the native widget.
     40   void SetScreenPosition(const gfx::Point& position);
     41 
     42   // Gets the image position in screen coordinates.
     43   gfx::Rect GetBoundsInScreen() const;
     44 
     45   // Sets the visibility of the native widget.
     46   void SetWidgetVisible(bool visible);
     47 
     48   // For touch drag drop, we show a hint corresponding to the drag operation
     49   // (since no mouse cursor is visible). These functions set the hint
     50   // parameters.
     51   void SetTouchDragOperationHintOff();
     52 
     53   // |operation| is a bit field indicating allowable drag operations from
     54   // ui::DragDropTypes::DragOperation.
     55   void SetTouchDragOperation(int operation);
     56   void SetTouchDragOperationHintPosition(const gfx::Point& position);
     57 
     58   // Sets the |opacity| of the image view between 0.0 and 1.0.
     59   void SetOpacity(float opacity);
     60 
     61  private:
     62   // Overridden from views::ImageView.
     63   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
     64 
     65   scoped_ptr<views::Widget> widget_;
     66   gfx::Size widget_size_;
     67 
     68   ui::DragDropTypes::DragEventSource drag_event_source_;
     69   int touch_drag_operation_;
     70   gfx::Point touch_drag_operation_indicator_position_;
     71 
     72   DISALLOW_COPY_AND_ASSIGN(DragImageView);
     73 };
     74 
     75 }  // namespace internal
     76 }  // namespace ash
     77 
     78 #endif  // ASH_DRAG_DROP_DRAG_IMAGE_VIEW_H_
     79