linux aura: Show the drag-image when available.

ui/views/widget/desktop_aura/x11_whole_screen_move_loop.h

 // Copyright (c) 2013 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_VIEWS_WIDGET_DESKTOP_AURA_X11_WHOLE_SCREEN_MOVE_LOOP_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_X11_WHOLE_SCREEN_MOVE_LOOP_H_
 
 #include "base/compiler_specific.h"
 #include "base/message_loop/message_loop.h"
+#include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/native_widget_types.h"
+#include "ui/gfx/vector2d_f.h"
 #include "ui/views/widget/desktop_aura/x11_whole_screen_move_loop_delegate.h"
 
+typedef struct _XDisplay XDisplay;
+
 namespace aura {
 class Window;
 }
 
 namespace views {
 
+class Widget;
+
 // Runs a nested message loop and grabs the mouse. This is used to implement
 // dragging.
 class X11WholeScreenMoveLoop : public base::MessageLoop::Dispatcher {
  public:
   explicit X11WholeScreenMoveLoop(X11WholeScreenMoveLoopDelegate* delegate);
   virtual ~X11WholeScreenMoveLoop();
 
   // Overridden from base::MessageLoop::Dispatcher:
   virtual bool Dispatch(const base::NativeEvent& event) OVERRIDE;
 
   // Runs the nested message loop. While the mouse is grabbed, use |cursor| as
   // the mouse cursor. Returns true if there we were able to grab the pointer
   // and run the move loop.
   bool RunMoveLoop(aura::Window* window, gfx::NativeCursor cursor);
 
   // Updates the cursor while the move loop is running.
   void UpdateCursor(gfx::NativeCursor cursor);
 
   // Ends the RunMoveLoop() that's currently in progress.
   void EndMoveLoop();
 
+  // Sets an image to be used during the drag.
+  void SetDragImage(const gfx::ImageSkia& image, gfx::Vector2dF offset);
+
  private:
   // Grabs the pointer, setting the mouse cursor to |cursor|. Returns true if
   // the grab was successful.
   bool GrabPointerWithCursor(gfx::NativeCursor cursor);
 
+  // Creates an input-only window to be used during the drag.
+  Window CreateDragInputWindow(XDisplay* display);
+
+  // Creates a window to show the drag image during the drag.
+  void CreateDragImageWindow();
+
   X11WholeScreenMoveLoopDelegate* delegate_;
 
   // Are we running a nested message loop from RunMoveLoop()?
   bool in_move_loop_;
 
   // An invisible InputOnly window . We create this window so we can track the
   // cursor wherever it goes on screen during a drag, since normal windows
   // don't receive pointer motion events outside of their bounds.
   ::Window grab_input_window_;
 
   base::Closure quit_closure_;
 
+  // A Widget is created during the drag if there is an image available to be
+  // used during the drag.
+  scoped_ptr<Widget> drag_widget_;
+  gfx::ImageSkia drag_image_;
+  gfx::Vector2dF drag_offset_;
+
   DISALLOW_COPY_AND_ASSIGN(X11WholeScreenMoveLoop);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_X11_WHOLE_SCREEN_MOVE_LOOP_H_