First shot at implementing drag&drop for Aura

ui/aura_shell/drag_drop_controller.h

+// Copyright (c) 2011 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_AURA_SHELL_DRAG_DROP_CONTROLLER_H_
+#define UI_AURA_SHELL_DRAG_DROP_CONTROLLER_H_
+#pragma once
+
+#include "ui/aura_shell/aura_shell_export.h"
+#include "ui/aura/client/drag_drop_client.h"
+#include "ui/aura/event.h"
+#include "ui/base/dragdrop/os_exchange_data.h"
+#include "ui/gfx/point.h"
+
+namespace aura {
+class Window;
+}
+
+namespace aura_shell {
+namespace internal {
+
+class DragImageView;
+namespace test {
+class DragDropControllerTest;
+}
+
+class AURA_SHELL_EXPORT DragDropController : public aura::DragDropClient {
+ public:
+  DragDropController();
+  virtual ~DragDropController();
+
+  void set_should_block_during_drag_drop(bool should_block_during_drag_drop) {
+    should_block_during_drag_drop_ = should_block_during_drag_drop;
+  }
+
+  // Overridden from aura::DragDropClient:
+  virtual void StartDragAndDrop(const ui::OSExchangeData& data,
+                                int operation) OVERRIDE;
+  virtual void DragUpdate(aura::Window* target,
+                          const aura::MouseEvent& event) OVERRIDE;
+  virtual void Drop(aura::Window* target,
+                    const aura::MouseEvent& event) OVERRIDE;
+  virtual void DragCancel() OVERRIDE;
+  virtual bool IsDragAndDropInProgress() OVERRIDE;
+
+ private:
+  friend class test::DragDropControllerTest;
+
+  // Helper method to reset everything.
+  void Cleanup();
+
+  scoped_ptr<DragImageView> drag_image_;
+  const ui::OSExchangeData* drag_data_;
+  int drag_operation_;
+  aura::Window* dragged_window_;
+
+  bool drag_drop_in_progress_;
+
+  // Indicates whether the caller should be blocked on a drag/drop session.
+  // Only be used for tests.
+  bool should_block_during_drag_drop_;
+
+  DISALLOW_COPY_AND_ASSIGN(DragDropController);
+};
+
+}  // namespace internal
+}  // namespace aura_shell
+
+#endif  // UI_AURA_SHELL_DRAG_DROP_CONTROLLER_H_