michael@0: // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #ifndef BASE_BASE_DRAG_SOURCE_H_
michael@0: #define BASE_BASE_DRAG_SOURCE_H_
michael@0: 
michael@0: #include <objidl.h>
michael@0: 
michael@0: #include "base/basictypes.h"
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: //
michael@0: // BaseDragSource
michael@0: //
michael@0: //  A base IDropSource implementation. Handles notifications sent by an active
michael@0: //  drag-drop operation as the user mouses over other drop targets on their
michael@0: //  system. This object tells Windows whether or not the drag should continue,
michael@0: //  and supplies the appropriate cursors.
michael@0: //
michael@0: class BaseDragSource : public IDropSource {
michael@0:  public:
michael@0:   BaseDragSource();
michael@0:   virtual ~BaseDragSource() { }
michael@0: 
michael@0:   // IDropSource implementation:
michael@0:   HRESULT __stdcall QueryContinueDrag(BOOL escape_pressed, DWORD key_state);
michael@0:   HRESULT __stdcall GiveFeedback(DWORD effect);
michael@0: 
michael@0:   // IUnknown implementation:
michael@0:   HRESULT __stdcall QueryInterface(const IID& iid, void** object);
michael@0:   ULONG __stdcall AddRef();
michael@0:   ULONG __stdcall Release();
michael@0: 
michael@0:  protected:
michael@0:   virtual void OnDragSourceCancel() { }
michael@0:   virtual void OnDragSourceDrop() { }
michael@0:   virtual void OnDragSourceMove() { }
michael@0: 
michael@0:  private:
michael@0:   LONG ref_count_;
michael@0: 
michael@0:   DISALLOW_EVIL_CONSTRUCTORS(BaseDragSource);
michael@0: };
michael@0: 
michael@0: #endif  // BASE_BASE_DRAG_SOURCE_H_