| // 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_BASE_DRAGDROP_DRAG_SOURCE_WIN_H_ |
| #define UI_BASE_DRAGDROP_DRAG_SOURCE_WIN_H_ |
| |
| #include <objidl.h> |
| #include <wrl/implements.h> |
| |
| #include "base/macros.h" |
| #include "base/memory/ref_counted.h" |
| #include "ui/base/ui_base_export.h" |
| |
| namespace ui { |
| |
| class OSExchangeData; |
| |
| // A base IDropSource implementation. Handles notifications sent by an active |
| // drag-drop operation as the user mouses over other drop targets on their |
| // system. This object tells Windows whether or not the drag should continue, |
| // and supplies the appropriate cursors. |
| class DragSourceWin |
| : public Microsoft::WRL::RuntimeClass< |
| Microsoft::WRL::RuntimeClassFlags<Microsoft::WRL::ClassicCom>, |
| IDropSource> { |
| public: |
| // Factory method to avoid exporting the class and all it derives from. |
| static UI_BASE_EXPORT Microsoft::WRL::ComPtr<ui::DragSourceWin> Create(); |
| |
| // Use Create() to construct these objects. Direct calls to the constructor |
| // are an error - it is only public because a WRL helper function creates the |
| // objects. |
| DragSourceWin(); |
| ~DragSourceWin() override = default; |
| |
| // Stop the drag operation at the next chance we get. This doesn't |
| // synchronously stop the drag (since Windows is controlling that), |
| // but lets us tell Windows to cancel the drag the next chance we get. |
| void CancelDrag() { |
| cancel_drag_ = true; |
| } |
| |
| // IDropSource implementation: |
| HRESULT __stdcall QueryContinueDrag(BOOL escape_pressed, |
| DWORD key_state) override; |
| HRESULT __stdcall GiveFeedback(DWORD effect) override; |
| |
| // Used to set the active data object for the current drag operation. The |
| // caller must ensure that |data| is not destroyed before the nested drag loop |
| // terminates. |
| void set_data(const OSExchangeData* data) { data_ = data; } |
| |
| protected: |
| virtual void OnDragSourceCancel() {} |
| virtual void OnDragSourceDrop(); |
| virtual void OnDragSourceMove() {} |
| |
| private: |
| // Set to true if we want to cancel the drag operation. |
| bool cancel_drag_; |
| |
| const OSExchangeData* data_; |
| |
| DISALLOW_COPY_AND_ASSIGN(DragSourceWin); |
| }; |
| |
| } // namespace ui |
| |
| #endif // UI_BASE_DRAGDROP_DRAG_SOURCE_WIN_H_ |