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// Copyright 2011 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef UI_VIEWS_DRAG_CONTROLLER_H_
#define UI_VIEWS_DRAG_CONTROLLER_H_
#include "ui/views/views_export.h"
namespace gfx {
class Point;
}
namespace ui {
class OSExchangeData;
}
namespace views {
class View;
// DragController is responsible for writing drag data for a view, as well as
// supplying the supported drag operations. Use DragController if you don't
// want to subclass.
class VIEWS_EXPORT DragController {
public:
// Writes the data for the drag.
virtual void WriteDragDataForView(View* sender,
const gfx::Point& press_pt,
ui::OSExchangeData* data) = 0;
// Returns the supported drag operations (see DragDropTypes for possible
// values). A drag is only started if this returns a non-zero value.
virtual int GetDragOperationsForView(View* sender, const gfx::Point& p) = 0;
// Returns true if a drag operation can be started.
// |press_pt| represents the coordinates where the mouse was initially
// pressed down. |p| is the current mouse coordinates.
virtual bool CanStartDragForView(View* sender,
const gfx::Point& press_pt,
const gfx::Point& p) = 0;
// Called when the drag on view will start.
virtual void OnWillStartDragForView(View* dragged_view) {}
protected:
virtual ~DragController() = default;
};
} // namespace views
#endif // UI_VIEWS_DRAG_CONTROLLER_H_
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