blob: ecb129c7155c0ee168a0ab15b03dd46e8148eafb [file] [log] [blame]
// 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.
#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<
IDropSource> {
// 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() 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; }
virtual void OnDragSourceCancel() {}
virtual void OnDragSourceDrop();
virtual void OnDragSourceMove() {}
// Set to true if we want to cancel the drag operation.
bool cancel_drag_;
const OSExchangeData* data_;
} // namespace ui