MacViews: Implemented Drag & Drop

ui/views/cocoa/drag_drop_client_mac.h

+// Copyright 2016 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_VIEWS_COCOA_DRAG_DROP_CLIENT_MAC_H_
+#define UI_VIEWS_COCOA_DRAG_DROP_CLIENT_MAC_H_
+
+#import <Cocoa/Cocoa.h>
+
+#include <memory>
+#include <vector>
+
+#import "base/mac/scoped_nsobject.h"
+#include "base/macros.h"
+#include "ui/base/dragdrop/drag_drop_types.h"
+#include "ui/views/views_export.h"
+#include "ui/views/widget/drop_helper.h"
+
+class DropHelper;
+
+// This class acts as a bridge between NSPasteboardItem and OSExchangeData by
+// implementing NSPasteboardItemDataProvider and writing data from
+// OSExchangeData into the pasteboard.
+VIEWS_EXPORT
+@interface CocoaDragDropDataProvider : NSObject<NSPasteboardItemDataProvider>
+
+- (id)initWithData:(const ui::OSExchangeData&)data;
+
+@end
+
+namespace gfx {
+class Point;
+}
+
+namespace ui {
+class OSExchangeData;
+}
+
+namespace views {
+namespace test {
+class CocoaDragDropTest;
+}
+
+class BridgedNativeWidget;
+
+// Implements drag and drop on MacViews. This class acts as a bridge between
+// the Views and native system's drag and drop. This class mimics
+// DesktopDragDropClientAuraX11.
+class VIEWS_EXPORT DragDropClientMac {
+ public:
+  explicit DragDropClientMac(BridgedNativeWidget* view);
+  ~DragDropClientMac();
+
+  // Initiates a drag and drop session. Returns the drag operation that was
+  // applied at the end of the drag drop session.
+  void StartDragAndDrop(View* view,
+                        const ui::OSExchangeData& data,
+                        const gfx::Point& location,
+                        int operation,
+                        ui::DragDropTypes::DragEventSource source);
+
+  // Called when mouse is dragged during a drag and drop.
+  NSDragOperation DragUpdate(id<NSDraggingInfo>);
+
+  // Called when mouse is released during a drag and drop.
+  NSDragOperation Drop(id<NSDraggingInfo> sender);
+
+  // Called when the drag and drop session has ended.
+  void EndDrag();
+
+  // Calls when the the views::View bridged by the content view is set or
+  // cleared.
+  void SetRootView(View* view);
+
+ private:
+  friend class test::CocoaDragDropTest;
+
+  // Converts the given NSPoint to the coordinate system in Views.
+  gfx::Point LocationInView(NSPoint point) const;
+
+  // Provides the data for the drag and drop session.
+  base::scoped_nsobject<CocoaDragDropDataProvider> data_source_;
+
+  // Used to handle drag and drop with Views.
+  std::unique_ptr<DropHelper> drop_helper_;
+
+  // The drag and drop operation.
+  int operation_;
+
+  // The source of the drag.
+  View* view_;
+
+  // The bridge between the content view and the drag drop client.
+  BridgedNativeWidget* bridge_;  // Weak. Owns |this|.
+
+  DISALLOW_COPY_AND_ASSIGN(DragDropClientMac);
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_COCOA_DRAG_DROP_CLIENT_MAC_H_