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 * modification, are permitted provided that the following conditions are
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 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
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 */

#ifndef DataObject_h
#define DataObject_h

#include "base/memory/scoped_refptr.h"
#include "core/CoreExport.h"
#include "core/clipboard/DataObjectItem.h"
#include "platform/PasteMode.h"
#include "platform/Supplementable.h"
#include "platform/heap/Handle.h"
#include "platform/wtf/Vector.h"
#include "platform/wtf/text/StringHash.h"
#include "platform/wtf/text/WTFString.h"

namespace blink {

class KURL;
class SharedBuffer;
class WebDragData;

// A data object for holding data that would be in a clipboard or moved
// during a drag-n-drop operation. This is the data that WebCore is aware
// of and is not specific to a platform.
class CORE_EXPORT DataObject : public GarbageCollectedFinalized<DataObject>,
                               public Supplementable<DataObject> {
  USING_GARBAGE_COLLECTED_MIXIN(DataObject);

 public:
  struct CORE_EXPORT Observer : public GarbageCollectedMixin {
    // Called whenever |item_list_| is modified. Note it can be called multiple
    // times for a single mutation. For example, DataObject::SetData() calls
    // both ClearData() and Add(), each of which can call this method.
    virtual void OnItemListChanged() = 0;
  };

  static DataObject* CreateFromPasteboard(PasteMode);
  static DataObject* CreateFromString(const String&);
  static DataObject* Create();
  static DataObject* Create(WebDragData);

  virtual ~DataObject();

  // DataTransferItemList support.
  size_t length() const;
  DataObjectItem* Item(unsigned long index);
  // FIXME: Implement V8DataTransferItemList::indexedPropertyDeleter to get this
  // called.
  void DeleteItem(unsigned long index);
  void ClearAll();
  // Returns null if an item already exists with the provided type.
  DataObjectItem* Add(const String& data, const String& type);
  DataObjectItem* Add(File*);
  DataObjectItem* Add(File*, const String& file_system_id);

  // WebCore helpers.
  void ClearData(const String& type);

  Vector<String> Types() const;
  String GetData(const String& type) const;
  void SetData(const String& type, const String& data);

  void UrlAndTitle(String& url, String* title = nullptr) const;
  void SetURLAndTitle(const String& url, const String& title);
  void HtmlAndBaseURL(String& html, KURL& base_url) const;
  void SetHTMLAndBaseURL(const String& html, const KURL& base_url);

  // Used for dragging in files from the desktop.
  bool ContainsFilenames() const;
  Vector<String> Filenames() const;
  void AddFilename(const String& filename,
                   const String& display_name,
                   const String& file_system_id);

  // Used for dragging in filesystem from the desktop.
  void SetFilesystemId(const String& file_system_id) {
    filesystem_id_ = file_system_id;
  }
  const String& FilesystemId() const {
    DCHECK(!filesystem_id_.IsEmpty());
    return filesystem_id_;
  }

  // Used to handle files (images) being dragged out.
  void AddSharedBuffer(scoped_refptr<SharedBuffer>,
                       const KURL&,
                       const String& filename_extension,
                       const AtomicString& content_disposition);

  int GetModifiers() const { return modifiers_; }
  void SetModifiers(int modifiers) { modifiers_ = modifiers; }

  // Adds an observer (and retains a reference to it) that is notified
  // whenever the underlying item_list_ changes.
  void AddObserver(Observer*);

  void Trace(blink::Visitor*);

  WebDragData ToWebDragData();

 private:
  DataObject();

  DataObjectItem* FindStringItem(const String& type) const;
  bool InternalAddStringItem(DataObjectItem*);
  void InternalAddFileItem(DataObjectItem*);

  void NotifyItemListChanged() const;

  HeapVector<Member<DataObjectItem>> item_list_;
  HeapHashSet<Member<Observer>> observers_;

  // State of Shift/Ctrl/Alt/Meta keys and Left/Right/Middle mouse buttons
  int modifiers_;
  String filesystem_id_;
};

}  // namespace blink

#endif