gecko-dev/dom/events/DataTransferItem.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_dom_DataTransferItem_h
#define mozilla_dom_DataTransferItem_h

#include "mozilla/ErrorResult.h"
#include "mozilla/dom/DataTransfer.h"
#include "mozilla/dom/DOMString.h"
#include "mozilla/dom/File.h"

namespace mozilla {
namespace dom {

class FileSystemEntry;
class FunctionStringCallback;

class DataTransferItem final : public nsISupports, public nsWrapperCache {
 public:
  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(DataTransferItem);

 public:
  // The spec only talks about the "file" and "string" kinds. Due to the Moz*
  // APIs, it is possible to attach any type to a DataTransferItem, meaning that
  // we can have other kinds then just FILE and STRING. These others are simply
  // marked as "other" and can only be produced throug the Moz* APIs.
  enum eKind {
    KIND_FILE,
    KIND_STRING,
    KIND_OTHER,
  };

  DataTransferItem(DataTransfer* aDataTransfer, const nsAString& aType,
                   eKind aKind = KIND_OTHER)
      : mIndex(0),
        mChromeOnly(false),
        mKind(aKind),
        mType(aType),
        mDataTransfer(aDataTransfer) {
    MOZ_ASSERT(mDataTransfer, "Must be associated with a DataTransfer");
  }

  already_AddRefed<DataTransferItem> Clone(DataTransfer* aDataTransfer) const;

  virtual JSObject* WrapObject(JSContext* aCx,
                               JS::Handle<JSObject*> aGivenProto) override;

  void GetAsString(FunctionStringCallback* aCallback,
                   nsIPrincipal& aSubjectPrincipal, ErrorResult& aRv);

  void GetKind(nsAString& aKind) const {
    switch (mKind) {
      case KIND_FILE:
        aKind = NS_LITERAL_STRING("file");
        return;
      case KIND_STRING:
        aKind = NS_LITERAL_STRING("string");
        return;
      default:
        aKind = NS_LITERAL_STRING("other");
        return;
    }
  }

  void GetInternalType(nsAString& aType) const { aType = mType; }

  void GetType(nsAString& aType);

  eKind Kind() const { return mKind; }

  already_AddRefed<File> GetAsFile(nsIPrincipal& aSubjectPrincipal,
                                   ErrorResult& aRv);

  already_AddRefed<FileSystemEntry> GetAsEntry(nsIPrincipal& aSubjectPrincipal,
                                               ErrorResult& aRv);

  DataTransfer* GetParentObject() const { return mDataTransfer; }

  nsIPrincipal* Principal() const { return mPrincipal; }
  void SetPrincipal(nsIPrincipal* aPrincipal) { mPrincipal = aPrincipal; }

  already_AddRefed<nsIVariant> DataNoSecurityCheck();
  // Data may return null if the clipboard state has changed since the type was
  // detected.
  already_AddRefed<nsIVariant> Data(nsIPrincipal* aPrincipal, ErrorResult& aRv);

  // Note: This can modify the mKind.  Callers of this method must let the
  // relevant DataTransfer know, because its types list can change as a result.
  void SetData(nsIVariant* aData);

  uint32_t Index() const { return mIndex; }
  void SetIndex(uint32_t aIndex) { mIndex = aIndex; }
  void FillInExternalData();

  bool ChromeOnly() const { return mChromeOnly; }
  void SetChromeOnly(bool aChromeOnly) { mChromeOnly = aChromeOnly; }

  static eKind KindFromData(nsIVariant* aData);

 private:
  ~DataTransferItem() {}
  already_AddRefed<File> CreateFileFromInputStream(nsIInputStream* aStream);

  // The index in the 2d mIndexedItems array
  uint32_t mIndex;

  bool mChromeOnly;
  eKind mKind;
  const nsString mType;
  nsCOMPtr<nsIVariant> mData;
  nsCOMPtr<nsIPrincipal> mPrincipal;
  RefPtr<DataTransfer> mDataTransfer;

  // File cache for nsIFile application/x-moz-file entries.
  RefPtr<File> mCachedFile;
};

}  // namespace dom
}  // namespace mozilla

#endif /* mozilla_dom_DataTransferItem_h */