DataTransferItemList.h

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/* -*- 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_DataTransferItemList_h

#define mozilla_dom_DataTransferItemList_h

#include "mozilla/dom/DataTransfer.h"

#include "mozilla/dom/DataTransferItem.h"

#include "mozilla/dom/FileList.h"

class nsIVariant;

namespace mozilla::dom {

class DataTransfer;

class DataTransferItem;

class DataTransferItemList final : public nsISupports, public nsWrapperCache {

 public:

  NS_DECL_CYCLE_COLLECTING_ISUPPORTS

  NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(DataTransferItemList);

  explicit DataTransferItemList(DataTransfer* aDataTransfer)

      : mDataTransfer(aDataTransfer) {

    MOZ_ASSERT(aDataTransfer);

    // We always allocate an index 0 in our DataTransferItemList. This is done

    // in order to maintain the invariants according to the spec. Mainly, within

    // the spec's list, there is intended to be a single copy of each mime type,

    // for string typed items. File typed items are allowed to have duplicates.

    // In the old moz* system, this was modeled by having multiple indexes, each

    // of which was independent. Files were fetched from all indexes, but

    // strings were only fetched from the first index. In order to maintain this

    // correlation and avoid breaking code with the new changes, index 0 is now

    // always present and used to store strings, and all file items are given

    // their own index starting at index 1.

    mIndexedItems.SetLength(1);

  already_AddRefed<DataTransferItemList> Clone(

      DataTransfer* aDataTransfer) const;

  virtual JSObject* WrapObject(JSContext* aCx,

                               JS::Handle<JSObject*> aGivenProto) override;

  uint32_t Length() const { return mItems.Length(); };

  DataTransferItem* Add(const nsAString& aData, const nsAString& aType,

                        nsIPrincipal& aSubjectPrincipal, ErrorResult& rv);

  DataTransferItem* Add(File& aData, nsIPrincipal& aSubjectPrincipal,

                        ErrorResult& aRv);

  void Remove(uint32_t aIndex, nsIPrincipal& aSubjectPrincipal,

              ErrorResult& aRv);

  DataTransferItem* IndexedGetter(uint32_t aIndex, bool& aFound) const;

  DataTransfer* GetParentObject() const { return mDataTransfer; }

  void Clear(nsIPrincipal& aSubjectPrincipal, ErrorResult& aRv);

  // @param aHidden true, iff the item should be hidden from non-chrome code.

  already_AddRefed<DataTransferItem> SetDataWithPrincipal(

      const nsAString& aType, nsIVariant* aData, uint32_t aIndex,

      nsIPrincipal* aPrincipal, bool aInsertOnly, bool aHidden,

      ErrorResult& aRv);

  already_AddRefed<FileList> Files(nsIPrincipal* aPrincipal);

  // Moz-style helper methods for interacting with the stored data

  void MozRemoveByTypeAt(const nsAString& aType, uint32_t aIndex,

                         nsIPrincipal& aSubjectPrincipal, ErrorResult& aRv);

  DataTransferItem* MozItemByTypeAt(const nsAString& aType, uint32_t aIndex);

  const nsTArray<RefPtr<DataTransferItem>>* MozItemsAt(uint32_t aIndex);

  uint32_t MozItemCount() const;

  // Causes everything in indexes above 0 to shift down one index.

  void PopIndexZero();

  // Delete every item in the DataTransferItemList, without checking for

  // permissions or read-only status (for internal use only).

  void ClearAllItems();

  void GetTypes(nsTArray<nsString>& aTypes, CallerType aCallerType) const;

  bool HasType(const nsAString& aType) const;

  bool HasFile() const;

 private:

  void ClearDataHelper(DataTransferItem* aItem, uint32_t aIndexHint,

                       uint32_t aMozOffsetHint, nsIPrincipal& aSubjectPrincipal,

                       ErrorResult& aRv);

  // @param aHidden true, iff the item should be hidden from non-chrome code.

  DataTransferItem* AppendNewItem(uint32_t aIndex, const nsAString& aType,

                                  nsIVariant* aData, nsIPrincipal* aPrincipal,

                                  bool aHidden);

  void RegenerateFiles();

  void GenerateFiles(FileList* aFiles, nsIPrincipal* aFilesPrincipal);

  ~DataTransferItemList() = default;

  RefPtr<DataTransfer> mDataTransfer;

  RefPtr<FileList> mFiles;

  // The principal for which mFiles is cached

  nsCOMPtr<nsIPrincipal> mFilesPrincipal;

  // mItems is the list of items that corresponds to the spec concept of a

  // DataTransferItemList.  That is, this is the thing the spec's indexed getter

  // operates on.  The items in here are a subset of the items present in the

  // arrays that live in mIndexedItems.

  nsTArray<RefPtr<DataTransferItem>> mItems;

  // mIndexedItems represents all our items.  For any given index, all items at

  // that index have different types in the GetType() sense.  That means that

  // representing multiple items with the same type (e.g. multiple files)

  // requires using multiple indices.

//

  // There is always a (possibly empty) list of items at index 0, so

  // mIndexedItems.Length() >= 1 at all times.

  nsTArray<nsTArray<RefPtr<DataTransferItem>>> mIndexedItems;

};

}  // namespace mozilla::dom

#endif  // mozilla_dom_DataTransferItemList_h