xpcom/ds/nsSimpleEnumerator.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "nsSimpleEnumerator.h"
   8
   9 #include "mozilla/dom/IteratorResultBinding.h"
  10 #include "mozilla/dom/RootedDictionary.h"
  11 #include "mozilla/dom/ToJSValue.h"
  12 #include "mozilla/ResultExtensions.h"
  13 #include "nsContentUtils.h"
  14
  15 using namespace mozilla;
  16 using namespace mozilla::dom;
  17
  18 namespace {
  19
  20 class JSEnumerator final : public nsIJSEnumerator {
  21   NS_DECL_ISUPPORTS
  22   NS_DECL_NSIJSENUMERATOR
  23
  24   explicit JSEnumerator(nsISimpleEnumerator* aEnumerator, const nsID& aIID)
  25       : mEnumerator(aEnumerator), mIID(aIID) {}
  26
  27  private:
  28   ~JSEnumerator() = default;
  29
  30   nsCOMPtr<nsISimpleEnumerator> mEnumerator;
  31   const nsID mIID;
  32 };
  33
  34 }  // anonymous namespace
  35
  36 nsresult JSEnumerator::Iterator(nsIJSEnumerator** aResult) {
  37   RefPtr<JSEnumerator> result(this);
  38   result.forget(aResult);
  39   return NS_OK;
  40 }
  41
  42 nsresult JSEnumerator::Next(JSContext* aCx, JS::MutableHandleValue aResult) {
  43   RootedDictionary<IteratorResult> result(aCx);
  44
  45   nsCOMPtr<nsISupports> elem;
  46   if (NS_FAILED(mEnumerator->GetNext(getter_AddRefs(elem)))) {
  47     result.mDone = true;
  48   } else {
  49     result.mDone = false;
  50
  51     JS::RootedValue value(aCx);
  52     MOZ_TRY(nsContentUtils::WrapNative(aCx, elem, &mIID, &value));
  53     result.mValue = value;
  54   }
  55
  56   if (!ToJSValue(aCx, result, aResult)) {
  57     return NS_ERROR_OUT_OF_MEMORY;
  58   }
  59   return NS_OK;
  60 }
  61
  62 NS_IMPL_ISUPPORTS(JSEnumerator, nsIJSEnumerator)
  63
  64 nsresult nsSimpleEnumerator::Iterator(nsIJSEnumerator** aResult) {
  65   auto result = MakeRefPtr<JSEnumerator>(this, DefaultInterface());
  66   result.forget(aResult);
  67   return NS_OK;
  68 }
  69
  70 nsresult nsSimpleEnumerator::Entries(const nsIID& aIface,
  71                                      nsIJSEnumerator** aResult) {
  72   auto result = MakeRefPtr<JSEnumerator>(this, aIface);
  73   result.forget(aResult);
  74   return NS_OK;
  75 }
  76
  77 NS_IMPL_ISUPPORTS(nsSimpleEnumerator, nsISimpleEnumerator,
  78                   nsISimpleEnumeratorBase)