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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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/. */
+
+/**
+ * The IterableIterator class is used for WebIDL interfaces that have a
+ * iterable<> member defined with two types (so a pair iterator). It handles
+ * the ES6 Iterator-like functions that are generated for the iterable
+ * interface.
+ *
+ * For iterable interfaces with a pair iterator, the implementation class will
+ * need to implement these two functions:
+ *
+ * - size_t GetIterableLength()
+ * - Returns the number of elements available to iterate over
+ * - [type] GetValueAtIndex(size_t index)
+ * - Returns the value at the requested index.
+ * - [type] GetKeyAtIndex(size_t index)
+ * - Returns the key at the requested index
+ *
+ * Examples of iterable interface implementations can be found in the bindings
+ * test directory.
+ */
+
+#ifndef mozilla_dom_IterableIterator_h
+#define mozilla_dom_IterableIterator_h
+
+#include "nsISupports.h"
+#include "nsWrapperCache.h"
+#include "nsPIDOMWindow.h"
+#include "nsCOMPtr.h"
+#include "mozilla/dom/ToJSValue.h"
+#include "jswrapper.h"
+#include "mozilla/dom/IterableIteratorBinding.h"
+
+namespace mozilla {
+namespace dom {
+
+class IterableIteratorBase : public nsISupports
+{
+public:
+ NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+ NS_DECL_CYCLE_COLLECTION_CLASS(IterableIteratorBase)
+ typedef enum {
+ Keys = 0,
+ Values,
+ Entries
+ } IterableIteratorType;
+
+ IterableIteratorBase() {}
+
+protected:
+ virtual ~IterableIteratorBase() {}
+ virtual void UnlinkHelper() = 0;
+ virtual void TraverseHelper(nsCycleCollectionTraversalCallback& cb) = 0;
+};
+
+template <typename T>
+class IterableIterator final : public IterableIteratorBase
+{
+public:
+ typedef bool (*WrapFunc)(JSContext* aCx,
+ IterableIterator<T>* aObject,
+ JS::Handle<JSObject*> aGivenProto,
+ JS::MutableHandle<JSObject*> aReflector);
+
+ explicit IterableIterator(T* aIterableObj,
+ IterableIteratorType aIteratorType,
+ WrapFunc aWrapFunc)
+ : mIterableObj(aIterableObj)
+ , mIteratorType(aIteratorType)
+ , mWrapFunc(aWrapFunc)
+ , mIndex(0)
+ {
+ MOZ_ASSERT(mIterableObj);
+ MOZ_ASSERT(mWrapFunc);
+ }
+
+ void
+ Next(JSContext* aCx, JS::MutableHandle<JSObject*> aResult, ErrorResult& aRv)
+ {
+ JS::Rooted<JS::Value> value(aCx, JS::UndefinedValue());
+ if (mIndex >= this->mIterableObj->GetIterableLength()) {
+ DictReturn(aCx, aResult, true, value, aRv);
+ return;
+ }
+ switch (mIteratorType) {
+ case IterableIteratorType::Keys:
+ {
+ if (!ToJSValue(aCx, this->mIterableObj->GetKeyAtIndex(mIndex), &value)) {
+ aRv.Throw(NS_ERROR_FAILURE);
+ return;
+ }
+ DictReturn(aCx, aResult, false, value, aRv);
+ break;
+ }
+ case IterableIteratorType::Values:
+ {
+ if (!ToJSValue(aCx, this->mIterableObj->GetValueAtIndex(mIndex), &value)) {
+ aRv.Throw(NS_ERROR_FAILURE);
+ return;
+ }
+ DictReturn(aCx, aResult, false, value, aRv);
+ break;
+ }
+ case IterableIteratorType::Entries:
+ {
+ JS::Rooted<JS::Value> key(aCx);
+ if (!ToJSValue(aCx, this->mIterableObj->GetKeyAtIndex(mIndex), &key)) {
+ aRv.Throw(NS_ERROR_FAILURE);
+ return;
+ }
+ if (!ToJSValue(aCx, this->mIterableObj->GetValueAtIndex(mIndex), &value)) {
+ aRv.Throw(NS_ERROR_FAILURE);
+ return;
+ }
+ KeyAndValueReturn(aCx, key, value, aResult, aRv);
+ break;
+ }
+ default:
+ MOZ_CRASH("Invalid iterator type!");
+ }
+ ++mIndex;
+ }
+
+ bool
+ WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto, JS::MutableHandle<JSObject*> aObj)
+ {
+ return (*mWrapFunc)(aCx, this, aGivenProto, aObj);
+ }
+
+protected:
+ static void
+ DictReturn(JSContext* aCx, JS::MutableHandle<JSObject*> aResult,
+ bool aDone, JS::Handle<JS::Value> aValue, ErrorResult& aRv)
+ {
+ RootedDictionary<IterableKeyOrValueResult> dict(aCx);
+ dict.mDone = aDone;
+ dict.mValue = aValue;
+ JS::Rooted<JS::Value> dictValue(aCx);
+ if (!ToJSValue(aCx, dict, &dictValue)) {
+ aRv.Throw(NS_ERROR_FAILURE);
+ return;
+ }
+ aResult.set(&dictValue.toObject());
+ }
+
+ static void
+ KeyAndValueReturn(JSContext* aCx, JS::Handle<JS::Value> aKey,
+ JS::Handle<JS::Value> aValue,
+ JS::MutableHandle<JSObject*> aResult, ErrorResult& aRv)
+ {
+ RootedDictionary<IterableKeyAndValueResult> dict(aCx);
+ dict.mDone = false;
+ // Dictionary values are a Sequence, which is a FallibleTArray, so we need
+ // to check returns when appending.
+ if (!dict.mValue.AppendElement(aKey, mozilla::fallible)) {
+ aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+ return;
+ }
+ if (!dict.mValue.AppendElement(aValue, mozilla::fallible)) {
+ aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+ return;
+ }
+ JS::Rooted<JS::Value> dictValue(aCx);
+ if (!ToJSValue(aCx, dict, &dictValue)) {
+ aRv.Throw(NS_ERROR_FAILURE);
+ return;
+ }
+ aResult.set(&dictValue.toObject());
+ }
+
+protected:
+ virtual ~IterableIterator() {}
+
+ // Since we're templated on a binding, we need to possibly CC it, but can't do
+ // that through macros. So it happens here.
+ virtual void UnlinkHelper() final
+ {
+ mIterableObj = nullptr;
+ }
+
+ virtual void TraverseHelper(nsCycleCollectionTraversalCallback& cb) override
+ {
+ IterableIterator<T>* tmp = this;
+ NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mIterableObj);
+ }
+
+ // Binding Implementation object that we're iterating over.
+ RefPtr<T> mIterableObj;
+ // Tells whether this is a key, value, or entries iterator.
+ IterableIteratorType mIteratorType;
+ // Function pointer to binding-type-specific Wrap() call for this iterator.
+ WrapFunc mWrapFunc;
+ // Current index of iteration.
+ uint32_t mIndex;
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_IterableIterator_h