dom/abort/AbortSignal.h

   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 #ifndef mozilla_dom_AbortSignal_h
   8 #define mozilla_dom_AbortSignal_h
   9
  10 #include "mozilla/DOMEventTargetHelper.h"
  11 #include "nsTObserverArray.h"
  12
  13 namespace mozilla {
  14 namespace dom {
  15
  16 class AbortSignal;
  17 class AbortSignalImpl;
  18
  19 // This class must be implemented by objects who want to follow a
  20 // AbortSignalImpl.
  21 class AbortFollower {
  22  public:
  23   virtual void Abort() = 0;
  24
  25   void Follow(AbortSignalImpl* aSignal);
  26
  27   void Unfollow();
  28
  29   bool IsFollowing() const;
  30
  31  protected:
  32   virtual ~AbortFollower();
  33
  34   // Subclasses of AbortFollower must Traverse this member and call
  35   // Unfollow() when Unlinking.
  36   RefPtr<AbortSignalImpl> mFollowingSignal;
  37 };
  38
  39 // Any subclass of this class must Traverse mFollowingSignal and call
  40 // Unfollow() when Unlinking.
  41 class AbortSignalImpl : public AbortFollower, public nsISupports {
  42  public:
  43   explicit AbortSignalImpl(bool aAborted);
  44
  45   bool Aborted() const;
  46
  47   void Abort() override;
  48
  49   void AddFollower(AbortFollower* aFollower);
  50
  51   void RemoveFollower(AbortFollower* aFollower);
  52
  53  protected:
  54   virtual ~AbortSignalImpl() = default;
  55
  56  private:
  57   // Raw pointers. AbortFollower unregisters itself in the DTOR.
  58   nsTObserverArray<AbortFollower*> mFollowers;
  59
  60   bool mAborted;
  61 };
  62
  63 class AbortSignal final : public DOMEventTargetHelper, public AbortSignalImpl {
  64  public:
  65   NS_DECL_ISUPPORTS_INHERITED
  66   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(AbortSignal, DOMEventTargetHelper)
  67
  68   AbortSignal(nsIGlobalObject* aGlobalObject, bool aAborted);
  69
  70   JSObject* WrapObject(JSContext* aCx,
  71                        JS::Handle<JSObject*> aGivenProto) override;
  72
  73   IMPL_EVENT_HANDLER(abort);
  74
  75   void Abort() override;
  76
  77  private:
  78   ~AbortSignal() = default;
  79 };
  80
  81 }  // namespace dom
  82 }  // namespace mozilla
  83
  84 #endif  // mozilla_dom_AbortSignal_h