dom/midi/MIDIPort.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
   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_MIDIPort_h
   8 #define mozilla_dom_MIDIPort_h
   9
  10 #include "nsWrapperCache.h"
  11 #include "mozilla/Attributes.h"
  12 #include "mozilla/Observer.h"
  13 #include "mozilla/DOMEventTargetHelper.h"
  14 #include "mozilla/dom/MIDIAccess.h"
  15 #include "mozilla/dom/MIDIPortChild.h"
  16 #include "mozilla/dom/MIDIPortInterface.h"
  17
  18 struct JSContext;
  19
  20 namespace mozilla::dom {
  21
  22 class Promise;
  23 class MIDIPortInfo;
  24 class MIDIAccess;
  25 class MIDIPortChangeEvent;
  26 class MIDIPortChild;
  27 class MIDIMessage;
  28
  29 /**
  30  * Implementation of WebIDL DOM MIDIPort class. Handles all port representation
  31  * and communication.
  32  *
  33  */
  34 class MIDIPort : public DOMEventTargetHelper,
  35                  public MIDIAccessDestructionObserver {
  36  public:
  37   NS_DECL_ISUPPORTS_INHERITED
  38   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(MIDIPort,
  39                                                          DOMEventTargetHelper)
  40  protected:
  41   MIDIPort(nsPIDOMWindowInner* aWindow, MIDIAccess* aMIDIAccessParent);
  42   bool Initialize(const MIDIPortInfo& aPortInfo, bool aSysexEnabled);
  43   virtual ~MIDIPort();
  44
  45  public:
  46   nsPIDOMWindowInner* GetParentObject() const { return GetOwner(); }
  47
  48   // Getters
  49   void GetId(nsString& aRetVal) const;
  50   void GetManufacturer(nsString& aRetVal) const;
  51   void GetName(nsString& aRetVal) const;
  52   void GetVersion(nsString& aRetVal) const;
  53   MIDIPortType Type() const;
  54   MIDIPortConnectionState Connection() const;
  55   MIDIPortDeviceState State() const;
  56   bool SysexEnabled() const;
  57
  58   already_AddRefed<Promise> Open(ErrorResult& aError);
  59   already_AddRefed<Promise> Close(ErrorResult& aError);
  60
  61   // MIDIPorts observe the death of their parent MIDIAccess object, and delete
  62   // their reference accordingly.
  63   virtual void Notify(const void_t& aVoid) override;
  64
  65   void FireStateChangeEvent();
  66
  67   virtual void StateChange();
  68   virtual void Receive(const nsTArray<MIDIMessage>& aMsg);
  69
  70   // This object holds a pointer to its corresponding IPC MIDIPortChild actor.
  71   // If the IPC actor is deleted, it cleans itself up via this method.
  72   void UnsetIPCPort();
  73
  74   IMPL_EVENT_HANDLER(statechange)
  75
  76   void DisconnectFromOwner() override;
  77   const nsString& StableId();
  78
  79  protected:
  80   // Helper class to ensure we always call DetachOwner when we drop the
  81   // reference to the the port.
  82   class PortHolder {
  83    public:
  84     void Init(already_AddRefed<MIDIPortChild> aArg) {
  85       MOZ_ASSERT(!mInner);
  86       mInner = aArg;
  87     }
  88     void Clear() {
  89       if (mInner) {
  90         mInner->DetachOwner();
  91         mInner = nullptr;
  92       }
  93     }
  94     ~PortHolder() { Clear(); }
  95     MIDIPortChild* Get() const { return mInner; }
  96
  97    private:
  98     RefPtr<MIDIPortChild> mInner;
  99   };
 100
 101   // IPC Actor corresponding to this class.
 102   PortHolder mPortHolder;
 103   MIDIPortChild* Port() const { return mPortHolder.Get(); }
 104
 105  private:
 106   void KeepAliveOnStatechange();
 107   void DontKeepAliveOnStatechange();
 108
 109   // MIDIAccess object that created this MIDIPort object, which we need for
 110   // firing port connection events. There is a chance this MIDIPort object can
 111   // outlive its parent MIDIAccess object, so this is a weak reference that must
 112   // be handled properly. It is set on construction of the MIDIPort object, and
 113   // set to null when the parent MIDIAccess object is destroyed, which fires an
 114   // notification we observe.
 115   MIDIAccess* mMIDIAccessParent;
 116   // Promise object generated on Open() call, that needs to be resolved once the
 117   // platform specific Open() function has completed.
 118   RefPtr<Promise> mOpeningPromise;
 119   // Promise object generated on Close() call, that needs to be resolved once
 120   // the platform specific Close() function has completed.
 121   RefPtr<Promise> mClosingPromise;
 122   // If true this object will be kept alive even without direct JS references
 123   bool mKeepAlive;
 124 };
 125
 126 }  // namespace mozilla::dom
 127
 128 #endif  // mozilla_dom_MIDIPort_h