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