dom/midi/MIDIAccessManager.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_MIDIAccessManager_h
   8 #define mozilla_dom_MIDIAccessManager_h
   9
  10 #include "nsPIDOMWindow.h"
  11 #include "mozilla/dom/MIDITypes.h"
  12 #include "mozilla/Observer.h"
  13
  14 namespace mozilla {
  15 namespace dom {
  16
  17 class MIDIAccess;
  18 class MIDIManagerChild;
  19 struct MIDIOptions;
  20 class MIDIPortChangeEvent;
  21 class MIDIPortInfo;
  22 class Promise;
  23
  24 /**
  25  * MIDIAccessManager manages creation and lifetime of MIDIAccess objects for the
  26  * process it lives in. It is in charge of dealing with permission requests,
  27  * creating new MIDIAccess objects, and updating live MIDIAccess objects with
  28  * new device listings.
  29  *
  30  * While a process/window can have many MIDIAccess objects, there is only one
  31  * MIDIAccessManager for any one process.
  32  */
  33 class MIDIAccessManager final {
  34  public:
  35   NS_INLINE_DECL_REFCOUNTING(MIDIAccessManager);
  36   // Handles requests from Navigator for MIDI permissions and MIDIAccess
  37   // creation.
  38   already_AddRefed<Promise> RequestMIDIAccess(nsPIDOMWindowInner* aWindow,
  39                                               const MIDIOptions& aOptions,
  40                                               ErrorResult& aRv);
  41   // Creates a new MIDIAccess object
  42   void CreateMIDIAccess(nsPIDOMWindowInner* aWindow, bool aNeedsSysex,
  43                         Promise* aPromise);
  44   // Getter for manager singleton
  45   static MIDIAccessManager* Get();
  46   // True if manager singleton has been created
  47   static bool IsRunning();
  48   // Send device connection updates to all known MIDIAccess objects.
  49   void Update(const MIDIPortList& aEvent);
  50   // Adds a device update observer (usually a MIDIAccess object)
  51   bool AddObserver(Observer<MIDIPortList>* aObserver);
  52   // Removes a device update observer (usually a MIDIAccess object)
  53   void RemoveObserver(Observer<MIDIPortList>* aObserver);
  54
  55  private:
  56   MIDIAccessManager();
  57   ~MIDIAccessManager();
  58   // True if object has received a device list from the MIDI platform service.
  59   bool mHasPortList;
  60   // List of known ports for the system.
  61   MIDIPortList mPortList;
  62   // Holds MIDIAccess objects until we've received the first list of devices
  63   // from the MIDI Service.
  64   nsTArray<RefPtr<MIDIAccess>> mAccessHolder;
  65   // Device state update observers (usually MIDIAccess objects)
  66   ObserverList<MIDIPortList> mChangeObservers;
  67   // IPC Object for MIDIManager. Created on first MIDIAccess object creation,
  68   // destroyed on last MIDIAccess object destruction.
  69   RefPtr<MIDIManagerChild> mChild;
  70 };
  71
  72 }  // namespace dom
  73 }  // namespace mozilla
  74
  75 #endif  // mozilla_dom_MIDIAccessManager_h