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