dom/midi/MIDIInput.cpp

   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 #include "mozilla/dom/MIDIInput.h"
   8 #include "mozilla/dom/Document.h"
   9 #include "mozilla/dom/MIDIPortChild.h"
  10 #include "mozilla/dom/MIDIInputBinding.h"
  11 #include "mozilla/dom/MIDIMessageEvent.h"
  12 #include "mozilla/dom/MIDIMessageEventBinding.h"
  13 #include "nsGlobalWindowInner.h"
  14
  15 #include "MIDILog.h"
  16
  17 namespace mozilla::dom {
  18
  19 MIDIInput::MIDIInput(nsPIDOMWindowInner* aWindow)
  20     : MIDIPort(aWindow), mKeepAlive(false) {}
  21
  22 // static
  23 RefPtr<MIDIInput> MIDIInput::Create(nsPIDOMWindowInner* aWindow,
  24                                     MIDIAccess* aMIDIAccessParent,
  25                                     const MIDIPortInfo& aPortInfo,
  26                                     const bool aSysexEnabled) {
  27   MOZ_ASSERT(static_cast<MIDIPortType>(aPortInfo.type()) ==
  28              MIDIPortType::Input);
  29   RefPtr<MIDIInput> port = new MIDIInput(aWindow);
  30   if (!port->Initialize(aPortInfo, aSysexEnabled, aMIDIAccessParent)) {
  31     return nullptr;
  32   }
  33   return port;
  34 }
  35
  36 JSObject* MIDIInput::WrapObject(JSContext* aCx,
  37                                 JS::Handle<JSObject*> aGivenProto) {
  38   return MIDIInput_Binding::Wrap(aCx, this, aGivenProto);
  39 }
  40
  41 void MIDIInput::Receive(const nsTArray<MIDIMessage>& aMsgs) {
  42   if (!GetOwnerWindow()) {
  43     return;  // Ignore messages once we've been disconnected from the owner
  44   }
  45
  46   nsCOMPtr<Document> doc = GetOwnerWindow()->GetDoc();
  47   if (!doc) {
  48     NS_WARNING("No document available to send MIDIMessageEvent to!");
  49     return;
  50   }
  51   for (const auto& msg : aMsgs) {
  52     RefPtr<MIDIMessageEvent> event(
  53         MIDIMessageEvent::Constructor(this, msg.timestamp(), msg.data()));
  54     DispatchTrustedEvent(event);
  55   }
  56 }
  57
  58 void MIDIInput::StateChange() {
  59   if (Port()->ConnectionState() == MIDIPortConnectionState::Open ||
  60       (Port()->DeviceState() == MIDIPortDeviceState::Connected &&
  61        Port()->ConnectionState() == MIDIPortConnectionState::Pending)) {
  62     KeepAliveOnMidimessage();
  63   } else {
  64     DontKeepAliveOnMidimessage();
  65   }
  66 }
  67
  68 void MIDIInput::EventListenerAdded(nsAtom* aType) {
  69   if (aType == nsGkAtoms::onmidimessage) {
  70     // HACK: the Web MIDI spec states that we should open a port only when
  71     // setting the midimessage event handler but Chrome does it even when
  72     // adding event listeners hence this.
  73     if (Port()->ConnectionState() != MIDIPortConnectionState::Open) {
  74       LOG("onmidimessage event listener added, sending implicit Open");
  75       Port()->SendOpen();
  76     }
  77   }
  78
  79   DOMEventTargetHelper::EventListenerAdded(aType);
  80 }
  81
  82 void MIDIInput::DisconnectFromOwner() {
  83   DontKeepAliveOnMidimessage();
  84
  85   MIDIPort::DisconnectFromOwner();
  86 }
  87
  88 void MIDIInput::KeepAliveOnMidimessage() {
  89   if (!mKeepAlive) {
  90     mKeepAlive = true;
  91     KeepAliveIfHasListenersFor(nsGkAtoms::onmidimessage);
  92   }
  93 }
  94
  95 void MIDIInput::DontKeepAliveOnMidimessage() {
  96   if (mKeepAlive) {
  97     IgnoreKeepAliveIfHasListenersFor(nsGkAtoms::onmidimessage);
  98     mKeepAlive = false;
  99   }
 100 }
 101
 102 }  // namespace mozilla::dom