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