third_party/WebKit/Source/modules/webmidi/MIDIInput.cpp

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#include "modules/webmidi/MIDIInput.h"

#include "core/dom/Document.h"
#include "core/frame/UseCounter.h"
#include "modules/webmidi/MIDIAccess.h"
#include "modules/webmidi/MIDIMessageEvent.h"
#include "platform/heap/Handle.h"

namespace blink {

using midi::mojom::PortState;

MIDIInput* MIDIInput::Create(MIDIAccess* access,
                             const String& id,
                             const String& manufacturer,
                             const String& name,
                             const String& version,
                             PortState state) {
  DCHECK(access);
  return new MIDIInput(access, id, manufacturer, name, version, state);
}

MIDIInput::MIDIInput(MIDIAccess* access,
                     const String& id,
                     const String& manufacturer,
                     const String& name,
                     const String& version,
                     PortState state)
    : MIDIPort(access, id, manufacturer, name, kTypeInput, version, state) {}

EventListener* MIDIInput::onmidimessage() {
  return GetAttributeEventListener(EventTypeNames::midimessage);
}

void MIDIInput::setOnmidimessage(EventListener* listener) {
  // Implicit open. It does nothing if the port is already opened.
  // See http://www.w3.org/TR/webmidi/#widl-MIDIPort-open-Promise-MIDIPort
  open();

  SetAttributeEventListener(EventTypeNames::midimessage, listener);
}

void MIDIInput::AddedEventListener(
    const AtomicString& event_type,
    RegisteredEventListener& registered_listener) {
  MIDIPort::AddedEventListener(event_type, registered_listener);
  if (event_type == EventTypeNames::midimessage) {
    // Implicit open. See setOnmidimessage().
    open();
  }
}

void MIDIInput::DidReceiveMIDIData(unsigned port_index,
                                   const unsigned char* data,
                                   size_t length,
                                   double time_stamp) {
  DCHECK(IsMainThread());

  if (!length)
    return;

  if (GetConnection() != kConnectionStateOpen)
    return;

  // Drop sysex message here when the client does not request it. Note that this
  // is not a security check but an automatic filtering for clients that do not
  // want sysex message. Also note that sysex message will never be sent unless
  // the current process has an explicit permission to handle sysex message.
  if (data[0] == 0xf0 && !midiAccess()->sysexEnabled())
    return;
  DOMUint8Array* array = DOMUint8Array::Create(data, length);
  DispatchEvent(MIDIMessageEvent::Create(time_stamp, array));

  UseCounter::Count(*ToDocument(GetExecutionContext()),
                    WebFeature::kMIDIMessageEvent);
}

void MIDIInput::Trace(blink::Visitor* visitor) {
  MIDIPort::Trace(visitor);
}

}  // namespace blink