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

/*
 * Copyright (C) 2013 Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
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 * in the documentation and/or other materials provided with the
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#include "modules/webmidi/MIDIAccess.h"

#include "core/dom/Document.h"
#include "core/loader/DocumentLoadTiming.h"
#include "core/loader/DocumentLoader.h"
#include "modules/webmidi/MIDIAccessInitializer.h"
#include "modules/webmidi/MIDIConnectionEvent.h"
#include "modules/webmidi/MIDIController.h"
#include "modules/webmidi/MIDIInput.h"
#include "modules/webmidi/MIDIInputMap.h"
#include "modules/webmidi/MIDIOutput.h"
#include "modules/webmidi/MIDIOutputMap.h"
#include "modules/webmidi/MIDIPort.h"
#include "platform/AsyncMethodRunner.h"
#include <memory>

namespace blink {

using PortState = MIDIAccessor::MIDIPortState;

MIDIAccess::MIDIAccess(std::unique_ptr<MIDIAccessor> accessor, bool sysexEnabled, const Vector<MIDIAccessInitializer::PortDescriptor>& ports, ExecutionContext* executionContext)
    : ActiveScriptWrappable(this)
    , ActiveDOMObject(executionContext)
    , m_accessor(std::move(accessor))
    , m_sysexEnabled(sysexEnabled)
    , m_hasPendingActivity(false)
{
    ThreadState::current()->registerPreFinalizer(this);
    m_accessor->setClient(this);
    for (size_t i = 0; i < ports.size(); ++i) {
        const MIDIAccessInitializer::PortDescriptor& port = ports[i];
        if (port.type == MIDIPort::TypeInput) {
            m_inputs.append(MIDIInput::create(this, port.id, port.manufacturer, port.name, port.version, port.state));
        } else {
            m_outputs.append(MIDIOutput::create(this, m_outputs.size(), port.id, port.manufacturer, port.name, port.version, port.state));
        }
    }
}

MIDIAccess::~MIDIAccess()
{
}

void MIDIAccess::dispose()
{
    m_accessor.reset();
}

EventListener* MIDIAccess::onstatechange()
{
    return getAttributeEventListener(EventTypeNames::statechange);
}

void MIDIAccess::setOnstatechange(EventListener* listener)
{
    m_hasPendingActivity = listener;
    setAttributeEventListener(EventTypeNames::statechange, listener);
}

bool MIDIAccess::hasPendingActivity() const
{
    return m_hasPendingActivity && !getExecutionContext()->activeDOMObjectsAreStopped();
}

MIDIInputMap* MIDIAccess::inputs() const
{
    HeapVector<Member<MIDIInput>> inputs;
    HashSet<String> ids;
    for (size_t i = 0; i < m_inputs.size(); ++i) {
        MIDIInput* input = m_inputs[i];
        if (input->getState() != PortState::MIDIPortStateDisconnected) {
            inputs.append(input);
            ids.add(input->id());
        }
    }
    if (inputs.size() != ids.size()) {
        // There is id duplication that violates the spec.
        inputs.clear();
    }
    return new MIDIInputMap(inputs);
}

MIDIOutputMap* MIDIAccess::outputs() const
{
    HeapVector<Member<MIDIOutput>> outputs;
    HashSet<String> ids;
    for (size_t i = 0; i < m_outputs.size(); ++i) {
        MIDIOutput* output = m_outputs[i];
        if (output->getState() != PortState::MIDIPortStateDisconnected) {
            outputs.append(output);
            ids.add(output->id());
        }
    }
    if (outputs.size() != ids.size()) {
        // There is id duplication that violates the spec.
        outputs.clear();
    }
    return new MIDIOutputMap(outputs);
}

void MIDIAccess::didAddInputPort(const String& id, const String& manufacturer, const String& name, const String& version, PortState state)
{
    DCHECK(isMainThread());
    MIDIInput* port = MIDIInput::create(this, id, manufacturer, name, version, state);
    m_inputs.append(port);
    dispatchEvent(MIDIConnectionEvent::create(port));
}

void MIDIAccess::didAddOutputPort(const String& id, const String& manufacturer, const String& name, const String& version, PortState state)
{
    DCHECK(isMainThread());
    unsigned portIndex = m_outputs.size();
    MIDIOutput* port = MIDIOutput::create(this, portIndex, id, manufacturer, name, version, state);
    m_outputs.append(port);
    dispatchEvent(MIDIConnectionEvent::create(port));
}

void MIDIAccess::didSetInputPortState(unsigned portIndex, PortState state)
{
    DCHECK(isMainThread());
    if (portIndex >= m_inputs.size())
        return;

    m_inputs[portIndex]->setState(state);
}

void MIDIAccess::didSetOutputPortState(unsigned portIndex, PortState state)
{
    DCHECK(isMainThread());
    if (portIndex >= m_outputs.size())
        return;

    m_outputs[portIndex]->setState(state);
}

void MIDIAccess::didReceiveMIDIData(unsigned portIndex, const unsigned char* data, size_t length, double timeStamp)
{
    DCHECK(isMainThread());
    if (portIndex >= m_inputs.size())
        return;

    // Convert from time in seconds which is based on the time coordinate system of monotonicallyIncreasingTime()
    // into time in milliseconds (a DOMHighResTimeStamp) according to the same time coordinate system as performance.now().
    // This is how timestamps are defined in the Web MIDI spec.
    Document* document = toDocument(getExecutionContext());
    DCHECK(document);

    double timeStampInMilliseconds = 1000 * document->loader()->timing().monotonicTimeToZeroBasedDocumentTime(timeStamp);

    m_inputs[portIndex]->didReceiveMIDIData(portIndex, data, length, timeStampInMilliseconds);
}

void MIDIAccess::sendMIDIData(unsigned portIndex, const unsigned char* data, size_t length, double timeStampInMilliseconds)
{
    if (!data || !length || portIndex >= m_outputs.size())
        return;
    // Convert from a time in milliseconds (a DOMHighResTimeStamp) according to the same time coordinate system as performance.now()
    // into a time in seconds which is based on the time coordinate system of monotonicallyIncreasingTime().
    double timeStamp;

    if (!timeStampInMilliseconds) {
        // We treat a value of 0 (which is the default value) as special, meaning "now".
        // We need to translate it exactly to 0 seconds.
        timeStamp = 0;
    } else {
        Document* document = toDocument(getExecutionContext());
        DCHECK(document);
        double documentStartTime = document->loader()->timing().referenceMonotonicTime();
        timeStamp = documentStartTime + 0.001 * timeStampInMilliseconds;
    }

    m_accessor->sendMIDIData(portIndex, data, length, timeStamp);
}

void MIDIAccess::stop()
{
    m_accessor.reset();
}

DEFINE_TRACE(MIDIAccess)
{
    visitor->trace(m_inputs);
    visitor->trace(m_outputs);
    EventTargetWithInlineData::trace(visitor);
    ActiveDOMObject::trace(visitor);
}

} // namespace blink