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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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#include "config.h"
#include "modules/webmidi/MIDIAccess.h"

#include "core/dom/DOMError.h"
#include "core/dom/Document.h"
#include "core/loader/DocumentLoadTiming.h"
#include "core/loader/DocumentLoader.h"
#include "modules/webmidi/MIDIAccessPromise.h"
#include "modules/webmidi/MIDIConnectionEvent.h"
#include "modules/webmidi/MIDIController.h"
#include "modules/webmidi/MIDIPort.h"

namespace WebCore {

PassRefPtr<MIDIAccess> MIDIAccess::create(ExecutionContext* context, MIDIAccessPromise* promise)
{
    RefPtr<MIDIAccess> midiAccess(adoptRef(new MIDIAccess(context, promise)));
    midiAccess->suspendIfNeeded();
    midiAccess->startRequest();
    return midiAccess.release();
}

MIDIAccess::~MIDIAccess()
{
    stop();
}

MIDIAccess::MIDIAccess(ExecutionContext* context, MIDIAccessPromise* promise)
    : ActiveDOMObject(context)
    , m_promise(promise)
    , m_hasAccess(false)
    , m_sysExEnabled(false)
    , m_requesting(false)
{
    ScriptWrappable::init(this);
    m_accessor = MIDIAccessor::create(this);
}

void MIDIAccess::setSysExEnabled(bool enable)
{
    m_requesting = false;
    m_sysExEnabled = enable;
    if (enable)
        m_accessor->startSession();
    else
        permissionDenied();
}

void MIDIAccess::didAddInputPort(const String& id, const String& manufacturer, const String& name, const String& version)
{
    ASSERT(isMainThread());

    m_inputs.append(MIDIInput::create(this, executionContext(), id, manufacturer, name, version));
}

void MIDIAccess::didAddOutputPort(const String& id, const String& manufacturer, const String& name, const String& version)
{
    ASSERT(isMainThread());

    unsigned portIndex = m_outputs.size();
    m_outputs.append(MIDIOutput::create(this, portIndex, executionContext(), id, manufacturer, name, version));
}

void MIDIAccess::didStartSession(bool success)
{
    ASSERT(isMainThread());

    m_hasAccess = success;
    if (success)
        m_promise->fulfill();
    else
        m_promise->reject(DOMError::create("InvalidStateError"));
}

void MIDIAccess::didReceiveMIDIData(unsigned portIndex, const unsigned char* data, size_t length, double timeStamp)
{
    ASSERT(isMainThread());

    if (m_hasAccess && portIndex < m_inputs.size()) {
        // 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(executionContext());
        ASSERT(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 (m_hasAccess && portIndex < m_outputs.size() && data && length > 1) {
        // 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(executionContext());
            ASSERT(document);
            double documentStartTime = document->loader()->timing()->referenceMonotonicTime();
            timeStamp = documentStartTime + 0.001 * timeStampInMilliseconds;
        }

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

void MIDIAccess::stop()
{
    m_hasAccess = false;
    if (!m_requesting)
        return;
    m_requesting = false;
    Document* document = toDocument(executionContext());
    ASSERT(document);
    MIDIController* controller = MIDIController::from(document->page());
    ASSERT(controller);
    controller->cancelSysExPermissionRequest(this);

    m_accessor.clear();
}

void MIDIAccess::startRequest()
{
    if (!m_promise->options()->sysex) {
        m_accessor->startSession();
        return;
    }
    Document* document = toDocument(executionContext());
    ASSERT(document);
    MIDIController* controller = MIDIController::from(document->page());
    if (controller) {
        m_requesting = true;
        controller->requestSysExPermission(this);
    } else {
        permissionDenied();
    }
}

void MIDIAccess::permissionDenied()
{
    ASSERT(isMainThread());

    m_hasAccess = false;
    m_promise->reject(DOMError::create("SecurityError"));
}

} // namespace WebCore