MediaRecorder Blink part

Source/modules/mediarecorder/MediaRecorder.cpp

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "modules/mediarecorder/MediaRecorder.h"
+
+#include "core/dom/DOMError.h"
+#include "core/fileapi/Blob.h"
+#include "modules/EventModules.h"
+#include "modules/EventTargetModules.h"
+#include "modules/mediarecorder/MediaRecorderErrorEvent.h"
+#include "platform/blob/BlobData.h"
+#include "public/platform/Platform.h"
+#include "public/platform/WebMediaStream.h"
+
+namespace blink {
+
+namespace {
+
+static String stateToString(MediaRecorder::State state)
+{
+    switch (state) {
+    case MediaRecorder::State::Inactive:
+        return "inactive";
+    case MediaRecorder::State::Recording:
+        return "recording";
+    case MediaRecorder::State::Paused:
+        return "paused";
+    }
+
+    ASSERT_NOT_REACHED();
+    return String();
+}
+
+} // namespace
+
+MediaRecorder* MediaRecorder::create(ExecutionContext* context, MediaStream* stream, ExceptionState& exceptionState)
+{
+    MediaRecorder* recorder = new MediaRecorder(context, stream, String(), exceptionState);
+    recorder->suspendIfNeeded();
+
+    return recorder;
+}
+
+MediaRecorder* MediaRecorder::create(ExecutionContext* context, MediaStream* stream,  const String& mimeType, ExceptionState& exceptionState)
+{
+    MediaRecorder* recorder = new MediaRecorder(context, stream, mimeType, exceptionState);
+    recorder->suspendIfNeeded();
+
+    return recorder;
+}
+
+MediaRecorder::MediaRecorder(ExecutionContext* context, MediaStream* stream, const String& mimeType, ExceptionState& exceptionState)
+    : ActiveDOMObject(context)
+    , m_stream(stream)
+    , m_mimeType(mimeType)
+    , m_stopped(true)
+    , m_ignoreMutedMedia(true)
+    , m_state(State::Inactive)
+    , m_dispatchScheduledEventRunner(this, &MediaRecorder::dispatchScheduledEvent)
+{
+    m_recorderHandler = adoptPtr(Platform::current()->createMediaRecorderHandler());
+
+    // TODO(mcasas): Once http://crbug.com/262211 has landed the Chromium parts,
+    // and more concretetely the createMediaRecorderHandler() implementation,
+    // ASSERT() here for |m_recorderHandler|.
+
+    // We deviate from the spec by not returning |UnsupportedOption|, see https://github.com/w3c/mediacapture-record/issues/18
+    if (!m_recorderHandler) {
+        exceptionState.throwDOMException(NotSupportedError, "No MediaRecorder handler can be created.");
+        return;
+    }
+    if (!m_recorderHandler->initialize(this, stream->descriptor(), m_mimeType)) {
+        exceptionState.throwDOMException(NotSupportedError, "Failed to initialize native MediaRecorder, the type provided " + m_mimeType + "is unsupported." );
+        return;
+    }
+    m_stopped = false;
+}
+
+String MediaRecorder::state() const
+{
+    return stateToString(m_state);
+}
+
+void MediaRecorder::start(ExceptionState& exceptionState)
+{
+    if (m_state != State::Inactive) {
+        exceptionState.throwDOMException(InvalidStateError, "The MediaRecorder's state is '" + stateToString(m_state) + "'.");
+        return;
+    }
+    m_state = State::Recording;
+
+    m_recorderHandler->start();
+}
+
+void MediaRecorder::start(int timeSlice, ExceptionState& exceptionState)
+{
+    if (m_state != State::Inactive) {
+        exceptionState.throwDOMException(InvalidStateError, "The MediaRecorder's state is '" + stateToString(m_state) + "'.");
+        return;
+    }
+    m_state = State::Recording;
+
+    m_recorderHandler->start(timeSlice);
+}
+
+void MediaRecorder::stop(ExceptionState& exceptionState)
+{
+    if (m_state == State::Inactive) {
+        exceptionState.throwDOMException(InvalidStateError, "The MediaRecorder's state is '" + stateToString(m_state) + "'.");
+        return;
+    }
+
+    stopRecording();
+}
+
+void MediaRecorder::pause(ExceptionState& exceptionState)
+{
+    if (m_state == State::Inactive) {
+        exceptionState.throwDOMException(InvalidStateError, "The MediaRecorder's state is '" + stateToString(m_state) + "'.");
+        return;
+    }
+    if (m_state == State::Paused)
+        return;
+
+    m_state = State::Paused;
+
+    m_recorderHandler->pause();
+
+    scheduleDispatchEvent(Event::create(EventTypeNames::pause));
+}
+
+void MediaRecorder::resume(ExceptionState& exceptionState)
+{
+    if (m_state == State::Inactive) {
+        exceptionState.throwDOMException(InvalidStateError, "The MediaRecorder's state is '" + stateToString(m_state) + "'.");
+        return;
+    }
+    if (m_state == State::Recording)
+        return;
+
+    m_state = State::Recording;
+
+    m_recorderHandler->resume();
+}
+
+void MediaRecorder::requestData(ExceptionState& exceptionState)
+{
+    if (m_state != State::Recording) {
+        exceptionState.throwDOMException(InvalidStateError, "The MediaRecorder's state is '" + stateToString(m_state) + "'.");
+        return;
+    }
+
+    createBlobEvent(BlobData::create());
+}
+
+String MediaRecorder::canRecordMimeType(const String& mimeType)
+{
+    RawPtr<WebMediaRecorderHandler> handler = Platform::current()->createMediaRecorderHandler();
+    if (!handler)
+        return emptyString();
+
+    // MediaRecorder canRecordMimeType() MUST return 'probably' "if the UA is
+    // confident that mimeType represents a type that it can record" [1], but a
+    // number of reasons could prevent the recording from happening as expected,
+    // so 'maybe' is a better option: "Implementors are encouraged to return
+    // "maybe" unless the type can be confidently established as being supported
+    // or not.". Hence this method returns '' or 'maybe', never 'probably'.
+    // [1] http://w3c.github.io/mediacapture-record/MediaRecorder.html#methods
+    return handler->canSupportMimeType(mimeType) ? "maybe" : emptyString();
+}
+
+const AtomicString& MediaRecorder::interfaceName() const
+{
+    return EventTargetNames::MediaRecorder;
+}
+
+ExecutionContext* MediaRecorder::executionContext() const
+{
+    return ActiveDOMObject::executionContext();
+}
+
+void MediaRecorder::suspend()
+{
+    m_dispatchScheduledEventRunner.suspend();
+}
+
+void MediaRecorder::resume()
+{
+    m_dispatchScheduledEventRunner.resume();
+}
+
+void MediaRecorder::stop()
+{
+    if (m_stopped)
+        return;
+
+    m_stopped = true;
+    m_stream.clear();
+    m_recorderHandler.clear();
+
+    scheduleDispatchEvent(Event::create(EventTypeNames::stop));
+}
+
+void MediaRecorder::writeData(const char* data, size_t length, bool lastInSlice)
+{
+    ASSERT(m_state == State::Recording);
+
+    if (m_stopped) {
+        m_stopped = false;
+        scheduleDispatchEvent(Event::create(EventTypeNames::start));
+    }
+
+    // TODO(mcasas): Act as |m_ignoredMutedMedia| instructs if |m_stream| track(s) is in muted() state.
+    // TODO(mcasas): Use |lastInSlice| to indicate to JS that recording is done.
+
+    OwnPtr<BlobData> blobData = BlobData::create();
+    blobData->appendBytes(data, length);
+    createBlobEvent(blobData.release());
+}
+
+void MediaRecorder::failOutOfMemory(const WebString& message)
+{
+    scheduleDispatchEvent(MediaRecorderErrorEvent::create(
+        EventTypeNames::error, false, false, "OutOfMemory", message));
+
+    if (m_state == State::Recording)
+        stopRecording();
+}
+
+void MediaRecorder::failIllegalStreamModification(const WebString& message)
+{
+    scheduleDispatchEvent(MediaRecorderErrorEvent::create(
+        EventTypeNames::error, false, false, "IllegalStreamModification", message));
+
+    if (m_state == State::Recording)
+        stopRecording();
+}
+
+void MediaRecorder::failOtherRecordingError(const WebString& message)
+{
+    scheduleDispatchEvent(MediaRecorderErrorEvent::create(
+        EventTypeNames::error, false, false, "OtherRecordingError", message));
+
+    if (m_state == State::Recording)
+        stopRecording();
+}
+
+void MediaRecorder::createBlobEvent(PassOwnPtr<BlobData> blobData)
+{
+    // TODO(mcasas): Launch a BlobEvent when that class is landed, but also see https://github.com/w3c/mediacapture-record/issues/17.
+    ASSERT_NOT_REACHED();
+}
+
+void MediaRecorder::stopRecording()
+{
+    ASSERT(m_state != State::Inactive);
+    m_state = State::Inactive;
+
+    m_recorderHandler->stop();
+
+    createBlobEvent(BlobData::create());
+
+    scheduleDispatchEvent(Event::create(EventTypeNames::stop));
+}
+
+void MediaRecorder::scheduleDispatchEvent(PassRefPtrWillBeRawPtr<Event> event)
+{
+    m_scheduledEvents.append(event);
+
+    m_dispatchScheduledEventRunner.runAsync();
+}
+
+void MediaRecorder::dispatchScheduledEvent()
+{
+    WillBeHeapVector<RefPtrWillBeMember<Event>> events;
+    events.swap(m_scheduledEvents);
+
+    WillBeHeapVector<RefPtrWillBeMember<Event>>::iterator it = events.begin();
+    for (; it != events.end(); ++it)
+        dispatchEvent((*it).release());

[Peter Beverloo, 2015/09/02 16:39:37]

nit: since both RefPtr and Member exercise the same memory semantics, you can
just pass in the Event w/o using release(). That will happen anyway then
|events| goes out of scope (the .clear() call below isn't necessary either).

[mcasas, 2015/09/02 21:01:47]

Cleaned up.

+
+    events.clear();
+}
+
+DEFINE_TRACE(MediaRecorder)
+{
+    visitor->trace(m_stream);
+    RefCountedGarbageCollectedEventTargetWithInlineData<MediaRecorder>::trace(visitor);
+    ActiveDOMObject::trace(visitor);
+}
+
+} // namespace blink