flutter_flutter/engine/core/html/HTMLMediaElement.h

/*
 * Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
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 *    notice, this list of conditions and the following disclaimer.
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 *    notice, this list of conditions and the following disclaimer in the
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 *
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 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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#ifndef HTMLMediaElement_h
#define HTMLMediaElement_h

#include "core/dom/ActiveDOMObject.h"
#include "core/events/GenericEventQueue.h"
#include "core/html/HTMLElement.h"
#include "platform/PODIntervalTree.h"
#include "platform/Supplementable.h"
#include "platform/graphics/media/MediaPlayer.h"
#include "public/platform/WebMediaPlayerClient.h"
#include "public/platform/WebMimeRegistry.h"

namespace blink {
class WebLayer;
}

namespace blink {

class ContentType;
class Event;
class ExceptionState;
class HTMLSourceElement;
class KURL;
class MediaError;
class HTMLMediaSource;
class TimeRanges;
class URLRegistry;

// FIXME: The inheritance from MediaPlayerClient here should be private inheritance.
// But it can't be until the Chromium WebMediaPlayerClientImpl class is fixed so it
// no longer depends on typecasting a MediaPlayerClient to an HTMLMediaElement.

class HTMLMediaElement : public HTMLElement, public Supplementable<HTMLMediaElement>, public MediaPlayerClient, public ActiveDOMObject
{
    DEFINE_WRAPPERTYPEINFO();
    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(HTMLMediaElement);
public:
    static blink::WebMimeRegistry::SupportsType supportsType(const ContentType&, const String& keySystem = String());

    virtual void trace(Visitor*) override;

    // Do not use player().
    // FIXME: Replace all uses with webMediaPlayer() and remove this API.
    MediaPlayer* player() const { return m_player.get(); }
    blink::WebMediaPlayer* webMediaPlayer() const { return m_player ? m_player->webMediaPlayer() : 0; }

    virtual bool hasVideo() const { return false; }
    bool hasAudio() const;

    bool supportsSave() const;

    blink::WebLayer* platformLayer() const;

    enum DelayedActionType {
        LoadMediaResource = 1 << 0,
    };
    void scheduleDelayedAction(DelayedActionType);

    bool isActive() const { return m_active; }

    // error state
    PassRefPtr<MediaError> error() const;

    // network state
    void setSrc(const AtomicString&);
    const KURL& currentSrc() const { return m_currentSrc; }

    enum NetworkState { NETWORK_EMPTY, NETWORK_IDLE, NETWORK_LOADING, NETWORK_NO_SOURCE };
    NetworkState networkState() const;

    String preload() const;
    void setPreload(const AtomicString&);

    PassRefPtr<TimeRanges> buffered() const;
    void load();
    String canPlayType(const String& mimeType, const String& keySystem = String()) const;

    // ready state
    enum ReadyState { HAVE_NOTHING, HAVE_METADATA, HAVE_CURRENT_DATA, HAVE_FUTURE_DATA, HAVE_ENOUGH_DATA };
    ReadyState readyState() const;
    bool seeking() const;

    // playback state
    double currentTime() const;
    void setCurrentTime(double, ExceptionState&);
    double duration() const;
    bool paused() const;
    double defaultPlaybackRate() const;
    void setDefaultPlaybackRate(double);
    double playbackRate() const;
    void setPlaybackRate(double);
    void updatePlaybackRate();
    PassRefPtr<TimeRanges> played();
    PassRefPtr<TimeRanges> seekable() const;
    bool ended() const;
    bool autoplay() const;
    bool loop() const;
    void setLoop(bool b);
    void play();
    void pause();

    // media source extensions
    void closeMediaSource();
    void durationChanged(double duration, bool requestSeek);

    double volume() const;
    void setVolume(double, ExceptionState&);
    bool muted() const;
    void setMuted(bool);

    // play/pause toggling that uses the media controller if present. togglePlayStateWillPlay() is
    // true if togglePlayState() will call play() or unpause() on the media element or controller.
    bool togglePlayStateWillPlay() const;
    void togglePlayState();

    virtual KURL mediaPlayerPosterURL() override { return KURL(); }

    // EventTarget function.
    // Both Node (via HTMLElement) and ActiveDOMObject define this method, which
    // causes an ambiguity error at compile time. This class's constructor
    // ensures that both implementations return document, so return the result
    // of one of them here.
    using HTMLElement::executionContext;

    bool isFullscreen() const;
    void enterFullscreen();
    void exitFullscreen();

    void sourceWasRemoved(HTMLSourceElement*);
    void sourceWasAdded(HTMLSourceElement*);

    bool isPlaying() const { return m_playing; }

    // ActiveDOMObject functions.
    virtual bool hasPendingActivity() const override final;
    virtual void contextDestroyed() override final;

    enum InvalidURLAction { DoNothing, Complain };
    bool isSafeToLoadURL(const KURL&, InvalidURLAction);

    void scheduleEvent(PassRefPtr<Event>);

    // Returns the "effective media volume" value as specified in the HTML5 spec.
    double effectiveMediaVolume() const;

#if ENABLE(OILPAN)
    bool isFinalizing() const { return m_isFinalizing; }

    // Oilpan: finalization of the media element is observable from its
    // attached MediaSource; it entering a closed state.
    //
    // Express that by having the MediaSource keep a weak reference
    // to the media element and signal that it wants to be notified
    // of destruction if it survives a GC, but the media element
    // doesn't.
    void setCloseMediaSourceWhenFinalizing();
#endif

    // Predicates also used when dispatching wrapper creation (cf. [SpecialWrapFor] IDL attribute usage.)
    virtual bool isHTMLAudioElement() const { return false; }
    virtual bool isHTMLVideoElement() const { return false; }

protected:
    HTMLMediaElement(const QualifiedName&, Document&);
    virtual ~HTMLMediaElement();

    virtual void parseAttribute(const QualifiedName&, const AtomicString&) override;
    virtual void finishParsingChildren() override final;
    virtual bool isURLAttribute(const Attribute&) const override;
    virtual void attach(const AttachContext& = AttachContext()) override;

    virtual void didMoveToNewDocument(Document& oldDocument) override;

    enum DisplayMode { Unknown, Poster, PosterWaitingForVideo, Video };
    DisplayMode displayMode() const { return m_displayMode; }
    virtual void setDisplayMode(DisplayMode mode) { m_displayMode = mode; }

private:
    void createMediaPlayer();

    virtual bool isMouseFocusable() const override final;
    virtual bool rendererIsNeeded(const RenderStyle&) override;
    virtual RenderObject* createRenderer(RenderStyle*) override;
    virtual InsertionNotificationRequest insertedInto(ContainerNode*) override final;
    virtual void didNotifySubtreeInsertionsToDocument() override;
    virtual void removedFrom(ContainerNode*) override final;
    virtual void didRecalcStyle(StyleRecalcChange) override final;

    virtual bool isInteractiveContent() const override final;
    virtual void defaultEventHandler(Event*) override final;

    // ActiveDOMObject functions.
    virtual void stop() override final;

    virtual void updateDisplayState() { }

    void setReadyState(ReadyState);
    void setNetworkState(blink::WebMediaPlayer::NetworkState);

    virtual void mediaPlayerNetworkStateChanged() override final;
    virtual void mediaPlayerReadyStateChanged() override final;
    virtual void mediaPlayerTimeChanged() override final;
    virtual void mediaPlayerDurationChanged() override final;
    virtual void mediaPlayerPlaybackStateChanged() override final;
    virtual void mediaPlayerRequestFullscreen() override final;
    virtual void mediaPlayerRequestSeek(double) override final;
    virtual void mediaPlayerRepaint() override final;
    virtual void mediaPlayerSizeChanged() override final;
    virtual void mediaPlayerSetWebLayer(blink::WebLayer*) override final;
    virtual void mediaPlayerMediaSourceOpened(blink::WebMediaSource*) override final;

    void loadTimerFired(Timer<HTMLMediaElement>*);
    void progressEventTimerFired(Timer<HTMLMediaElement>*);
    void playbackProgressTimerFired(Timer<HTMLMediaElement>*);
    void startPlaybackProgressTimer();
    void startProgressEventTimer();
    void stopPeriodicTimers();

    void seek(double time, ExceptionState&);
    void finishSeek();
    void checkIfSeekNeeded();
    void addPlayedRange(double start, double end);

    void scheduleTimeupdateEvent(bool periodicEvent);
    void scheduleEvent(const AtomicString& eventName); // FIXME: Rename to scheduleNamedEvent for clarity.

    // loading
    void prepareForLoad();
    void loadInternal();
    void selectMediaResource();
    void loadResource(const KURL&, ContentType&, const String& keySystem);
    void startPlayerLoad();
    void setPlayerPreload();
    blink::WebMediaPlayer::LoadType loadType() const;
    void scheduleNextSourceChild();
    void loadNextSourceChild();
    void userCancelledLoad();
    void clearMediaPlayer(int flags);
    void clearMediaPlayerAndAudioSourceProviderClientWithoutLocking();
    bool havePotentialSourceChild();
    void noneSupported();
    void mediaEngineError(PassRefPtr<MediaError>);
    void cancelPendingEventsAndCallbacks();
    void waitForSourceChange();
    void prepareToPlay();

    KURL selectNextSourceChild(ContentType*, String* keySystem, InvalidURLAction);

    void mediaLoadingFailed(blink::WebMediaPlayer::NetworkState);

    // deferred loading (preload=none)
    bool loadIsDeferred() const;
    void deferLoad();
    void cancelDeferredLoad();
    void startDeferredLoad();
    void executeDeferredLoad();
    void deferredLoadTimerFired(Timer<HTMLMediaElement>*);

    // This does not check user gesture restrictions.
    void playInternal();

    void allowVideoRendering();

    void updateVolume();
    void updatePlayState();
    bool potentiallyPlaying() const;
    bool endedPlayback() const;
    bool stoppedDueToErrors() const;
    bool couldPlayIfEnoughData() const;

    // Pauses playback without changing any states or generating events
    void setPausedInternal(bool);

    void setShouldDelayLoadEvent(bool);
    void invalidateCachedTime();
    void refreshCachedTime() const;

    void prepareMediaFragmentURI();
    void applyMediaFragmentURI();

    virtual void* preDispatchEventHandler(Event*) override final;

    void changeNetworkStateFromLoadingToIdle();

    const AtomicString& mediaGroup() const;
    void setMediaGroup(const AtomicString&);
    bool isBlocked() const;
    bool isAutoplaying() const { return m_autoplaying; }

    blink::WebMediaPlayer::CORSMode corsMode() const;

    // Returns the "direction of playback" value as specified in the HTML5 spec.
    enum DirectionOfPlayback { Backward, Forward };
    DirectionOfPlayback directionOfPlayback() const;

    // Returns the "effective playback rate" value as specified in the HTML5 spec.
    double effectivePlaybackRate() const;

    Timer<HTMLMediaElement> m_loadTimer;
    Timer<HTMLMediaElement> m_progressEventTimer;
    Timer<HTMLMediaElement> m_playbackProgressTimer;
    RefPtr<TimeRanges> m_playedTimeRanges;
    OwnPtr<GenericEventQueue> m_asyncEventQueue;

    double m_playbackRate;
    double m_defaultPlaybackRate;
    NetworkState m_networkState;
    ReadyState m_readyState;
    ReadyState m_readyStateMaximum;
    KURL m_currentSrc;

    RefPtr<MediaError> m_error;

    double m_volume;
    double m_lastSeekTime;

    double m_previousProgressTime;

    // Cached duration to suppress duplicate events if duration unchanged.
    double m_duration;

    // The last time a timeupdate event was sent (wall clock).
    double m_lastTimeUpdateEventWallTime;

    // The last time a timeupdate event was sent in movie time.
    double m_lastTimeUpdateEventMovieTime;

    // Loading state.
    enum LoadState { WaitingForSource, LoadingFromSrcAttr, LoadingFromSourceElement };
    LoadState m_loadState;
    RefPtr<HTMLSourceElement> m_currentSourceNode;
    RefPtr<Node> m_nextChildNodeToConsider;

    // "Deferred loading" state (for preload=none).
    enum DeferredLoadState {
        // The load is not deferred.
        NotDeferred,
        // The load is deferred, and waiting for the task to set the
        // delaying-the-load-event flag (to false).
        WaitingForStopDelayingLoadEventTask,
        // The load is the deferred, and waiting for a triggering event.
        WaitingForTrigger,
        // The load is deferred, and waiting for the task to set the
        // delaying-the-load-event flag, after which the load will be executed.
        ExecuteOnStopDelayingLoadEventTask
    };
    DeferredLoadState m_deferredLoadState;
    Timer<HTMLMediaElement> m_deferredLoadTimer;

    OwnPtr<MediaPlayer> m_player;
    blink::WebLayer* m_webLayer;

    MediaPlayer::Preload m_preload;

    DisplayMode m_displayMode;

    RefPtr<HTMLMediaSource> m_mediaSource;

    // Cached time value. Only valid when ready state is HAVE_METADATA or
    // higher, otherwise the current time is assumed to be zero.
    mutable double m_cachedTime;

    double m_fragmentStartTime;
    double m_fragmentEndTime;

    typedef unsigned PendingActionFlags;
    PendingActionFlags m_pendingActionFlags;

    // FIXME: MediaElement has way too many state bits.
    bool m_userGestureRequiredForPlay : 1;
    bool m_playing : 1;
    bool m_shouldDelayLoadEvent : 1;
    bool m_haveFiredLoadedData : 1;
    bool m_active : 1;
    bool m_autoplaying : 1;
    bool m_muted : 1;
    bool m_paused : 1;
    bool m_seeking : 1;

    // data has not been loaded since sending a "stalled" event
    bool m_sentStalledEvent : 1;

    // time has not changed since sending an "ended" event
    bool m_sentEndEvent : 1;

    bool m_pausedInternal : 1;

    bool m_closedCaptionsVisible : 1;

    bool m_completelyLoaded : 1;
    bool m_havePreparedToPlay : 1;
    bool m_delayingLoadForPreloadNone : 1;

    bool m_processingPreferenceChange : 1;
#if ENABLE(OILPAN)
    bool m_isFinalizing : 1;
    bool m_closeMediaSourceWhenFinalizing : 1;
#endif

    static URLRegistry* s_mediaStreamRegistry;
};

#ifndef NDEBUG
// Template specializations required by PodIntervalTree in debug mode.
template <>
struct ValueToString<double> {
    static String string(const double value)
    {
        return String::number(value);
    }
};
#endif

inline bool isHTMLMediaElement(const HTMLElement& element)
{
    return isHTMLAudioElement(element) || isHTMLVideoElement(element);
}

DEFINE_HTMLELEMENT_TYPE_CASTS_WITH_FUNCTION(HTMLMediaElement);

} // namespace blink

#endif // HTMLMediaElement_h