path: root/src/multimediaquick/Video.qml

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import QtQuick
import QtMultimedia

/*!
    \qmltype Video
    \inherits Item
    \ingroup multimedia_qml
    \ingroup multimedia_video_qml
    \inqmlmodule QtMultimedia
    \brief A convenience type for showing a specified video.

    \c Video is a convenience type combining the functionality
    of a \l MediaPlayer and a \l VideoOutput into one. It provides
    simple video playback functionality without having to declare multiple
    types.

    The following is sample code to implement video playback in a scene.

    \qml
    Video {
        id: video
        width : 800
        height : 600
        source: "video.avi"

        MouseArea {
            anchors.fill: parent
            onClicked: {
                video.play()
            }
        }

        focus: true
        Keys.onSpacePressed: video.playbackState == MediaPlayer.PlayingState ? video.pause() : video.play()
        Keys.onLeftPressed: video.seek(video.position - 5000)
        Keys.onRightPressed: video.seek(video.position + 5000)
    }
    \endqml

    The source file, \c video.avi, plays when you click the parent
    of MouseArea. The video plays in an area of 800 by 600 pixels, and its \c id
    property has the value \b{video}.

    Notice that because signals for the \l Keys have been defined pressing the:
    \list
    \li \uicontrol Spacebar toggles the pause button.
    \li \uicontrol{Left Arrow} moves the current position in the video to 5 seconds
    previously.
    \li \uicontrol{Right Arrow} advances the current position in the video by 5 seconds.
    \endlist

    Video supports un-transformed, stretched, and uniformly scaled
    video presentation. For a description of stretched uniformly scaled
    presentation, see the \l fillMode property description.

    \sa MediaPlayer, VideoOutput

\omit
    \section1 Screen Saver

    If it is likely that an application will be playing video for an extended
    period of time without user interaction, it may be necessary to disable
    the platform's screen saver. The \l ScreenSaver (from \l QtSystemInfo)
    may be used to disable the screensaver in this fashion:

    \qml
    import QtSystemInfo 5.0

    ScreenSaver { screenSaverEnabled: false }
    \endqml
\endomit
*/

// TODO: Restore Qt System Info docs when the module is released

Item {
    id: video

    /*** Properties of VideoOutput ***/
    /*!
        \qmlproperty enumeration Video::fillMode

        Set this property to define how the video is scaled to fit the target
        area.

        \list
        \li VideoOutput.Stretch - the video is scaled to fit
        \li VideoOutput.PreserveAspectFit - the video is scaled uniformly to fit without
            cropping
        \li VideoOutput.PreserveAspectCrop - the video is scaled uniformly to fill, cropping
            if necessary
        \endlist

        Because this type is for convenience in QML, it does not
        support enumerations directly, so enumerations from \c VideoOutput are
        used to access the available fill modes.

        The default fill mode is preserveAspectFit.
    */
    property alias fillMode:            videoOut.fillMode

    /*!
        \qmlproperty int Video::orientation

        The orientation of the \c Video in degrees. Only multiples of 90
        degrees is supported, that is 0, 90, 180, 270, 360, etc.
    */
    property alias orientation:         videoOut.orientation


    /*** Properties of MediaPlayer ***/

    /*!
        \qmlproperty enumeration Video::playbackState

        This read only property indicates the playback state of the media.

        \list
        \li MediaPlayer.PlayingState - the media is playing
        \li MediaPlayer.PausedState - the media is paused
        \li MediaPlayer.StoppedState - the media is stopped
        \endlist

        The default state is MediaPlayer.StoppedState.
    */
    property alias playbackState:        player.playbackState

    /*!
        \qmlproperty real Video::bufferProgress

        This property holds how much of the data buffer is currently filled,
        from 0.0 (empty) to 1.0
        (full).
    */
    property alias bufferProgress:  player.bufferProgress

    /*!
        \qmlproperty int Video::duration

        This property holds the duration of the media in milliseconds.

        If the media doesn't have a fixed duration (a live stream for example)
        this will be 0.
    */
    property alias duration:        player.duration

    /*!
        \qmlproperty enumeration Video::error

        This property holds the error state of the video.  It can be one of:

        \list
        \li MediaPlayer.NoError - there is no current error.
        \li MediaPlayer.ResourceError - the video cannot be played due to a problem
            allocating resources.
        \li MediaPlayer.FormatError - the video format is not supported.
        \li MediaPlayer.NetworkError - the video cannot be played due to network issues.
        \li MediaPlayer.AccessDenied - the video cannot be played due to insufficient
            permissions.
        \li MediaPlayer.ServiceMissing -  the video cannot be played because the media
            service could not be
        instantiated.
        \endlist
    */
    property alias error:           player.error

    /*!
        \qmlproperty string Video::errorString

        This property holds a string describing the current error condition in more detail.
    */
    property alias errorString:     player.errorString

    /*!
        \qmlproperty bool Video::hasAudio

        This property holds whether the current media has audio content.
    */
    property alias hasAudio:        player.hasAudio

    /*!
        \qmlproperty bool Video::hasVideo

        This property holds whether the current media has video content.
    */
    property alias hasVideo:        player.hasVideo

    /*!
        \qmlproperty object Video::metaData

        This property holds the meta data for the current media.

        See \l{MediaPlayer::metaData}{MediaPlayer.metaData} for details about each meta data key.

        \sa {QMediaMetaData}
    */
    property alias metaData:        player.metaData

    /*!
        \qmlproperty bool Video::muted

        This property holds whether the audio output is muted.
    */
    property alias muted:           audioOutput.muted

    /*!
        \qmlproperty real Video::playbackRate

        This property holds the rate at which video is played at as a multiple
        of the normal rate.
    */
    property alias playbackRate:    player.playbackRate

    /*!
        \qmlproperty int Video::position

        This property holds the current playback position in milliseconds.

        To change this position, use the \l seek() method.

        \sa seek()
    */
    property alias position:        player.position

    /*!
        \qmlproperty bool Video::seekable

        This property holds whether the playback position of the video can be
        changed.

        If true, calling the \l seek() method will cause playback to seek to the new position.
    */
    property alias seekable:        player.seekable

    /*!
        \qmlproperty url Video::source

        This property holds the source URL of the media.
    */
    property alias source:          player.source

    /*!
        \qmlproperty real Video::volume

        This property holds the audio volume.

        The volume is scaled linearly from \c 0.0 (silence) to \c 1.0
        (full volume). Values outside this range will be clamped.

        The default volume is \c 1.0.

        UI volume controls should usually be scaled nonlinearly. For example,
        using a logarithmic scale will produce linear changes in perceived
        loudness, which is what a user would normally expect from a volume
        control. See \l {QAudio::convertVolume()} for more details.
    */
    property alias volume:          audioOutput.volume

    /*!
        \qmlsignal Video::paused()

        This signal is emitted when playback is paused.
    */
    signal paused

    /*!
        \qmlsignal Video::stopped()

        This signal is emitted when playback is stopped.
    */
    signal stopped

    /*!
        \qmlsignal Video::playing()

        This signal is emitted when playback is started or continued.
    */
    signal playing

    VideoOutput {
        id: videoOut
        anchors.fill: video
    }

    MediaPlayer {
        id: player
        onPlaybackStateChanged: function(newState) {
            if (newState === MediaPlayer.PausedState)
                video.paused();
            else if (newState === MediaPlayer.StoppedState)
                video.stopped();
            else
                video.playing();
        }
        videoOutput: videoOut
        audioOutput: AudioOutput {
            id: audioOutput
        }
    }

    /*!
        \qmlmethod Video::play()

        Starts playback of the media.
    */
    function play() {
        player.play();
    }

    /*!
        \qmlmethod Video::pause()

        Pauses playback of the media.
    */
    function pause() {
        player.pause();
    }

    /*!
        \qmlmethod Video::stop()

        Stops playback of the media.
    */
    function stop() {
        player.stop();
    }

    /*!
        \qmlmethod Video::seek(offset)

        If the \l seekable property is true, seeks the current
        playback position to \a offset.

        Seeking may be asynchronous, so the \l position property
        may not be updated immediately.

        \sa seekable, position
    */
    function seek(offset) {
        player.seek(offset);
    }
}