Package eu.webtoolkit.jwt

Class WAbstractMedia

  • Direct Known Subclasses:
    WAudio, WVideo
    public abstract class WAbstractMedia
extends WInteractWidget
    Abstract baseclass for native media elements.

    This class is an abstract base class for HTML5 media elements (<audio>, <video>).

    • Constructor Detail

      • WAbstractMedia

        public WAbstractMedia​(WContainerWidget parentContainer)
        Consctructor for a media widget.

        A freshly constructed media widget has no options set, no media sources, and has preload mode set to PreloadAuto.

    • Method Detail

      • setOptions

        public void setOptions​(java.util.EnumSet<PlayerOption> flags)
        Set the media element options.

      • getOptions

        public java.util.EnumSet<PlayerOption> getOptions()
        Retrieve the configured options.

      • setPreloadMode

        public void setPreloadMode​(MediaPreloadMode mode)
        Set the preload mode.

      • getPreloadMode

        public MediaPreloadMode getPreloadMode()
        Retrieve the preload mode.

      • clearSources

        public void clearSources()
        Removes all source elements.

        This method can be used to remove all media sources. Afterward, you may add new media sources with calls to addSource().

        Use this to reuse a WAbstractMedia instantiation to play something else.

      • addSource

        public void addSource​(WLink link,
                      java.lang.String type,
                      java.lang.String media)
        Add a media source.

        This method specifies a media source (which may be a URL or dynamic resource). You may add as many media sources as you want. The browser will select the appropriate media stream to display to the user.

        This method specifies a media source using the URL, the mime type, and the media attribute. HTML allows for empty type and media attributes.

      • setAlternativeContent

        public void setAlternativeContent​(WWidget alternative)
        Content to be shown when media cannot be played.

        As not all browsers are HTML5 compliant, it is a good idea to provide fallback options when the media cannot be displayed. If the media can be played by the browser, the alternative content will be suppressed.

        The two reasons to display the alternative content are (1) the media tag is not supported, or (2) the media tag is supported, but none of the media sources are supported by the browser. In the first case, fall-back is automatic and does not rely on JavaScript in the browser; in the latter case, JavaScript is required to make the fallback work.

        The alternative content can be any widget: you can set it to an alternative media player (QuickTime, Flash, ...), show a Flash movie, an animated gif, a text, a poster image, ...

      • play

        public void play()
        Invoke play() on the media element.

        JavaScript must be available for this function to work.

      • pause

        public void pause()
        Invoke pause() on the media element.

        JavaScript must be available for this function to work.

      • isPlaying

        public boolean isPlaying()
        Returns whether the media is playing.

      • getReadyState

        public MediaReadyState getReadyState()
        Returns the media's readyState.

      • playbackStarted

        public EventSignal playbackStarted()
        Event signal emitted when playback has begun.

        This event fires when play was invoked, or when the media element starts playing because the Autoplay option was provided.

        Note: When JavaScript is disabled, the signal will never fire.

      • playbackPaused

        public EventSignal playbackPaused()
        Event signal emitted when the playback has paused.

        Note: When JavaScript is disabled, the signal will never fire.

      • ended

        public EventSignal ended()
        Event signal emitted when the playback stopped because the end of the media was reached.

        Note: When JavaScript is disabled, the signal will never fire.

      • timeUpdated

        public EventSignal timeUpdated()
        Event signal emitted when the current playback position has changed.

        This event is fired when the playback position has changed, both when the media is in a normal playing mode, but also when it has changed discontinuously because of another reason.

        Note: When JavaScript is disabled, the signal will never fire.

      • volumeChanged

        public EventSignal volumeChanged()
        Event signal emitted when the playback volume has changed.

        Note: When JavaScript is disabled, the signal will never fire.

      • getJsMediaRef

        public java.lang.String getJsMediaRef()
        Returns the JavaScript reference to the media object, or null.

        It is possible, for browser compatibility reasons, that WWidget.getJsRef() is not the media element. getJsMediaRef() is guaranteed to be an expression that evaluates to the media object. This expression may yield null, if the video object is not rendered at all (e.g. on older versions of Internet Explorer).

      • getDomChanges

        protected void getDomChanges​(java.util.List<DomElement> result,
                             WApplication app)
        Description copied from class: WWebWidget
        Get DOM changes for this widget.

        This is an internal function, and should not be called directly, or be overridden!

        Overrides:
        getDomChanges in class WWebWidget

      • enableAjax

        protected void enableAjax()
        Description copied from class: WWidget
        Progresses to an Ajax-enabled widget.

        This method is called when the progressive bootstrap method is used, and support for AJAX has been detected. The default behavior will upgrade the widget's event handling to use AJAX instead of full page reloads, and propagate the call to its children.

        You may want to reimplement this method if you want to make changes to widget when AJAX is enabled. You should always call the base implementation.

        Overrides:
        enableAjax in class WWebWidget
        See Also:
        WApplication.enableAjax()