Wt  4.11.0
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Public Member Functions | List of all members
Wt::WVideo Class Reference

A video-playing widget. More...

#include <Wt/WVideo.h>

Inheritance diagram for Wt::WVideo:
[legend]

Public Member Functions

 WVideo ()
 Creates a video widget.
 
void setPoster (const std::string &url)
 Set the poster image.
 
std::string jsVideoRef () const
 Returns the JavaScript reference to the video object, or null.
 
virtual void resize (const WLength &width, const WLength &height) override
 Resizes the widget.
 
- Public Member Functions inherited from Wt::WAbstractMedia
 WAbstractMedia ()
 Consctructor for a media widget.
 
void setOptions (const WFlags< PlayerOption > &flags)
 Set the media element options.
 
WFlags< PlayerOptiongetOptions () const
 Retrieve the configured options.
 
void setPreloadMode (MediaPreloadMode mode)
 Set the preload mode.
 
MediaPreloadMode preloadMode () const
 Retrieve the preload mode.
 
void clearSources ()
 Removes all source elements.
 
void addSource (const WLink &source, const std::string &type="", const std::string &media="")
 Add a media source.
 
void setAlternativeContent (std::unique_ptr< WWidget > alternative)
 Content to be shown when media cannot be played.
 
void play ()
 Invoke play() on the media element.
 
void pause ()
 Invoke pause() on the media element.
 
bool playing () const
 Returns whether the media is playing.
 
MediaReadyState readyState () const
 Returns the media's readyState.
 
EventSignalplaybackStarted ()
 Event signal emitted when playback has begun.
 
EventSignalplaybackPaused ()
 Event signal emitted when the playback has paused.
 
EventSignalended ()
 Event signal emitted when the playback stopped because the end of the media was reached.
 
EventSignaltimeUpdated ()
 Event signal emitted when the current playback position has changed.
 
EventSignalvolumeChanged ()
 Event signal emitted when the playback volume has changed.
 
std::string jsMediaRef () const
 Returns the JavaScript reference to the media object, or null.
 
- Public Member Functions inherited from Wt::WInteractWidget
 WInteractWidget ()
 Create an InteractWidget.
 
EventSignal< WKeyEvent > & keyWentDown ()
 Event signal emitted when a keyboard key is pushed down.
 
EventSignal< WKeyEvent > & keyPressed ()
 Event signal emitted when a "character" was entered.
 
EventSignal< WKeyEvent > & keyWentUp ()
 Event signal emitted when a keyboard key is released.
 
EventSignalenterPressed ()
 Event signal emitted when enter was pressed.
 
EventSignalescapePressed ()
 Event signal emitted when escape was pressed.
 
EventSignal< WMouseEvent > & clicked ()
 Event signal emitted when the primary mouse button was clicked on this widget.
 
EventSignal< WMouseEvent > & doubleClicked ()
 Event signal emitted when the primary mouse button was double clicked on this widget.
 
EventSignal< WMouseEvent > & mouseWentDown ()
 Event signal emitted when a mouse button was pushed down on this widget.
 
EventSignal< WMouseEvent > & mouseWentUp ()
 Event signal emitted when a mouse button was released on this widget.
 
EventSignal< WMouseEvent > & mouseWentOut ()
 Event signal emitted when the mouse went out of this widget.
 
EventSignal< WMouseEvent > & mouseWentOver ()
 Event signal emitted when the mouse entered this widget.
 
EventSignal< WMouseEvent > & mouseMoved ()
 Event signal emitted when the mouse moved over this widget.
 
EventSignal< WMouseEvent > & mouseDragged ()
 Event signal emitted when the mouse is dragged over this widget.
 
EventSignal< WMouseEvent > & mouseWheel ()
 Event signal emitted when the mouse scroll wheel was used.
 
EventSignal< WTouchEvent > & touchStarted ()
 Event signal emitted when a finger is placed on the screen.
 
EventSignal< WTouchEvent > & touchEnded ()
 Event signal emitted when a finger is removed from the screen.
 
EventSignal< WTouchEvent > & touchMoved ()
 Event signal emitted when a finger, which is already placed on the screen, is moved across the screen.
 
EventSignal< WGestureEvent > & gestureStarted ()
 Event signal emitted when a gesture is started.
 
EventSignal< WGestureEvent > & gestureChanged ()
 Event signal emitted when a gesture is changed.
 
EventSignal< WGestureEvent > & gestureEnded ()
 Event signal emitted when a gesture is ended.
 
void setDraggable (const std::string &mimeType, WWidget *dragWidget=nullptr, bool isDragWidgetOnly=false, WObject *sourceWidget=nullptr)
 Configure dragging for drag and drop.
 
void unsetDraggable ()
 Disable drag & drop for this widget.
 
void setMouseOverDelay (int delay)
 Sets a delay for the mouse over event.
 
int mouseOverDelay () const
 Returns the mouse over signal delay.
 
virtual void setPopup (bool popup) override
 Lets the widget overlay over other sibling widgets.
 
virtual void load () override
 Loads content just before the widget is used.
 
virtual bool isEnabled () const override
 Returns whether the widget is enabled.
 
- Public Member Functions inherited from Wt::WWebWidget
 WWebWidget ()
 Construct a WebWidget.
 
virtual std::vector< WWidget * > children () const override
 Returns child widgets.
 
SignalchildrenChanged ()
 Signal emitted when children have been added or removed.
 
virtual void setPositionScheme (PositionScheme scheme) override
 Sets the CSS position scheme.
 
virtual PositionScheme positionScheme () const override
 Returns the CSS position scheme.
 
virtual void setOffsets (const WLength &offset, WFlags< Side > sides=AllSides) override
 Sets CSS offsets for a non-statically positioned widget.
 
virtual WLength offset (Side s) const override
 Returns a CSS offset.
 
virtual WLength width () const override
 Returns the width.
 
virtual WLength height () const override
 Returns the height.
 
virtual void setMinimumSize (const WLength &width, const WLength &height) override
 Sets a minimum size.
 
virtual WLength minimumWidth () const override
 Returns the minimum width.
 
virtual WLength minimumHeight () const override
 Returns the minimum height.
 
virtual void setMaximumSize (const WLength &width, const WLength &height) override
 Sets a maximum size.
 
virtual WLength maximumWidth () const override
 Returns the maximum width.
 
virtual WLength maximumHeight () const override
 Returns the maximum height.
 
virtual void setLineHeight (const WLength &height) override
 Sets the CSS line height for contained text.
 
virtual WLength lineHeight () const override
 Returns the CSS line height for contained text.
 
virtual void setFloatSide (Side s) override
 Specifies a CSS float side.
 
virtual Side floatSide () const override
 Returns the CSS float side.
 
virtual void setClearSides (WFlags< Side > sides) override
 Sets the sides that should be cleared of floats.
 
virtual WFlags< SideclearSides () const override
 Returns the sides that should remain empty.
 
virtual void setMargin (const WLength &margin, WFlags< Side > sides=AllSides) override
 Sets CSS margins around the widget.
 
virtual WLength margin (Side side) const override
 Returns a CSS margin set.
 
virtual void setHiddenKeepsGeometry (bool enabled) override
 Sets whether the widget keeps its geometry when hidden.
 
virtual bool hiddenKeepsGeometry () const override
 Returns whether the widget keeps its geometry when hidden.
 
virtual void setHidden (bool hidden, const WAnimation &animation=WAnimation()) override
 Hides or shows the widget.
 
virtual bool isHidden () const override
 Returns whether the widget is set hidden.
 
virtual bool isVisible () const override
 Returns whether the widget is visible.
 
virtual void setDisabled (bool disabled) override
 Sets whether the widget is disabled.
 
virtual bool isDisabled () const override
 Returns whether the widget is set disabled.
 
virtual bool isPopup () const override
 Returns whether the widget is overlayed.
 
virtual void setInline (bool isInline) override
 Sets whether the widget is displayed inline or as a block.
 
virtual bool isInline () const override
 Returns whether the widget is displayed inline or as block.
 
virtual void setDecorationStyle (const WCssDecorationStyle &style) override
 Sets a CSS decoration style.
 
virtual WCssDecorationStyledecorationStyle () override
 Returns the decoration style of this widget.
 
virtual void setStyleClass (const WString &styleClass) override
 Sets (one or more) CSS style classes.
 
virtual WString styleClass () const override
 Returns the CSS style class.
 
virtual void addStyleClass (const WString &styleClass, bool force=false) override
 Adds a CSS style class.
 
virtual void removeStyleClass (const WString &styleClass, bool force=false) override
 Removes a CSS style class.
 
virtual bool hasStyleClass (const WString &styleClass) const override
 Returns whether the widget has a style class.
 
virtual void setVerticalAlignment (AlignmentFlag alignment, const WLength &length=WLength()) override
 Sets the vertical alignment.
 
virtual AlignmentFlag verticalAlignment () const override
 Returns the vertical alignment.
 
virtual WLength verticalAlignmentLength () const override
 Returns the fixed vertical alignment that was set.
 
virtual void setToolTip (const WString &text, TextFormat textFormat=TextFormat::Plain) override
 Sets a tooltip.
 
virtual void setDeferredToolTip (bool enable, TextFormat textFormat=TextFormat::Plain) override
 Enable deferred tooltip.
 
virtual WString toolTip () const override
 Returns the tooltip.
 
virtual void refresh () override
 Refresh the widget.
 
virtual void setAttributeValue (const std::string &name, const WString &value) override
 Sets an attribute value.
 
virtual WString attributeValue (const std::string &name) const override
 Returns an attribute value.
 
virtual void setJavaScriptMember (const std::string &name, const std::string &value) override
 Sets a JavaScript member.
 
virtual std::string javaScriptMember (const std::string &name) const override
 Returns the value of a JavaScript member.
 
virtual void callJavaScriptMember (const std::string &name, const std::string &args) override
 Calls a JavaScript member.
 
virtual bool loaded () const override
 Returns whether this widget has been loaded.
 
virtual void setId (const std::string &id) override
 Sets the CSS Id.
 
virtual WWidgetfind (const std::string &name) override
 Finds a descendent widget by name.
 
virtual WWidgetfindById (const std::string &id) override
 Finds a descendent widget by id.
 
virtual void setSelectable (bool selectable) override
 Sets as selectable.
 
virtual void doJavaScript (const std::string &javascript) override
 Executes the given JavaScript statements when the widget is rendered or updated.
 
virtual const std::string id () const override
 Returns the (unique) identifier for this object.
 
void setLoadLaterWhenInvisible (bool)
 Change the way the widget is loaded when invisible.
 
std::string htmlTagName () const
 returns the current html tag name
 
void setHtmlTagName (const std::string &tag)
 set the custom HTML tag name
 
virtual void setCanReceiveFocus (bool enabled) override
 Sets whether the widget can receive focus.
 
virtual bool canReceiveFocus () const override
 Returns whether the widget can receive focus.
 
virtual bool setFirstFocus () override
 Set focus on the widget's first descendant.
 
virtual void setFocus (bool focus) override
 Sets focus.
 
virtual bool hasFocus () const override
 Returns whether the widget currently has the focus.
 
virtual void setTabIndex (int index) override
 Sets the tab index.
 
virtual int tabIndex () const override
 Returns the tab index.
 
EventSignalblurred ()
 Signal emitted when the widget lost focus.
 
EventSignalfocussed ()
 Signal emitted when the widget recieved focus.
 
virtual bool scrollVisibilityEnabled () const final override
 Returns whether scroll visibility detection is enabled for this widget.
 
virtual void setScrollVisibilityEnabled (bool enabled) final override
 Sets whether scroll visibility detection is enabled for this widget.
 
virtual int scrollVisibilityMargin () const final override
 Returns the margin around the viewport within which the widget is considered visible.
 
virtual void setScrollVisibilityMargin (int margin) final override
 Sets the margin around the viewport within which the widget is considered visible.
 
virtual Signal< bool > & scrollVisibilityChanged () final override
 Signal triggered when the scroll visibility of this widget changes.
 
virtual bool isScrollVisible () const final override
 Returns whether this widget is currently considered scroll visible.
 
virtual void setThemeStyleEnabled (bool enabled) final override
 Sets whether theme styling for a widget is enabled or disabled.
 
virtual bool isThemeStyleEnabled () const final override
 Returns whether this widget is currently styled by the chosen theme.
 
virtual void setObjectName (const std::string &name) override
 Sets an object name.
 
void setFocus ()
 Sets focus.
 
virtual void setFocus (bool focus)=0
 Sets focus.
 
- Public Member Functions inherited from Wt::WWidget
virtual ~WWidget ()
 Destructor.
 
WWidgetparent () const
 Returns the parent widget.
 
virtual std::unique_ptr< WWidgetremoveWidget (WWidget *widget)
 Removes a child widget.
 
template<typename Widget >
std::unique_ptr< Widget > removeWidget (Widget *widget)
 Removes a child widget.
 
std::unique_ptr< WWidgetremoveFromParent ()
 Removes the widget from its parent.
 
void setWidth (const WLength &width)
 Sets the width.
 
void setHeight (const WLength &height)
 Sets the height.
 
virtual void positionAt (const WWidget *widget, Orientation orientation=Orientation::Vertical)
 Positions a widget next to another widget.
 
virtual void toggleStyleClass (const WString &styleClass, bool add, bool force=false)
 Toggles a CSS style class.
 
std::string jsRef () const
 Returns a JavaScript expression to the corresponding DOM node.
 
void setFocus ()
 Sets focus.
 
virtual void acceptDrops (const std::string &mimeType, const WString &hoverStyleClass=WString())
 Sets a mime type to be accepted for dropping.
 
virtual void stopAcceptDrops (const std::string &mimeType)
 Indicates that a mime type is no longer accepted for dropping.
 
virtual void htmlText (std::ostream &out)
 Streams the (X)HTML representation.
 
bool isRendered () const
 Returns whether the widget is rendered.
 
void hide ()
 Hides the widget.
 
void animateHide (const WAnimation &animation)
 Hides the widget using an animation.
 
void show ()
 Shows the widget.
 
void animateShow (const WAnimation &animation)
 Shows the widget using an animation.
 
void enable ()
 Enables the widget.
 
void disable ()
 Disable thes widget.
 
bool layoutSizeAware () const
 Returns whether the widget is layout size aware.
 
- Public Member Functions inherited from Wt::WObject
void addChild (std::unique_ptr< WObject > child)
 Add a child WObject whose lifetime is determined by this WObject.
 
template<typename Child >
ChildaddChild (std::unique_ptr< Child > child)
 Add a child WObject, returning a raw pointer.
 
std::unique_ptr< WObjectremoveChild (WObject *child)
 Remove a child WObject, so its lifetime is no longer determined by this WObject.
 
template<typename Child >
std::unique_ptr< ChildremoveChild (Child *child)
 Remove a child WObject, so its lifetime is no longer determined by this WObject.
 
virtual std::string objectName () const
 Returns the object name.
 
void resetLearnedSlots ()
 Resets learned stateless slot implementations.
 
template<class T >
void resetLearnedSlot (void(T::*method)())
 Resets a learned stateless slot implementation.
 
template<class T >
WStatelessSlot * implementStateless (void(T::*method)())
 Declares a slot to be stateless and learn client-side behaviour on first invocation.
 
template<class T >
WStatelessSlot * implementStateless (void(T::*method)(), void(T::*undoMethod)())
 Declares a slot to be stateless and learn client-side behaviour in advance.
 
void isNotStateless ()
 Marks the current function as not stateless.
 
template<class T >
WStatelessSlot * implementJavaScript (void(T::*method)(), const std::string &jsCode)
 Provides a JavaScript implementation for a method.
 
- Public Member Functions inherited from Wt::Core::observable
 observable () noexcept
 Default constructor.
 
virtual ~observable ()
 Destructor.
 
template<typename... Args, typename C >
auto bindSafe (void(C::*method)(Args...)) noexcept
 Protects a method call against object destruction.
 
template<typename... Args, typename C >
auto bindSafe (void(C::*method)(Args...) const) const noexcept
 Protects a const method call against object destruction.
 
template<typename Function >
auto bindSafe (const Function &function) noexcept
 Protects a function against object destruction.
 

Additional Inherited Members

- Public Types inherited from Wt::WAbstractMedia
typedef PlayerOption Option
 Typedef for enum Wt::PlayerOption.
 
typedef MediaPreloadMode PreloadMode
 Typedef for enum Wt::MediaPreloadMode.
 
typedef MediaReadyState ReadyState
 Typedef for enum Wt::MediaReadyState.
 
- Public Types inherited from Wt::WObject
typedef void(WObject::* Method) ()
 Typedef for a WObject method without arguments.
 
- Static Public Member Functions inherited from Wt::WWebWidget
static std::string jsStringLiteral (const std::string &v, char delimiter='\'')
 Turn a CharEncoding::UTF8 encoded string into a JavaScript string literal.
 
- Static Public Member Functions inherited from Wt::WWidget
static WString tr (const char *key)
 Short hand for WString::tr()
 
- Protected Member Functions inherited from Wt::WAbstractMedia
virtual void enableAjax () override
 Progresses to an Ajax-enabled widget.
 
- Protected Member Functions inherited from Wt::WInteractWidget
virtual void propagateSetEnabled (bool enabled) override
 Propagates that a widget was enabled or disabled through children.
 
- Protected Member Functions inherited from Wt::WWebWidget
virtual WStatelessSlot * getStateless (Method method) override
 On-demand stateless slot implementation.
 
virtual void render (WFlags< RenderFlag > flags) override
 Renders the widget.
 
- Protected Member Functions inherited from Wt::WWidget
void setLayoutSizeAware (bool sizeAware)
 Sets the widget to be aware of its size set by a layout manager.
 
virtual void layoutSizeChanged (int width, int height)
 Virtual method that indicates a size change.
 
 WWidget ()
 Creates a widget.
 
virtual void dropEvent (WDropEvent dropEvent)
 Handles a drop event.
 
virtual int boxPadding (Orientation orientation) const
 Returns the widget's built-in padding.
 
virtual int boxBorder (Orientation orientation) const
 Returns the widget's built-in border width.
 
void scheduleRender (WFlags< RepaintFlag > flags=None)
 Schedules rerendering of the widget.
 

Detailed Description

A video-playing widget.

This is a low-level widget, mapping directly onto a <video> element available in HTML5 compliant browsers.

In almost every situation you should use the WMediaPlayer widget instead, which has fallback and flexible user-interface options.

Usage of the video element consists of adding one or more video sources and setting some options. Since not every browser supports HTML5 video, the class provides a mechanism to display alternative content in browsers that cannot play the video.

Usage example:

WVideo *v = addWidget(std::make_unique<WVideo>());
v->setOptions(WVideo::Autoplay | WVideo::Controls);
// Addsources may be called multiple times for different formats:
// Firefox only plays ogg
v->addSource("wt.ogv");
// many others play mp4
v->addSource("wt.mp4", "video/mp4");
// Image to be displayed before playback starts
v->setPoster("wt.jpg");
// You may display a simple text to explain that you need html5 support...
// v->setAlternativeContent(new WText("You have no HTML5 Video!"));
// ... or provide an alternative player, e.g. Flash-based
auto f = std::make_unique<WFlashObject>("player.swf");
f->setFlashVariable("startimage", "wt.jpg");
f->setFlashVariable("flv", "wt.mp4");
f->resize(640, 384);
v->setAlternativeContent(std::move(f));
void setOptions(const WFlags< PlayerOption > &flags)
Set the media element options.
Definition WAbstractMedia.C:378
void setAlternativeContent(std::unique_ptr< WWidget > alternative)
Content to be shown when media cannot be played.
Definition WAbstractMedia.C:417
void addSource(const WLink &source, const std::string &type="", const std::string &media="")
Add a media source.
Definition WAbstractMedia.C:408
A video-playing widget.
Definition WVideo.h:65
void setPoster(const std::string &url)
Set the poster image.
Definition WVideo.C:55

There are two reasons why the a browser may use the alternative content: either because the browser does not support the HTML5 video tag (alternative content is displayed even when JavaScript is not available), or because none of the specified sources contain a video format that is understood by the browser (requires JavaScript to display the alternative content).

The addSource() and setAlternativeContent() may not be called after the widget is rendered.

See also
WMediaPlayer

Constructor & Destructor Documentation

◆ WVideo()

WVideo::WVideo ( )

Creates a video widget.

The constructor sets the 'controls' option, which causes the browser to display a bar with play/pauze/volume/... controls.

A freshly constructed video widget has no poster image, no media sources, has preload mode set to PreloadAuto, and only the Controls flag is set.

Member Function Documentation

◆ jsVideoRef()

std::string WVideo::jsVideoRef ( ) const

Returns the JavaScript reference to the video object, or null.

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

◆ resize()

void WVideo::resize ( const WLength width,
const WLength height 
)
overridevirtual

Resizes the widget.

Specifies a fixed size for this widget, setting CSS width and height properties. By default a widget has automatic width and height, which sets a size for the widget following CSS rules.

When the widget is not managed by a layout manager, the automatic (natural) size of a widget depends on whether they widget is a block or inline widget:

  • a block widget takes by default the width of the parent, and the height that it needs based on its contents
  • an inline widget takes the width and height that it needs based on its contents (possibly wrapping over multiple lines). The width and height of an inline widget cannot be changed (by the letter of CSS, although most browsers will react to it in varying ways).

When inserted in a layout manager, the size set will be used as a widget's preferred size, but the widget may be given a different size by the layout manager based on available space and stretch factors. The actual size given by a layout manager may be retrieved by making the widget "layout size aware", using setLayoutSizeAware(). If you have defined a "wtResize()" JavaScript method for the widget, then this method will also be called.

The default width and height of a widget is WLength::Auto.

See also
width(), height()

Reimplemented from Wt::WWebWidget.

◆ setPoster()

void WVideo::setPoster ( const std::string &  url)

Set the poster image.

On browsers that support it, the poster image is displayed before the video is playing. Some browsers display the first frame of the video stream once the video stream is loaded; it is therefore a good idea to include the poster image as first frame in the video feed too.