The abstract base class for a user-interface component. More...

#include <Wt/WWidget>

Inheritance diagram for Wt::WWidget:

[legend]

Public Member Functions
virtual	~WWidget ()
	Destructor. More...

WWidget *	parent () const
	Returns the parent widget. More...

virtual void	removeChild (WObject *child)
	Removes a child object. More...

virtual void	setPositionScheme (PositionScheme scheme)=0
	Sets the CSS position scheme. More...

virtual PositionScheme	positionScheme () const =0
	Returns the CSS position scheme. More...

virtual void	setOffsets (const WLength &offset, WFlags< Side > sides=All)=0
	Sets CSS offsets for a non-statically positioned widget. More...

virtual WLength	offset (Side side) const =0
	Returns a CSS offset. More...

virtual void	resize (const WLength &width, const WLength &height)
	Resizes the widget. More...

virtual WLength	width () const =0
	Returns the width. More...

void	setWidth (const WLength &width)
	Sets the width. More...

virtual WLength	height () const =0
	Returns the height. More...

void	setHeight (const WLength &height)
	Sets the height. More...

virtual void	setMinimumSize (const WLength &width, const WLength &height)=0
	Sets a minimum size. More...

virtual WLength	minimumWidth () const =0
	Returns the minimum width. More...

virtual WLength	minimumHeight () const =0
	Returns the minimum height. More...

virtual void	setMaximumSize (const WLength &width, const WLength &height)=0
	Sets a maximum size. More...

virtual WLength	maximumWidth () const =0
	Returns the maximum width. More...

virtual WLength	maximumHeight () const =0
	Returns the maximum height. More...

virtual void	positionAt (const WWidget *widget, Orientation orientation=Vertical)
	Positions a widget next to another widget. More...

virtual void	setLineHeight (const WLength &height)=0
	Sets the CSS line height for contained text.

virtual WLength	lineHeight () const =0
	Returns the CSS line height for contained text. More...

virtual void	setFloatSide (Side s)=0
	Specifies a CSS float side. More...

virtual Side	floatSide () const =0
	Returns the CSS float side. More...

virtual void	setClearSides (WFlags< Side > sides)=0
	Sets the sides that should be cleared of floats. More...

virtual WFlags< Side >	clearSides () const =0
	Returns the sides that should remain empty. More...

virtual void	setMargin (const WLength &margin, WFlags< Side > sides=All)=0
	Sets CSS margins around the widget. More...

virtual WLength	margin (Side side) const =0
	Returns a CSS margin set. More...

virtual void	setHiddenKeepsGeometry (bool enabled)=0
	Sets whether the widget keeps its geometry when hidden. More...

virtual bool	hiddenKeepsGeometry () const =0
	Returns whether the widget keeps its geometry when hidden. More...

virtual void	setHidden (bool hidden, const WAnimation &animation=WAnimation())=0
	Hides or shows the widget. More...

virtual bool	isHidden () const =0
	Returns whether the widget is set hidden. More...

virtual bool	isVisible () const =0
	Returns whether the widget is visible. More...

virtual void	setDisabled (bool disabled)=0
	Sets whether the widget is disabled. More...

virtual bool	isDisabled () const =0
	Returns whether the widget is set disabled. More...

virtual bool	isEnabled () const =0
	Returns whether the widget is enabled. More...

virtual void	setPopup (bool popup)=0
	Lets the widget overlay over other sibling widgets. More...

virtual bool	isPopup () const =0
	Returns whether the widget is overlayed. More...

virtual void	setInline (bool inlined)=0
	Sets whether the widget is displayed inline or as a block. More...

virtual bool	isInline () const =0
	Returns whether the widget is displayed inline or as block. More...

virtual void	setDecorationStyle (const WCssDecorationStyle &style)=0
	Sets a CSS decoration style. More...

virtual WCssDecorationStyle &	decorationStyle ()=0
	Returns the decoration style of this widget. More...

virtual void	setStyleClass (const WString &styleClass)=0
	Sets (one or more) CSS style classes. More...

virtual WString	styleClass () const =0
	Returns the CSS style class. More...

virtual void	addStyleClass (const WString &styleClass, bool force=false)=0
	Adds a CSS style class. More...

virtual void	removeStyleClass (const WString &styleClass, bool force=false)=0
	Removes a CSS style class. More...

virtual void	toggleStyleClass (const WString &styleClass, bool add, bool force=false)
	Toggles a CSS style class.

virtual bool	hasStyleClass (const WString &styleClass) const =0
	Returns whether the widget has a style class.

virtual void	setVerticalAlignment (AlignmentFlag alignment, const WLength &length=WLength::Auto)=0
	Sets the vertical alignment. More...

virtual AlignmentFlag	verticalAlignment () const =0
	Returns the vertical alignment. More...

virtual WLength	verticalAlignmentLength () const =0
	Returns the fixed vertical alignment that was set. More...

virtual void	setToolTip (const WString &text, TextFormat textFormat=PlainText)=0
	Sets a tooltip. More...

virtual WString	toolTip () const =0
	Returns the tooltip.

virtual void	setDeferredToolTip (bool enable, TextFormat textFormat=PlainText)=0
	Enable deferred tooltip. More...

virtual void	refresh ()
	Refresh the widget. More...

std::string	jsRef () const
	Returns a JavaScript expression to the corresponding DOM node. More...

virtual void	setAttributeValue (const std::string &name, const WString &value)=0
	Sets an attribute value. More...

virtual WString	attributeValue (const std::string &name) const =0
	Returns an attribute value. More...

virtual void	setJavaScriptMember (const std::string &name, const std::string &value)=0
	Sets a JavaScript member. More...

virtual std::string	javaScriptMember (const std::string &name) const =0
	Returns the value of a JavaScript member. More...

virtual void	callJavaScriptMember (const std::string &name, const std::string &args)=0
	Calls a JavaScript member. More...

virtual void	load ()=0
	Loads content just before the widget is used. More...

virtual bool	loaded () const =0
	Returns whether this widget has been loaded. More...

virtual void	setCanReceiveFocus (bool enabled)=0
	Sets whether the widget can receive focus. More...

virtual bool	canReceiveFocus () const =0
	Returns whether the widget can receive focus. More...

void	setFocus ()
	Sets focus. More...

virtual void	setFocus (bool focus)=0
	Sets focus. More...

virtual bool	setFirstFocus ()=0
	Set focus on the widget's first descendant. More...

virtual bool	hasFocus () const =0
	Returns whether the widget currently has the focus.

virtual void	setTabIndex (int index)=0
	Sets the tab index. More...

virtual int	tabIndex () const =0
	Returns the tab index. More...

virtual void	acceptDrops (const std::string &mimeType, const WString &hoverStyleClass=WString())
	Sets a mime type to be accepted for dropping. More...

virtual void	stopAcceptDrops (const std::string &mimeType)
	Indicates that a mime type is no longer accepted for dropping. More...

virtual void	setId (const std::string &id)=0
	Sets the CSS Id. More...

virtual WWidget *	find (const std::string &name)=0
	Finds a descendent widget by name. More...

virtual void	setObjectName (const std::string &name)
	Sets an object name. More...

virtual WWidget *	findById (const std::string &id)=0
	Finds a descendent widget by id.

virtual void	htmlText (std::ostream &out)
	Streams the (X)HTML representation. More...

virtual void	setSelectable (bool selectable)=0
	Sets as selectable. More...

virtual void	doJavaScript (const std::string &js)=0
	Executes the given JavaScript statements when the widget is rendered or updated. More...

bool	isRendered () const
	Returns whether the widget is rendered. More...

void	hide ()
	Hides the widget. More...

void	animateHide (const WAnimation &animation)
	Hides the widget using an animation. More...

void	show ()
	Shows the widget. More...

void	animateShow (const WAnimation &animation)
	Shows the widget using an animation. More...

void	enable ()
	Enables the widget. More...

void	disable ()
	Disable thes widget. More...

bool	layoutSizeAware () const
	Returns whether the widget is layout size aware. More...

virtual bool	scrollVisibilityEnabled () const =0
	Returns whether scroll visibility detection is enabled for this widget. More...

virtual void	setScrollVisibilityEnabled (bool enabled)=0
	Sets whether scroll visibility detection is enabled for this widget. More...

virtual int	scrollVisibilityMargin () const =0
	Returns the margin around the viewport within which the widget is considered visible. More...

virtual void	setScrollVisibilityMargin (int margin)=0
	Sets the margin around the viewport within which the widget is considered visible. More...

virtual Signal< bool > &	scrollVisibilityChanged ()=0
	Signal triggered when the scroll visibility of this widget changes. More...

virtual bool	isScrollVisible () const =0
	Returns whether this widget is currently considered scroll visible. More...

virtual void	setThemeStyleEnabled (bool enabled)=0
	Sets whether theme styling for a widget is enabled or disabled. More...

virtual bool	isThemeStyleEnabled () const =0
	Returns whether this widget is currently styled by the chosen theme. More...

Public Member Functions inherited from Wt::WObject
	WObject (WObject *parent=0)
	Create a WObject with a given parent object. More...

virtual	~WObject ()
	Destructor. More...

virtual const std::string	id () const
	Returns the (unique) identifier for this object. More...

virtual std::string	objectName () const
	Returns the object name. More...

void	resetLearnedSlots ()
	Resets learned stateless slot implementations. More...

template<class T >
void	resetLearnedSlot (void(T::*method)())
	Resets a learned stateless slot implementation. More...

template<class T >
WStatelessSlot *	implementStateless (void(T::*method)())
	Declares a slot to be stateless and learn client-side behaviour on first invocation. More...

template<class T >
WStatelessSlot *	implementStateless (void(T::method)(), void(T::undoMethod)())
	Declares a slot to be stateless and learn client-side behaviour in advance. More...

void	isNotStateless ()
	Marks the current function as not stateless. More...

template<class T >
WStatelessSlot *	implementJavaScript (void(T::*method)(), const std::string &jsCode)
	Provides a JavaScript implementation for a method. More...

void	addChild (WObject *child)
	Adds a child object. More...

const std::vector< WObject * > &	children () const
	Returns the children.

WObject *	parent () const
	Returns the parent object.

Static Public Member Functions
static WString	tr (const char *key)
	Short hand for WString::tr() More...

Protected Member Functions
void	setLayoutSizeAware (bool sizeAware)
	Sets the widget to be aware of its size set by a layout manager. More...

virtual void	layoutSizeChanged (int width, int height)
	Virtual method that indicates a size change. More...

	WWidget (WContainerWidget *parent=0)
	Creates a widget. More...

virtual void	dropEvent (WDropEvent dropEvent)
	Handles a drop event. More...

virtual void	enableAjax ()=0
	Progresses to an Ajax-enabled widget. More...

virtual int	boxPadding (Orientation orientation) const
	Returns the widget's built-in padding. More...

virtual int	boxBorder (Orientation orientation) const
	Returns the widget's built-in border width. More...

virtual void	propagateSetEnabled (bool enabled)=0
	Propagates that a widget was enabled or disabled through children. More...

void	scheduleRender (WFlags< RepaintFlag > flags=0)
	Schedules rerendering of the widget. More...

virtual void	render (WFlags< RenderFlag > flags)
	Renders the widget. More...

virtual WStatelessSlot *	getStateless (Method method)
	On-demand stateless slot implementation. More...

Additional Inherited Members
Public Types inherited from Wt::WObject
typedef void(WObject::*	Method) ()
	Typedef for a WObject method without arguments.

Static Protected Member Functions inherited from Wt::WObject
static WObject *	sender ()
	Returns the sender of the current slot call. More...

Detailed Description

The abstract base class for a user-interface component.

The user-interface is organized in a tree structure, in which each node is a widget. All widgets, except for the application's root widget and dialogs, have a parent which is usually a WContainerWidget.

When a widget is deleted, it is also visually removed from the user-interface and all children are deleted recursively.

This is an abstract base class. Implementations derive either from the abstract WWebWidget (for basic widgets with a direct HTML counter-part) or from the abstract WCompositeWidget (for anything else). To add a WWebWidget directly to a parent container, either specify the parent in the constructor (which is conventionally the last constructor argument), or add the widget to the parent using WContainerWidget::addWidget(). Alternatively, you may add the widget to a layout manager set for a WContainerWidget.

A widget provides methods to manage its decorative style base on CSS. It also provides access to CSS-based layout, which you may not use when the widget is not inserted into a layout manager.

Constructor & Destructor Documentation

◆ ~WWidget()

Wt::WWidget::~WWidget ( )

virtual

Destructor.

Deletes a widget and all children (recursively). If the widget is contained in another widget, it is removed first.

See also: WContainerWidget::removeWidget()

◆ WWidget()

Wt::WWidget::WWidget ( WContainerWidget * parent = 0 )

protected

Creates a widget.

When a parent container is specified, the widget is added to the container, using WContainerWidget::addWidget().

Member Function Documentation

◆ acceptDrops()

void Wt::WWidget::acceptDrops	(	const std::string &	mimeType,
		const WString &	hoverStyleClass = `WString()`
	)

virtual

Sets a mime type to be accepted for dropping.

You may specify a style class that is applied to the widget when the specified mimetype hovers on top of it.

See also: dropEvent(), WInteractWidget::setDraggable(), stopAcceptDrops()

◆ addStyleClass()

virtual void Wt::WWidget::addStyleClass	(	const WString &	styleClass,
		bool	force = `false`
	)

pure virtual

Adds a CSS style class.

When force = true, a JavaScript call will be used to add the style class to the DOM element (if JavaScript is available). This may be necessary when client-side JavaScript manipulates the same style class.

The styleClass should be a single class (although multiple classes will work for the common case that the additional style classes are all not yet present on the element.

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ animateHide()

void Wt::WWidget::animateHide ( const WAnimation & animation )

Hides the widget using an animation.

To hide the widget, the animation is replayed in reverse.

See also: setHidden()

◆ animateShow()

void Wt::WWidget::animateShow ( const WAnimation & animation )

Shows the widget using an animation.

See also: setHidden()

◆ attributeValue()

virtual WString Wt::WWidget::attributeValue ( const std::string & name ) const

pure virtual

Returns an attribute value.

See also: setAttributeValue()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ boxBorder()

int Wt::WWidget::boxBorder ( Orientation orientation ) const

protectedvirtual

Returns the widget's built-in border width.

This is used by the layout managers to correct for a built-in border which interferes with setting a widget's width (or height) to 100%.

A layout manager needs to set the width to 100% only for form widgets (WTextArea, WLineEdit, WComboBox, etc...). Therefore, only for those widgets this needs to return the border width (the default implementation returns 0).

For form widgets, the border width depends on the specific browser/platform combination, unless an explicit border is set for the widget.

When setting an explicit border for the widget using a style class, you will want to reimplement this method to return this border width, in case you want to set the widget inside a layout manager.

See also: boxPadding()

Reimplemented in Wt::WLineEdit, Wt::WTextEdit, Wt::WCompositeWidget, and Wt::WTextArea.

◆ boxPadding()

int Wt::WWidget::boxPadding ( Orientation orientation ) const

protectedvirtual

Returns the widget's built-in padding.

This is used by the layout managers to correct for a built-in padding which interferes with setting a widget's width (or height) to 100%.

A layout manager needs to set the width to 100% only for form widgets (WTextArea, WLineEdit, WComboBox, etc...). Therefore, only for those widgets this needs to return the padding (the default implementation returns 0).

For form widgets, the padding depends on the specific browser/platform combination, unless an explicit padding is set for the widget.

When setting an explicit padding for the widget using a style class, you will want to reimplement this method to return this padding in case you want to set the widget inside a layout manager.

See also: boxBorder()

Reimplemented in Wt::WLineEdit, Wt::WTextEdit, Wt::WCompositeWidget, Wt::WTextArea, and Wt::WAbstractSpinBox.

◆ callJavaScriptMember()

virtual void Wt::WWidget::callJavaScriptMember	(	const std::string &	name,
		const std::string &	args
	)

pure virtual

Calls a JavaScript member.

This calls a JavaScript member.

See also: setJavaScriptMember()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ canReceiveFocus()

virtual bool Wt::WWidget::canReceiveFocus ( ) const

pure virtual

Returns whether the widget can receive focus.

See also: setCanReceiveFocus()

Implemented in Wt::WAnchor, Wt::WWebWidget, Wt::WFormWidget, and Wt::WCompositeWidget.

◆ clearSides()

virtual WFlags<Side> Wt::WWidget::clearSides ( ) const

pure virtual

Returns the sides that should remain empty.

See also: setClearSides(WFlags<Side>)

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ decorationStyle()

virtual WCssDecorationStyle& Wt::WWidget::decorationStyle ( )

pure virtual

Returns the decoration style of this widget.

This groups all decorative aspects of the widget, which do not affect the widget layout (except for the border properties which may behave like extra margin around the widget).

When a decoration style has not been previously set, it returns a default decoration style object.

See also: setDecorationStyle()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ disable()

void Wt::WWidget::disable ( )

Disable thes widget.

This calls setDisabled(true).

◆ doJavaScript()

virtual void Wt::WWidget::doJavaScript ( const std::string & js )

pure virtual

Executes the given JavaScript statements when the widget is rendered or updated.

Calling WApplication::doJavaScript() with JavaScript code that refers to a widget using jsRef(), that is still to be rendered may cause JavaScript errors because the corresponding DOM node does not exist. This happens for example when a widget is created, but not yet inserted in the widget tree.

This method guarantees that the JavaScript code is only run when the corresponding DOM node (using jsRef()) resolves to a valid DOM object.

See also: jsRef()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ dropEvent()

void Wt::WWidget::dropEvent ( WDropEvent dropEvent )

protectedvirtual

Handles a drop event.

Reimplement this method to handle a drop events for mime types you declared to accept using acceptDrops.

The default implementation simply completes the drag and drop operation as if nothing happened.

See also: acceptDrops(), WInteractWidget::setDraggable()

◆ enable()

void Wt::WWidget::enable ( )

Enables the widget.

This calls setDisabled(false).

◆ enableAjax()

virtual void Wt::WWidget::enableAjax ( )

protectedpure virtual

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.

See also: WApplication::enableAjax()

Implemented in Wt::WTemplate, Wt::WMenuItem, Wt::WAnchor, Wt::WPushButton, Wt::WWebWidget, Wt::WCalendar, Wt::WFileUpload, Wt::WPaintedWidget, Wt::WTreeView, Wt::WFileDropWidget, Wt::WSlider, Wt::WAbstractMedia, Wt::WFormWidget, Wt::WCompositeWidget, and Wt::WTableView.

◆ find()

virtual WWidget* Wt::WWidget::find ( const std::string & name )

pure virtual

Finds a descendent widget by name.

See also: setObjectName()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ floatSide()

virtual Side Wt::WWidget::floatSide ( ) const

pure virtual

Returns the CSS float side.

See also: setFloatSide(Side)

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ getStateless()

WStatelessSlot * Wt::WWidget::getStateless ( Method method )

protectedvirtual

On-demand stateless slot implementation.

This method returns a stateless slot implementation for the given method. To avoid the cost of declaring methods to be stateless when they are not used, you may reimplement this method to provide a stateless implementation for a method only when the method is involved in a slot connection.

Use implementStateless() to provide a stateless implementation of the given method, or return the base class implementation otherwise.

Reimplemented from Wt::WObject.

Reimplemented in Wt::WWebWidget, and Wt::WAbstractToggleButton.

◆ height()

virtual WLength Wt::WWidget::height ( ) const

pure virtual

Returns the height.

Returns the height set for this widget. This is not a calculated height, based on layout, but the height as specified previously with resize(const WLength& width, const WLength& height).

This applies to CSS-based layout.

See also: resize(const WLength&, const WLength&), width()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ hiddenKeepsGeometry()

virtual bool Wt::WWidget::hiddenKeepsGeometry ( ) const

pure virtual

Returns whether the widget keeps its geometry when hidden.

See also: setHiddenKeepsGeometry()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ hide()

void Wt::WWidget::hide ( )

Hides the widget.

See also: setHidden()

◆ htmlText()

void Wt::WWidget::htmlText ( std::ostream & out )

virtual

Streams the (X)HTML representation.

Streams the widget as UTF8-encoded (HTML-compatible) XHTML.

This may be useful as a debugging tool for the web-savvy, or in other rare situations. Usually, you will not deal directly with HTML, and calling this method on a widget that is rendered may interfere with the library keeping track of changes to the widget.

◆ isDisabled()

virtual bool Wt::WWidget::isDisabled ( ) const

pure virtual

Returns whether the widget is set disabled.

A widget that is not set disabled may still be disabled when one of its ancestor widgets is set disabled. Use isEnabled() to find out whether a widget is enabled.

See also: setDisabled(), isEnabled()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ isEnabled()

virtual bool Wt::WWidget::isEnabled ( ) const

pure virtual

Returns whether the widget is enabled.

A widget is enabled if it is not disabled, and none of its ancestors are disabled. This method returns whether the widget is rendered as enabled, while isDisabled() returns whether a widget has been explicitly disabled.

Note that a widget may be at the same time not enabled, and not disabled, in case one of its ancestors was disabled.

See also: isDisabled()

Implemented in Wt::WInteractWidget, Wt::WWebWidget, and Wt::WCompositeWidget.

◆ isHidden()

virtual bool Wt::WWidget::isHidden ( ) const

pure virtual

Returns whether the widget is set hidden.

A widget that is not hidden may still be not visible when one of its ancestor widgets is hidden. Use isVisible() to check the visibility of a widget.

See also: setHidden(), isVisible()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ isInline()

virtual bool Wt::WWidget::isInline ( ) const

pure virtual

Returns whether the widget is displayed inline or as block.

See also: setInline(bool)

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ isPopup()

virtual bool Wt::WWidget::isPopup ( ) const

pure virtual

Returns whether the widget is overlayed.

This applies to CSS-based layout.

See also: setPopup(bool)

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ isRendered()

bool Wt::WWidget::isRendered ( ) const

Returns whether the widget is rendered.

See also: jsRef()

◆ isScrollVisible()

virtual bool Wt::WWidget::isScrollVisible ( ) const

pure virtual

Returns whether this widget is currently considered scroll visible.

isScrollVisible() is initially false.

See also: setScrollVisibilityEnabled()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ isThemeStyleEnabled()

virtual bool Wt::WWidget::isThemeStyleEnabled ( ) const

pure virtual

Returns whether this widget is currently styled by the chosen theme.

isThemeEnabled() is initially true.

See also: setThemeStyleEnabled()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ isVisible()

virtual bool Wt::WWidget::isVisible ( ) const

pure virtual

Returns whether the widget is visible.

A widget is visible if it is not hidden, and none of its ancestors are hidden. This method returns the true visibility, while isHidden() returns whether a widget has been explicitly hidden.

Note that a widget may be at the same time not hidden, and not visible, in case one of its ancestors was hidden.

See also: isHidden()

Implemented in Wt::WWebWidget, Wt::WCompositeWidget, and Wt::WTableCell.

◆ javaScriptMember()

virtual std::string Wt::WWidget::javaScriptMember ( const std::string & name ) const

pure virtual

Returns the value of a JavaScript member.

See also: setJavaScriptMember()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ jsRef()

std::string Wt::WWidget::jsRef ( ) const

Returns a JavaScript expression to the corresponding DOM node.

You may want to use this in conjunction with JSlot or doJavaScript() in custom JavaScript code.

See also: isRendered()

◆ layoutSizeAware()

bool Wt::WWidget::layoutSizeAware ( ) const

Returns whether the widget is layout size aware.

See also: setLayoutSizeAware()

◆ layoutSizeChanged()

void Wt::WWidget::layoutSizeChanged	(	int	width,
		int	height
	)

protectedvirtual

Virtual method that indicates a size change.

This method propagates the client-side width and height of the widget when the widget is contained by a layout manager and setLayoutSizeAware(true) was called.

See also: setLayoutSizeAware()

Reimplemented in Wt::WGLWidget, Wt::WPaintedWidget, and Wt::WSlider.

◆ lineHeight()

virtual WLength Wt::WWidget::lineHeight ( ) const

pure virtual

Returns the CSS line height for contained text.

sa setLineHeight()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ load()

virtual void Wt::WWidget::load ( )

pure virtual

Loads content just before the widget is used.

This method is called after a widget is inserted in the widget hierarchy and fully constructed, but before the widget is rendered. Widgets that get inserted in the widget hierarchy will be rendered. Visible widgets are rendered immediately, and invisible widgets in the back-ground (or not for a plain HTML session). This method is called when the widget is directly or indirectly inserted into the widget tree.

The default implementation simply propagates the load signal to its children. You may want to override this method to delay loading of resource-intensive contents.

During the life-time of a widget, this method may be called multiple times, so you should make sure that you do a deferred initializiation only once.

Implemented in Wt::WMenu, Wt::WInteractWidget, Wt::WCalendar, Wt::WWebWidget, Wt::WCompositeWidget, Wt::WDateEdit, Wt::WTimeEdit, and Wt::WViewWidget.

◆ loaded()

virtual bool Wt::WWidget::loaded ( ) const

pure virtual

Returns whether this widget has been loaded.

See also: load()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ margin()

virtual WLength Wt::WWidget::margin ( Side side ) const

pure virtual

Returns a CSS margin set.

This applies to CSS-based layout.

See also: setMargin()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ maximumHeight()

virtual WLength Wt::WWidget::maximumHeight ( ) const

pure virtual

Returns the maximum height.

Returns the minmum height set for this widget with setMaximumSize().

See also: setMaximumSize(), maximumWidth()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ maximumWidth()

virtual WLength Wt::WWidget::maximumWidth ( ) const

pure virtual

Returns the maximum width.

Returns the maximum width set for this widget with setMaximumSize().

See also: setMaximumSize(), maximumHeight()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ minimumHeight()

virtual WLength Wt::WWidget::minimumHeight ( ) const

pure virtual

Returns the minimum height.

Returns the minmum height set for this widget with setMinimumSize().

See also: setMinimumSize(), minimumWidth()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ minimumWidth()

virtual WLength Wt::WWidget::minimumWidth ( ) const

pure virtual

Returns the minimum width.

Returns the minimum width set for this widget with setMinimumSize().

See also: setMinimumSize(), minimumHeight()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ offset()

virtual WLength Wt::WWidget::offset ( Side side ) const

pure virtual

Returns a CSS offset.

This applies to CSS-based layout.

See also: setOffsets(const WLength&, WFlags<Side>)

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ parent()

WWidget* Wt::WWidget::parent ( ) const

Returns the parent widget.

With a few exceptions, the parent is a WContainerWidget, and has been set implicitly when adding the widget to a container using WContainerWidget::addWidget(), by passing a container as a parent to the constructor, or by inserting the widget into a layout manager.

◆ positionAt()

void Wt::WWidget::positionAt	(	const WWidget *	widget,
		Orientation	orientation = `Vertical`
	)

virtual

Positions a widget next to another widget.

Positions this absolutely positioned widget next to another widget. Both widgets must be visible (including all their ancestors). The current widget is shown automatically if needed.

When orientation = Wt::Vertical, the widget is displayed below the other widget (or above in case there is not enough room below). It is aligned so that the left edges align (or the right edges if there is not enough room to the right).

Conversely, when orientation = Wt::Horizontal, the widget is displayed to the right of the other widget (or to the left in case there is not enough room to the right). It is aligned so that the top edges align (or the bottom edges if there is not enough room below).

Note: This only works if JavaScript is available.

Reimplemented in Wt::WDialog.

◆ positionScheme()

virtual PositionScheme Wt::WWidget::positionScheme ( ) const

pure virtual

Returns the CSS position scheme.

This applies to CSS-based layout.

See also: Wt::PositionScheme, setPositionScheme(PositionScheme)

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ propagateSetEnabled()

virtual void Wt::WWidget::propagateSetEnabled ( bool enabled )

protectedpure virtual

Propagates that a widget was enabled or disabled through children.

When enabling or disabling a widget, you usually also want to disable contained children. This method is called by setDisabled() to propagate its state to all children.

You may want to reimplement this method if they wish to render differently when a widget is disabled. The default implementation will propagate the signal to all children.

Implemented in Wt::WFileUpload, Wt::WAnchor, Wt::WInteractWidget, Wt::WPushButton, Wt::WWebWidget, Wt::WTextEdit, Wt::WFormWidget, Wt::WLabel, Wt::WCompositeWidget, Wt::WDateEdit, Wt::WTimeEdit, and Wt::Ext::Component.

◆ refresh()

void Wt::WWidget::refresh ( )

virtual

Refresh the widget.

The refresh method is invoked when the locale is changed using WApplication::setLocale() or when the user hit the refresh button.

The widget must actualize its contents in response.

Note: This does *not* rerender the widget! Calling refresh() usually does not have any effect (unless you've reimplemented refresh() to attach to it an effect).

Reimplemented in Wt::WTemplate, Wt::WMediaPlayer, Wt::Ext::TableView, Wt::WPushButton, Wt::Ext::Panel, Wt::WText, Wt::WComboBox, Wt::Ext::ComboBox, Wt::Ext::MessageBox, Wt::WFormWidget, Wt::Ext::TabWidget, Wt::WAbstractToggleButton, Wt::WWebWidget, Wt::WDateEdit, Wt::WCompositeWidget, Wt::WDoubleSpinBox, Wt::WViewWidget, Wt::Ext::AbstractButton, Wt::WGroupBox, Wt::WAbstractSpinBox, and Wt::Ext::FormField.

◆ removeChild()

void Wt::WWidget::removeChild ( WObject * child )

virtual

Removes a child object.

The child must have been previously added.

See also: addChild()

Reimplemented from Wt::WObject.

◆ removeStyleClass()

virtual void Wt::WWidget::removeStyleClass	(	const WString &	styleClass,
		bool	force = `false`
	)

pure virtual

Removes a CSS style class.

When force = true, a JavaScript call will be used to remove the style class from the DOM element (if JavaScript is available). This may be necessary when client-side JavaScript manipulates the same style class.

The styleClass should be a single class

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ render()

void Wt::WWidget::render ( WFlags< RenderFlag > flags )

protectedvirtual

Renders the widget.

This function renders the widget (or an update for the widget), after this has been scheduled using scheduleRender().

The default implementation will render the widget by serializing changes to JavaScript and HTML. You may want to reimplement this widget if you have been postponing some of the layout / rendering implementation until the latest moment possible. In that case you should make sure you call the base implementation however.

Reimplemented in Wt::WGLWidget, Wt::Chart::WCartesianChart, Wt::WMenu, Wt::WSuggestionPopup, Wt::WMediaPlayer, Wt::WDialog, Wt::WMenuItem, Wt::WLineEdit, Wt::WWebWidget, Wt::WLeafletMap, Wt::Auth::AuthWidget, Wt::WPaintedWidget, Wt::WCalendar, Wt::WGoogleMap, Wt::WText, Wt::WSlider, Wt::WTreeView, Wt::WImage, Wt::WPopupMenu, Wt::WFormWidget, Wt::WDatePicker, Wt::WCompositeWidget, Wt::WInPlaceEdit, Wt::WTableView, Wt::WTreeTable, Wt::Chart::WAxisSliderWidget, Wt::WDateEdit, Wt::WDoubleSpinBox, Wt::WTimeEdit, Wt::WStackedWidget, Wt::WViewWidget, Wt::WPopupWidget, Wt::Ext::FormField, Wt::WAbstractSpinBox, and Wt::Auth::RegistrationWidget.

◆ resize()

void Wt::WWidget::resize	(	const WLength &	width,
		const WLength &	height
	)

virtual

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 in Wt::WGLWidget, Wt::Chart::WCartesian3DChart, Wt::WSlider, Wt::WTextEdit, Wt::WTreeView, Wt::WPaintedWidget, Wt::WProgressBar, Wt::WTableView, Wt::WVideo, Wt::WWebWidget, Wt::Ext::TextEdit, Wt::WCompositeWidget, and Wt::WFlashObject.

◆ scheduleRender()

void Wt::WWidget::scheduleRender ( WFlags< RepaintFlag > flags = 0 )

protected

Schedules rerendering of the widget.

This schedules a rendering phase after all events have been processed. This method is used internally whenever a property of a widget has been changed. But you may want to use this if you are deferring actual changes to a widget in response to an event, and instead postpone this until all events have been received.

See also: render()

◆ scrollVisibilityChanged()

virtual Signal<bool>& Wt::WWidget::scrollVisibilityChanged ( )

pure virtual

Signal triggered when the scroll visibility of this widget changes.

The boolean parameter indicates whether the widget is currently scroll visible.

See also: setScrollVisibilityEnabled()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ scrollVisibilityEnabled()

virtual bool Wt::WWidget::scrollVisibilityEnabled ( ) const

pure virtual

Returns whether scroll visibility detection is enabled for this widget.

See also: setScrollVisibilityEnabled()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ scrollVisibilityMargin()

virtual int Wt::WWidget::scrollVisibilityMargin ( ) const

pure virtual

Returns the margin around the viewport within which the widget is considered visible.

See also: setScrollVisibilityMargin()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setAttributeValue()

virtual void Wt::WWidget::setAttributeValue	(	const std::string &	name,
		const WString &	value
	)

pure virtual

Sets an attribute value.

Sets the value for an HTML attribute.

This is only useful for HTML features that are not supported directly in Wt (and beware that browsers have non-consistent support for many more exotic HTML features).

See also: JSlot, doJavaScript()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setCanReceiveFocus()

virtual void Wt::WWidget::setCanReceiveFocus ( bool enabled )

pure virtual

Sets whether the widget can receive focus.

By default, only form widgets (descendants of WFormWidget), anchors (WAnchor) and buttons (WPushButton) can receive focus.

Any other widget can be configured to receive focus however.

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setClearSides()

virtual void Wt::WWidget::setClearSides ( WFlags< Side > sides )

pure virtual

Sets the sides that should be cleared of floats.

This pushes the widget down until it is not surrounded by floats at the sides (which may be a combination of Wt::Left and Wt::Right).

This applies to CSS-based layout.

See also: setFloatSide()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setDecorationStyle()

virtual void Wt::WWidget::setDecorationStyle ( const WCssDecorationStyle & style )

pure virtual

Sets a CSS decoration style.

This copies the style over its current decorationStyle()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setDeferredToolTip()

virtual void Wt::WWidget::setDeferredToolTip	(	bool	enable,
		TextFormat	textFormat = `PlainText`
	)

pure virtual

Enable deferred tooltip.

You may override toolTip() to read data only when the user hovers over the widget.

When textFormat is XHTMLText, the tooltip may contain any valid XHTML snippet. The tooltip will then be rendered using JavaScript.

Note: To change existing toolTip call setDeferredToolTip() again.

See also: toolTip

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setDisabled()

virtual void Wt::WWidget::setDisabled ( bool disabled )

pure virtual

Sets whether the widget is disabled.

Enables or disables the widget (including all its descendant widgets). setDisabled(false) will enable this widget and all descendant widgets that are not disabled. A widget is only enabled if it and all its ancestors in the widget tree are disabled.

Typically, a disabled form widget will not allow changing the value, and disabled widgets will not react to mouse click events.

Note: enable() and disable() are considered to be stateless slots by default. If you override setDisabled() and need to modify server state whenever it is called, you'll need to call WObject::isNotStateless().

See also: disable(), enable()

Implemented in Wt::WMenuItem, Wt::WSlider, Wt::WDatePicker, Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setFirstFocus()

virtual bool Wt::WWidget::setFirstFocus ( )

pure virtual

Set focus on the widget's first descendant.

Set focus on the widget itself, or on a first descendant which can receive focus.

Returns whether focus could be set.

Implemented in Wt::WAnchor, Wt::WPushButton, Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setFloatSide()

virtual void Wt::WWidget::setFloatSide ( Side s )

pure virtual

Specifies a CSS float side.

This only applies to widgets with a Wt::Static positionScheme().

This lets the widget float to one of the sides of the parent widget, at the current line. A typical use is to position images within text. Valid values for Side or Wt::Nonejava {javadoclink Side::None None} , Wt::Left or Wt::Right.

This applies to CSS-based layout.

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setFocus() [1/2]

void Wt::WWidget::setFocus ( )

Sets focus.

This only has an effect for a widget which can receive focus, and is equivalent to setFocus(true).

See also: setCanReceiveFocus()

◆ setFocus() [2/2]

virtual void Wt::WWidget::setFocus ( bool focus )

pure virtual

Sets focus.

When using focus = false, you can undo a previous setFocus() call.

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setHeight()

void Wt::WWidget::setHeight ( const WLength & height )

Sets the height.

This is a convenience method to change only the width of a widget, and is implemented as:

resize(width(), height)

This applies to CSS-based layout.

See also: resize(), setWidth()

◆ setHidden()

virtual void Wt::WWidget::setHidden	(	bool	hidden,
		const WAnimation &	animation = `WAnimation()`
	)

pure virtual

Hides or shows the widget.

Hides or show the widget (including all its descendant widgets). When setting hidden = false, this widget and all descendant widgets that are not hidden will be shown. A widget is only visible if it and all its ancestors in the widget tree are visible, which may be checked using isVisible().

Note: hide() and show() are considered to be stateless slots by default. If you override setHidden() and need to modify server state whenever it is called, you'll need to call WObject::isNotStateless().

Implemented in Wt::WMenuItem, Wt::WDialog, Wt::WMessageBox, Wt::WPopupMenu, Wt::Ext::MessageBox, Wt::WDatePicker, Wt::Ext::Dialog, Wt::WTableView, Wt::WDateEdit, Wt::WWebWidget, Wt::WPopupWidget, Wt::WCompositeWidget, Wt::WTimeEdit, Wt::WFormWidget, and Wt::Ext::Widget.

◆ setHiddenKeepsGeometry()

virtual void Wt::WWidget::setHiddenKeepsGeometry ( bool enabled )

pure virtual

Sets whether the widget keeps its geometry when hidden.

Normally, a widget that is hidden will no longer occupy space, causing a reflow of sibling widgets. Using this method you may change this behavior to keep an (open) space when hidden.

Note: Currently you can only set this before initial rendering.

See also: setHidden()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setId()

virtual void Wt::WWidget::setId ( const std::string & id )

pure virtual

Sets the CSS Id.

Sets a custom Id. Note that the Id must be unique across the whole widget tree, can only be set right after construction and cannot be changed. This is mostly useful for in tests using a test plan that manipulates DOM elements by Id.

By default, auto-generated id's are used.

Note: An id must start with a letter ([A-Za-z]), followed by one or more letters, digits ([0-9]), hyphens ("-"), underscores ("_"), colons (":"), and periods (".").

See also: WObject::id()

Implemented in Wt::WTreeView, Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setInline()

virtual void Wt::WWidget::setInline ( bool inlined )

pure virtual

Sets whether the widget is displayed inline or as a block.

This option changes whether this widget must be rendered in line with sibling widgets wrapping at the right edge of the parent container (like text), or whether this widget must be rendered as a rectangular block that stacks vertically with sibling widgets (unless a CSS float property is applied). Depending on the widget type, the default value is inline (such as for example for WText, or WPushButton), or block (such as for example for a WContainerWidget).

This applies to CSS-based layout.

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setJavaScriptMember()

virtual void Wt::WWidget::setJavaScriptMember	(	const std::string &	name,
		const std::string &	value
	)

pure virtual

Sets a JavaScript member.

This binds a JavaScript member, which is set as a JavaScript property to the DOM object that implements this widget. The value may be any JavaScript expression, including a function.

Members that start with "wt" are reserved for internal use. You may define a member "wtResize(self, width, height)" method if your widget needs active layout management. If defined, this method will be used by layout managers and when doing resize() to set the size of the widget, instead of setting the CSS width and height properties.

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setLayoutSizeAware()

void Wt::WWidget::setLayoutSizeAware ( bool sizeAware )

protected

Sets the widget to be aware of its size set by a layout manager.

When the widget is inserted in a layout manager, it will be resized to fit within the constraints imposed by the layout manager. By default, this done client-side only by setting the CSS height (and if needed, width) properties of the DOM element corresponding to the widget.

A widget may define a JavaScript method, "wtResize(self, width, height)", to actively manage its client-side width and height, if it wants to react to these client-side size hints in a custom way (see setJavaScriptMember()).

By setting sizeAware to true, the widget will propagate the width and height provided by the layout manager to the virtual layoutSizeChanged() method, so that you may for example change the size of contained children in a particular way (doing a custom, manual, layout).

See also: layoutSizeChanged()

◆ setMargin()

virtual void Wt::WWidget::setMargin	(	const WLength &	margin,
		WFlags< Side >	sides = `All`
	)

pure virtual

Sets CSS margins around the widget.

Setting margin has the effect of adding a distance between the widget and surrounding widgets. The default margin (with an automatic length) is zero.

Use any combination of Wt::Left, Wt::Right, Wt::Bottom, or Wt::Top.

This applies to CSS-based layout.

See also: margin()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setMaximumSize()

virtual void Wt::WWidget::setMaximumSize	(	const WLength &	width,
		const WLength &	height
	)

pure virtual

Sets a maximum size.

Specifies a maximum size for this widget, setting CSS max-width and max-height properties.

The default the maximum width and height are WLength::Auto, indicating no maximum size. A WLength::Percentage size should not be used, as this is (in virtually all cases) undefined behaviour.

When the widget is a container widget that contains a layout manager, then setting a maximum size will have the effect of letting the size of the container to reflect the preferred size of the contents (rather than constraining the size of the children based on the size of the container), up to the specified maximum size.

See also: resize(), setMinimumSize()

Implemented in Wt::WDialog, Wt::WPopupMenu, Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setMinimumSize()

virtual void Wt::WWidget::setMinimumSize	(	const WLength &	width,
		const WLength &	height
	)

pure virtual

Sets a minimum size.

Specifies a minimum size for this widget, setting CSS min-width and min-height properties.

The default minimum width and height is 0. The special value WLength::Auto indicates that the initial width is used as minimum size. A WLength::Percentage size should not be used, as this is (in virtually all cases) undefined behaviour.

When the widget is inserted in a layout manager, then the minimum size will be taken into account.

See also: resize(), minimumWidth(), minimumHeight()

Implemented in Wt::WDialog, Wt::WPopupMenu, Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setObjectName()

void Wt::WWidget::setObjectName ( const std::string & name )

virtual

Sets an object name.

The object name can be used to easily identify a type of object in the DOM, and does not need to be unique. It will usually reflect the widget type or role. The object name is prepended to the auto-generated object id().

The default object name is empty.

Note: Only letters ([A-Za-z]), digits ([0-9]), hyphens ("-"), underscores ("_"), colons (":"), and periods (".") are allowed in the id.

See also: id()

Reimplemented from Wt::WObject.

Reimplemented in Wt::WAbstractItemView, Wt::WTreeView, and Wt::WCompositeWidget.

◆ setOffsets()

virtual void Wt::WWidget::setOffsets	(	const WLength &	offset,
		WFlags< Side >	sides = `All`
	)

pure virtual

Sets CSS offsets for a non-statically positioned widget.

The argument sides may be a combination of Wt::Left, Wt::Right, Wt::Top, and Wt::Bottom.

This applies only to widgets that have a position scheme that is Wt::Relative, Wt::Absolute, or Wt::Fixed, and has a slightly different meaning for these three cases.

For a relatively positioned widget, an offset applies relative to the position the widget would have when layed-out using a static position scheme. The widget may be shifted to the left or right by specifying an offset for the left or right) side. The widget may be shifted vertically, by specifying an offset for the top or bottom side.

For an absolutely positioned widget, an offset specifies a distance of the corresponding side of the widget with respect to the corresponding side of the reference parent widget. Thus, setting all offsets to 0 result in a widget that spans the entire reference widget. The reference parent widget is the first ancestor widget that is a table cell, or a widget with a relative, absolute or fixed position scheme.

For an fixed positioned widget, an offset specifies a distance of the corresponding side of the widget with respect to the browser window, regardless of scrolling. Thus, setting all offsets to 0 result in a widget that spans the entire browser window.

This applies to CSS-based layout.

See also: offset(Side) const

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setPopup()

virtual void Wt::WWidget::setPopup ( bool popup )

pure virtual

Lets the widget overlay over other sibling widgets.

A widget that isPopup() will be rendered on top of any other sibling widget contained within the same parent (including other popup widgets previously added to the container).

This will only have an effect when the widgetis either Wt::Absolute or Wt::Fixed positionScheme().

This applies to CSS-based layout, and configures the z-index property.

Implemented in Wt::WInteractWidget, Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setPositionScheme()

virtual void Wt::WWidget::setPositionScheme ( PositionScheme scheme )

pure virtual

Sets the CSS position scheme.

Establishes how the widget must be layed-out relative to its siblings. The default position scheme is Static.

This applies to CSS-based layout.

See also: Wt::PositionScheme, positionScheme()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setScrollVisibilityEnabled()

virtual void Wt::WWidget::setScrollVisibilityEnabled ( bool enabled )

pure virtual

Sets whether scroll visibility detection is enabled for this widget.

Disabled by default. When enabled, the client keeps track of whether this widget is currently visible inside of the browser window. A widget is "scroll visible" if it is currently visible according to isVisible(), and its position is inside of the browser window, with an extra margin determined by scrollVisibilityMargin().

If scroll visibility changes, the scrollVisibilityChanged() signal is fired, and isScrollVisible() is updated.

This feature can be useful to implement infinite scroll, where a sentinel widget placed at the bottom of the page causes more content to be loaded when it becomes visible, see the infinite-scroll example.

This feature can also be used to lazy load widgets when they become visible.

Note: If the widget is "scroll visible" when scroll visibility detection is first enabled, the scrollVisibilityChanged() signal will be emitted. If it is outside of the browser's viewport when first enabled, the scrollVisibilityChanged() signal will not be emitted.; If scroll visibility is enabled, disabled, and then enabled again, isScrollVisible() may not be correctly updated, and scrollVisibilityChanged() may not be correctly emitted, because then Wt can't properly keep track of the state that the widget is in on the client side. This feature is not intended to be toggled on and off, but rather enabled once and disabled once after that.

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setScrollVisibilityMargin()

virtual void Wt::WWidget::setScrollVisibilityMargin ( int margin )

pure virtual

Sets the margin around the viewport within which the widget is considered visible.

This causes the widget to be considered "scroll visible" before it is within the viewport. Setting this margin could be useful to trigger the loading of content before it is in view.

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setSelectable()

virtual void Wt::WWidget::setSelectable ( bool selectable )

pure virtual

Sets as selectable.

When a widget is made unselectable, a selection of text (or images) will not be visible (but may still be possible).

By default, the widget inherits this property from its parent, and this property propagates to all children. The top level container (WApplication::root()) selectable by default.

Implemented in Wt::WMenuItem, Wt::WTreeNode, Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setStyleClass()

virtual void Wt::WWidget::setStyleClass ( const WString & styleClass )

pure virtual

Sets (one or more) CSS style classes.

You may set one or more space separated style classes. CSS style class works in conjunction with style sheet, and provides a flexible way to provide many widgets the same markup.

Setting an empty string removes the style class(es).

See also: WApplication::styleSheet()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setTabIndex()

virtual void Wt::WWidget::setTabIndex ( int index )

pure virtual

Sets the tab index.

For widgets that receive focus (canReceiveFocus()), focus is passed on to the next widget in the tabbing chain based on their tab index. When the user navigates through form widgets using the keyboard, widgets receive focus starting from the element with the lowest tab index to elements with the highest tab index.

Widgets with a same tab index will receive focus in the same order as they are inserted in the widget tree.

The default tab index is 0 (for a widget that can receive focus).

See also: setTabOrder()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setThemeStyleEnabled()

virtual void Wt::WWidget::setThemeStyleEnabled ( bool enabled )

pure virtual

Sets whether theme styling for a widget is enabled or disabled.

By default all widgets are styled according to the chosen theme. Disabling the theme style could be useful to completely customize the style of the widget outside of the theme.

Note: This should be changed after the construction but before the rendering of the widget.

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setToolTip()

virtual void Wt::WWidget::setToolTip	(	const WString &	text,
		TextFormat	textFormat = `PlainText`
	)

pure virtual

Sets a tooltip.

The tooltip is displayed when the cursor hovers over the widget.

When textFormat is XHTMLText, the tooltip may contain any valid XHTML snippet. The tooltip will then be rendered using JavaScript.

Note: This will set deferred tooltip to false.

See also: setDeferredTooltip()

Implemented in Wt::WFormWidget, Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setVerticalAlignment()

virtual void Wt::WWidget::setVerticalAlignment	(	AlignmentFlag	alignment,
		const WLength &	length = `WLength::Auto`
	)

pure virtual

Sets the vertical alignment.

This only applies to inline widgets, and determines how to position itself on the current line, with respect to sibling inline widgets.

This applies to CSS-based layout.

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ setWidth()

void Wt::WWidget::setWidth ( const WLength & width )

Sets the width.

This is a convenience method to change only the width of a widget, and is implemented as:

resize(width, height())

See also: resize(), setHeight()

◆ show()

void Wt::WWidget::show ( )

Shows the widget.

See also: setHidden()

◆ stopAcceptDrops()

void Wt::WWidget::stopAcceptDrops ( const std::string & mimeType )

virtual

Indicates that a mime type is no longer accepted for dropping.

See also: acceptDrops()

◆ styleClass()

virtual WString Wt::WWidget::styleClass ( ) const

pure virtual

Returns the CSS style class.

See also: setStyleClass()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ tabIndex()

virtual int Wt::WWidget::tabIndex ( ) const

pure virtual

Returns the tab index.

See also: setTabIndex()

Implemented in Wt::WAnchor, Wt::WWebWidget, Wt::WFormWidget, and Wt::WCompositeWidget.

◆ tr()

WString Wt::WWidget::tr ( const char * key )

static

Short hand for WString::tr()

Creates a localized string with the given key.

◆ verticalAlignment()

virtual AlignmentFlag Wt::WWidget::verticalAlignment ( ) const

pure virtual

Returns the vertical alignment.

This applies to CSS-based layout.

See also: setVerticalAlignment()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ verticalAlignmentLength()

virtual WLength Wt::WWidget::verticalAlignmentLength ( ) const

pure virtual

Returns the fixed vertical alignment that was set.

This applies to CSS-based layout.

See also: setVerticalAlignment()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

◆ width()

virtual WLength Wt::WWidget::width ( ) const

pure virtual

Returns the width.

Returns the width set for this widget. This is not a calculated width, based on layout, but the width as specified with resize(const WLength&, const WLength&).

This applies to CSS-based layout.

See also: resize(const WLength&, const WLength&), height()

Implemented in Wt::WWebWidget, and Wt::WCompositeWidget.

Public Member Functions

Static Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ ~WWidget()

◆ WWidget()

Member Function Documentation

◆ acceptDrops()

◆ addStyleClass()

◆ animateHide()

◆ animateShow()

◆ attributeValue()

◆ boxBorder()

◆ boxPadding()

◆ callJavaScriptMember()

◆ canReceiveFocus()

◆ clearSides()

◆ decorationStyle()

◆ disable()

◆ doJavaScript()

◆ dropEvent()

◆ enable()

◆ enableAjax()

◆ find()

◆ floatSide()

◆ getStateless()

◆ height()

◆ hiddenKeepsGeometry()

◆ hide()

◆ htmlText()

◆ isDisabled()

◆ isEnabled()

◆ isHidden()

◆ isInline()

◆ isPopup()

◆ isRendered()

◆ isScrollVisible()

◆ isThemeStyleEnabled()

◆ isVisible()

◆ javaScriptMember()

◆ jsRef()

◆ layoutSizeAware()

◆ layoutSizeChanged()

◆ lineHeight()

◆ load()

◆ loaded()

◆ margin()

◆ maximumHeight()

◆ maximumWidth()

◆ minimumHeight()

◆ minimumWidth()

◆ offset()

◆ parent()

◆ positionAt()

◆ positionScheme()

◆ propagateSetEnabled()

◆ refresh()

◆ removeChild()

◆ removeStyleClass()

◆ render()

◆ resize()

◆ scheduleRender()

◆ scrollVisibilityChanged()

◆ scrollVisibilityEnabled()

◆ scrollVisibilityMargin()

◆ setAttributeValue()

◆ setCanReceiveFocus()

◆ setClearSides()

◆ setDecorationStyle()

◆ setDeferredToolTip()

◆ setDisabled()

◆ setFirstFocus()

◆ setFloatSide()

◆ setFocus() [1/2]

◆ setFocus() [2/2]

◆ setHeight()

◆ setHidden()

◆ setHiddenKeepsGeometry()