Class “Widget”

Object > NativeObject > Widget

Base class for all widgets

Type:	Widget extends NativeObject
Constructor:	protected
Singleton:	No
Namespace:	tabris
Direct subclasses:	Action, ActivityIndicator, Button, CameraView, CheckBox, Composite, ImageView, Picker, ProgressBar, RadioButton, Slider, Switch, TextInput, TextView, ToggleButton, Video, WebView
JSX Support:	No

See also:

Understanding layouts in Tabris.js
Understanding gesture events in Tabris.js
JSX A Widget with padding
JSX A card style Widget with corner radius and elevation
JS A Widget with a linear-gradient background
JS Using touch events on a Widget
JSX widget-elevation.jsx
JSX widget-exclude-from-layout.jsx
JSX widget-highlightontouch.jsx
JS widget-touch.js

Methods

animate(properties, options)

Starts an animation that transforms the given properties from their current values to the given ones. Supported properties are transform and opacity. Returns a promise that is resolved once the animation is completed and is rejected if the animation is aborted.

Parameter	Type	Description
properties	{   transform: Transformation, // optional   opacity: number // optional }	The properties and target values to animate.
options	AnimationOptions	Configures the animation itself.

Returns: Promise

appendTo(parent)

Appends this widget to the given parent. The parent widget must support children (extending Composite). If the widget already has a parent, it is removed from the old parent.

Parameter	Type	Description
parent	Composite

Returns: this

detach()

Removes this widget from its parent.

Returns: this

dispose()

Removes this widget from its parent and destroys it. Also disposes of all its children. Triggers a remove event on the parent and a dispose event on itself. The widget can no longer be used.

Returns: undefined

insertAfter(widget)

Inserts this widget directly after the given widget. If the widget already has a parent, it is removed from the old parent.

Parameter	Type	Description
widget	Widget

Returns: this

insertBefore(widget)

Inserts this widget directly before the given widget. If the widget already has a parent, it is removed from the old parent.

Parameter	Type	Description
widget	Widget

Returns: this

isDisposed()

Returns true if the widget has been disposed, otherwise false.

Returns: boolean

parent()

Returns the parent of this widget or null if this widget is not appended to a parent.

Returns: Composite

parent(selector)

Returns the first (nearest) parent of this widget that matches the given selector, or null if no parent matches.

Parameter	Type	Description
selector	Selector	A selector expression or a predicate function to filter the results.

Returns: Result

siblings(selector?)

Returns a (possibly empty) collection of all siblings of this widget that match the given selector.

Parameter	Type	Description
selector	Selector	A selector expression or a predicate function to filter the results. Optional.

Returns: WidgetCollection

Protected Methods

These methods are accessible only in classes extending Widget.

_setParent(parent, index?)

Sets the parent of the widget. If an index is given the widget will be inserted at that position.

Parameter	Type	Description
parent	Composite
index	number	Optional.

Returns: undefined

Properties

absoluteBounds

The actual location and size of the widget, relative to contentView.

Type:	Bounds
Settable:	No
Change Event:	Not supported

background

The background of the widget. If given a plain string it is interpreted first as a gradient, then as a color, and finally as an image path, whichever passes first. Use object literals or instances of LinearGradient, Color or Image to avoid any ambiguity.

Type:	LinearGradientValue | ColorValue | ImageValue
Settable:	Yes
Change Event:	backgroundChanged

baseline

The vertical position of the widget’s baseline relative to a sibling widget. Value true is treated like 'prev()' and aligns it with the previous sibling.

Type:	SiblingReferenceValue | 'auto' | true
Default:	'auto'
Settable:	Yes
Change Event:	baselineChanged

bottom

The position of the widget’s bottom edge relative to the parent or a sibling widget.

Type:	ConstraintValue
Default:	'auto'
Settable:	Yes
Change Event:	bottomChanged

bounds

The actual location and size of the widget, relative to its parent.

Type:	Bounds
Settable:	No
Change Event:	boundsChanged

centerX

The horizontal position of the widget’s center relative to the parent’s center. Value true is treated like 0 and puts it at the exact center without offset.

Type:	Offset | 'auto' | true
Default:	'auto'
Settable:	Yes
Change Event:	centerXChanged

centerY

The vertical position of the widget’s center relative to the parent’s center. Value true is treated like 0 and puts it at the exact center without offset.

Type:	Offset | 'auto' | true
Default:	'auto'
Settable:	Yes
Change Event:	centerYChanged

class

A class name or a whitespace separated list of class names to identify the widget. Class names are arbitrary strings that describe a state or a category and help to select widgets using a selector expression. A class name may only contain alphanumeric characters, _ and -. Class names can also be added or removed using the field classList.

Type:	string
Settable:	Yes
Change Event:	classChanged

classList

Provides convenient access to the list of class names set to this widget. Class names can either be set using the class property or by modifying the classList directly.

Type:	string[]
Settable:	Yes
Change Event:	classListChanged

cornerRadius

Configure a widget to have equally rounded corners. The widget content is clipped by the rounded corners.

Type:	number
Settable:	Yes
Change Event:	cornerRadiusChanged

See also:

JSX widget-cornerradius.jsx

data

A general-purpose object that allows the application to attach arbitrary data to the widget. Manipulations on this object have no effect on the widget itself in any way. Example: widget.data.myData = myData;

Type:	object
Settable:	No
Change Event:	Not supported

elevation

The position of the widget on the z-axis. Setting an elevation casts a shadow in the shape of the widget.

To have the shadow properly applied on Android it is required to set the background on the widget as well.

Type:	number
Settable:	Yes
Change Event:	elevationChanged

See also:

JSX widget-elevation.jsx

enabled

Whether the widget can be interacted with.

Type:	boolean
Default:	true
Settable:	Yes
Change Event:	enabledChanged

excludeFromLayout

If set to true the widget will be invisible and ignored in the layout of the parent. Visually it is treated like it was not attached to its parent, but it will still included in the return value of children().

Type:	boolean
Default:	false
Settable:	Yes
Change Event:	excludeFromLayoutChanged

height

The height of the widget.

Type:	Dimension | 'auto'
Default:	'auto'
Settable:	Yes
Change Event:	heightChanged

highlightOnTouch

Whether the widget should show visual feedback while touched. Enabling highlightOnTouch will not prevent the touch event from being propagated to the parent widget.

Type:	boolean
Default:	false
Settable:	Yes
Change Event:	highlightOnTouchChanged

See also:

JSX widget-highlightontouch.jsx

id

A string to identify the widget by using selectors. IDs are optional. It is strongly recommended that they are unique within a page.

Type:	string
Settable:	Yes
Change Event:	idChanged

layoutData

Provides information for a widget to be used by the parent when determining its size and position. While this property accepts any valid LayoutData expression (see LayoutDataValue, it will always return an instance of the class LayoutData.

Widget provides an alias property for each property of LayoutData. Setting these properties will change the value of the layoutData property, while getting them is the same as accessing them via the layoutData property. I.e. widget.left === widget.layoutData.left.

There are multiple presets for layoutData available as static properties on the LayoutData class: center, [stretch](/3.3/api/LayoutData.html#stretch), stretchX and [stretchY](/3.3/api/LayoutData.html#stretchy). They may be set directly (new TextView({layoutData: LayoutData.stretch});), via string (e.g. new TextView({layoutData: 'stretch'});), or in JSX via a special shorthand syntax: <TextView stretch/>. The presets can be merged with widget properties, e.g. <TextView stretch left={10}/> or <TextView stretchX centerY/>

Type:	LayoutDataValue
Default:	LayoutData
Settable:	Yes
Change Event:	layoutDataChanged

left

The position of the widget’s left edge relative to the parent or a sibling widget.

Type:	ConstraintValue
Default:	'auto'
Settable:	Yes
Change Event:	leftChanged

opacity

Opacity of the entire widget, in the range [0..1]. Can be used for fade animations.

Type:	number
Default:	1
Settable:	Yes
Change Event:	opacityChanged

padding

Additional space to add inside the widgets bounds.

Type:	BoxDimensions | null
Settable:	By Constructor or JSX
Change Event:	Not supported

See also:

JSX widget-padding.jsx

right

The position of the widget’s right edge relative to the parent or a sibling widget.

Type:	ConstraintValue
Default:	'auto'
Settable:	Yes
Change Event:	rightChanged

top

The position of the widget’s top edge relative to the parent or a sibling widget.

Type:	ConstraintValue
Default:	'auto'
Settable:	Yes
Change Event:	topChanged

transform

Modifications to the widget’s shape, size, or position. Can be used for animations. Note: In Android the transform property does not affect the bounds property, while it does so in iOS.

Type:	Transformation
Settable:	Yes
Change Event:	transformChanged

visible

If set to false the widget will be invisible, but still occupy space in the parents layout. Visually it is treated like a widget with an opacity of 0, but in addition the widget can also not be interacted with anymore.

Type:	boolean
Default:	true
Settable:	Yes
Change Event:	visibleChanged

width

The width of the widget.

Type:	Dimension | 'auto'
Default:	'auto'
Settable:	Yes
Change Event:	widthChanged

Events

tap

Fired once when a finger briefly touched the widget.

EventObject Type: WidgetTapEvent<Widget>

Property	Type	Description
touches	[{x: number, y: number}]	Touch coordinates relative to the origin coordinates of the widget.

longPress

Fired after pressing a widget for a specific amount of time (about a second), and again on lifting the finger.

EventObject Type: WidgetLongPressEvent<Widget>

Property	Type	Description
state	'start' | 'end' | 'cancel'	‘start’ when the widget has been hold down long enough, ‘end’ when the finger has been lifted and ‘cancel’ when the gesture has been interrupted.
touches	[{x: number, y: number}]	Touch coordinates relative to the origin coordinates of the widget.

See also:

JS widget-longpress-to-drag.js

pan

Fired continuously after a finger touching the widget moved for a certain distance.

EventObject Type: WidgetPanEvent<Widget>

Property	Type	Description
state	'start' | 'change' | 'end' | 'cancel'	‘start’ when the finger starts moving, ‘change’ while the finger is moving, ‘end’ when the finger has been lifted and ‘cancel’ when the gesture has been interrupted.
touches	[{x: number, y: number}]	Touch coordinates relative to the origin coordinates of the widget.
translationX	number	Current horizontal touch offset relative to the first touch.
translationY	number	Current vertical touch offset relative to the first touch.
velocityX	number	Current horizontal velocity in pixels per second.
velocityY	number	Current vertical velocity in pixels per second.

panUp

Fired when a finger starts moving up.

EventObject Type: WidgetPanEvent<Widget>

Property	Type	Description
state	'start' | 'change' | 'end' | 'cancel'	‘start’ when the finger starts moving, ‘change’ while the finger is moving, ‘end’ when the finger has been lifted and ‘cancel’ when the gesture has been interrupted.
touches	[{x: number, y: number}]	Touch coordinates relative to the origin coordinates of the widget.
translationX	number	Current horizontal touch offset relative to the first touch.
translationY	number	Current vertical touch offset relative to the first touch.
velocityX	number	Current horizontal velocity in pixels per second.
velocityY	number	Current vertical velocity in pixels per second.

panDown

Fired when a finger starts moving down.

EventObject Type: WidgetPanEvent<Widget>

Property	Type	Description
state	'start' | 'change' | 'end' | 'cancel'	‘start’ when the finger starts moving, ‘change’ while the finger is moving, ‘end’ when the finger has been lifted and ‘cancel’ when the gesture has been interrupted.
touches	[{x: number, y: number}]	Touch coordinates relative to the origin coordinates of the widget.
translationX	number	Current horizontal touch offset relative to the first touch.
translationY	number	Current vertical touch offset relative to the first touch.
velocityX	number	Current horizontal velocity in pixels per second.
velocityY	number	Current vertical velocity in pixels per second.

panLeft

Fired when a finger starts moving left.

EventObject Type: WidgetPanEvent<Widget>

Property	Type	Description
state	'start' | 'change' | 'end' | 'cancel'	‘start’ when the finger starts moving, ‘change’ while the finger is moving, ‘end’ when the finger has been lifted and ‘cancel’ when the gesture has been interrupted.
touches	[{x: number, y: number}]	Touch coordinates relative to the origin coordinates of the widget.
translationX	number	Current horizontal touch offset relative to the first touch.
translationY	number	Current vertical touch offset relative to the first touch.
velocityX	number	Current horizontal velocity in pixels per second.
velocityY	number	Current vertical velocity in pixels per second.

panRight

Fired when a finger starts moving right.

EventObject Type: WidgetPanEvent<Widget>

Property	Type	Description
state	'start' | 'change' | 'end' | 'cancel'	‘start’ when the finger starts moving, ‘change’ while the finger is moving, ‘end’ when the finger has been lifted and ‘cancel’ when the gesture has been interrupted.
touches	[{x: number, y: number}]	Touch coordinates relative to the origin coordinates of the widget.
translationX	number	Current horizontal touch offset relative to the first touch.
translationY	number	Current vertical touch offset relative to the first touch.
velocityX	number	Current horizontal velocity in pixels per second.
velocityY	number	Current vertical velocity in pixels per second.

panHorizontal

Fired when a finger starts moving left or right.

EventObject Type: WidgetPanEvent<Widget>

Property	Type	Description
state	'start' | 'change' | 'end' | 'cancel'	‘start’ when the finger starts moving, ‘change’ while the finger is moving, ‘end’ when the finger has been lifted and ‘cancel’ when the gesture has been interrupted.
touches	[{x: number, y: number}]	Touch coordinates relative to the origin coordinates of the widget.
translationX	number	Current horizontal touch offset relative to the first touch.
translationY	number	Current vertical touch offset relative to the first touch.
velocityX	number	Current horizontal velocity in pixels per second.
velocityY	number	Current vertical velocity in pixels per second.

panVertical

Fired when a finger starts moving up or down.

EventObject Type: WidgetPanEvent<Widget>

Property	Type	Description
state	'start' | 'change' | 'end' | 'cancel'	‘start’ when the finger starts moving, ‘change’ while the finger is moving, ‘end’ when the finger has been lifted and ‘cancel’ when the gesture has been interrupted.
touches	[{x: number, y: number}]	Touch coordinates relative to the origin coordinates of the widget.
translationX	number	Current horizontal touch offset relative to the first touch.
translationY	number	Current vertical touch offset relative to the first touch.
velocityX	number	Current horizontal velocity in pixels per second.
velocityY	number	Current vertical velocity in pixels per second.

swipeUp

Fired when a finger moves up quickly.

EventObject Type: WidgetSwipeEvent<Widget>

Property	Type	Description
touches	[{x: number, y: number}]	Touch coordinates relative to the origin coordinates of the widget.

swipeDown

Fired when a finger moves down quickly.

EventObject Type: WidgetSwipeEvent<Widget>

Property	Type	Description
touches	[{x: number, y: number}]	Touch coordinates relative to the origin coordinates of the widget.

swipeLeft

Fired when a finger moves left quickly.

EventObject Type: WidgetSwipeEvent<Widget>

Property	Type	Description
touches	[{x: number, y: number}]	Touch coordinates relative to the origin coordinates of the widget.

swipeRight

Fired when a finger moves right quickly.

EventObject Type: WidgetSwipeEvent<Widget>

Property	Type	Description
touches	[{x: number, y: number}]	Touch coordinates relative to the origin coordinates of the widget.

touchStart

Fired when a widget is touched. See Touch Events.

EventObject Type: WidgetTouchEvent<Widget>

Property	Type	Description
touches	[{x: number, y: number, absoluteX: number, absoluteY: number}]	Touch coordinates relative to the origin coordinates of the widget.

touchMove

Fired repeatedly while swiping across the screen.

EventObject Type: WidgetTouchEvent<Widget>

Property	Type	Description
touches	[{x: number, y: number, absoluteX: number, absoluteY: number}]	Touch coordinates relative to the origin coordinates of the widget.

touchEnd

Fired when a touch ends on the same widget than it started on.

EventObject Type: WidgetTouchEvent<Widget>

Property	Type	Description
touches	[{x: number, y: number, absoluteX: number, absoluteY: number}]	Touch coordinates relative to the origin coordinates of the widget.

touchCancel

Fired instead of touchEnd when the touch ends on another widget than it started on.

EventObject Type: WidgetTouchEvent<Widget>

Property	Type	Description
touches	[{x: number, y: number, absoluteX: number, absoluteY: number}]	Touch coordinates relative to the origin coordinates of the widget.

resize

Fired when the widget’s size has changed.

EventObject Type: WidgetResizeEvent<Widget>

Property	Type	Description
height	number	The height of the widget in dip.
left	number	The horizontal offset from the parent’s left edge in dip.
top	number	The vertical offset from the parent’s top edge in dip.
width	number	The width of the widget in dip.

dispose

Fired when the widget is about to be disposed. At this point the widget and its children are still accessible.

EventObject Type: EventObject<Widget>

This event has no additional parameter.

Change Events

idChanged

Fired when the id property has changed.

EventObject Type: PropertyChangedEvent<Widget, string>

Property	Type	Description
value	string	The new value of id.

classChanged

Fired when the class property has changed.

EventObject Type: PropertyChangedEvent<Widget, string>

Property	Type	Description
value	string	The new value of class.

classListChanged

Fired when the classList property has changed.

EventObject Type: PropertyChangedEvent<Widget, Array>

Property	Type	Description
value	string[]	The new value of classList.

enabledChanged

Fired when the enabled property has changed.

EventObject Type: PropertyChangedEvent<Widget, boolean>

Property	Type	Description
value	boolean	The new value of enabled.

excludeFromLayoutChanged

Fired when the excludeFromLayout property has changed.

EventObject Type: PropertyChangedEvent<Widget, boolean>

Property	Type	Description
value	boolean	The new value of excludeFromLayout.

visibleChanged

Fired when the visible property has changed.

EventObject Type: PropertyChangedEvent<Widget, boolean>

Property	Type	Description
value	boolean	The new value of visible.

layoutDataChanged

Fired when the layoutData property has changed.

EventObject Type: PropertyChangedEvent<Widget, LayoutDataValue>

Property	Type	Description
value	LayoutDataValue	The new value of layoutData.

leftChanged

Fired when the left property has changed.

EventObject Type: PropertyChangedEvent<Widget, ConstraintValue>

Property	Type	Description
value	ConstraintValue	The new value of left.

rightChanged

Fired when the right property has changed.

EventObject Type: PropertyChangedEvent<Widget, ConstraintValue>

Property	Type	Description
value	ConstraintValue	The new value of right.

topChanged

Fired when the top property has changed.

EventObject Type: PropertyChangedEvent<Widget, ConstraintValue>

Property	Type	Description
value	ConstraintValue	The new value of top.

bottomChanged

Fired when the bottom property has changed.

EventObject Type: PropertyChangedEvent<Widget, ConstraintValue>

Property	Type	Description
value	ConstraintValue	The new value of bottom.

widthChanged

Fired when the width property has changed.

EventObject Type: PropertyChangedEvent<Widget, Dimension | 'auto'>

Property	Type	Description
value	Dimension | 'auto'	The new value of width.

heightChanged

Fired when the height property has changed.

EventObject Type: PropertyChangedEvent<Widget, Dimension | 'auto'>

Property	Type	Description
value	Dimension | 'auto'	The new value of height.

centerXChanged

Fired when the centerX property has changed.

EventObject Type: PropertyChangedEvent<Widget, Offset | 'auto' | true>

Property	Type	Description
value	Offset | 'auto' | true	The new value of centerX.

centerYChanged

Fired when the centerY property has changed.

EventObject Type: PropertyChangedEvent<Widget, Offset | 'auto' | true>

Property	Type	Description
value	Offset | 'auto' | true	The new value of centerY.

baselineChanged

Fired when the baseline property has changed.

EventObject Type: PropertyChangedEvent<Widget, SiblingReferenceValue | 'auto' | true>

Property	Type	Description
value	SiblingReferenceValue | 'auto' | true	The new value of baseline.

elevationChanged

Fired when the elevation property has changed.

EventObject Type: PropertyChangedEvent<Widget, number>

Property	Type	Description
value	number	The new value of elevation.

cornerRadiusChanged

Fired when the cornerRadius property has changed.

EventObject Type: PropertyChangedEvent<Widget, number>

Property	Type	Description
value	number	The new value of cornerRadius.

boundsChanged

Fired when the bounds property has changed.

EventObject Type: PropertyChangedEvent<Widget, Bounds>

Property	Type	Description
value	Bounds	The new value of bounds.

backgroundChanged

Fired when the background property has changed.

EventObject Type: PropertyChangedEvent<Widget, LinearGradientValue | ColorValue | ImageValue>

Property	Type	Description
value	LinearGradientValue | ColorValue | ImageValue	The new value of background.

opacityChanged

Fired when the opacity property has changed.

EventObject Type: PropertyChangedEvent<Widget, number>

Property	Type	Description
value	number	The new value of opacity.

transformChanged

Fired when the transform property has changed.

EventObject Type: PropertyChangedEvent<Widget, Transformation>

Property	Type	Description
value	Transformation	The new value of transform.

highlightOnTouchChanged

Fired when the highlightOnTouch property has changed.

EventObject Type: PropertyChangedEvent<Widget, boolean>

Property	Type	Description
value	boolean	The new value of highlightOnTouch.