Packagefeathers.layout
Classpublic class VerticalSpinnerLayout
InheritanceVerticalSpinnerLayout Inheritance starling.events.EventDispatcher
Implements ISpinnerLayout, ITrimmedVirtualLayout

Product Version : Feathers 2.1.0

For use with the SpinnerList component, positions items from top to bottom in a single column and repeats infinitely.

See also

How to use VerticalSpinnerLayout with the Feathers SpinnerList component


Public Properties
 PropertyDefined By
  afterVirtualizedItemCount : int
Used internally by a component, such as List, to set the number of virtualized items that appear after the items passed to layout().
VerticalSpinnerLayout
  beforeVirtualizedItemCount : int
Used internally by a component, such as List, to set the number of virtualized items that appear before the items passed to layout().
VerticalSpinnerLayout
  gap : Number
The space, in pixels, between items.
VerticalSpinnerLayout
  horizontalAlign : String
The alignment of the items horizontally, on the x-axis.
VerticalSpinnerLayout
  padding : Number
Quickly sets all padding properties to the same value.
VerticalSpinnerLayout
  paddingLeft : Number
The minimum space, in pixels, to the left of the items.
VerticalSpinnerLayout
  paddingRight : Number
The minimum space, in pixels, to the right of the items.
VerticalSpinnerLayout
  repeatItems : Boolean
If set to true, the layout will repeat the items infinitely, if there are enough items to allow this behavior.
VerticalSpinnerLayout
  requestedRowCount : int
Requests that the layout set the view port dimensions to display a specific number of rows (plus gaps and padding), if possible.
VerticalSpinnerLayout
  requiresLayoutOnScroll : Boolean
[read-only] Determines if the container calls layout() when the scroll position changes.
VerticalSpinnerLayout
  resetTypicalItemDimensionsOnMeasure : Boolean
If set to true, the width and height of the typicalItem will be reset to typicalItemWidth and typicalItemHeight, respectively, whenever the typical item needs to be measured.
VerticalSpinnerLayout
  snapInterval : Number
[read-only] The interval, in pixels, between snapping points.
VerticalSpinnerLayout
  typicalItem : DisplayObject
Used internally by a component that supports layout virtualization, such as List, to provide a display object with dimensions that represent a "typical" item in the layout.
VerticalSpinnerLayout
  typicalItemHeight : Number
Used to reset the height, in pixels, of the typicalItem for measurement.
VerticalSpinnerLayout
  typicalItemWidth : Number
Used to reset the width, in pixels, of the typicalItem for measurement.
VerticalSpinnerLayout
  useVirtualLayout : Boolean
Determines if virtual layout should be used.
VerticalSpinnerLayout
Public Methods
 MethodDefined By
  
Constructor.
VerticalSpinnerLayout
  
calculateNavigationDestination(items:Vector.<DisplayObject>, index:int, keyCode:uint, bounds:LayoutBoundsResult):int
Using the current index and a key press, calculates the new index.
VerticalSpinnerLayout
  
getNearestScrollPositionForIndex(index:int, scrollX:Number, scrollY:Number, items:Vector.<DisplayObject>, x:Number, y:Number, width:Number, height:Number, result:Point = null):Point
Calculates the scroll position nearest to the current scroll position that will display the full bounds of the item within the view port.
VerticalSpinnerLayout
  
getScrollPositionForIndex(index:int, items:Vector.<DisplayObject>, x:Number, y:Number, width:Number, height:Number, result:Point = null):Point
Using the item dimensions, calculates a scroll position that will ensure that the item at a given index will be visible within the specified bounds.
VerticalSpinnerLayout
  
getVisibleIndicesAtScrollPosition(scrollX:Number, scrollY:Number, width:Number, height:Number, itemCount:int, result:Vector.<int> = null):Vector.<int>
Used internally by a component, such as List, to determines which indices are visible with the specified view port bounds and scroll position.
VerticalSpinnerLayout
  
layout(items:Vector.<DisplayObject>, viewPortBounds:ViewPortBounds = null, result:LayoutBoundsResult = null):LayoutBoundsResult
Positions (and possibly resizes) the supplied items within the optional bounds argument.
VerticalSpinnerLayout
  
measureViewPort(itemCount:int, viewPortBounds:ViewPortBounds = null, result:Point = null):Point
Used internally by a component, such as List, to measure the view port based on the typical item dimensions or cached dimensions, if available.
VerticalSpinnerLayout
Events
 Event Summary Defined By
  Dispatched when a property of the layout changes, indicating that a redraw is probably needed.VerticalSpinnerLayout
Property Detail
afterVirtualizedItemCountproperty
afterVirtualizedItemCount:int

Used internally by a component, such as List, to set the number of virtualized items that appear after the items passed to layout(). Allows the array of items to be smaller than the full size. Does not work if the layout has variable item dimensions.

This property is meant to be set by the List or other component that uses the virtual layout. If you're simply creating a layout for a List or another component, do not use this property. It is meant for developers creating custom components only.


Implementation
    public function get afterVirtualizedItemCount():int
    public function set afterVirtualizedItemCount(value:int):void
beforeVirtualizedItemCountproperty 
beforeVirtualizedItemCount:int

Used internally by a component, such as List, to set the number of virtualized items that appear before the items passed to layout(). Allows the array of items to be smaller than the full size. Does not work if the layout has variable item dimensions.

This property is meant to be set by the List or other component that uses the virtual layout. If you're simply creating a layout for a List or another component, do not use this property. It is meant for developers creating custom components only.


Implementation
    public function get beforeVirtualizedItemCount():int
    public function set beforeVirtualizedItemCount(value:int):void
gapproperty 
gap:Number

The space, in pixels, between items.

The default value is 0.


Implementation
    public function get gap():Number
    public function set gap(value:Number):void
horizontalAlignproperty 
horizontalAlign:String

The alignment of the items horizontally, on the x-axis.

The default value is feathers.layout.HorizontalAlign.JUSTIFY.


Implementation
    public function get horizontalAlign():String
    public function set horizontalAlign(value:String):void

See also

paddingproperty 
padding:Number

Quickly sets all padding properties to the same value. The padding getter always returns the value of paddingLeft, but the other padding values may be different.

The default value is 0.


Implementation
    public function get padding():Number
    public function set padding(value:Number):void

See also

paddingLeftproperty 
paddingLeft:Number

The minimum space, in pixels, to the left of the items.

The default value is 0.


Implementation
    public function get paddingLeft():Number
    public function set paddingLeft(value:Number):void
paddingRightproperty 
paddingRight:Number

The minimum space, in pixels, to the right of the items.

The default value is 0.


Implementation
    public function get paddingRight():Number
    public function set paddingRight(value:Number):void
repeatItemsproperty 
repeatItems:Boolean

If set to true, the layout will repeat the items infinitely, if there are enough items to allow this behavior. If the total height of the items is smaller than the height of the view port, the items cannot repeat.

The default value is true.


Implementation
    public function get repeatItems():Boolean
    public function set repeatItems(value:Boolean):void
requestedRowCountproperty 
requestedRowCount:int

Requests that the layout set the view port dimensions to display a specific number of rows (plus gaps and padding), if possible. If the explicit height of the view port is set, then this value will be ignored. If the view port's minimum and/or maximum height are set, the actual number of visible rows may be adjusted to meet those requirements. Set this value to 0 to display as many rows as possible.

The default value is 0.


Implementation
    public function get requestedRowCount():int
    public function set requestedRowCount(value:int):void
requiresLayoutOnScrollproperty 
requiresLayoutOnScroll:Boolean  [read-only]

Determines if the container calls layout() when the scroll position changes. Useful for transforming items as the view port scrolls. This value should be true for layouts that implement the IVirtualLayout interface and the useVirtualLayout property is set to true. May also be used by layouts that toggle item visibility as the items scroll into and out of the view port.


Implementation
    public function get requiresLayoutOnScroll():Boolean
resetTypicalItemDimensionsOnMeasureproperty 
resetTypicalItemDimensionsOnMeasure:Boolean

If set to true, the width and height of the typicalItem will be reset to typicalItemWidth and typicalItemHeight, respectively, whenever the typical item needs to be measured. The measured dimensions of the typical item are used to fill in the blanks of a virtualized layout for virtual items that don't have their own display objects to measure yet.

The default value is false.


Implementation
    public function get resetTypicalItemDimensionsOnMeasure():Boolean
    public function set resetTypicalItemDimensionsOnMeasure(value:Boolean):void

See also

snapIntervalproperty 
snapInterval:Number  [read-only]

The interval, in pixels, between snapping points.


Implementation
    public function get snapInterval():Number
typicalItemproperty 
typicalItem:DisplayObject

Used internally by a component that supports layout virtualization, such as List, to provide a display object with dimensions that represent a "typical" item in the layout. These dimensions will be used to fill in blanks for the layout when an item is virtual and isn't actually on the display list. If you are simply passing a layout to a component, setting this property will have no effect. It is meant to be used by the component, and the component will replace any value you pass to this property.


Implementation
    public function get typicalItem():DisplayObject
    public function set typicalItem(value:DisplayObject):void

See also

typicalItemHeightproperty 
typicalItemHeight:Number

Used to reset the height, in pixels, of the typicalItem for measurement. The measured dimensions of the typical item are used to fill in the blanks of a virtualized layout for virtual items that don't have their own display objects to measure yet.

This value is only used when resetTypicalItemDimensionsOnMeasure is set to true. If resetTypicalItemDimensionsOnMeasure is set to false, this value will be ignored and the typicalItem dimensions will not be reset before measurement.

If typicalItemHeight is set to NaN, the typical item will auto-size itself to its preferred height. If you pass a valid Number value, the typical item's height will be set to a fixed size. May be used in combination with typicalItemWidth.

The default value is NaN.


Implementation
    public function get typicalItemHeight():Number
    public function set typicalItemHeight(value:Number):void

See also

typicalItemWidthproperty 
typicalItemWidth:Number

Used to reset the width, in pixels, of the typicalItem for measurement. The measured dimensions of the typical item are used to fill in the blanks of a virtualized layout for virtual items that don't have their own display objects to measure yet.

This value is only used when resetTypicalItemDimensionsOnMeasure is set to true. If resetTypicalItemDimensionsOnMeasure is set to false, this value will be ignored and the typicalItem dimensions will not be reset before measurement.

If typicalItemWidth is set to NaN, the typical item will auto-size itself to its preferred width. If you pass a valid Number value, the typical item's width will be set to a fixed size. May be used in combination with typicalItemHeight.

The default value is NaN.


Implementation
    public function get typicalItemWidth():Number
    public function set typicalItemWidth(value:Number):void

See also

useVirtualLayoutproperty 
useVirtualLayout:Boolean

Determines if virtual layout should be used. Some components don't support virtual layouts, and they will always change this property to false. In those cases, the virtual layout options will be ignored.

The default value is true.


Implementation
    public function get useVirtualLayout():Boolean
    public function set useVirtualLayout(value:Boolean):void
Constructor Detail
VerticalSpinnerLayout()Constructor
public function VerticalSpinnerLayout()

Constructor.

Method Detail
calculateNavigationDestination()method
public function calculateNavigationDestination(items:Vector.<DisplayObject>, index:int, keyCode:uint, bounds:LayoutBoundsResult):int

Using the current index and a key press, calculates the new index. This might be use to change a list's selectedIndex when a key is pressed.

Parameters

items:Vector.<DisplayObject>
 
index:int
 
keyCode:uint
 
bounds:LayoutBoundsResult

Returns
int
getNearestScrollPositionForIndex()method 
public function getNearestScrollPositionForIndex(index:int, scrollX:Number, scrollY:Number, items:Vector.<DisplayObject>, x:Number, y:Number, width:Number, height:Number, result:Point = null):Point

Calculates the scroll position nearest to the current scroll position that will display the full bounds of the item within the view port. If the item is already fully displayed in the view port, the current scroll position will be returned unchanged.

While the item will be displayed in the view port without being clipped in any way, it may not be placed in the most prominent position possible. To give the item a more prominent location, use getScrollPositionForIndex() instead.

This function should always be called after the layout() function. The width and height arguments are the final bounds of the view port, which may be calculated in the layout() function.

Parameters

index:int
 
scrollX:Number
 
scrollY:Number
 
items:Vector.<DisplayObject>
 
x:Number
 
y:Number
 
width:Number
 
height:Number
 
result:Point (default = null)

Returns
Point
getScrollPositionForIndex()method 
public function getScrollPositionForIndex(index:int, items:Vector.<DisplayObject>, x:Number, y:Number, width:Number, height:Number, result:Point = null):Point

Using the item dimensions, calculates a scroll position that will ensure that the item at a given index will be visible within the specified bounds.

Typically, this function is used to show the item in the most prominent way, such as centering. To scroll a minimum distance required to display the full bounds of the item in the view port, use getNearestScrollPositionForIndex() instead.

This function should always be called after the layout() function. The width and height arguments are the final bounds of the view port, which may be calculated in the layout() function.

Parameters

index:int
 
items:Vector.<DisplayObject>
 
x:Number
 
y:Number
 
width:Number
 
height:Number
 
result:Point (default = null)

Returns
Point
getVisibleIndicesAtScrollPosition()method 
public function getVisibleIndicesAtScrollPosition(scrollX:Number, scrollY:Number, width:Number, height:Number, itemCount:int, result:Vector.<int> = null):Vector.<int>

Used internally by a component, such as List, to determines which indices are visible with the specified view port bounds and scroll position. Indices that aren't returned are typically not displayed and can be replaced virtually. Uses the typical items dimensions, or cached dimensions, if available.

This function is meant to be called by the List or other component that uses the virtual layout. If you're simply creating a layout for a List or another component, do not call this function. It is meant for developers creating custom components only.

Parameters

scrollX:Number
 
scrollY:Number
 
width:Number
 
height:Number
 
itemCount:int
 
result:Vector.<int> (default = null)

Returns
Vector.<int>
layout()method 
public function layout(items:Vector.<DisplayObject>, viewPortBounds:ViewPortBounds = null, result:LayoutBoundsResult = null):LayoutBoundsResult

Positions (and possibly resizes) the supplied items within the optional bounds argument. If no bounds are specified, the layout algorithm will assume that the bounds start a 0,0 and have unbounded dimensions. Returns the actual bounds of the content, which may be different than the specified bounds.

Note: The items are not absolutely restricted to appear only within the bounds. The bounds can affect positioning, but the algorithm may very well ignore them completely.

If a layout implementation needs to access accurate width and height values from items that are of type IFeathersControl, it must call validate() manually. For performance reasons, the container that is the parent of the items will not call validate() before passing the items to a layout implementation. Meeting this requirement may be as simple as looping through the items at the beginning of layout() and validating all items that are Feathers UI controls:

const itemCount:int = items.length;
for(var i:int = 0; i < itemCount; i++)
{
    var item:IFeathersControl = items[i] as IFeathersControl;
    if(item)
    {
        item.validate();
    }
}

Parameters

items:Vector.<DisplayObject>
 
viewPortBounds:ViewPortBounds (default = null)
 
result:LayoutBoundsResult (default = null)

Returns
LayoutBoundsResult
measureViewPort()method 
public function measureViewPort(itemCount:int, viewPortBounds:ViewPortBounds = null, result:Point = null):Point

Used internally by a component, such as List, to measure the view port based on the typical item dimensions or cached dimensions, if available.

This function is meant to be called by the List or other component that uses the virtual layout. If you're simply creating a layout for a List or another component, do not call this function. It is meant for developers creating custom components only.

Parameters

itemCount:int
 
viewPortBounds:ViewPortBounds (default = null)
 
result:Point (default = null)

Returns
Point
Event Detail
change Event
Event Object Type: starling.events.Event
Event.type property = starling.events.Event.CHANGE

Dispatched when a property of the layout changes, indicating that a redraw is probably needed.

The properties of the event object have the following values:

PropertyValue
bubblesfalse
currentTargetThe Object that defines the event listener that handles the event. For example, if you use myButton.addEventListener() to register an event listener, myButton is the value of the currentTarget.
datanull
targetThe Object that dispatched the event; it is not always the Object listening for the event. Use the currentTarget property to always access the Object listening for the event.