spark.layouts

# FormItemLayout - AS3 Flex

Package | spark.layouts
Class | public class FormItemLayout
Inheritance | FormItemLayout ConstraintLayout LayoutBase OnDemandEventDispatcher Object

Language Version: | ActionScript 3.0

Product Version: | Flex 4.5

Runtime Versions: | Flash Player 10, AIR 2.5

The FormItemLayout is used by FormItems to provide a constraint based layout. Elements using FormItemLayout within a FormLayout are aligned along columns.

More examples

Using the FormItemLayout layout class

Public Properties
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| Property | Defined By
--- | --- | ---
|  | clipAndEnableScrolling : Boolean If true, specifies to clip the children to the boundaries of the viewport. | LayoutBase
|  | constraintColumns : Vector.<ConstraintColumn> A Vector of ConstraintColumn instances that partition the target container. | ConstraintLayout
|  | constraintRows : Vector.<ConstraintRow> A Vector of ConstraintRow instances that partition the target container. | ConstraintLayout
|  | constructor : Object A reference to the class object or constructor function for a given object instance. | Object
|  | dropIndicator : DisplayObject The DisplayObject that this layout uses for the drop indicator during a drag-and-drop operation. | LayoutBase
|  | horizontalScrollPosition : Number The x coordinate of the origin of the viewport in the component's coordinate system, where the default value is (0,0) corresponding to the upper-left corner of the component. | LayoutBase
|  | target : GroupBase The GroupBase container whose elements are measured, sized and positioned by this layout. | LayoutBase
|  | typicalLayoutElement : ILayoutElement Used by layouts when fixed row/column sizes are requested but a specific size isn't specified. | LayoutBase
|  | useVirtualLayout : Boolean A container can hold any number of children. | LayoutBase
|  | verticalScrollPosition : Number The y coordinate of the origin of the viewport in the component's coordinate system, where the default value is (0,0) corresponding to the upper-left corner of the component. | LayoutBase

Public Methods
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| Method | Defined By
--- | --- | ---
|  | FormItemLayout() Constructor. | FormItemLayout
|  | addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void Registers an event listener object with an EventDispatcher object so that the listener receives notification of an event. | OnDemandEventDispatcher
|  | calculateDropLocation(dragEvent:DragEvent):DropLocation Calculates the drop location in the data provider of the drop target for the specified dragEvent. | LayoutBase
|  | clearVirtualLayoutCache():void When useVirtualLayout is true, this method can be used by the layout target to clear cached layout information when the target changes. | LayoutBase
|  | dispatchEvent(event:Event):Boolean Dispatches an event into the event flow. | OnDemandEventDispatcher
|  | elementAdded(index:int):void Called by the target after a layout element has been added and before the target's size and display list are validated. | LayoutBase
|  | elementRemoved(index:int):void This method must is called by the target after a layout element has been removed and before the target's size and display list are validated. | LayoutBase
|  | getElementBounds(index:int):Rectangle Returns the specified element's layout bounds as a Rectangle or null if the index is invalid, the corresponding element is null, includeInLayout=false, or if this layout's target property is null. | LayoutBase
|  | getHorizontalScrollPositionDelta(navigationUnit:uint):Number Returns the change to the horizontal scroll position to handle different scrolling options. | LayoutBase
|  | getNavigationDestinationIndex(currentIndex:int, navigationUnit:uint, arrowKeysWrapFocus:Boolean):int Delegation method that determines which item to navigate to based on the current item in focus and user input in terms of NavigationUnit. | LayoutBase
|  | getScrollPositionDeltaToElement(index:int):Point Computes the verticalScrollPosition and horizontalScrollPosition deltas needed to scroll the element at the specified index into view. | LayoutBase
|  | getVerticalScrollPositionDelta(navigationUnit:uint):Number Returns the change to the vertical scroll position to handle different scrolling options. | LayoutBase
|  | hasEventListener(type:String):Boolean Checks whether the EventDispatcher object has any listeners registered for a specific type of event. | OnDemandEventDispatcher
|  | hasOwnProperty(name:String):Boolean Indicates whether an object has a specified property defined. | Object
|  | hideDropIndicator():void Hides the previously shown drop indicator, created by the showDropIndicator() method, removes it from the display list and also stops the drag scrolling. | LayoutBase
|  | isPrototypeOf(theClass:Object):Boolean Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter. | Object
|  | measure():void Measures the target's default size based on its content, and optionally measures the target's default minimum size. | LayoutBase
|  | propertyIsEnumerable(name:String):Boolean Indicates whether the specified property exists and is enumerable. | Object
|  | removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void Removes a listener from the EventDispatcher object. | OnDemandEventDispatcher
|  | setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Sets the availability of a dynamic property for loop operations. | Object
|  | showDropIndicator(dropLocation:DropLocation):void Sizes, positions and parents the drop indicator based on the specified drop location. | LayoutBase
|  | toLocaleString():String Returns the string representation of this object, formatted according to locale-specific conventions. | Object
|  | toString():String Returns the string representation of the specified object. | Object
|  | updateDisplayList(width:Number, height:Number):void Sizes and positions the target's elements. | LayoutBase
|  | updateScrollRect(w:Number, h:Number):void Called by the target at the end of its updateDisplayList to have the layout update its scrollRect. | LayoutBase
|  | valueOf():Object Returns the primitive value of the specified object. | Object
|  | willTrigger(type:String):Boolean Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type. | OnDemandEventDispatcher

Protected Methods
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| Method | Defined By
--- | --- | ---
|  | calculateDragScrollDelta(dropLocation:DropLocation, elapsedTime:Number):Point Calculates how much to scroll for the specified dropLocation during a drag and drop gesture. | LayoutBase
|  | calculateDropIndex(x:Number, y:Number):int Returns the index where a new item should be inserted if the user releases the mouse at the specified coordinates while completing a drag and drop gesture. | LayoutBase
|  | calculateDropIndicatorBounds(dropLocation:DropLocation):Rectangle Calculates the bounds for the drop indicator that provides visual feedback to the user of where the items will be inserted at the end of a drag and drop gesture. | LayoutBase
|  | getElementBoundsAboveScrollRect(scrollRect:Rectangle):Rectangle Returns the bounds of the first layout element that either spans or is above the scrollRect's top edge. | LayoutBase
|  | getElementBoundsBelowScrollRect(scrollRect:Rectangle):Rectangle Returns the bounds of the first layout element that either spans or is below the scrollRect's bottom edge. | LayoutBase
|  | getElementBoundsLeftOfScrollRect(scrollRect:Rectangle):Rectangle Returns the bounds of the first layout element that either spans or is to the left of the scrollRect's left edge. | LayoutBase
|  | getElementBoundsRightOfScrollRect(scrollRect:Rectangle):Rectangle Returns the bounds of the first layout element that either spans or is to the right of the scrollRect's right edge. | LayoutBase
|  | getScrollRect():Rectangle Returns the bounds of the target's scroll rectangle in layout coordinates. | LayoutBase
|  | layoutContent(unscaledWidth:Number, unscaledHeight:Number):void Lays out the elements of the layout target using the current widths and heights of the columns and rows. | ConstraintLayout
|  | measureAndPositionColumnsAndRows(constrainedWidth:Number = NaN, constrainedHeight:Number = NaN):void Used by FormItemLayout to measure and set new column widths and row heights before laying out the elements. | ConstraintLayout
|  | scrollPositionChanged():void Called when the verticalScrollPosition or horizontalScrollPosition properties change. | LayoutBase

Constructor Detail

### FormItemLayout

()
Constructor

`public function FormItemLayout()`

Language Version: | ActionScript 3.0

Product Version: | Flex 4.5

Runtime Versions: | Flash Player 10, AIR 2.5

Constructor.

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Mon Apr 10 2017, 12:28 PM -07:00