Adobe® Flex® 4 Language Reference
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mx.charts.chartClasses 
IAxis 
Packagemx.charts.chartClasses
Interfacepublic interface IAxis extends IEventDispatcher
Implementors CategoryAxis, NumericAxis

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

The IAxis class is an abstract interface for defining label, tick mark, and data positioning properties for a chart axis.

Classes implement this interface to provide range definition functionality.

See also



Public Properties
 PropertyDefined By
  baseline : Number
[read-only] The baseline position for the axis.
IAxis
  chartDataProvider : Object
[write-only] The data provider assigned to the enclosing chart.
IAxis
  displayName : String
[read-only] The name of the axis.
IAxis
  title : String
[read-only] The text for the title displayed along the axis.
IAxis
  unitSize : Number
[read-only] The size of one unit of data as represented by this axis.
IAxis
Public Methods
 MethodDefined By
 Inherited
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.
IEventDispatcher
  
Triggers events that inform the range object when the chart data has changed.
IAxis
 Inherited
Dispatches an event into the event flow.
IEventDispatcher
  
filterCache(cache:Array, field:String, filteredString:String):void
Filters a set of values of arbitrary type to a set of numbers that can be mapped.
IAxis
  
Formats values for display in DataTips.
IAxis
  
Determines the range to estimate what the axis labels should be.
IAxis
  
getLabels(minimumAxisLength:Number):AxisLabelSet
Gets the labels text that is rendered.
IAxis
 Inherited
Checks whether the EventDispatcher object has any listeners registered for a specific type of event.
IEventDispatcher
  
Maps a position along the axis back to a numeric data value.
IAxis
  
mapCache(cache:Array, field:String, convertedField:String, indexValues:Boolean = false):void
Converts a set of values of arbitrary type to a set of numbers that can be transformed into screen coordinates.
IAxis
  
Determines how the axis handles overlapping labels.
IAxis
  
reduceLabels(intervalStart:AxisLabel, intervalEnd:AxisLabel):AxisLabelSet
Invoked when an AxisRenderer is unable to cleanly render the labels without overlap, and would like the Axis object to reduce the set of labels.
IAxis
  
Each DataTransform that makes use of an axis registers itself with that axis.
IAxis
 Inherited
removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void
Removes a listener from the EventDispatcher object.
IEventDispatcher
  
transformCache(cache:Array, field:String, convertedField:String):void
Maps a set of values from data space to screen space.
IAxis
  
Each DataTransform that makes use of an axis registers itself with that axis.
IAxis
  
Updates the chart.
IAxis
 Inherited
Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type.
IEventDispatcher
Property Detail

baseline

property
baseline:Number  [read-only]

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

The baseline position for the axis. Some series, such as ColumnSeries or AreaSeries, use this value to define the base of a filled region when no minimum value is specified.



Implementation
    public function get baseline():Number

chartDataProvider

property 
chartDataProvider:Object  [write-only]

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

The data provider assigned to the enclosing chart. Axis types that are data provider-based can choose to inherit the data provider associated with the enclosing chart. If an axis is shared among multiple charts, the value of this property is undefined (most likely it will be the last data provider assigned to one of the associated charts).



Implementation
    public function set chartDataProvider(value:Object):void

displayName

property 
displayName:String  [read-only]

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

The name of the axis. If set, Flex uses this name to format DataTip controls.



Implementation
    public function get displayName():String

title

property 
title:String  [read-only]

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

The text for the title displayed along the axis.



Implementation
    public function get title():String

unitSize

property 
unitSize:Number  [read-only]

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

The size of one unit of data as represented by this axis. This value is used by various series types to help in rendering. The ColumnSeries class, for example, uses this value to determine how wide columns should be rendered. Different axis types return different values, sometimes dependent on the data being represented. The DateTimeAxis class, for example, might return the number of milliseconds in a day, or a year, depending on the data that is rendered in the chart. Because this value is dependant on collecting the represented data, custom series cannot assume this value is accurate in their updateData() or updateMapping() methods.



Implementation
    public function get unitSize():Number
Method Detail

dataChanged

()method
public function dataChanged():void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Triggers events that inform the range object when the chart data has changed.

filterCache

()method 
public function filterCache(cache:Array, field:String, filteredString:String):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Filters a set of values of arbitrary type to a set of numbers that can be mapped.

Parameters

cache:Array — An Array of objects where converted values are read from and stored.
 
field:String — The field of the objects in the cache Array containing the pre-filtered values.
 
filteredString:String — The field of the objects in the cache Array where filtered values should be stored.

formatForScreen

()method 
public function formatForScreen(value:Object):String

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Formats values for display in DataTips. Returns a user-readable string.

Parameters

value:Object — The value to convert to a String.

Returns
String — The text of the DataTip.

getLabelEstimate

()method 
public function getLabelEstimate():AxisLabelSet

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Determines the range to estimate what the axis labels should be. The axis almost immediately calls the getLabels() method to get the real values. The axis uses the estimated values to adjust chart margins, so any difference between the estimated labels and actual labels (returned from the getLabels() method) results in scaling the labels to fit.

An axis need only return the minimum and maximum labels when returning an estimate. If the label set is fairly static, without depending on the size of the axis being rendered on screen, an axis can return the entire label set from this function, and mark the estimate as accurate.

Returns
AxisLabelSet — An Array of AxisLabel objects.

getLabels

()method 
public function getLabels(minimumAxisLength:Number):AxisLabelSet

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Gets the labels text that is rendered. When Flex calls this method, the axis has already determined the minimum length of the label.

Parameters

minimumAxisLength:Number — The minimum length of the axis, in pixels. The axis can be longer than this value, but not shorter.

Returns
AxisLabelSet — An array of AxisLabel objects.

invertTransform

()method 
public function invertTransform(value:Number):Object

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Maps a position along the axis back to a numeric data value.

Parameters

value:Number — The bound of the axis. This parameter should be between 0 and 1, with 0 representing the minimum bound of the axis, and 1 the maximum.

Returns
Object — An object containing the transformed value.

mapCache

()method 
public function mapCache(cache:Array, field:String, convertedField:String, indexValues:Boolean = false):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Converts a set of values of arbitrary type to a set of numbers that can be transformed into screen coordinates.

Parameters

cache:Array — An Array of objects where converted values are read from and stored.
 
field:String — The field of the objects in the cache Array containing the pre-converted values.
 
convertedField:String — The field of the objects in the cache Array where converted values should be stored.
 
indexValues:Boolean (default = false) — This parameter is true if the values being mapped are index values, and false if they are natural data values.

preferDropLabels

()method 
public function preferDropLabels():Boolean

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Determines how the axis handles overlapping labels. Typically, numeric ranges return true, while discrete value-based ranges do not. You can can override this property by setting it directly on the axis.

Returns
Booleantrue if labels can be dropped without loss of data; otherwise, false.

reduceLabels

()method 
public function reduceLabels(intervalStart:AxisLabel, intervalEnd:AxisLabel):AxisLabelSet

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Invoked when an AxisRenderer is unable to cleanly render the labels without overlap, and would like the Axis object to reduce the set of labels. The method is passed the two labels that are overlapping.

Parameters

intervalStart:AxisLabel — The start of the interval where labels overlap.
 
intervalEnd:AxisLabel — The end of the interval where labels overlap.

Returns
AxisLabelSet — A new label set that resolves the overlap by reducing the number of labels.

registerDataTransform

()method 
public function registerDataTransform(transform:mx.charts.chartClasses:DataTransform, dimensionName:String):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Each DataTransform that makes use of an axis registers itself with that axis. The axis is responsible for informing the transform when its relevant values have changed. It should also request values from the transform when it wants to autogenerate minimum and maximum values.

Parameters

transform:mx.charts.chartClasses:DataTransform — The DataTransform to register.
 
dimensionName:String — The name of the dimension.

transformCache

()method 
public function transformCache(cache:Array, field:String, convertedField:String):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Maps a set of values from data space to screen space.

Parameters

cache:Array — An Array of objects where mapped values are read from and stored.
 
field:String — The field of the objects in the cache Array containing the pre-mapped values.
 
convertedField:String — The field of the objects in the cache Array where mapped values should be stored.

unregisterDataTransform

()method 
public function unregisterDataTransform(transform:mx.charts.chartClasses:DataTransform):void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Each DataTransform that makes use of an axis registers itself with that axis. The axis is responsible for informing the transform when its relevant values have changed. It should also request values from the transform when it wants to autogenerate minimum and maximum values.

Parameters

transform:mx.charts.chartClasses:DataTransform — The DataTransform to unregister.

update

()method 
public function update():void

Language Version: ActionScript 3.0
Product Version: Flex 3
Runtime Versions: Flash Player 9, AIR 1.1

Updates the chart. This can be called multiple times per frame.