Gumbo FxNumericStepper - Functional and Design Specification

package mx.components
{

import flash.display.DisplayObject;
import flash.events.Event;

import mx.events.FlexEvent;
import mx.managers.IFocusManagerComponent;

/**
 *  The FxNumericStepper control lets the user select
 *  a number from an ordered set.
 *  The FxNumericStepper control consists of a single-line
 *  input text field and a pair of arrow buttons
 *  for stepping through the possible values.
 *  The Up Arrow and Down Arrow keys also cycle through 
 *  the values. An inputted value is committed whenever
 *  the user presses enter, focuses out of the
 *  FxNumericStepper, or steps the FxNumericStepper.
 * 
 *  @see mx.components.FxSpinner
 */
public class FxNumericStepper extends FxSpinner implements IFocusManagerComponent
{
    include "../core/Version.as";
    
    //--------------------------------------------------------------------------
    //
    //  Constructor
    //
    //--------------------------------------------------------------------------
    
    /**
     *  Constructor
     */  
    public function FxNumericStepper();
    
    //--------------------------------------------------------------------------
    //
    // SkinParts
    //
    //--------------------------------------------------------------------------

    [SkinPart]
    
    /**
     *  <code>textInput</code> is a SkinPart that defines a
     *  FxTextInput which allows a user to edit the value of
     *  the FxNumericStepper. The value is rounded and committed
     *  when the user presses enter, focuses out of
     *  the FxNumericStepper, or steps the FxNumericStepper.
     */
    public var textInput:FxTextInput;

    //--------------------------------------------------------------------------
    //
    // Methods
    //
    //--------------------------------------------------------------------------

    /**
     *  @private
     */
    override protected function partAdded(partName:String, instance:*):void;
    
    /**
     *  @private
     */
    override protected function partRemoved(partName:String, instance:*):void;

    /**
     *  @private
     */
    override protected function enableSkinParts(value:Boolean):void;

    /**
     *  @private
     */
    override public function setFocus():void;
    
    /**
     *  @private
     */
    override protected function isOurFocus(target:DisplayObject):Boolean;

    /**
     *  @private
     *  Calls commitTextInput() before stepping.
     */
    override public function step(increase:Boolean = true):void;
    
    /**
     *  Commits the current text of <code>textInput</code> as
     *  <code>value</code> after rounding the new value using
     *  <code>nearestValidValue</code>.
     */
    protected function commitTextInput():void;

    //--------------------------------------------------------------------------
    // 
    // Event Handlers
    //
    //--------------------------------------------------------------------------
    
    //--------------------------------- 
    // Keyboard handlers
    //---------------------------------
    
    /**
     *  When the enter key is pressed, FxNumericStepper commits the
     *  text currently displayed.
     */
    protected function textInput_enterHandler(event:Event):void;
}

}