package flare.animate.interpolate
{
    /**
     * Interpolator for <code>Number</code> and <code>int</code> values.
     */
    public class NumberInterpolator extends Interpolator
    {
        private var _start:Number;
        private var _end:Number;
        
        /**
         * Creates a new NumberInterpolator.
         * @param target the object whose property is being interpolated
         * @param property the property to interpolate
         * @param start the starting number to interpolate from
         * @param end the target number to interpolate to
         */
        public function NumberInterpolator(target:Object, property:String,
                                           start:Object, end:Object)
        {
            super(target, property, start, end);
        }
        
        /**
         * Initializes this interpolator.
         * @param start the starting value of the interpolation
         * @param end the target value of the interpolation
         */
        protected override function init(start:Object, end:Object) : void
        {
            _start = Number(start);
            _end = Number(end);
            if (isNaN(_start)) _start = _end;
            _end = _end - _start;
        }
        
        /**
         * Calculate and set an interpolated property value.
         * @param f the interpolation fraction (typically between 0 and 1)
         */
        public override function interpolate(f:Number) : void
        {
            _prop.setValue(_target, _start + f*_end);
        }
        
    } // end of class NumberInterpolator
}