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   1 package flare.animate.interpolate
   2 {
   3         /**
   4          * Interpolator for arbitrary <code>Object</code> values. Simply swaps the
   5          * initial value for the end value for interpolation fractions greater
   6          * than or equal to 0.5.
   7          */
   8         public class ObjectInterpolator extends Interpolator
   9         {
  10                 private var _start:Object;
  11                 private var _end:Object;
  12
  13                 /**
  14                  * Creates a new ObjectInterpolator.
  15                  * @param target the object whose property is being interpolated
  16                  * @param property the property to interpolate
  17                  * @param start the starting object value to interpolate from
  18                  * @param end the target object value to interpolate to
  19                  */
  20                 public function ObjectInterpolator(target:Object, property:String,
  21                                                    start:Object, end:Object)
  22                 {
  23                         super(target, property, start, end);
  24                 }
  25
  26                 /**
  27                  * Initializes this interpolator.
  28                  * @param start the starting value of the interpolation
  29                  * @param end the target value of the interpolation
  30                  */
  31                 protected override function init(start:Object, end:Object) : void
  32                 {
  33                         _start = start;
  34                         _end = end;
  35                 }
  36
  37                 /**
  38                  * Calculate and set an interpolated property value. This method sets
  39                  * the target object's property to the starting value if the
  40                  * interpolation fraction is less than 0.5 and to the ending value if
  41                  * the fraction is greather than or equal to 0.5.
  42                  * @param f the interpolation fraction (typically between 0 and 1)
  43                  */
  44                 public override function interpolate(f:Number) : void
  45                 {
  46                         _prop.setValue(_target, f < 0.5 ? _start : _end);
  47                 }
  48
  49         } // end of class ObjectInterpolator
  50 }