package 
  {
          import flash.events.Event;
          import flash.events.EventDispatcher;
          import flash.filters.BitmapFilter;
          import flash.filters.ConvolutionFilter;
          
          // ------- Events -------
          [Event(name="change", type="flash.events.Event")]
          
          
          public class @ax-actionscript-book-FilterWorkbench-com-example-programmingas3-filterWorkbench-ConvolutionFactory extends EventDispatcher implements actionscript_book_FilterWorkbench_com_example_programmingas3_filterWorkbench_IFilterFactory
          {
                  // ------- Private vars -------
                  private var _filter:ConvolutionFilter;
                  private var _paramString:String;
                  
                  
                  // ------- Constructor -------
                  public function @ax-actionscript-book-FilterWorkbench-com-example-programmingas3-filterWorkbench-ConvolutionFactory(matrixX:Number = 3, 
                                                                                           matrixY:Number = 3, 
                                                                                           matrix:Array = null, 
                                                                                           divisor:Number = 1.0, 
                                                                                           bias:Number = 0.0, 
                                                                                           preserveAlpha:Boolean = true, 
                                                                                           clamp:Boolean = true, 
                                                                                           color:uint = 0, 
                                                                                           alpha:Number = 0.0)
                  {
                          if (matrix == null)
                          {
                                  matrix = makeDefaultMatrix(matrixX, matrixY);
                          }
                          _filter = new ConvolutionFilter(matrixX, matrixY, matrix, divisor, bias, preserveAlpha, clamp, color, alpha);
                          _paramString = buildParamString(matrixX, matrixY, matrix, divisor, bias, preserveAlpha, clamp, color, alpha);
                  }
                  
                  
                  // ------- IFilterFactory implementation -------
                  public function getFilter():BitmapFilter
                  {
                          return _filter;
                  }
                  
                  
                  public function getCode():String
                  {
                          var result:String = "";
                          result += "import flash.filters.ConvolutionFilter;\n";
                          result += "\n";
                          result += "var convolution:ConvolutionFilter;\n";
                          result += "convolution = new ConvolutionFilter(" + _paramString + ");\n";
                          result += "\n";
                          result += "myDisplayObject.filters = [convolution];";
                          return result;
                  }
                  
                  
                  // ------- Public methods -------
                  public function modifyFilter(matrixX:Number = 3, 
                                                                             matrixY:Number = 3, 
                                                                             matrix:Array = null, 
                                                                             divisor:Number = 1.0, 
                                                                             bias:Number = 0.0, 
                                                                             preserveAlpha:Boolean = true, 
                                                                             clamp:Boolean = true, 
                                                                             color:uint = 0, 
                                                                             alpha:Number = 0.0):void
                  {
                          if (matrix == null)
                          {
                                  matrix = makeDefaultMatrix(matrixX, matrixY);
                          }
                          _filter = new ConvolutionFilter(matrixX, matrixY, matrix, divisor, bias, preserveAlpha, clamp, color, alpha);
                          _paramString = buildParamString(matrixX, matrixY, matrix, divisor, bias, preserveAlpha, clamp, color, alpha);
                          dispatchEvent(new Event(Event.CHANGE));
                  }
                  
                  
                  // ------- Private methods -------
                  private function makeDefaultMatrix(matrixX:Number, matrixY:Number):Array
                  {
                          var numFields:Number = matrixX * matrixY;
                          var centerIndex:Number = Math.floor(numFields / 2);
                          var result:Array = new Array(numFields);
                          for (var i:int = 0; i < numFields; i++)
                          {
                                  result[i] = (i == centerIndex) ? 1 : 0;
                          }
                          
                          return result;
                  }
                  
                  
                  private function buildParamString(matrixX:Number, matrixY:Number, matrix:Array, divisor:Number, bias:Number, preserveAlpha:Boolean, clamp:Boolean, color:uint, alpha:Number):String
                  {
                          var result:String = "\n\t\t\t" + matrixX.toString() + ",\n\t\t\t" + matrixY.toString() + ",\n\t\t\t";
                          
                          result += "[";
                          for (var i:Number = 0, numElements:Number = matrix.length; i < numElements; i++)
                          {
                                  if (i > 0)
                                  {
                                          result += ", ";
                                  }
                                  if (i != 0 && i % matrixX == 0)
                                  {
                                          result += "\n\t\t\t ";
                                  }
                                  result += matrix[i].toString();
                          }
                          result += "],\n\t\t\t";
                          
                          result += divisor.toString() + ",\n\t\t\t" + bias.toString() + ",\n\t\t\t";
                          result += preserveAlpha.toString() + ",\n\t\t\t" + clamp.toString() + ",\n\t\t\t";
                          result += actionscript_book_FilterWorkbench_com_example_programmingas3_filterWorkbench_ColorStringFormatter.formatColorHex24(color) + ",\n\t\t\t" + alpha.toString();
                          
                          return result;
                  }
          }
  }