topical media & game development
[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _

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actionscript-book-NewsLayout-com-example-programmingas3-newslayout-HeadlineTextField.ax

actionscript-book-NewsLayout-com-example-programmingas3-newslayout-HeadlineTextField.ax [swf] flex 


  package
  {
          import flash.text.TextFieldAutoSize;
          import flash.text.TextFormat;
          import flash.text.TextFormatAlign;
          
          import flash.text.TextLineMetrics;
          import flash.text.TextField;
Changes the size of the text to fit a given width and number of lines. Useful for news headlines that should extend across a full column. We need to know: - which font family, weight, and style to use - the max width of the headline - the max height in pixels of the headline - the max number of lines Algorithm 1: - figure out the N-width of a character that should work based on pixelWidth / numChars - translate that N-width into a point size - try the point size, if outside of tolerance,; - if too wide, adjust down a point, try again - if too small, adjust up a point, try again - if too wide last time, too small this time or vice versa, stick with the too small size Pixels per character (width-wise) is roughly 1/2 the point size, so that's a good starting point. So to get a starting point size, divide the overall width by the number of characters to get pixels-per-character, then double to get the point size. 

  
          public class @ax-actionscript-book-NewsLayout-com-example-programmingas3-newslayout-HeadlineTextField extends actionscript_book_NewsLayout_com_example_programmingas3_newslayout_FormattedTextField
          {
  
                  public static var MIN_POINT_SIZE:uint = 6;
                  public static var MAX_POINT_SIZE:uint = 128;
                  
                  public function @ax-actionscript-book-NewsLayout-com-example-programmingas3-newslayout-HeadlineTextField(tf:TextFormat = null) 
                  {
                          super(tf);
                          this.autoSize = TextFieldAutoSize.LEFT;
                  }
                                  
                  public function fitText(msg:String, maxLines:uint = 1, toUpper:Boolean = false, targetWidth:Number = -1):uint
                  {
                          this.text = toUpper ? msg.toUpperCase() : msg;
                          
                          if (targetWidth == -1)
                          {
                                  targetWidth = this.width;
                          }
                          
                          var pixelsPerChar:Number = targetWidth / msg.length;
                          
                          var pointSize:Number = Math.min(MAX_POINT_SIZE, Math.round(pixelsPerChar * 1.8 * maxLines));
                          
                          if (pointSize < 6)
                          {
                                  // the point size is too small
                                  return pointSize;
                          }
                          
                          this.changeSize(pointSize);
                          
                          if (this.numLines > maxLines)
                          {
                                  return shrinkText(--pointSize, maxLines);
                          }
                          else
                          {
                                  return growText(pointSize, maxLines);
                          }
                  }
                  
                  public function growText(pointSize:Number, maxLines:uint = 1):Number
                  {
                          if (pointSize >= MAX_POINT_SIZE)
                          {
                                  return pointSize;
                          }
                          
                          this.changeSize(pointSize + 1);
                          
                          if (this.numLines > maxLines)
                          {
                                  // set it back to the last size
                                  this.changeSize(pointSize);
                                  return pointSize;
                          }
                          else
                          {
                                  return growText(pointSize + 1, maxLines);
                          }
                  }
                  
                  public function shrinkText(pointSize:Number, maxLines:uint=1):Number
                  {
                          if (pointSize <= MIN_POINT_SIZE)
                          {
                                  return pointSize;
                          }
                          
                          this.changeSize(pointSize);
                          
                          if (this.numLines > maxLines)
                          {
                                  return shrinkText(pointSize - 1, maxLines);
                          }
                          else
                          {
                                  return pointSize;
                          }
                  }
          }
  }
[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _

(C) Æliens 27/08/2009

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