Map Scale vs Zoom scale

JayHalligan — Wed, 27 Apr 2011 13:49:45 GMT

I am working on a widget that prints to a template, but I need the map print scale to be at 1:24000 or 1"=2000'. I have taken apart a few other widgets and got the results I was looking for except when I change the window size, the correct zoom scale is still shown on the screen but the image is captured at a larger scale. Is the code below my problem, or is the code that screen captures and resizes to a set template scale my problem?

Zoom Function on click

   protected function zoom_clickHandler(event:MouseEvent):void
   {
    if (map.scale > zoomScale)
    {
     map.scale = zoomScale;
    }

Screengrab

 public class PrintMapUtil
 {
  // Draw the maps print extent ractangle as a graphic on the map, based on
  // an image controls width and height
  public static function trimmedExtent(map:Map, containerWidth:Number, containerHeight:Number):Graphic
  {
   var rectangle:Rectangle = clipRectangle(map, containerWidth, containerHeight);
   var minMapPoint:MapPoint = map.toMap(new Point(rectangle.x,rectangle.y));
   var maxMapPoint:MapPoint = map.toMap(new Point(rectangle.x + rectangle.width,
               rectangle.y + rectangle.height));
   var extent:Extent = new Extent(minMapPoint.x,minMapPoint.y,maxMapPoint.x,maxMapPoint.y)
   
   return new Graphic(extent);
  } // end trimmedExtent
  
  // Get the maps print extent image as a BitMap. Used for the source of an image control.
  // Image controls width and height are paramaters of this function.
  public static function trimmedMap(map:Map, containerWidth:Number, containerHeight:Number):Bitmap
  {
   var rectangle:Rectangle = clipRectangle(map, containerWidth, containerHeight);
   
   //get the map as bitmapdata so the part we want can be copied and clipped
   var myBitmapData:BitmapData = new BitmapData(map.width,map.height);
   myBitmapData.draw(map,null,null,null,rectangle,true);
   
   // create a new cropped image to fit the map print area
   var newBitmapData:BitmapData = new BitmapData(rectangle.width, rectangle.height)
   newBitmapData.copyPixels(myBitmapData, rectangle, new Point(0, 0));
   
   return new Bitmap(newBitmapData);
  } // end trimmedMap
  
  // Get the print Extent Rectangle based on a container's width and height
  private static function clipRectangle(map:Map, containerWidth:Number, containerHeight:Number ):Rectangle
  {
   // check if the container is portrait or Landscape
          var orientation:String="PORTRAIT";
          if (containerWidth > containerHeight)
          {
           orientation="LANDSCAPE";
          }
          
          var ratioWidth:Number;
          var ratioHeight:Number;
          var clipRect:Rectangle = new Rectangle();
          
          var ratio:Number;
          var mapRatio:Number;
          
          switch (orientation)
          {
           case "PORTRAIT":
           {
            ratio = containerWidth / containerHeight;
            mapRatio = map.width / map.height;
            //check the maps width and height to get the cropped size
            //if (map.width > map.height)
            if (mapRatio > ratio)
            {
             ratioHeight = map.height;
             ratioWidth = map.height * ratio;
             //centre the clip rectangle
             clipRect.x = (map.width - ratioWidth) / 2;
             clipRect.y = 0;
            }
            else
            {
             ratioWidth = map.width;
             ratioHeight = map.width / ratio ;
             clipRect.x = 0;
       clipRect.y = (map.height - ratioHeight) / 2;
            } 
            break;
           }
           case "LANDSCAPE":
           {
            ratio = containerHeight / containerWidth;
            mapRatio = map.height / map.width;
            //check the maps width and height to get the ratio
            if (mapRatio < ratio)
            {
             ratioHeight = map.height;
             ratioWidth = map.height / ratio;
             //centre the clip rectangle
             clipRect.x = (map.width - ratioWidth) / 2;
             clipRect.y = 0;
            }
             else
            {
             ratioWidth = map.width;
             ratioHeight = map.width * ratio;
             clipRect.x = 0;
       clipRect.y = (map.height - ratioHeight) / 2;
            } 
            break;
           }
          }
          clipRect.width=ratioWidth;
    clipRect.height=ratioHeight;
    
    return clipRect;
  } // end clipRectangle
 
 } // end class PrintMapUtil
} // end package

topic Map Scale vs Zoom scale in ArcGIS API for Flex Questions

Map Scale vs Zoom scale