Question

I have written a custom component for drawing a circle in Flex. But When I try to write a click event or mouseDown event for that component, it doesn t work.

I have the circle component inside a VBox.

 <mx:VBox label="Currents Quote" width="100%" backgroundColor="#DDDDDD">

<comp:MyCircle id="circlle" x1="175" y1="150" 
                    radius="140" click= {Alert.show("Hello");} 
                    mouseDown="handleMouseDown(event);"/>
<comp:MyLine x1="175" y1="104"/> 
 </mx:VBox>

  private function handleMouseDown(event:MouseEvent):void {

        var pt:Point = new Point(event.localX, event.localY);
        pt = event.target.localToGlobal(pt);   
        pt = circlle.globalToContent(pt);   
        var whichColor:String = "border area";

        if (pt.x < 150) {
            if (pt.y < 150)
                whichColor = "red";
            else
                whichColor = "blue";
        }
        else {
            if (pt.y < 150)
                whichColor = "green";
            else
                whichColor = "magenta";
        }

        Alert.show("You clicked on the " + whichColor);
      }

Circle component:

  package components
  {
 import mx.core.UIComponent;

 public class MyCircle extends UIComponent
 {
       public var x1:int; 
          public var y1:int; 
          public var radius:int; 

          override protected function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void 
         { 
        graphics.lineStyle(1, 0x000000);
        graphics.drawCircle(x1, y1, radius); 

        graphics.lineStyle(1, 0x000000);
        graphics.drawCircle(x1, y1, radius-40); 

        graphics.lineStyle(1, 0x000000);
        graphics.drawCircle(x1, y1, radius-100);
         }
     }
 }

The "Hello" Alert is displayed only at a particular point and guess is, at the point, (175,150) the x, y co-ordinates of the circle. But shouldn t it be displayed wherever I click on the MyCircle component?? how to enable it in that way?

Also the mouseDown function doesn t work for MyCircle,but if have the event for the VBox, the Alerts are displayed. Why so? Can someone guide me?

Should I write events for custom components in a different manner?

Answer 1

I m not sure if this is applicable or not, but there is a bug where some UIComponents don t recognized click/mouseDown events correctly unless they have a background color. See if adding a background color to your circle helps.

Answer 2

There s also a few errors in your code, for example, you re missing script tags around your actionscript, and you might need to import Alert.

 <mx:VBox label="Currents Quote" width="100%" backgroundColor="#DDDDDD">

<comp:MyCircle id="circlle" x1="175" y1="150" 
                    radius="140" click= {Alert.show("Hello");} 
                    mouseDown="handleMouseDown(event);"/>
<comp:MyLine x1="175" y1="104"/> 
 </mx:VBox>

<mx:Script>
<![CDATA[
  private function handleMouseDown(event:MouseEvent):void {

        var pt:Point = new Point(event.localX, event.localY);
        pt = event.target.localToGlobal(pt);   
        pt = circlle.globalToContent(pt);   
        var whichColor:String = "border area";

        if (pt.x < 150) {
            if (pt.y < 150)
                whichColor = "red";
            else
                whichColor = "blue";
        }
        else {
            if (pt.y < 150)
                whichColor = "green";
            else
                whichColor = "magenta";
        }

        Alert.show("You clicked on the " + whichColor);
      }
]]>
</mx:Script>

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