Actionscript Cookbook

Stage Two

In stage two, we want to use the calculations that were worked out in the first stage to create a component. The advantage of a component, in this case, is that you can create the component code once and then create as many instances as you want. Here are the steps you should complete to create the second stage of the application:

1. Open stage1.fla and save it as stage2.fla.

2. Delete all the code from the first frame of the main timeline. You may want to select it and cut it because you will use much of the same code within the component.

3. Create a new movie clip symbol named Circle.

4. Open the linkage properties for the Circle movie clip symbol.

5. Select the Export for ActionScript and Export on First Frame options and give the symbol a linkage identifier of CircleSymbol.

6. Click OK to close the linkage properties dialog box.

7. Edit Circle.

8. On the first frame of the default layer within the Circle symbol, add the following code:

   // Component class code should always be enclosed within #initclip/#endinitclip.
   #initclip
    
   function CircleClass (  ) {}
   
   CircleClass.prototype = new MovieClip(  );
   
   CircleClass.prototype.init = function (minX, minY, maxX, maxY, vel, 
                                          col, radius) {
   
     // Draw the circle with radius specified by the radius parameter. with (this) { lineStyle(0, 0x000000, 0); beginFill(0, 100); drawCircle(radius); endFill( ); } // Define the area within which the circle moves. this.minX = minX; this.minY = minY; this.maxX = maxX; this.maxY = maxY; // Assign a random coordinate at which the circle ...