/** * Box.as: ActionScript code to demonstrate JavaScript <-> Flash communication * * This file is written in ActionScript 2.0, a language that is based on * JavaScript, but extended for stronger object-oriented programming. * All we're doing here is defining a single static function named main() * in a class named Box. *  * You can compile this code with the open source ActionScript compiler mtasc * using a command like this: * *   mtasc -header 300:300:1 -main -swf Box1.swf Box1.as * * mtasc produces a SWF file that invokes the main() method from the first * frame of the movie. If you use the Flash IDE, you must insert your own * call to Box.main() in the first frame. */class Box {    static function main() {        // This is an ActionScript function we want to use from JavaScript.        // It draws a box and returns the area of the box.        var drawBox = function(x,y,w,h) {            _root.beginFill(0xaaaaaa, 100);            _root.lineStyle(5, 0x000000, 100);            _root.moveTo(x,y);            _root.lineTo(x+w, y);            _root.lineTo(x+w, y+h);            _root.lineTo(x, y+h);            _root.lineTo(x,y);            _root.endFill();            return w*h;        }                // Here's how we can allow the function to be invoked from JavaScript        // prior to Flash 8.  First, we define properties in our root timeline        // to hold the function arguments and return value.        _root.arg1 = 0;             _root.arg2 = 0;        _root.arg3 = 0;        _root.arg4 = 0;        _root.result = 0;        // Then we define another property with the same name as the function.        _root.drawBox = 0;        // Now we use the Object.watch() method to "watch" this property.        // Whenever it is set, the function we specify will be called.        // This means that JavaScript code can use SetVariable to trigger        // a function invocation.        _root.watch("drawBox",    // The name of the property to watch                    function() {  // The function to invoke when it changes                        // Call the drawBox() function, converting the                        // arguments from strings to numbers, and storing                        // the return value.                        _root.result = drawBox(Number(_root.arg1),                                               Number(_root.arg2),                                               Number(_root.arg3),                                               Number(_root.arg4));                        // Return 0 so that the value of the property we                        // are watching does not change.                        return 0;                    });                        // This is an ActionScript event handler.        // It calls the global fscommand() function to pass the         // coordinates of a mouse click to JavaScript.        _root.onMouseDown = function() {            fscommand("mousedown", _root._xmouse + "," + _root._ymouse);        }                // Here we use fscommand() again to tell JavaScript that the         // Flash movie has loaded and is ready to go.        fscommand("loaded", "");    }}