My Dart project doesn't works even if i compile it as js. It works only in dartium

Question

I'm writing a basic application in dart that uses canvas, it basically has 2 squares one of them move from right to left of screen and the second move when the user presse Arrow keys.

Now the problem is that When i try it in Dartium it works fine. But if i try to open it in Chrome/Firefox, i can see only an empty rectangle.

Dart editor doesn't show any error, even when i compile it as javascript code.

But when i look into console of Inspect element of Chrome there is that error message:

Uncaught TypeError: Object [object Window] has no method 'webkitRequestAnimationFrame$1' 

The calls to that method are here:

  void main() { 
  var maincharacter = new Player(10,10, 70, 70, "red");
  var secondCharacter = new Player(400,250, 50,50, "yellow");
  player = maincharacter;

  sprites = new Set();
  randomnumbergenerator = new Random();
  window.on.keyDown.add(myKeyDownEvent);
  CanvasElement element = query("canvas");  
  context = element.context2d;
  maincharacter.context = context;
  secondCharacter.context = context;
  maincharacter.type = 'player';
  sprites.add(maincharacter);
  sprites.add(secondCharacter);  
  window.webkitRequestAnimationFrame(animate);   
}

And here:

void animate(num time){
  enemyCreator(time);
  context.clearRect(0,0,400,400);  
  for(final sprite in sprites){
    if(!sprite.isPlayer()) {
      sprite.move(5, 0);
      // sprite.isOutside(0);
      if(!(sprite.posx<0)){ 
        query('#text').text = " Posx: ${sprite.posx.toString()} Length: ${sprites.length}";
        sprite.draw();
      } else {
        query('#text').text = "Destroyed";
        sprites.remove(sprite);
      }      
    } else {
      sprite.draw();
      query('#text').text = " Time: $counter Length: ${sprites.length}";
    }
  }
  window.webkitRequestAnimationFrame(animate);  
}

This is the javascript line that throws the exception:

 $.window().webkitRequestAnimationFrame$1($.animate)

Any idea?

Answer 1

The method is called requestAnimationFrame() not webkitRequestAnimationFrame() in Dart: http://api.dartlang.org/docs/bleeding_edge/dart_html/LocalWindow.html#requestAnimationFrame

int requestAnimationFrame(RequestAnimationFrameCallback callback)

As John said, try:

window.requestAnimationFrame(animate);

You probably confused Dart's method with the "native" DOM method

Window.prototype.webkitRequestAnimationFrame

in Dart you do not specify that prefix.

Answer 2

Try

window.requestAnimationFrame(animate);

instead.