Closure call with mismatched arguments: function 'call' again

Question

Exactly one month ago I encountered this problem Closure call with mismatched arguments: function 'call' with js interop.

Now I have the same problem with the SnapSVG library. I'm using it in combination with JsInterop since a moment. Today i tried to use the mouseover function and I get the same exception.

But when I hover the SVG element my function is fired four times :

hover in
hover in
hover in
hover in 
Breaking on exception: Closure call with mismatched arguments: function 'call'

I tried :

var img = s.image("$url", x, y, image.width/2, image.height/2); 
js.FunctionProxy hover = new js.FunctionProxy(() {
  print("hover in");
});

img.mouseover(hover);

and

var img = s.image("$url", x, y, image.width/2, image.height/2);
img.mouseover(() {
  print("hover in");
});

This time I checked twice and there is no extra arguments for the callback function.

Answer 1

Considering the logs you paste, the mouseover handler seems to be called sometimes with parameters sometimes without. To handle that you can use a function with optional parameters :

var img = s.image("$url", x, y, image.width/2, image.height/2);
img.mouseover(([p1, p2, p3, p4]) {
  print("hover in");
});

The above callback now handles calls with from 0 to 4 parameters.