Gamepad API “gamepadconnected” not working

Question

I am using the Gamepad API "gamepadconnected" function which is not working properly. However, the "gamepaddisconnected" function works for some reason. Upon connecting my bluetooth controller, nothing shows in the console, however, it does show the information displayed when disconnected.

What I have here is very basic and standard:

window.addEventListener("gamepadconnected", function(e) {
  console.log("Controller connected");
});

window.addEventListener("gamepaddisconnected", function(e) {
  console.log("Controller disconnected");
});

What am I missing here? Where did go wrong? I made sure the first focused page is the one with the scripts above. Thanks for your help.

Answer 1

MDN states that "If a gamepad is already connected when the page loaded, the gamepadconnected event is dispatched to the focused page when the user presses a button or moves an axis.". So your page will not always receive the gamepadconnected event when you connect the pad. https://developer.mozilla.org/en-US/docs/Web/API/Gamepad_API/Using_the_Gamepad_API

So it's best to eg let the user press a button to get your application started. This is also useful when there are multiple gamepads connected to the computer and your application has to know which one to use.

Answer 2

Chrome is notorious (certainly to me after working with it!) for its, shall we say, individual implementation of the GamePad API. One issue being that as far as I'm aware, it doesn't yet support the "gamepadconnected" event robustly, and you have to poll the gamePadConnected property of the GamePad object in order to do anything sensible with connections and disconnections. A total pain I know, but this is probably a reflection of the fact that the W3C standard for this API is still in flux. You'll also find that there are other issues, such as browser X on Windows behaving differently to browser X on Linux.

I don't know if anyone's tried plugging these devices into an Android or iOS device (probably superfluous to requirements on something with a touch screen unless you're planning to port a flight sim thereto!), but I suspect even more compatibility issues will arise if these experiments are performed. If you have the ability to dive into an Android smartphone with a USB port, and tinker with JavaScript in the smartphone browser, you may find even more hilarious issues coming to light.

As for legacy joysticks (such as my 10 year old Microsoft Sidewinder Pro USB), those have their own hilarity to throw at you. I'm currently struggling to make otherwise reasonable code work with the weirdness thereof, such as an axis property in the GamePad object being assigned to, wait for it, the hat switch, which on this device is a digital data source, not an analogue one. Be aware of a tidal wave of compatibility woes heading your way as you persevere with the GamePad API, until the W3C finalises the standard.