[pointerevents] Add feature detection section

RByers has just created a new issue for 
https://github.com/w3c/pointerevents:

== Add feature detection section ==
Discussed on the call today that we should add a non-normative section
 about suggested feature detection.  Perhaps something like this?

```javascript
  if (window.PointerEvent) {
    // Listen only for pointer events when they're supported.
    // Don't bother listening for mouse/touch as they're redundant and
 will only cause confusion.
    target.addEventListener("pointerdown", ondown);
    ...
  } else {
    // Listen for both touch and (non-touch-derived) mouse events.  No
 need for feature detection.
    target.addEventListener("touchstart", ondown);
    target.addEventListener("mousedown", function(e) {
      if (!e.sourceCapabilities || 
!e.sourceCapabilities.firesTouchEvents)
        ondown(e);
      });
    ...
  }
````

@patrickhlauke says he'll write up a PR to discuss further.

Please view or discuss this issue at 
https://github.com/w3c/pointerevents/issues/94 using your GitHub 
account

Received on Wednesday, 22 June 2016 16:14:03 UTC