KeyboardDragListener addHotkey does not work with 1 key.

[pixelzoom]

KeyboardDragListener addHotkey is broken when 1 key is specified.

This works:

    keyboardDragListener.addHotkeys( [ {
      keys: [ KeyboardUtils.KEY_J, KeyboardUtils.KEY_W ],
      callback: () => {
        console.log( 'escape' );
        ruler.visibleProperty.value = false;
        this.iconNode.focus();
      }
    } ] );

This doesn't work:

    keyboardDragListener.addHotkeys( [ {
      keys: [ KeyboardUtils.KEY_J ],
      callback: () => {
        console.log( 'escape' );
        ruler.visibleProperty.value = false;
        this.iconNode.focus();
      }
    } ] );

We also tried holding the key down for > 800ms, and setting hotkeyHoldInterval: 0.

[zepumph]

Bug fixed. Thanks for the help @jessegreenberg. @pixelzoom I updated the usage in GO. Anything else here?

[pixelzoom]

Looks great,and working great in geometric optics. Thanks for the quick turnaround. Closing.

[jessegreenberg]

This fix introduced a bug identified in #1334. Just checking the length of hotkeysDownList wasn't sufficient because that means the callback would fire if any one of the hotkeys are down. It is fixed with the above commit, @zepumph is this change OK?

[zepumph]

Aha! Yes that makes sense. Sorry about that. I tested before and after changes in GO and BASE, all looks good to me.