Add Magic Remote directional navigation and OK activation

app/remote.js

@@ -0,0 +1,30 @@
+/* Directional control for webOS remotes and standard keyboards. */
+function setupRemoteNavigation(buttons, doc, win) {
+ var lastFocused=buttons[0], enterDown=false;
+ buttons.forEach(function(button){
+  button.addEventListener('focus',function(){lastFocused=button;});
+  button.addEventListener('mouseenter',function(){if(!button.disabled)button.focus();});
+ });
+ doc.addEventListener('keydown',function(event){
+  var code=event.keyCode||event.which;
+  var direction=event.key==='ArrowLeft'||event.key==='ArrowUp'||code===37||code===38?-1:
+   event.key==='ArrowRight'||event.key==='ArrowDown'||code===39||code===40?1:0;
+  var enter=event.key==='Enter'||code===13;
+  if(!direction&&!enter)return;
+  event.preventDefault();
+  var enabled=buttons.filter(function(button){return !button.disabled;});
+  if(!enabled.length)return;
+  var focused=doc.activeElement,index=enabled.indexOf(focused);
+  if(direction){
+   if(index<0){index=enabled.indexOf(lastFocused);if(index<0)index=0;enabled[index].focus();}
+   else enabled[(index+direction+enabled.length)%enabled.length].focus();
+  }else{
+   if(enterDown||event.repeat)return;
+   enterDown=true;
+   if(index<0){index=enabled.indexOf(lastFocused);enabled[index<0?0:index].focus();}
+   else focused.click();
+  }
+ });
+ doc.addEventListener('keyup',function(event){if(event.key==='Enter'||event.keyCode===13||event.which===13)enterDown=false;});
+ win.addEventListener('blur',function(){enterDown=false;});
+}